JP5920115B2 - Power storage device and stacking deviation inspection method - Google Patents

Description

  The present invention relates to a power storage device including an electrode assembly, and a method for inspecting stacking misalignment of a positive electrode, a negative electrode, and a separator constituting the electrode assembly.

  A vehicle such as an EV (Electric Vehicle) or a PHV (Plug in Hybrid Vehicle) is equipped with a secondary battery such as a lithium ion battery as a power storage device that stores power supplied to an electric motor serving as a prime mover. This type of secondary battery is disclosed in Patent Document 1, for example. The secondary battery includes, for example, an electrode assembly that is layered by alternately stacking a positive electrode, a negative electrode, and a separator that insulates them.

JP 2000-285963 A

  By the way, in this type of electrode assembly, there was a possibility that a stacking error occurred. As a method for inspecting misalignment, for example, there is a method of confirming by performing image processing. Such a method is for confirming the presence or absence of misalignment by confirming images of two laminated layers. It is impossible to check the stacking deviation of the assembly. Another method for inspecting misalignment includes a method of confirming the laminated electrode assembly by transmitting X-rays. With such an X-ray inspection method, it is possible to check the stacking deviation of the electrode assembly after stacking. However, in the X-ray inspection method, since the presence or absence of misalignment is confirmed based on the density of each layer of the electrode assembly, the entire electrode assembly is multifaceted in order to confirm which layer is displaced from the normal position. Need to check. For this reason, a certain amount of time is required for the inspection, and the production efficiency of the electrode assembly may be reduced.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power storage device that can suppress a decrease in production efficiency and a power storage device by efficiently inspecting stacking deviation. It is an object of the present invention to provide a stacking deviation inspection method capable of suppressing a decrease in production efficiency.

In the following, means for achieving the above object and its effects are described.
According to a first aspect of the present invention, there is provided a power storage device including an electrode assembly in which a positive electrode, a first separator and a second separator sandwiching the positive electrode, and a negative electrode are stacked. A first protruding portion that covers one surface of the positive electrode and a portion of which protrudes from at least a part of the positive electrode; the second separator covers the other surface of the positive electrode; and A part of the first protruding part has a second protruding part protruding in the same direction as the first protruding part, and the first protruding part and the second protruding part are joined to each other . One surface of the positive electrode is covered, and a part of the positive electrode protrudes in the same direction as the first protrusion and the second protrusion, and the first separator, the second separator, and the negative electrode are Is product When the positive electrode is laminated, the hole is close to two opposite sides of the positive electrode and the positive electrode is laminated. It said position near close to the corner portion located on a diagonal of the positive electrode is, the first separator and the second separator, and its gist to have the hole in the joint.

  According to the above configuration, depending on whether or not the hole is in a penetrating state by performing light projection or the like on the hole that each of the first separator, the second separator, and the negative electrode has two, there is a problem. It is possible to easily determine whether or not the electrode assembly is stacked in a state where the stacking deviation is as small as possible. Therefore, a decrease in production efficiency can be suppressed.

In addition, according to the above configuration, when two layers are provided at positions where the first separator, the second separator, and the negative electrode overlap when stacked, each layer in which the stacking deviation is stacked has a width direction or a diagonal direction. Whether or not there is a stacking misalignment can be suitably determined regardless of whether it is a linear misalignment due to misalignment or a rotational misalignment due to misalignment of each layer in the rotational direction.
According to the said structure, when a positive electrode is laminated | stacked, the position of a hole can be easily set by setting it as the position which adjoins two opposing sides in a positive electrode.
In the case where each layer when laminated has a state where the holes overlap each other and a state where the laminated layers are in different positions due to rotational displacement caused by displacement in the rotational direction, the two holes The longer the distance between them, the larger the amount of hole displacement between the layers.
According to the above configuration, the distance between the two holes can be increased by providing the hole in a position close to a corner on the diagonal line of the positive electrode when the positive electrode is stacked. Therefore, it is possible to more easily determine the misalignment.

  According to the above configuration, since the first separator and the second separator have holes in the joint portion, the holes of the first separator and the second separator overlap when the first separator, the second separator, and the negative electrode are stacked. Positioning can be easily performed.

