JP7809787B2 - battery - Google Patents

Description

An embodiment of the present invention relates to a battery.

Some batteries, such as lithium-ion secondary batteries, house an electrode group including a positive electrode and a negative electrode in the internal cavity of an outer container. In such batteries, the outer container has a bottom wall and a peripheral wall, and the internal cavity of the outer container opens on the opposite side of the bottom wall in the height direction of the battery. A lid member is attached to the peripheral wall of the outer container, and the opening of the internal cavity is closed by the lid member. In addition, in the battery, electrode terminals are attached to the outer surface of the lid member in a state exposed to the outside of the battery. In addition, in the battery, conductive leads are placed in the internal cavity of the outer container, and the leads electrically connect the current collecting tabs of the electrode group to the electrode terminals. In addition, the connection position of the electrode terminal to the lead is located laterally inward, intersecting the height direction, compared to the connection position of the current collecting tabs of the electrode group to the lead.

As mentioned above, some batteries in which an electrode group is housed in the internal cavity of an outer container have a hole such as a liquid inlet formed in the lid member. In such batteries, the hole formed in the lid member, such as a liquid inlet, penetrates the lid member from the outer surface to the inner surface. The hole formed in the lid member is located laterally inward relative to the electrode terminal and the position where the electrode terminal is connected to the lead. In batteries in which a hole such as a liquid inlet is formed in the lid member at a position laterally inward relative to the electrode terminal, as mentioned above, it is necessary to ensure that the strength of the hole and its vicinity in the lid member is appropriate.

Japanese Patent Application Publication No. 2005-142026 Japanese Patent Application Publication No. 2013-225500 Japanese Patent Application Publication No. 2015-23026

The problem that this invention aims to solve is to provide a battery in which a hole is formed in the lid member at a position laterally inside the electrode terminal, and in which the strength of the lid member at and near the hole is appropriately ensured.

According to an embodiment, the battery includes an outer container, an electrode group, a lid member, an electrode terminal, and a lead. The outer container includes a bottom wall and a peripheral wall, and the outer container has an internal cavity that opens to the side opposite the bottom wall in the height direction. The electrode group includes a current collecting tab and is housed in the internal cavity of the outer container. The lid member is attached to the peripheral wall of the outer container in a state that closes the opening of the internal cavity, and the lid member has a first hole that penetrates from the outer surface to the inner surface. The electrode terminal is exposed to the outside on the outer surface of the lid member and is located away from the first hole on the outer side in a horizontal direction that intersects the height direction. The lead electrically connects the current collecting tab of the electrode group to the electrode terminal in the internal cavity, and the connection position of the electrode terminal on the lead is located laterally inward compared to the connection position of the current collecting tab. The lead includes an extension extending laterally inward from the connection position of the electrode terminal, and when projected from the height direction, the extension does not overlap with the first hole and covers the outer periphery of the first hole over an angular range of 120° or approximately 120° . The lead extension includes a lead protrusion protruding laterally inward relative to other portions of the extension, and the lead protrusion is positioned offset from the first hole in a depth direction intersecting both the height direction and the width direction. The lead protrusions include a first lead protrusion adjacent to the first hole from one side in the depth direction and a second lead protrusion adjacent to the first hole from the side opposite the first lead protrusion in the depth direction. The extension includes a lead recess recessed laterally outward between the first lead protrusion and the second lead protrusion. The bottom of the lead recess is adjacent to the first hole from the outer side in the width direction.

FIG. 1 is a perspective view showing a battery according to a first embodiment. FIG. 2 is a perspective view showing the battery according to the first embodiment with the lid assembly and the electrode group assembled and the lid assembly and the electrode group separated from the outer container. FIG. 3 is a perspective view showing the lid assembly of the battery according to the first embodiment, exploded into individual components. FIG. 4 is a perspective view showing the lid assembly of the battery according to the first embodiment in an assembled state. FIG. 5 is a view showing the lid assembly of the battery according to the first embodiment, as viewed from the side where the bottom wall is located in the height direction of the battery. FIG. 6 is a perspective view showing one of a pair of leads of the battery according to the first embodiment. FIG. 7 is a view showing a part of a lid assembly of a battery according to a first modified example, as viewed from the side where the bottom wall is located in the height direction of the battery. FIG. 8 is a perspective view showing one of a pair of leads of a battery according to a first modified example. FIG. 9 is a view showing a part of a lid assembly of a battery according to a second modified example, as viewed from the side where the bottom wall is located in the height direction of the battery. FIG. 10 is a perspective view showing one of a pair of leads of a battery according to a first modified example.

The following describes the embodiments with reference to the drawings.

(First embodiment)
1 and 2 show a battery 1 according to a first embodiment. As shown in FIGS. 1 and 2 , the battery 1 includes an electrode group 2, an outer container 3, and a lid assembly 4. The lid assembly 4 includes a lid member 5. The outer container 3 and the lid member 5 are each formed of a metal such as aluminum, an aluminum alloy, iron, copper, or stainless steel. The battery 1 (outer container 3) has a depth direction (direction indicated by arrows X1 and X2), a lateral direction (direction indicated by arrows Y1 and Y2) that intersects (orthogonal or approximately perpendicular to) the depth direction, and a height direction (direction indicated by arrows Z1 and Z2) that intersects (orthogonal or approximately perpendicular to) both the depth and lateral directions. The battery 1 and the outer container 3 each have a smaller depth dimension than their respective lateral and height dimensions. 1 is a perspective view, and FIG. 2 is a perspective view showing a state in which the lid assembly 4 and the electrode group 2 are assembled and the lid assembly 4 and the electrode group 2 are separated from the outer container 3. FIG.

The outer container 3 has a bottom wall 6 and a peripheral wall 7. The bottom wall 6 and the peripheral wall 7 define an internal cavity 8 in which the electrode group 2 is housed. In the outer container 3, the internal cavity 8 opens toward the side opposite the bottom wall 6 in the height direction. The peripheral wall 7 has two pairs of side walls 11, 12. The pair of side walls 11 face each other in the horizontal direction, sandwiching the internal cavity 8 therebetween. The pair of side walls 12 face each other in the depth direction, sandwiching the internal cavity 8 therebetween. Each of the side walls 11 extends continuously between the side walls 12 in the depth direction. Each of the side walls 12 extends continuously between the side walls 11 in the horizontal direction. The lid member 5 is attached to the peripheral wall 7 at the end opposite the bottom wall 6. Therefore, the lid member 5 closes the opening of the internal cavity 8 of the outer container 3. The lid member 5 and the bottom wall 6 face each other in the height direction, sandwiching the internal cavity 8 therebetween.

The electrode group 2 includes a negative electrode 13A and a positive electrode 13B. In the electrode group 2, a separator (not shown) is interposed between the negative electrode 13A and the positive electrode 13B. The separator is made of an electrically insulating material and electrically insulates the negative electrode 13A from the positive electrode 13B.

The negative electrode 13A comprises a negative electrode current collector such as a negative electrode current collector foil, and a negative electrode active material-containing layer (not shown) supported on the surface of the negative electrode current collector. The negative electrode current collector may be, but is not limited to, aluminum foil, aluminum alloy foil, or copper foil, for example, and has a thickness of approximately 10 μm to 20 μm. The negative electrode active material-containing layer comprises a negative electrode active material and may optionally contain a binder and a conductive agent. Examples of negative electrode active materials include, but are not limited to, metal oxides, metal sulfides, metal nitrides, and carbon materials capable of absorbing and releasing lithium ions. The negative electrode current collector comprises a negative electrode current collector tab in the portion not supporting the negative electrode active material-containing layer.

The positive electrode 13B comprises a positive electrode current collector such as a positive electrode current collector foil, and a positive electrode active material-containing layer (not shown) supported on the surface of the positive electrode current collector. The positive electrode current collector may be, but is not limited to, aluminum foil or aluminum alloy foil, for example, and has a thickness of approximately 10 μm to 20 μm. The positive electrode active material-containing layer comprises a positive electrode active material and may optionally contain a binder and a conductive agent. Examples of positive electrode active materials include, but are not limited to, oxides, sulfides, and polymers capable of absorbing and releasing lithium ions. The positive electrode current collector comprises a positive electrode current collecting tab in the portion not supporting the positive electrode active material-containing layer.

In one example of an electrode group 2, such as that shown in Figure 2, the negative electrode 13A, positive electrode 13B, and separator are wound around the winding axis W, with the separator sandwiched between the negative electrode active material-containing layer and the positive electrode active material-containing layer. In another example, the electrode group 2 has a stack structure in which multiple negative electrodes 13A and multiple positive electrodes 13B are alternately stacked, and a separator is provided between the negative electrode 13A and the positive electrode 13B. In one example of the electrode group 2, such as that shown in Figure 2, the current collecting tab 15A serves as a negative electrode current collecting tab, and the current collecting tab 15B serves as a positive electrode current collecting tab. In the electrode group 2, the current collecting tab 15A, which serves as a negative electrode current collecting tab, protrudes relative to the positive electrode 13B and the separator. The current collecting tab 15B, which serves as a positive electrode current collecting tab, protrudes relative to the negative electrode 13A and the separator in the direction opposite to the protruding direction of the current collecting tab 15A. In one example such as FIG. 2, a pair of current collecting tabs 15 (negative electrode current collecting tab and positive electrode current collecting tab) protrude in opposite directions from each other in the direction along the winding axis W.

2 and other examples, the electrode group 2 is disposed in the internal cavity 8 with the winding axis W aligned along the lateral direction of the battery 1. Each of the pair of current collecting tabs 15 in the electrode group 2 protrudes outward in the lateral direction of the battery 1. The current collecting tab 15A, which serves as the negative electrode current collecting tab, protrudes toward one lateral side of the battery 1 relative to the positive electrode 13B and separator, while the current collecting tab 15B, which serves as the positive electrode current collecting tab, protrudes toward the negative electrode 13A and separator, etc., on the side opposite the side from which the current collecting tab 15A protrudes, in the lateral direction of the battery 1. Each of the pair of current collecting tabs 15 bundles multiple strip-shaped portions.

In addition, an electrolyte solution (not shown) is retained (impregnated) in the internal cavity 8 in the electrode group 2. The electrolyte solution may be a nonaqueous electrolyte solution in which an electrolyte is dissolved in an organic solvent, or an aqueous electrolyte solution such as an aqueous solution. Instead of the electrolyte solution, a gel electrolyte or a solid electrolyte may be used. When a solid electrolyte is used as the electrolyte, the solid electrolyte is interposed between the negative electrode 13A and the positive electrode 13B in the electrode group, instead of a separator. In this case, the solid electrolyte electrically insulates the negative electrode 13A from the positive electrode 13B.

Figures 3 to 5 show the lid assembly 4. Figure 3 is an oblique view showing the lid assembly 4 disassembled into its individual components, and Figure 4 is an oblique view showing the lid assembly 4 assembled. Figure 5 shows the battery 1 as viewed from the side where the bottom wall 6 is located in the height direction. As shown in Figures 3 to 5, the lid assembly 4 includes, in addition to the lid member 5, a pair of electrode terminals 16, an electrode group presser (internal insulating member) 17, and a pair of leads 20.

In the lid assembly 4, a pair of electrode terminals 16 are attached to the lid member 5. The electrode terminals 16 are formed from a conductive material such as metal. One of the pair of electrode terminals 16 is the negative terminal of the battery 1, and the other of the pair of electrode terminals 16 is the positive terminal of the battery 1. In one example, such as Figure 2, electrode terminal 16A is the negative terminal and electrode terminal 16B is the positive terminal. Each of the electrode terminals 16 is disposed on the outer surface of the lid member 5 in a state exposed to the outside of the battery 1. The pair of electrode terminals 16 are disposed spaced apart from each other in the lateral direction of the battery 1.

A pair of through holes 21 are also formed in the lid member 5. Each of the through holes 21 extends along the height direction of the battery 1 and penetrates the lid member 5 from the outer surface to the inner surface. Each of the pair of electrode terminals 16 is inserted into a corresponding one of the pair of through holes 21. A portion of each of the pair of electrode terminals 16 is inserted into the internal cavity 8 through the corresponding one of the through holes 21. As a result, a portion of each electrode terminal 16 is located in the internal cavity 8. An insulating member 22 is provided on the outer surface of the lid member 5 between each of the electrode terminals 16 and the lid member 5. An insulating gasket 23 is also disposed in each of the through holes 21. Each of the electrode terminals 16 is electrically insulated from the lid member 5 and the outer container 3 by the insulating member 22 and the insulating gasket 23.

A pair of leads 20 are disposed in the internal cavity 8 of the outer container 3. One of the pair of leads 20 is a negative electrode lead, and the other of the pair of leads 20 is a positive electrode lead. In one example, such as FIG. 2, lead 20A is the negative electrode lead, and lead 20B is the positive electrode lead. The negative electrode lead forms at least a portion of the electrical path between the negative electrode current collector tab and the negative electrode terminal, electrically connecting the negative electrode current collector tab of the electrode group 2 to the negative electrode terminal. The positive electrode lead forms at least a portion of the electrical path between the positive electrode current collector tab and the positive electrode terminal, electrically connecting the positive electrode current collector tab of the electrode group 2 to the positive electrode terminal. Each of the leads 20 is formed from a conductive material such as a metal. Examples of conductive materials for forming the leads 20 include aluminum, stainless steel, copper, and iron.

The electrode group presser 17 is disposed in the internal cavity 8. The electrode group presser 17 is disposed between the electrode group 2 and the lid member 5 in the height direction of the battery 1, and between each of the pair of leads 20 and the lid member 5 in the height direction of the battery 1. The electrode group presser (internal insulating member) 17 is formed from an electrically insulating material. The electrode group presser 17 prevents the pair of current collecting tabs 15 and the pair of leads 20 from contacting the lid member 5, and electrically insulates them from the lid member 5. Furthermore, in the internal cavity 8, the electrode group presser 17 presses the electrode group 2 toward the side where the bottom wall 6 is located in the height direction of the battery 1. Therefore, the electrode group presser 17 restricts movement of the electrode group 2 toward the side where the lid member 5 is located in the height direction of the battery 1.

The internal cavity 8 is also provided with an insulating guard (not shown) made of an electrically insulating material. The insulating guard prevents the pair of current collecting tabs 15 and the pair of leads 20 from contacting the outer casing 3, electrically insulating them from the outer casing 3. In this embodiment, a gas release valve 25 is formed in the lid member 5. The lid member 5 has a thinner wall thickness at the gas release valve 25 than at other portions of the lid member 5. The gas release valve 25 is positioned between the pair of electrode terminals 16 (the pair of through-holes 21) in the lateral direction of the battery 1 and is positioned inside each of the electrode terminals 16 in the lateral direction of the battery 1. When the pressure in the internal cavity 8 increases beyond the upper limit of the battery's operating range, the gas release valve 25 opens, establishing communication between the internal cavity 8 and the outside of the outer casing 3. This allows gas to be released from the internal cavity 8 through the gas release valve 25 to the outside of the outer casing 3.