The invention according to claim 2 is a power storage device that includes a positive electrode, a negative electrode, and a separator, and an electrode assembly in which the positive electrode and the negative electrode are stacked with the separator interposed therebetween. The positive electrode, the negative electrode, and the separator each have two holes at positions that overlap when they are stacked, and the holes are formed when the positive electrode is stacked. The gist of the present invention is that it is close to the two opposite sides and close to a corner on the diagonal line of the positive electrode when the positive electrode is laminated.

  According to the above configuration, by projecting light or the like to the holes that each of the positive electrode, the negative electrode, and the separator has two, depending on whether or not the hole is in a penetrating state, there is no problem. It is possible to easily determine whether or not the electrode assembly can be stacked with a small stacking deviation. Therefore, a decrease in production efficiency can be suppressed.

In addition, as in the above-described configuration, according to the holes having at least two holes at the positions where the positive electrode, the negative electrode, and the separator overlap when stacked, each layer in which the stacking deviation is stacked shifts in the width direction or the diagonal direction. Even if it is a linear shift caused by this, or a rotational shift caused by shifting each layer in the rotation direction, it can be suitably determined whether or not a stacking shift has occurred.
According to the said structure, when a positive electrode is laminated | stacked, the position of a hole can be easily set by setting it as the position which adjoins two opposing sides in a positive electrode.
In the case where each layer when laminated has a state where the holes overlap each other and a state where the laminated layers are in different positions due to rotational displacement caused by displacement in the rotational direction, the two holes The longer the distance between them, the larger the amount of hole displacement between the layers.
According to the above configuration, the distance between the two holes can be increased by providing the hole in a position close to a corner on the diagonal line of the positive electrode when the positive electrode is stacked. Therefore, it is possible to more easily determine the misalignment.

According to a third aspect of the present invention, in the power storage device according to the second aspect , the positive electrode includes a coated portion on which an active material is coated and an uncoated portion on which the active material is not coated. And the positive electrode has the hole in the uncoated portion as its gist.

  According to the said structure, since the positive electrode has a hole in an uncoated part, the reduction | decrease of the electrical capacitance in a positive electrode can be suppressed with formation of a hole. Moreover, it can suppress that the short circuit of a positive electrode and a negative electrode arises through the hole penetrated in the laminated | stacked state.

The invention according to claim 5 is a method for inspecting a stacking deviation of the positive electrode, the negative electrode, and the separator in an electrode assembly in which a positive electrode and a negative electrode are stacked via a separator, the positive electrode the negative electrode and the separator, has two by two holes at a position overlapping when they are stacked, the holes, the two sides facing in the positive electrode when the positive electrode are laminated When the positive electrode is stacked, it is in a position close to a corner portion on the diagonal line of the positive electrode, and any of the holes when at least one of the negative electrode and the separator is stacked The gist of the inspection is to check the stacking deviation as a requirement for determining that no stacking deviation has occurred.

According to the above configuration, as determined requirements to holes are not occur laminating misalignment that they are in the through state, positive electrode in a state laminated deviation is small to the extent of no problem, negative electrode, and laminating the separator Can be easily determined. Therefore, it is possible to suppress a reduction in the production efficiency of the power storage device by efficiently inspecting the stacking deviation.

  In the above configuration, it is determined that there is no stacking deviation because all the holes in each stacked layer are in a through state, and the holes in each stacked layer are in a through state and pass therethrough. And determining that there is no stacking deviation when the area is a predetermined size or larger.

According to a sixth aspect of the present invention, in the stacking deviation inspection method according to the fifth aspect , the stacking shift inspection is performed in a state where a predetermined number or more of the positive electrode, the negative electrode, and the separator are stacked. Is the gist.

  Regardless of the number of stacked positive electrodes, negative electrodes, and separators, the stacking deviation is reflected in the penetration state of the holes. Therefore, as in the above configuration, if the number of stacked layers is equal to or greater than the predetermined number, it is possible to inspect the stacking deviation. In addition, the inspection of the stacking deviation in a state where a predetermined number of stacked negative electrodes or the like can be performed can be performed as follows. That is, for example, when an inspection plate provided with a mark such as a hole is provided at the same position in the stacking direction of the negative electrode hole and the electrode assembly, and when one negative electrode is stacked on this inspection plate, the inspection of the negative electrode hole is performed. By checking the positional relationship with the mark on the plate, it is possible to inspect the stacking deviation.