The lid member 5 also has a hole (first hole) 26, which serves as a liquid inlet, formed between one of the pair of electrode terminals 16 and the gas release valve 25 in the horizontal direction of the battery 1. Therefore, the hole 26 is formed in the lid member 5 at a position on the inside of the electrode terminal 16 in the horizontal direction of the battery 1. In the example shown in Figures 3 to 5, the hole 26 is located between the electrode terminal 16A and the gas release valve 25 in the horizontal direction of the battery 1. Therefore, the electrode terminal 16A and the through-hole 21 through which the electrode terminal 16A is inserted are located on the outside of the hole 26 in the horizontal direction of the battery 1, and the gas release valve 25 is located on the inside of the hole 26 in the horizontal direction of the battery 1. The hole (first hole) 26 is formed along the height of the battery 1 and penetrates the lid member 5 in the vertical direction of the battery 1 from the outer surface to the inner surface. During battery 1 manufacturing, electrolyte is injected into the internal cavity 8 through the hole 26, which serves as a liquid inlet. A sealing plate 27 is welded to the outer surface of the lid member 5 so as to close a hole 26 serving as a liquid inlet.

A pair of through holes 31 are formed in the electrode group holder 17. Each of the through holes 31 extends along the height direction of the battery 1 and penetrates the electrode group holder 17 in the height direction of the battery 1. Each of the pair of through holes 31 faces a corresponding one of the pair of through holes 21 in the lid member 5 from the side where the electrode group 2 is located in the height direction of the battery 1. When projected from the height direction of the battery 1, each of the pair of through holes 31 overlaps with a corresponding one of the pair of through holes 21. Each of the pair of electrode terminals 16 is inserted into a corresponding one of the pair of through holes 21 as described above, and is also inserted into a corresponding one of the pair of through holes 31 in the electrode group holder 17 in the internal cavity 8.

In addition to the aforementioned through hole 31, the electrode group presser 17 is formed with a pair of holes 32 and an opening hole 33. The pair of holes 32 and the opening hole 33 are located between the pair of through holes 31 in the horizontal direction of the battery 1, and between the pair of electrode terminals 16 in the horizontal direction of the battery 1. Therefore, the holes 32 and the opening hole 33 are located inside the electrode terminals 16 and the through hole 31 in the horizontal direction of the battery 1. The holes 32 and the opening hole 33 each extend along the height direction of the battery 1 and penetrate the electrode group presser 17 in the height direction of the battery 1. The opening hole 33 is located between the pair of holes 32 in the horizontal direction of the battery 1. Therefore, the opening hole 33 is located inside the holes 32 in the horizontal direction of the battery 1.

The opening 33 faces the gas exhaust valve 25 of the lid member 5 from the side where the electrode group 2 is located in the height direction of the battery 1. When projected from the height direction of the battery 1, the opening 33 overlaps with the gas exhaust valve 25. One of the pair of holes 32, the hole (second hole) 32A, faces the hole (first hole) 26 of the lid member 5 from the side where the electrode group 2 is located in the height direction of the battery 1. When projected from the height direction of the battery 1, the hole 32A overlaps with the hole 26. In the example shown in Figures 3 to 5, the cross-sectional area of the hole 32A in a cross section perpendicular or approximately perpendicular to the height direction of the battery 1 is larger than the cross-sectional area of the hole 26 in a cross section perpendicular or approximately perpendicular to the height direction of the battery 1. When projected from the height direction of the battery 1, the outer periphery of the hole (second hole) 32A completely surrounds the outer periphery of the hole (first hole) 26. Furthermore, the outer edge of the hole 32A in the horizontal direction of the battery 1 is located further outward in the horizontal direction of the battery 1 than the outer edge of the hole 26. The other of the pair of holes 32, other than hole 32A, is designated hole 32B.

The electrode group presser 17 also has a protrusion 35 that protrudes toward the side where the electrode group 2 is located in the height direction of the battery 1. In one example, such as those shown in Figures 3 to 5, two protrusions 35 are provided on the electrode group presser 17, one protrusion 35 provided on each side of the opening 33 in the horizontal direction of the battery 1. Therefore, one of the two protrusions 35 is located between the opening 32A and the opening 33 in the horizontal direction of the battery 1, and the other of the two protrusions 35 is located between the opening 32B and the opening 33 in the horizontal direction of the battery 1. In one example, such as those shown in Figures 3 to 5, in the internal cavity 8, each of the protrusions 35 of the electrode group presser 17 abuts against the electrode group 2 from the side where the lid member 5 is located in the height direction of the battery 1. Each of the protrusions 35 presses the electrode group 2 toward the side where the bottom wall 6 is located in the height direction of the battery 1.

Figure 6 shows a perspective view of the configuration of one of a pair of leads 20. Note that in this embodiment, the configuration of the other of the pair of leads 20 is the same as the configuration in Figure 6. As shown in Figures 3 to 6, each of the pair of leads 20 (20A, 20B) has a top plate portion 41 and a leg plate portion 42. In the example shown in Figure 6, each lead 20 has only one leg plate portion 42. The top plate portion 41 of each lead 20 defines a plate length direction (direction indicated by arrows Y3 and Y4), a plate width direction (direction indicated by arrows X3 and X4) that intersects (orthogonal or approximately orthogonal to) the plate length direction, and a plate thickness direction (direction indicated by arrows Z3 and Z4) that intersects (orthogonal or approximately orthogonal to) both the plate length direction and the plate width direction.

In each of the leads 20, the top plate portion 41 extends along the plate length direction from the extension end (first extension end) E1 to the extension end (second extension end) E2. In each of the top plate portions 41 of the leads 20, the extension end E1 is the end on one side in the plate length direction, and the extension end E2 is the end opposite the extension end E1 in the plate length direction. In each of the leads 20, a through hole 43 is formed that penetrates the top plate portion 41 in the plate thickness direction of the top plate portion 41. In each of the top plate portions 41 of the leads 20, the through hole 43 is formed between the extension ends E1 and E2 in the plate length direction.

In each of the leads 20, the leg plate portion 42 is connected to the top plate portion 41 at a position opposite the extended end E1 with respect to the through hole 43 in the lengthwise direction of the top plate portion 41. In one example, such as those shown in Figures 3 to 6, in each of the leads 20, the leg plate portion 42 is connected to the top plate portion 41 between the through hole 43 and the extended end E2 in the lengthwise direction of the top plate portion 41. In each of the leads 20, the leg plate portion 42 is bent relative to the top plate portion 41 to one side in the thickness direction of the top plate portion 41. In one example, such as those shown in Figures 3 to 6, in each of the leads 20, the bending line at the bending position of the leg plate portion 42 relative to the top plate portion 41 is aligned along the lengthwise direction of the top plate portion 41. In each of the leads 20, the leg plate portion 42 extends from the connection position to the top plate portion 41 (the bending position relative to the top plate portion 41) along the thickness direction of the top plate portion 41.

3 to 6, in each of the leads 20, a portion of the leg plate portion 42 protrudes from the extension end E2 on the opposite side of the extension end E1 in the length direction of the top plate portion 41. Therefore, in each of the leads 20, the leg plate portion 42 forms an end E3 on the opposite side of the extension end E1 in the length direction of the top plate portion 41. The distance between the extension end E1 and the end E3 in each of the leads 20 along the length direction of the top plate portion 41 is defined as the dimension of each of the leads 20 along the length direction of the top plate portion 41.

Each lead 20 is placed in the internal cavity 8 with the thickness direction of the top plate portion 41 aligned or approximately aligned with the height direction of the battery 1, and the width direction of the top plate portion 41 aligned or approximately aligned with the depth direction of the battery 1. Furthermore, in the internal cavity 8, the top plate portion 41 of each lead 20 is positioned between the lid member 5 and the electrode group 2 in the height direction of the battery 1, and between the electrode group presser 17 and the electrode group 2 in the height direction of the battery 1. Therefore, the electrode group presser 17 is positioned between the top plate portion 41 of each lead 20 and the lid member 5. Furthermore, for each lead 20 placed in the internal cavity 8, the extended end E2 of the top plate portion 41 is positioned laterally outward of the battery 1 relative to the extended end E1. Therefore, for each top plate portion 41 of each lead 20, the extended end E1 is the inner end of the battery 1 in the lateral direction, and the extended end E2 is the outer end of the battery 1 in the lateral direction. In the internal cavity 8, each of the top plate portions 41 extends laterally outward from an extension end E1 to an extension end E2.