The invention according to claim 7 is the stack misalignment inspection method according to claim 5 or 6 , wherein the light is projected onto the through-row row of the holes and the light transmitted through the through-row row of the holes is received. The gist of the invention is to inspect the misalignment of the electrode assembly.

  According to the above configuration, the stacking deviation can be inspected by an easy method such as light projection. When the layers such as the positive electrode, the negative electrode, and the separator are stacked with a small stacking deviation, the holes are overlapped in the stacking direction of the stacked body to form a row through which the holes pass. In the above-described configuration, the holes in a state where the layers of the laminate are penetrated in a row are referred to as a penetration row.

The invention according to claim 8 is the stack misalignment inspection method according to claim 7 , wherein light is projected onto the through-rows of the holes during the stacking of the positive electrode, the negative electrode, and the separator. The gist of the present invention is to inspect the misalignment of the electrode assembly.

  According to the above configuration, the stacking shift inspection can be performed together within the time required for stacking, so the stacking shift inspection can be performed more efficiently, and the reduction in the production efficiency of the power storage device is further suppressed. be able to.

  According to the present invention, it is possible to suppress a decrease in production efficiency.

The disassembled perspective view of the secondary battery in embodiment. The disassembled perspective view which shows the structure of an electrode assembly. The top view of a negative electrode. The top view of an electrode storage separator. (A) is a perspective view which shows a state when newly laminated | stacked, (b) is a perspective view which shows the state in which the lamination | stacking shift | offset | difference does not arise when newly laminated | stacked. (A) is a perspective view which shows the state when newly laminated | stacked, (b) is a perspective view which shows the state which the lamination | stacking deviation has arisen when newly laminated | stacked. (A), (b) is explanatory drawing which shows the state judged that lamination | stacking deviation has not arisen. Explanatory drawing which shows the state judged that the lamination | stacking deviation has arisen. Explanatory drawing of a hole. The disassembled perspective view which shows the structure of the electrode assembly in 2nd Embodiment. The top view of the electrode assembly in 3rd Embodiment.

(First embodiment)
Hereinafter, a first embodiment in which the present invention is embodied in a secondary battery mounted on a vehicle such as an industrial vehicle or a passenger vehicle will be described with reference to FIGS.

  As shown in FIG. 1, the secondary battery 10 includes an electrode assembly 11 and an aluminum case 20 that houses the electrode assembly 11. The case 20 includes a case main body 21 having a bottomed rectangular box shape in which an opening 21 a into which the electrode assembly 11 can be inserted is formed, and a rectangular plate-shaped lid 22 that closes the opening 21 a of the case main body 21. Has been. An electrolyte is injected into the case 20. The lid 22 has two through holes 22a, and a positive electrode terminal 23a and a negative electrode terminal 23b are provided so as to penetrate the through holes 22a.

  As shown in FIG. 2, the electrode assembly 11 is formed by laminating a plurality of electrode storage separators 30 each having a bag shape and containing a sheet-like positive electrode 12 therein, and a sheet-like negative electrode 13. Has been. That is, the electrode assembly 11 of this embodiment is a stacked electrode assembly in which the electrode storage separator 30 that stores the positive electrode 12 and the negative electrode 13 are stacked.

  The positive electrode 12 includes a positive metal foil 121 and a positive electrode coating part 12 a in which an active material is coated on both the front and back surfaces of the positive metal foil 121. Moreover, the positive electrode uncoated part 12b is comprised by the site | part in which the active material in the positive electrode metal foil 121 is not coated. From a part of the side 122a which is one side of the positive electrode 12, a positive electrode tab 12c made of a positive electrode uncoated portion 12b protrudes. The negative electrode 13 has a negative electrode metal foil 131 and a negative electrode coating portion 13 a in which an active material is coated on both the front and back surfaces of the negative electrode metal foil 131. Moreover, the negative electrode uncoated part 13b is comprised by the site | part in which the active material in the negative electrode metal foil 131 is not coated. From a part of one side 131b constituting the outer edge 131a of the negative electrode 13, a negative electrode tab 13c made of a negative electrode uncoated portion 13b protrudes. The arrangement positions of the positive electrode tab 12c and the negative electrode tab 13c are positions where the positive electrode 12 and the negative electrode 13 are not overlapped with each other when the positive electrode 12 and the negative electrode 13 are stacked. Each positive electrode 12 is laminated in a certain direction so that each positive electrode tab 12c overlaps, and each negative electrode 13 is laminated in a certain direction so that each negative electrode tab 13c overlaps. The positive electrode metal foil 121 is an aluminum foil, and the negative electrode metal foil 131 is a copper foil.

  As shown in FIG. 3, the negative electrode 13 is large so as to cover either the front surface 12 e or the back surface 12 f of the positive electrode 12. And when the negative electrode 13 is laminated | stacked with the positive electrode 12, the outer edge 131a has the protrusion part 132 which makes the shape which protrudes from the four sides 122a, 122b, 122c, 122d of the positive electrode 12, respectively.

  As shown in FIG. 1, the electrode assembly 11 has a positive electrode tab group 12d formed by collecting the positive electrode tabs 12c. A positive electrode conductive member 19a having a rectangular plate shape is joined to the positive electrode tab group 12d. The electrode assembly 11 has a negative electrode tab group 13d formed by collecting the negative electrode tabs 13c. A negative electrode conductive member 19b having a rectangular plate shape is joined to the negative electrode tab group 13d. The positive electrode tab group 12 d and the negative electrode tab group 13 d extend from one side of the electrode assembly 11.

  The positive electrode conductive member 19a is connected to the positive electrode terminal 23a, and the negative electrode conductive member 19b is connected to the negative electrode terminal 23b. Thus, the positive electrode tab group 12d and the positive electrode terminal 23a are electrically connected via the positive electrode conductive member 19a, and the negative electrode tab group 13d and the negative electrode terminal 23b are electrically connected via the negative electrode conductive member 19b. The Further, in a state where the electrode assembly 11 is accommodated in the case main body 21, the lid 22 and the case main body 21 are joined, and the opening 21 a of the case main body 21 is closed and sealed by the lid 22. A secondary battery 10 is configured. Insulation between the electrode assembly 11 and the inner surface of the case 20 is secured by an insulating sheet (not shown).

Next, the electrode storage separator 30 will be described.
As shown in FIG. 2, the electrode housing separator 30 includes a sheet-like first separator 31 and a sheet-like second separator 32. The 1st separator 31 and the 2nd separator 32 consist of a porous layer, and have comprised the same magnitude | size. The first separator 31 is disposed so as to face the front surface 12 e of the positive electrode 12, while the second separator 32 is disposed so as to face the back surface 12 f of the positive electrode 12. Then, the positive electrode 12 is disposed between the first separator 31 and the second separator 32.

  As shown in FIG. 4, the first separator 31 is large so as to cover the surface 12 e of the positive electrode 12. The first separator 31 is in a state where the positive electrode 12 is sandwiched between the first separator 31 and the outer edge 231a of the first separator 31 protrudes from the four sides 122a, 122b, 122c, 122d of the positive electrode 12, respectively. have. The second separator 32 is large so as to cover the back surface 12 f of the positive electrode 12. The second separator 32 is in a state where the positive electrode 12 is sandwiched between the first separator 31 and the outer edge 232a of the second separator 32 protrudes from the four sides 122a, 122b, 122c, 122d of the positive electrode 12, respectively. have. The first separator 31 and the second separator 32 have the same size as the negative electrode 13. The first separator 31 and the second separator 32 have a joint 40 where the first separator 31 and the second separator 32 are joined at a portion of the outer edges 231a and 232a excluding the portion facing the positive electrode tab 12c. doing. The joining portion 40 is provided on the outer edges (outer edges 231a and 232a) of the first protruding portion 331 and the second protruding portion 332. And the outer edge of the 1st protrusion part 331 and the 2nd protrusion part 332 is joined by this junction part 40. FIG. Further, the joint portion 40 is formed by welding at a plurality of locations at predetermined intervals so as to follow the four sides 122a, 122b, 122c, and 122d of the positive electrode 12, respectively. Then, the outer edges of the first protruding portion 331 and the second protruding portion 332 are bonded by the bonding portion 40, whereby the first separator 31 and the second separator 32 are bonded.