For each lead 20 disposed in the internal cavity 8, the through hole 43 in the top plate portion 41 is aligned along the height direction of the battery 1. For each pair of leads 20, the through hole 43 in the top plate portion 41 faces a corresponding one of the pair of through holes 31 in the electrode group presser 17 from the side where the electrode group 2 is located in the height direction of the battery 1. For each pair of leads 20, the through hole 43 in the top plate portion 41 faces a corresponding one of the pair of through holes 21 in the lid member 5 from the side where the electrode group 2 is located in the height direction of the battery 1, with a corresponding one of the through holes 31 sandwiched between them. When projected from the height direction of the battery 1, the through hole 43 of each of the pair of leads 20 overlaps with a corresponding one of the pair of through holes 31 and a corresponding one of the pair of through holes 21.

As described above, each of the pair of electrode terminals 16 is sequentially inserted into a corresponding one of the pair of through holes 21 and a corresponding one of the pair of through holes 31, and is also inserted into a corresponding one of the through holes 43 of a pair of leads 20 in the internal cavity 8. Furthermore, in each of the leads 20, a corresponding one of the electrode terminals 16 is connected at the through hole 43. Therefore, in each of the leads 20, the through hole 43 is the connection position for a corresponding one of the electrode terminals 16. Each of the electrode terminals 16 is connected to a corresponding one of the top plate portions 41 of the lead 20 at the through hole 43, for example, by crimping.

In addition, for each of the leads 20 arranged in the internal cavity 8, the leg plate portion 42 is located laterally outward of the battery 1 relative to the through-hole 43 (the connection position of the electrode terminal 16), and the leg plate portion 42 is connected to the top plate portion 41 at a position laterally outward of the connection position of the electrode terminal 16. For each of the leads 20, the leg plate portion 42 extends along the height direction of the battery 1 from the connection position to the top plate portion 41 (the bending position relative to the top plate portion 41) and bends toward the side where the bottom wall 6 is located relative to the top plate portion 41. In the example shown in Figures 3 to 6, for each of the leads 20, the bending line at the bending position of the leg plate portion 42 relative to the top plate portion 41 is aligned with the horizontal direction of the battery 1.

2 and other examples, a bundling portion where multiple strips are bundled is formed in one location in each of a pair of current collecting tabs 15. A pair of backup leads 18 are also disposed in the internal cavity 8. Each of the backup leads 18 is formed from a conductive material such as metal. The bundling portion of each of the current collecting tabs 15 is sandwiched between a corresponding one of the pair of backup leads 18. The bundling portion of each of the current collecting tabs 15 is then joined to a corresponding leg plate portion 42 of a lead 20 via a corresponding one of the backup leads 18. Note that the bundling portion of each of the current collecting tabs 15 is joined to a corresponding one of the leg plate portions 42 of a lead 20 by, for example, ultrasonic welding. Alternatively, a backup lead 18 may not be provided. In one example, the bundling portion of each of the current collecting tabs 15 is directly joined to a corresponding one of the leg plate portions 42 of a lead 20 without an intervening backup lead 18 or the like.

As described above, in each lead 20, a corresponding one of a pair of electrode terminals 16 is connected via the through-hole 43, and a corresponding one of a pair of current collecting tabs 15 is connected to the leg plate portion 42. Therefore, in each pair of leads 20, the connection position of the corresponding one of the electrode terminals 16 is located laterally inward of the battery 1 relative to the connection position of the corresponding one of the current collecting tabs 15. Furthermore, in each lead 20, a portion of the leg plate portion 42 protrudes laterally outward of the battery 1 relative to the extended end E2 of the top plate portion 41, and the end E3 formed on the leg plate portion 42 is located laterally outward of the battery 1 relative to the extended end E2 of the top plate portion 41. Therefore, in each lead 20, the extended end E1 is the inner end of the battery 1 in the horizontal direction, and the end E3 is the outer end of the battery 1 in the horizontal direction. The distance between the extended end E1 and the end E3 of each lead 20 along the lateral direction of the battery 1 is defined as the dimension L1 of each lead 20 along the lateral direction of the battery 1.

The top plate portion 41 of each lead 20 has an extension 51 extending along the length of the top plate portion 41 between the through hole 43 and the extended end E1. For each lead 20, the extension 51 extends laterally inward of the battery 1 from the through hole 43, which is the connection position of one of the corresponding electrode terminals 16, to the extended end E1. For each lead 20, the extension 51 forms the extended end E1, i.e., the inner end of the battery 1 in the horizontal direction. The gas release valve 25 and opening hole 33 are located laterally inward of the battery 1 relative to the extension 51 of each lead 20, and are located laterally inward of the battery 1 relative to the extended end E1 of each lead 20.

The extension 51 of each of the pair of leads 20 includes a pair of lead projections 52A, 52B. For each lead 20, the lead projections 52A, 52B protrude laterally inward of the battery 1 relative to the rest of the extension 51. For each lead 20, the protruding ends of the lead projections 52A, 52B form an extended end E1, which forms the inner lateral end of the battery 1. Furthermore, for each lead 20, the pair of lead projections 52A, 52B are positioned apart from each other in the depth direction of the battery 1 (the width direction of the top panel 41). For each extension 51 of the lead 20, the lead projection (first lead projection) 52A forms part of one edge of the battery 1 in the depth direction, and the lead projection (second lead projection) 52B forms part of the edge on the opposite side of the lead projection 52A in the depth direction of the battery 1.

In addition, in each extension 51 of the lead 20, a lead recess 53 is formed between the pair of lead projections 52A, 52B in the depth direction of the battery 1 (the width direction of the top plate 41). In each lead 20, the lead recess 53 is recessed toward the side where the extension end E2 is located in the length direction of the top plate 41, i.e., toward the outside in the lateral direction of the battery 1. In each lead 20, the lead projection (first lead projection) 52A is adjacent to the lead recess 53 from one side in the depth direction of the battery 1, and the lead projection (second lead projection) 52B is adjacent to the lead recess 53 from the side opposite the lead projection 52A in the depth direction of the battery 1.

In one example shown in Figures 3 to 5, the imaginary central plane that defines the center position of the battery 1 in the depth direction passes through each lead recess 53 of the leads 20. Also, in one example shown in Figures 3 to 6, the lead projections 52A, 52B and lead recess 53 form the inner end surface of the battery 1 in the lateral direction for each of the pair of leads 20. When projected from the height direction of the battery 1, the lead projections 52A, 52B and lead recess 53 form a U-shape or approximately U-shape that is recessed outward in the lateral direction for each of the leads 20 on the inner end surface of the battery 1 in the lateral direction.

For lead 20A, one of the pair of leads 20, the pair of lead projections 52A, 52B and lead recess 53 are located near the hole (first hole) 26 in the cover member 5 and the hole (second hole) 32A in the electrode group retainer 17. However, the lead projections 52A, 52B of lead 20A are offset from the holes 26, 32A in the depth direction of the battery 1. The lead projection (first lead projection) 52A of lead 20A is adjacent to the holes 26, 32A from one side in the depth direction of the battery 1. The lead projection (second lead projection) 52B of lead 20A is adjacent to the holes 26, 32A from the opposite side in the depth direction of the battery 1 from the lead projection 52A. The bottom of the lead recess 53 of lead 20A is adjacent to the holes 26, 32A from the outer lateral side.