  The first separator 31 has a first hole 331 a and a second hole 331 b in the joint portion 40. In a state where the positive electrode 12 is sandwiched between the first separator 31 and the second separator 32, the first hole 331a is located close to the side 122a of the positive electrode 12, and the second hole 331b is the side 122c of the positive electrode 12. Is close to These sides 122 a and 122 c are sides facing each other in the positive electrode 12. Further, the first hole 331a is in a position close to the corner 122e of the positive electrode 12, and the second hole 331b is in a position close to the corner 122f of the positive electrode 12. These corners 122e and 122f are corners on the diagonal line of the positive electrode 12.

  The second separator 32 has a first hole 332 a and a second hole 332 b in the joint portion 40. In a state where the positive electrode 12 is sandwiched between the second separator 32 and the first separator 31, the first hole 332 a is located close to the side 122 a of the positive electrode 12, and the second hole 332 b is the side 122 c of the positive electrode 12. Is close to These sides 122 a and 122 c are sides facing each other in the positive electrode 12. Further, the first hole 332a is located near the corner 122e of the positive electrode 12, and the second hole 332b is located near the corner 122f of the positive electrode 12.

  The first hole 331 a of the first separator 31 and the first hole 332 a of the second separator 32 are in the state where the positive electrode 12 is sandwiched between the first separator 31 and the second separator 32, and the first separator 31 and the second separator 32. Are formed at positions overlapping each other. And the 1st hole 331a and the 1st hole 332a are each formed in the position which overlaps between the electrode storage separators 30 when the electrode storage separator 30 is laminated | stacked. Similarly, the second hole 331b of the first separator 31 and the second hole 332b of the second separator 32 are in contact with the first separator 31 and the second separator 32 when the positive electrode 12 is sandwiched between the first separator 31 and the second separator 32. The two separators 32 are respectively formed at overlapping positions. And the 2nd hole 331b and the 2nd hole 332b are each formed in the position which overlaps between the electrode storage separators 30 when the electrode storage separator 30 is laminated | stacked. The positive electrode 12 is provided at a position that does not overlap the first protruding portion 331 and the second protruding portion 332 in a state sandwiched between the first separator 31 and the second separator 32. The joint 40 is provided on the outer edges of the first protruding portion 331 and the second protruding portion 332. Therefore, the first holes 331a and 332a and the second holes 331b and 332b located in the joint portion 40 do not overlap with the positive electrode 12 when the positive electrode 12 is sandwiched between the first separator 31 and the second separator 32. It is like that.

  As shown in FIG. 3, the negative electrode 13 has a first hole 132a and a second hole 132b at a position close to the outer edge 131a. When the negative electrode 13 is laminated with the positive electrode 12, the first hole 132a is in a position close to the side 122a of the positive electrode 12, and the second hole 132b is in a position close to the side 122c of the positive electrode 12. . Further, the first hole 132a is located near the corner 122e of the positive electrode 12, and the second hole 132b is located near the corner 122f of the positive electrode 12. The positive electrode 12 is provided at a position that does not overlap the protruding portion 132 of the negative electrode 13 when the positive electrode 12 is laminated with the negative electrode 13. And the 1st hole 132a and the 2nd hole 132b are provided in the outer edge (outer edge 131a) of this protrusion part 132. FIG. For this reason, the first hole 132a and the second hole 132b do not overlap the positive electrode 12 when the positive electrode 12 and the negative electrode 13 are laminated.

  The negative electrode 13, the first separator 31, and the second separator 32 have first holes 132a, 331a, and 332a at positions that overlap when they are stacked. Further, the negative electrode 13, the first separator 31, and the second separator 32 have second holes 132b, 331b, and 332b at positions where they overlap when they are stacked. The first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b all have the same diameter. The first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b have a larger diameter than the holes of the porous first separator 31 and the second separator 32. Further, all of the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b are circular.