Because the lead projections 52A, 52B and lead recess 53 of lead 20A are positioned as described above, when projected from the height direction of the battery 1, the extension 51 of lead 20A covers part of the outer periphery of the hole (first hole) 26 in the lid member 5 and part of the outer periphery of the hole (second hole) 32A in the electrode group retainer 17. In the example shown in Figures 3 to 5, when projected from the height direction of the battery 1, the outer periphery of each of the holes 26, 32A is covered by the extension 51 of lead 20A (lead projections 52A, 52B and lead recess 53) over an angular range of 120° or approximately 120°. Also, as described above, the lead projections 52A, 52B of lead 20A are offset from the holes 26, 32A in the depth direction of the battery 1. Therefore, when projected from the height direction of the battery 1, the extension 51 of lead 20A does not overlap with the holes 26, 32A.

In addition, in this embodiment, the extended end E1 of lead 20A, i.e., the protruding ends of lead projections 52A and 52B of lead 20A, is located laterally inward of the battery 1 relative to the outer lateral end of hole (second hole) 32A. In other words, the inner lateral end of lead 20A relative to the outer lateral end of hole 32A is located laterally inward of the battery 1 relative to the outer lateral end of hole 32A. In the example shown in Figures 3 to 5, etc., the inner lateral end of lead 20A relative to the outer lateral end of hole (first hole) 26 is located laterally outward of the battery 1.

In lead 20B, which is the other of the pair of leads 20 other than lead 20A, the pair of lead projections 52A, 52B and lead recess 53 are located near the hole 32B in the electrode group presser 17. However, the lead projections 52A, 52B of lead 20B are offset from the hole 32B in the depth direction of the battery 1. The lead projection (first lead projection) 52A of lead 20B is adjacent to the hole 32B from one side in the depth direction of the battery 1. The lead projection (second lead projection) 52B of lead 20B is adjacent to the hole 32B from the opposite side in the depth direction of the battery 1 from lead projection 52A. The bottom of the lead recess 53 of lead 20B is adjacent to the hole 32B from the outer lateral side.

As described above, the lead projections 52A, 52B and lead recess 53 of lead 20B are positioned so that, when projected from the height direction of the battery 1, the extension 51 of lead 20B covers part of the outer periphery of hole 32B in the electrode group retainer 17. In the example shown in Figures 3 to 5, the outer periphery of hole 32B is covered by the extension 51 of lead 20B (lead projections 52A, 52B and lead recess 53) over an angular range of 120° or approximately 120° when projected from the height direction of the battery 1. Also, as described above, the lead projections 52A, 52B of lead 20B are offset from hole 32B in the depth direction of the battery 1. Therefore, when projected from the height direction of the battery 1, the extension 51 of lead 20B does not overlap with hole 32B.

In addition, in this embodiment, the extended end E1 of lead 20B, i.e., the protruding ends of lead projections 52A and 52B of lead 20B, is located laterally inward of the battery 1 relative to the outer lateral end of hole 32B. In other words, the inner lateral end of lead 20B is located laterally inward of the battery 1 relative to the outer lateral end of hole 32B.

Furthermore, for each of a pair of leads 20, a distance D1 along the lateral direction of the battery 1 from one corresponding connection position (through hole 43) of the electrode terminal 16 to the inner lateral end (extension end E1) of the battery 1, and a distance D2 along the lateral direction of the battery 1 from one corresponding connection position (through hole 43) of the electrode terminal 16 to the outer lateral end (end E3) of the battery 1 are specified. For each lead 20, it is preferable that distance D1 be greater than distance D2.

As mentioned above, the distance (separation dimension) from the extended end E1 to the end E3 of each lead 20 along the lateral direction of the battery 1 is defined as the dimension L1 of each lead 20 along the lateral direction of the battery 1. The dimension L2 of the lid member 5 along the lateral direction of the battery 1 is then defined. It is preferable that the dimension L1 of each lead 20 is 50% or more of half the dimension L2 of the lid member 5. In other words, it is preferable that the sum of the dimension L1 of lead 20A and the dimension L1 of lead 20B is 50% or more of the dimension L2 of the lid member 5.

As described above, in this embodiment, each lead 20 includes an extension 51 that extends laterally inward of the battery 1 from the connection position of one of the corresponding electrode terminals 16. The extension 51 of lead 20A, one of the pair of leads 20, covers part of the outer periphery of the hole (first hole) 26 in the lid member 5 that serves as the inlet, when projected from the height direction of the battery 1. Therefore, the extension 51 of lead 20A extends laterally inward of the battery 1 to a position in the vicinity of the hole 26 in the lid member 5. By extending the extension 51 of lead 20A to a position in the vicinity of the hole 26, the strength of the hole 26 and its vicinity in the lid member 5 is appropriately ensured. In other words, in a configuration in which the hole 26, such as the inlet, is formed in the lid member 5 at a position inward of the electrode terminal 16 in the laterally direction of the battery 1, the strength of the lid member 5 at the hole 26 and its vicinity is appropriately ensured.

By ensuring the strength of the lid member 5 at and near the hole 26, damage to the lid member 5 at and near the hole 26 before the gas release valve 25 is opened is effectively prevented when the pressure in the internal cavity 8 reaches a certain level. As a result, when the pressure in the internal cavity 8 rises above the upper limit of the battery 1's operating range, the gas release valve 25 is opened appropriately, and gas is properly released from the internal cavity 8 through the gas release valve 25 to the outside of the outer container 3.

In addition, in this embodiment, when projected from the height direction of the battery 1, the extension 51 of the lead 20A does not overlap with the hole (first hole) 26, which serves as the electrolyte inlet. Therefore, even if the extension 51 of the lead 20A is configured to extend close to the hole 26, the electrolyte can be properly injected into the internal cavity 8 through the hole 26 during the manufacture of the battery 1, etc.

In addition, in this embodiment, the hole (second hole) 32A in the electrode group presser 17 faces the hole (first hole) 26 in the cover member 5 from the side where the electrode group 2 is located in the height direction of the battery 1. When projected from the height direction of the battery 1, the extension 51 of the lead 20A does not overlap with the hole 32A and covers part of the outer periphery of the hole 32A. Therefore, even in a configuration in which the electrode group presser 17 is provided and the extension 51 of the lead 20A extends close to the hole 26, electrolyte can be appropriately injected into the internal cavity 8 through the hole 26 during battery 1 manufacturing, etc.

The inner end (extended end E1) of lead 20A in the horizontal direction of the battery 1 is located laterally inward compared to the outer end of hole 32A in the horizontal direction. Lead extension 51 of lead 20A is provided with lead protrusions 52A, 52B and lead recess 53, which are configured as described above. This allows for an appropriate configuration in which, when projected from the height direction of the battery 1, lead extension 51 of lead 20A does not overlap holes 26, 32A and covers at least a portion of the outer periphery of holes 26, 32A.

Because the extension 51 of lead 20A extends laterally inward of the battery 1 to the vicinity of hole 26 as described above, a large volume for lead 20A is ensured. Furthermore, when projected from the height direction of the battery 1, the extension 51 of lead 20B covers part of the outer periphery of hole 32B in the electrode group retainer 17. Therefore, the extension 51 of lead 20B extends laterally inward of the battery 1 to a position in the vicinity of hole 32B in the cover member 5. Because the extension 51 of lead 20B extends laterally inward of the battery 1 to the vicinity of hole 32B as described above, a large volume for lead 20B is ensured.

As the volume of each lead 20 increases, the heat capacity also increases. The increased heat capacity of each lead 20 reduces the amount of heat generated by each lead 20, even when the current flowing through the lead 20 increases. By reducing the amount of heat generated by each lead 20 when the battery 1 is energized, the temperature rise of the leads 20 and components disposed near the leads 20, such as the insulating gasket 23, is effectively reduced. This effectively prevents deformation of the insulating gasket 23 and ensures proper sealing of the internal cavity 8 of the battery 1. Furthermore, by reducing the amount of heat generated by each lead 20 due to current when the battery 1 is energized, it becomes possible to increase the value of the current that can be passed through the battery 1.

When distances D1, D2 and dimensions L1, L2 are specified as described above, by making distance D1 larger than distance D2 for each lead 20, the volume of each lead 20 becomes even larger, and the heat capacity of each lead 20 becomes even larger. Furthermore, by making dimension L1 of each lead 20 50% or more of half the value of dimension L2 of lid member 5, the volume of each lead 20 becomes even larger, and the heat capacity of each lead 20 becomes even larger.

Furthermore, by extending lead 20A to the vicinity of hole 26, the area of the electrode group presser 17 that is sandwiched between lead 20A and the lid member 5 is increased. Similarly, by extending lead 20B to the vicinity of hole 32B, the area of the electrode group presser 17 that is sandwiched between lead 20B and the lid member 5 is increased. Therefore, in this embodiment, the area of the electrode group presser 17 that is sandwiched between each lead 20 and the lid member 5 is increased.

When manufacturing the battery 1, one of the electrode terminals 16 is connected to each of the pair of leads 20 by crimping or other means. At this time, the area where the electrode group presser 17 is sandwiched between each lead 20 and the lid member 5 is increased, effectively preventing the electrode group presser 17 from lifting off the lid member 5. By effectively preventing the electrode group presser 17 from lifting off the lid member 5, in the manufactured battery 1, the electrode group presser 17 appropriately presses the electrode group 2 toward the bottom wall 6 in the height direction of the battery 1. This improves the holding force of the electrode group 2 by the electrode group presser 17, improving the vibration resistance of the battery 1.

In addition, in this embodiment, the gas release valve 25 and opening hole 33 are located laterally inward of the battery 1 relative to the extensions 51 of each lead 20. Therefore, even if the extensions 51 described above are formed on each lead 20, the extensions 51 of the leads 20 do not prevent the gas release valve 25 from opening. Therefore, even if the extensions 51 described above are formed on each lead 20, the gas release valve 25 will open appropriately when the pressure in the internal cavity 8 increases beyond the upper limit of the battery 1's operating range.

(Modification)
In the first modified example shown in Figures 7 and 8, each lead 20 also has an extension 51, and each extension 51 of the lead 20 includes a lead projection 52A, 52B and a lead recess 53. When projected from the height direction of the battery 1, the extension 51 of the lead 20A does not overlap with the holes 26, 32A and covers at least a portion of the outer periphery of the holes 26, 32A. Therefore, in this modified example, the lead 20A also extends laterally inward of the battery 1 to the vicinity of the hole 26. However, in this modified example, the extension end E1 of the lead 20A, i.e., the protruding ends of the lead projections 52A, 52B of the lead 20A, are located laterally inward of the holes 26, 32A. Note that Figure 7 shows a portion of the lid assembly 4 as viewed from the side where the bottom wall 6 is located in the height direction of the battery 1, and Figure 8 shows a perspective view of the configuration of one of the pair of leads 20. In this modification, the other of the pair of leads 20 has the same configuration as that shown in FIG.

In this modified example, the inner end of lead 20A in the horizontal direction of battery 1 is located more inward in the horizontal direction of battery 1 than the outer end of hole (first hole) 26 and the outer end of hole (second hole) 32A. Furthermore, in the example shown in Figure 7, etc., the inner end of lead 20A in the horizontal direction of battery 1 is located more inward in the horizontal direction of battery 1 than the inner end of hole (first hole) 26 and the inner end of hole (second hole) 32A. However, even in this modified example, the gas release valve 25 and opening hole 33 are located more inward in the horizontal direction of battery 1 than the extension 51 and extended end E1 of lead 20A.

In addition, in this modified example, when projected from the height direction of the battery 1, the extension 51 of the lead 20B does not overlap the hole 32B and covers at least a portion of the outer periphery of the hole 32B. Therefore, in this modified example, the lead 20B extends laterally inward of the battery 1 to the vicinity of the hole 32B. However, in this modified example, the extension end E1 of the lead 20B, i.e., the protruding ends of the lead projections 52A and 52B of the lead 20B, is located laterally inward of the battery 1 relative to the hole 32B. Therefore, the inner end of the lead 20B in the horizontal direction of the battery 1 is located laterally inward of the battery 1 relative to the outer end of the hole 32B in the horizontal direction of the battery 1. However, in this modified example, the gas release valve 25 and the opening hole 33 are located laterally inward of the extension 51 and extension end E1 of the lead 20B.

In the second variant shown in Figures 9 and 10, an extension 51 is also provided on each lead 20. However, in this variant, the extension 51 of each lead 20 does not have lead protrusions 52A, 52B or lead recesses 53. Instead, each lead 20 has a lead hole 55 that penetrates the extension 51 in the thickness direction of the top plate 41. For each lead 20, the lead hole 55 is located between the through hole 43 and the extended end E1 in the horizontal direction of the battery 1, and is located laterally inward of the connection position of the corresponding electrode terminal 16. For each lead 20, the lead hole 55 also penetrates the extension 51 in the height direction of the battery 1. Note that Figure 9 shows a portion of the lid assembly 4 as viewed from the side where the bottom wall 6 is located in the vertical direction of the battery 1, and Figure 10 shows a perspective view of the configuration of one of the pair of leads 20. In this modification, the other of the pair of leads 20 has the same configuration as that shown in FIG.

The lead hole 55 of the lead 20A faces the hole (second hole) 32A in the electrode group presser 17 from the side where the electrode group 2 is located in the height direction of the battery 1. The lead hole 55 of the lead 20A faces the hole (first hole) 26 in the cover member 5, with hole 32A in between, from the side where the electrode group 2 is located in the height direction of the battery 1. The cross-sectional area of the lead hole 55 of the lead 20A in a cross section perpendicular or approximately perpendicular to the height direction of the battery 1 is larger than the cross-sectional areas of the holes 26 and 32A in a cross section perpendicular or approximately perpendicular to the height direction of the battery 1. When projected from the height direction of the battery 1, the outer periphery of the lead hole 55 of the lead 20A completely surrounds the outer periphery of the hole (first hole) 26 and the outer periphery of the hole (second hole) 32A.

As described above, the extension 51 and lead hole 55 are formed on the lead 20A. Therefore, in this modified example, when projected from the height direction of the battery 1, the extension 51 of the lead 20A completely covers the outer periphery of the hole (first hole) 26 in the lid member 5 and the outer periphery of the hole (second hole) 32A in the electrode group retainer 17. Also, in this modified example, when projected from the height direction of the battery 1, the extension 51 of the lead 20A does not overlap with the holes 26 and 32A.

In addition, in this modified example, the extended end E1 of the lead 20A is located laterally inward of the battery 1 relative to the lead hole 55 of the lead 20A. Therefore, the inner end of the lead 20A in the horizontal direction of the battery 1 (extended end E1) is located laterally inward of each of the holes 26 and 32A. Therefore, the inner end of the lead 20A in the horizontal direction of the battery 1 is located laterally inward of the battery 1 relative to the outer end of the hole (second hole) 32A. Furthermore, the inner end of the lead 20A in the horizontal direction of the battery 1 is located laterally outward of the battery 1 relative to the outer end of the hole (first hole) 26. However, even in this modified example, the gas release valve 25 and opening hole 33 are located laterally inward of the battery 1 relative to the extension 51 and extended end E1 of the lead 20A.