  Next, the stacking deviation inspection method of this embodiment will be described with reference to FIGS. In the present embodiment, during the lamination of the laminated body in which the negative electrode 13 and the electrode storage separator 30 are laminated, the projection to the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b in each layer is performed. As a result, the stacking deviation is inspected. The stacking misalignment inspection indicates that the first hole 132a, 331a, 332a and the second hole 132b, 331b, 332b are in a penetrating state when at least one of the negative electrode 13 and the electrode storage separator 30 is stacked. It is a requirement for judgment that it has not occurred. In addition, the lamination | stacking operation | work of a laminated body is performed by laminating | stacking the negative electrode 13 and the electrode accommodating separator 30 so that it may make the uppermost layer of a laminated body one by one. Further, when the layers such as the negative electrode 13 and the electrode storage separator 30 are stacked with a small stacking deviation, the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b are formed in the stacking direction of the stacked body. It will overlap. Thereby, these 1st hole 132a, 331a, 332a and 2nd hole 132b, 331b, 332b make the row | line | column shape penetrated. Hereinafter, the first holes 132a, 331a, and 332a and the second holes 132b, 331b, and 332b that are penetrated in a row in each layer of the stacked body are referred to as a through row.

  As shown in FIG. 5A, when the electrode storage separator 30 is stacked, the electrode storage separator 30 becomes the uppermost layer in the stacked body, and the layer immediately below the electrode storage separator 30 is connected to the negative electrode 13. Become. In the following description of FIGS. 5 to 8, the electrode storage separator 30 that is the uppermost layer of the laminate and the negative electrode 13 that is one layer below the electrode storage separator 30 are simply stored in the electrodes. They are referred to as separator 30 and negative electrode 13.

  Here, each layer laminated below the negative electrode 13 is in a state in which the laminating deviation is small enough to cause no trouble. This is because in each layer laminated below the negative electrode 13, each time one layer is laminated, the stacking deviation between the laminated layer and the laminated body laminated below is inspected. Because it is. When the stacking deviation is large, the stacking position is advanced by correcting the stacking position of the uppermost layer so that the stacking shift is small enough to prevent the stacking shift.

  As shown in FIG. 5B, it is inspected whether or not the generated stacking deviation is small enough to prevent the electrode storage separator 30 from being stacked. This inspection includes the penetration of the first holes 331a, 332a of the electrode storage separator 30 and the first holes 132a, 331a, 332a in the layer below the negative electrode 13, and the second holes 331b, 332b of the electrode storage separator 30 and the negative electrode. This is performed by inspecting the penetration state with the second holes 132b, 331b, and 332b in the layers below the electrode 13, respectively. The penetrating state of the first holes 132a, 331a, 332a and the penetrating state of the second holes 132b, 331b, 332b project light to the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b, respectively. The inspection is performed. Specifically, the first holes 132a, 331a, and the like that penetrate through the stacked body through two holes of the layer stacked on the lowermost layer such as the first hole 132a and the second hole 132b of the negative electrode 13. Light is projected in the stacking direction of the stacked body on the through-rows of 332a and the through-rows of the second holes 132b, 331b, and 332b. And the light which permeate | transmitted the penetration row | line | column of 1st hole 132a, 331a, 332a and the penetration row | line | column of 2nd hole 132b, 331b, 332b is light-received by two places in the uppermost layer side, Therefore It is determined that all of the holes 132a, 331a, 332a and the second holes 132b, 331b, 332b are in the penetrating state. Here, when the first holes 132a, 331a, 332a are in a penetrating state, the two sides sandwiching the corners of the negative electrode 13 and the electrode storage separator 30 where the first holes 132a, 331a, 332a are located are It is in a state where all layers are almost aligned. In addition, when the second holes 132b, 331b, 332b are in a penetrating state, the two sides sandwiching the corners of the negative electrode 13 and the electrode storage separator 30 where the second holes 132b, 331b, 332b are located are each layer of the laminate. They are almost in line. The first holes 132a, 331a, and 332a are all in a penetrating state, and the second holes 132b, 331b, and 332b are all in a penetrating state. It is judged to be small enough.

  As shown in FIG. 7A, in the present embodiment, the negative electrodes 13 and the electrode storage separators 30 stacked in the stacked body such that all of the first holes 132a, 331a, and 332a are in a penetrating state without deviation. When there is no stacking shift in all, it is determined that the stacking shift is small enough to prevent problems. Further, as shown in FIG. 7B, in the present embodiment, the first holes 132a, 331a, and 332a are displaced, but they are stacked in a stacked body, such as being in a penetrating state enough to transmit light. Even when a small misalignment occurs in the negative electrode 13 and the electrode storage separator 30, it is determined that the misalignment is as small as possible without any problem.

  On the other hand, as shown in FIG. 6A, the case where the electrode storage separator 30 is stacked as in the case illustrated in FIG. ) Will be described below. In the example shown in FIG. 6B, a linear shift occurs due to a shift in the diagonal direction in the stacked electrode storage separator 30.

  As shown in FIG. 6B, light is projected to the first hole 132a of the negative electrode 13 through the through-holes of the first holes 132a, 331a, and 332a in the layer below the negative electrode 13. However, the first hole 132 a of the negative electrode 13 is blocked by the surface of the electrode storage separator 30. For this reason, on the uppermost layer side of the stacked body, light transmitted through the through-rows of the first holes 132a, 331a, and 332a of each layer is not received. On the other hand, the second hole 132 b of the negative electrode 13 is not blocked by the surface of the electrode storage separator 30. For this reason, although light does not permeate | transmit to the 2nd holes 331b and 332b of the electrode storage separator 30, the light permeate | transmitted through the penetration row | line | column of 2nd hole 132b, 331b, 332b of each layer is received. And on the uppermost layer side of the laminated body, light is received only at one place, so that one of the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b in the laminated body is It is determined that there is no penetration state. Then, it is determined that the stacking deviation caused by the stacking of the electrode storage separator 30 is large. In response to such a determination, the stacking position of the electrode storage separator 30 is corrected. Then, the stacking operation is performed after the stacking shift is set to a state that does not hinder the stacking shift.

  As shown in FIG. 8, in this embodiment, all of the first holes 132a, 331a, and 332a are shifted beyond the diameter of the holes and are not in a penetrating state. When a large misalignment occurs in at least one of the separators 30, it is determined that the misalignment is large.

  As shown in FIG. 9, the diameters of the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b are set to a value (X + α). This value X is twice the allowable value of stacking error. That is, the allowable value of stacking deviation can be expressed as a value (X / 2). For example, if the allowable value (X / 2) of the stacking deviation is 0.5 mm, 1 mm is set as the value X. The value α is a value set as follows. That is, when the diameters of the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b are set to the value X, the hole 132a of the entire laminated body is obtained when the stacking deviation is less than the allowable value (X / 2). , 132b, 331a, 331b, 332a, 332b are in a through state. However, if the penetrating region is small, it may not be possible to transmit light to the penetrating rows of the holes 132a, 132b, 331a, 331b, 332a, 332b of the entire laminate. Then, since light is not transmitted through the through-rows of the holes 132a, 132b, 331a, 331b, 332a, and 332b of the entire laminate, it is erroneously assumed that the misalignment occurring in the electrode assembly 11 is unacceptable. May be judged. In the present embodiment, as described above, by setting the diameters of the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b to the value (X + α), the stacking deviation close to the allowable value (X / 2) can be obtained. Even if it occurs, light can be transmitted through the through-rows of the holes 132a, 132b, 331a, 331b, 332a, 332b of the entire laminate. When the diameter of the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b is set to the value (X + α), the stacking deviation close to the allowable value (X / 2) occurred. Even so, the region penetrating the holes 132a, 132b, 331a, 331b, 332a, 332b of the entire laminate is a value that allows light to pass through these layers.

  Further, the protruding portion 132 has a size that allows the first hole 132a and the second hole 132b to be formed. That is, for example, the outer edge 131a of the negative electrode 13 has a shape that protrudes from the four sides 122a, 122b, 122c, and 122d of the positive electrode 12 by about 3 mm. In addition, the first protruding portion 331 and the second protruding portion 332 have such a size that the first holes 331a and 332a and the second holes 331b and 332b can be formed. That is, for example, the first separator 31 has a shape in which the outer edge 231 a protrudes from the four sides 122 a, 122 b, 122 c, 122 d of the positive electrode 12 by about 3 mm with the positive electrode 12 sandwiched between the second separator 32. Make. The second separator 32 has a shape in which the outer edge 232a protrudes from the four sides 122a, 122b, 122c, and 122d of the positive electrode 12 by about 3 mm with the positive electrode 12 sandwiched between the first separator 31 and the first separator 31. .