The lead hole 55 of lead 20B faces hole 32B of electrode group presser 17 from the side where electrode group 2 is located in the height direction of the battery 1. The cross-sectional area of lead hole 55 of lead 20A in a cross section perpendicular or approximately perpendicular to the height direction of the battery 1 is larger than the cross-sectional area of hole 32B in a cross section perpendicular or approximately perpendicular to the height direction of the battery 1. Furthermore, when projected from the height direction of the battery 1, the outer periphery of lead hole 55 of lead 20B completely surrounds the outer periphery of hole 32B. Because the extension 51 and lead hole 55 are formed in lead 20B as described above, in this modified example, when projected from the height direction of the battery 1, the extension 51 of lead 20B completely covers the outer periphery of hole 32B of the electrode group presser 17. Furthermore, in this modified example, when projected from the height direction of the battery 1, the extension 51 of lead 20B does not overlap with hole 32B.

In addition, in this modified example, the extended end E1 of lead 20B is located laterally inside the battery 1 relative to the lead hole 55 of lead 20B. Therefore, the inner end of lead 20B in the horizontal direction of the battery 1 (extended end E1) is located laterally inside the battery 1 relative to hole 32B. Therefore, the inner end of lead 20B in the horizontal direction of the battery 1 is located laterally inside the battery 1 relative to the outer end of hole 32B in the horizontal direction of the battery 1. However, even in this modified example, the gas release valve 25 and opening hole 33 are located laterally inside the battery 1 relative to the extension 51 and extended end E1 of lead 20B.

In one variation, the cross-sectional area of hole 32A in a cross section perpendicular or approximately perpendicular to the height direction of battery 1 is smaller than the cross-sectional area of hole 26 in a cross section perpendicular or approximately perpendicular to the height direction of battery 1. When projected from the height direction of battery 1, the outer periphery of hole (first hole) 26 completely surrounds the outer periphery of hole (second hole) 32A. The outer edge of hole 26 in the horizontal direction of battery 1 is located further outward in the horizontal direction of battery 1 than the outer edge of hole 32A in the horizontal direction of battery 1. In this variation, as in the previously described embodiment, when projected from the height direction of battery 1, extension 51 of lead 20A does not overlap holes 26 and 32A and covers at least a portion of the outer periphery of holes 26 and 32A. Therefore, in this variation, lead 20A extends to the inner lateral direction of battery 1, close to hole 26.

In addition, in this modified example, the extended end E1 of lead 20A, i.e., the inner end of lead 20A in the horizontal direction of the battery 1, is located laterally inside of the battery 1 compared to the outer end of hole 26. Note that in this modified example, the inner end of lead 20A in the horizontal direction of the battery 1 may be located laterally inside of the battery 1 or outside of the battery 1 compared to the outer end of hole 32A in the horizontal direction of the battery 1. However, even in this modified example, the gas release valve 25 and opening hole 33 are located laterally inside of the battery 1 relative to the extension 51 and extended end E1 of lead 20A.

Therefore, in the above-described embodiment, the inner edge of the lead 20A in the horizontal direction of the battery 1 is located laterally inward relative to at least one of the outer edge of the hole (first hole) 26 in the lid member 5 in the horizontal direction of the battery 1 and the outer edge of the hole (second hole) 32A in the electrode group retainer 17 in the horizontal direction of the battery 1. With this configuration, the extension 51 of the lead 20A extends laterally inward relative to the battery 1 up to the vicinity of the hole 26, as described above.

Furthermore, as long as the configuration of the top plate portion 41 including the extension 51 in each of the pair of leads 20 is the same as that in any of the above-described embodiments, the configuration of the leg plate portion and other components is not limited to that of the above-described embodiments. In one variation, two leg plate portions are provided on each lead 20, spaced apart from each other in the depth direction of the battery 1. In another variation, the leg plate portion is connected to the extended end E2 of the top plate portion 41 in each lead 20. In this case, the extended end E2 of the top plate portion 41 in each lead 20 is the bending position of the leg plate portion relative to the top plate portion 41, and the bending line of the leg plate portion relative to the top plate portion 41 is along the plate width direction of the top plate portion 41 (depth direction of the battery 1). However, in either configuration, the leg plate portion in each lead 20 is located laterally outside the through-hole 43 (connection position of the electrode terminal 16) in the battery 1. In each lead 20 , the connection position of one of the electrode terminals 16 is located laterally inward of the battery 1 compared to the connection position of one of the current collecting tabs 15 .

All of the above-described embodiments achieve the same effects and advantages as the first embodiment. That is, in all of the above-described embodiments, when a hole (e.g., 26) is formed in the cover member 5 at a position laterally inward relative to the electrode terminal 16, the strength of the cover member at and near the hole (e.g., 26) is appropriately ensured. Furthermore, even when the lead 20A is provided with the extension 51 described above, the electrolyte is appropriately injected into the internal cavity 8 through the hole 26.

Furthermore, of the pair of leads 20, lead 20A, which is located on the side where hole 26 is located relative to gas exhaust valve 25, may have the same configuration as any of the above-described embodiments and modified examples. In other words, of the pair of leads 20, lead 20B, which is located on the opposite side of the side where hole 26 is located relative to gas exhaust valve 25, does not need to have the same configuration as any of the above-described embodiments and modified examples. Furthermore, lead 20A may function as both a negative electrode lead between the negative electrode current collecting tab and the negative electrode terminal, and as one of the positive electrode leads between the positive electrode current collecting tab and the positive electrode terminal.

According to at least one of these embodiments or examples, a first hole penetrating from the outer surface to the inner surface is formed in the battery lid member, and the electrode terminal is located laterally outward relative to the first hole. In the battery lead, the connection position of the electrode terminal is located laterally inward relative to the connection position of the current collecting tab. The lead has an extension extending laterally inward from the connection position of the electrode terminal, and when projected from the height direction, the extension does not overlap with the first hole and covers at least a portion of the outer periphery of the first hole. This makes it possible to provide a battery in which the strength of the lid member in and around the hole is appropriately ensured in a configuration in which a hole is formed in the lid member at a position laterally inward relative to the electrode terminal.

Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.
The following are additional notes.
[1] An outer container having a bottom wall and a peripheral wall, and an internal cavity formed therein that opens to the side opposite to the side where the bottom wall is located in the height direction;
an electrode group including a current collecting tab and housed in the internal cavity of the outer container;
a cover member attached to the peripheral wall of the outer container in a state of closing the opening of the internal cavity, the cover member having a first hole penetrating from the outer surface to the inner surface;
an electrode terminal exposed to the outside on the outer surface of the lid member and positioned outside the first hole in a lateral direction intersecting the height direction;
a lead that electrically connects the current collecting tab of the electrode group and the electrode terminal in the internal cavity, the connection position of the electrode terminal being located more inward in the lateral direction than the connection position of the current collecting tab, the lead including an extension that extends from the connection position of the electrode terminal to the more inward in the lateral direction, the extension not overlapping with the first hole when projected from the height direction, and covering at least a part of the outer periphery of the first hole;
A battery comprising:
[2] The battery of [1], wherein the inner end of the lead in the horizontal direction is located on the inner side in the horizontal direction compared to the outer end of the first hole in the horizontal direction.
[3] The extension of the lead includes a lead protrusion that protrudes inward in the lateral direction relative to other portions of the extension,
the lead projection is positioned offset from the first hole in a depth direction that intersects both the height direction and the lateral direction;
[1] or [2] battery.
[4] The lead projections include a first lead projection adjacent to the first hole from one side in the depth direction, and a second lead projection adjacent to the first hole from the opposite side to the first lead projection in the depth direction,
the extension includes a lead recess formed between the first lead projection and the second lead projection in the depth direction and recessed outward in the lateral direction;
a bottom of the lead recess adjacent to the first hole from the outer side in the lateral direction;
[3] Battery.
[5] A lead hole is formed in the extension of the lead, penetrating the lead in the height direction;
the lead hole of the extension faces the first hole of the lid member from a side on which the electrode group is located in the height direction;
When projected from the height direction, an outer periphery of the lead hole completely surrounds the outer periphery of the first hole.
[1] or [2] battery.
[6] The device further includes an electrode group presser that is disposed between the lead and the lid member in the internal cavity and that restricts movement of the electrode group toward the side where the lid member is located;
a second hole penetrating the electrode group presser in the height direction is formed in the electrode group presser;
the second hole of the electrode group presser faces the first hole of the lid member from a side on which the electrode group is located in the height direction,
When projected from the height direction, the extension of the lead does not overlap the second hole and covers at least a part of the outer periphery of the second hole.
[1] Battery.
[7] The battery of [6], wherein the inner end of the lead in the horizontal direction is located on the inner side in the horizontal direction compared to at least one of the outer end of the first hole in the horizontal direction and the outer end of the second hole in the horizontal direction.
[8] The extension of the lead includes a lead protrusion that protrudes inward in the lateral direction relative to other portions of the extension,
the lead projection is positioned offset with respect to the first hole and the second hole in a depth direction that intersects both the height direction and the lateral direction;
[6] or [7].
[9] The lead projections include a first lead projection adjacent to the first hole and the second hole from one side in the depth direction, and a second lead projection adjacent to the first hole and the second hole from the opposite side to the first lead projection in the depth direction,
the extension includes a lead recess formed between the first lead projection and the second lead projection in the depth direction and recessed outward in the lateral direction;
a bottom of the lead recess adjacent to the first hole and the second hole from the outer side in the lateral direction;
[8] Battery.
[10] A lead hole is formed in the extension of the lead, penetrating the lead in the height direction;
the lead hole of the extension faces the second hole of the electrode group presser from a side on which the electrode group is located in the height direction;
When projected from the height direction, an outer periphery of the lead hole completely surrounds the outer periphery of the first hole and the outer periphery of the second hole.
[6] or [7].
[11] Any one of the batteries [1] to [10], wherein the cover member is provided on the inner side in the lateral direction relative to the first hole and the extension of the lead, and is provided with a gas exhaust valve having a thickness thinner than other parts of the cover member.
[12] A battery according to any one of [1] to [11], wherein the distance from the connection position of the electrode terminal to the inner end in the horizontal direction on the lead is greater than the distance from the connection position of the electrode terminal to the outer end in the horizontal direction on the lead.
[13] The battery according to any one of [1] to [12], wherein the dimension of the lead along the horizontal direction is 50% or more of half the dimension of the lid member along the horizontal direction.
[14] The current collecting tabs include a negative electrode current collecting tab that protrudes from the electrode group to one side in the lateral direction, and a positive electrode current collecting tab that protrudes from the electrode group to the side opposite to the side from which the negative electrode current collecting tab protrudes,
the electrode terminals include a negative electrode terminal and a positive electrode terminal disposed on the outer surface of the lid member and spaced apart from the negative electrode terminal in the lateral direction;
In the cover member, the first hole is formed between the negative electrode terminal and the positive electrode terminal in the lateral direction,
the lead electrically connects the negative electrode current collecting tab and the negative electrode terminal, or the lead electrically connects the positive electrode current collecting tab and the positive electrode terminal;
[1] to [13].

Claims (12)

an outer container having a bottom wall and a peripheral wall, and an internal cavity formed therein that opens to the side opposite to the side where the bottom wall is located in the height direction;
an electrode group including a current collecting tab and housed in the internal cavity of the outer container;
a cover member attached to the peripheral wall of the outer container in a state of closing the opening of the internal cavity, the cover member having a first hole penetrating from the outer surface to the inner surface;
an electrode terminal exposed to the outside on the outer surface of the cover member and positioned away from the first hole on the outer side in a lateral direction intersecting the height direction;
a lead that electrically connects the current collecting tabs of the electrode group and the electrode terminals in the internal cavity, the connection position of the electrode terminals being located more inward in the lateral direction than the connection position of the current collecting tabs, the lead including an extension that extends from the connection position of the electrode terminal to the more inward in the lateral direction, the extension not overlapping with the first hole when projected from the height direction, and covering an outer periphery of the first hole over an angular range of 120° or approximately 120° ;
the extension of the lead includes a lead protrusion that protrudes inward in the lateral direction relative to other portions of the extension,
the lead projection is positioned offset with respect to the first hole in a depth direction intersecting both the height direction and the lateral direction,
the lead projections include a first lead projection adjacent to the first hole from one side in the depth direction, and a second lead projection adjacent to the first hole from the opposite side in the depth direction from the first lead projection,
the extension has a lead recess that is recessed outward in the lateral direction between the first lead projection and the second lead projection,
a bottom of the lead recess adjacent to the first hole from the outer side in the lateral direction;
battery. The battery of claim 1, wherein the inner lateral end of the lead is located more inward in the lateral direction than the outer lateral end of the first hole. a lead hole is formed in the extension of the lead, the lead passing through the lead in the height direction;
the lead hole of the extension faces the first hole of the lid member from a side on which the electrode group is located in the height direction;
When projected from the height direction, an outer periphery of the lead hole completely surrounds the outer periphery of the first hole.
The battery of claim 1 or 2. an electrode group presser that is disposed between the lead and the lid member in the internal cavity and that restricts movement of the electrode group toward the side where the lid member is located;
a second hole penetrating the electrode group presser in the height direction is formed in the electrode group presser;
the second hole of the electrode group presser faces the first hole of the lid member from a side on which the electrode group is located in the height direction,
When projected from the height direction, the extension of the lead does not overlap the second hole and covers the outer periphery of the second hole over an angular range of 120° or approximately 120° .
10. The battery of claim 1. 5. The battery of claim 4, wherein the inner lateral end of the lead is located more inward in the lateral direction than at least one of the outer lateral end of the first hole and the outer lateral end of the second hole. 6. The battery according to claim 4 , wherein the lead projection is positioned offset from the second hole in the depth direction. the first lead projection is adjacent to the second hole from one side in the depth direction,
the second lead piece is adjacent to the second hole from the opposite side of the first lead piece in the depth direction,
a bottom of the lead recess adjacent to the second hole from the outer side in the lateral direction;
7. The battery of claim 6 . a lead hole is formed in the extension of the lead, the lead passing through the lead in the height direction;
the lead hole of the extension faces the second hole of the electrode group presser from a side on which the electrode group is located in the height direction;
When projected from the height direction, an outer periphery of the lead hole completely surrounds the outer periphery of the first hole and the outer periphery of the second hole.
6. The battery of claim 4 or 5 . 9. The battery according to claim 1, wherein the cover member has a gas release valve on the inner side in the lateral direction relative to the first hole and the extension of the lead, the gas release valve having a thickness thinner than other portions of the cover member. 10. The battery according to claim 1, wherein the distance from the connection position of the electrode terminal to the inner end in the lateral direction of the lead is greater than the distance from the connection position of the electrode terminal to the outer end in the lateral direction of the lead. 11. The battery according to claim 1, wherein a dimension of the lead along the lateral direction is 50% or more of half the dimension of the lid member along the lateral direction. the current collecting tabs include a negative electrode current collecting tab that protrudes from the electrode group to one side in the lateral direction, and a positive electrode current collecting tab that protrudes from the electrode group to the side opposite to the side from which the negative electrode current collecting tab protrudes,
the electrode terminals include a negative electrode terminal and a positive electrode terminal disposed on the outer surface of the lid member and spaced apart from the negative electrode terminal in the lateral direction;
In the lid member, the first hole is formed between the negative electrode terminal and the positive electrode terminal,
the lead electrically connects the negative electrode current collecting tab and the negative electrode terminal, or the lead electrically connects the positive electrode current collecting tab and the positive electrode terminal;
12. The battery of any one of claims 1 to 11 .