  Further, FIG. 6B illustrates a case in which a stacking shift occurs in the electrode storage separator 30, but a stacking shift may occur in the negative electrode 13 and the electrode storage separator 30 that are already stacked. Even when a large stacking shift occurs in the stacking direction of the stacked body, light cannot be received by the uppermost layer, and therefore it is possible to similarly check the stacking shift.

  The electrode storage separator 30 is formed by bonding the first separator 31 and the second separator 32 by the bonding portion 40, and the positive electrode 12 is stored therein. In other words, the positive electrode 12 is disposed in a state that does not reach the positions where the first holes 331 a and 332 a and the second holes 331 b and 332 b are formed in the electrode storage separator 30. Therefore, when the stacking deviation of the electrode storage separator 30 is inspected, the stacking deviation of the positive electrode 12 is naturally inspected.

Next, the operation of this embodiment will be described.
By projecting light to the through-holes of the two holes such as the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b of the first separator 31, the second separator 32, and the negative electrode 13 Depending on whether or not the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b are penetrated to such a degree that light passes through the through-holes, the stacking deviation is small to the extent that there is no problem. It is possible to easily determine whether or not stacking can be performed in the state.

  In addition, two holes such as the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b are located at positions where the first separator 31, the second separator 32, and the negative electrode 13 overlap when stacked. Whether or not stacking misalignment has occurred even if the stacking misalignment is a linear misalignment caused by shifting each layer in the width direction or a rotational misalignment caused by shifting each layer in the rotational direction. Can be suitably determined.

As described above, according to the present embodiment, the following effects can be obtained.
(1) Light is projected onto the through-holes of the two holes such as the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b of the first separator 31, the second separator 32, and the negative electrode 13. Depending on whether or not the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b are penetrated to such a degree that light passes through, the layers are laminated to the extent that there is no problem. It is possible to easily determine whether or not stacking can be performed with a small deviation. Therefore, a decrease in production efficiency can be suppressed.

  In addition, two holes such as the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b are located at positions where the first separator 31, the second separator 32, and the negative electrode 13 overlap when stacked. Whether or not stacking misalignment has occurred even if the stacking misalignment is a linear misalignment caused by shifting each layer in the width direction or a rotational misalignment caused by shifting each layer in the rotational direction. Can be suitably determined.

  (2) According to this embodiment, since the first separator 31 and the second separator 32 have the first holes 331a and 332a and the second holes 331b and 332b in the joint portion 40, the first separator 31 and the second separator 32 are provided. The first holes 132a, 331a, and 332a and the second holes 132b, 331b, and 332b can be easily positioned to overlap when the first separator 31, the second separator 32, and the negative electrode 13 are stacked. it can.

  (3) According to this embodiment, the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b are close to the opposite sides 122a, 122c of the positive electrode 12 when the positive electrode 12 is laminated. By setting it as the position which performs, the position of 1st hole 132a, 331a, 332a and 2nd hole 132b, 331b, 332b can be set easily.

  (4) According to the present embodiment, the first holes 132 a, 331 a, 332 a and the second holes 132 b, 331 b, 332 b are connected to the corners 122 e that are on the diagonal line of the positive electrode 12 when the positive electrode 12 is laminated. Since the distance between the first holes 132a, 331a, and 332a and the second holes 132b, 331b, and 332b can be increased by making the position close to 122f, it is easier to determine the stacking deviation. It can be carried out.

  (5) Regardless of the number of stacked positive electrodes 12, negative electrodes 13, and separators 31.32, the stacking deviation is reflected in the penetrating state of the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b. Is done. Therefore, as in the present embodiment, if there are a plurality of stacked sheets, it is possible to inspect the stacking deviation.

  (6) According to the present embodiment, light is projected onto the through-rows of the first holes 132a, 331a, 332a and the second holes 132b, 331b, 332b during the stacking, so that the time required for the stacking can be increased. Thus, it is possible to inspect the stacking deviation. Therefore, the stacking deviation can be inspected more efficiently, and the reduction in the production efficiency of the secondary battery 10 can be further suppressed.

(Second Embodiment)
Hereinafter, a second embodiment in which the present invention is embodied in a secondary battery mounted on a vehicle (for example, an industrial vehicle or a passenger vehicle) will be described with reference to FIG. Note that in the embodiments described below, the same reference numerals are given to the same configurations as those of the embodiments already described, and redundant descriptions thereof are omitted or simplified.

  As shown in FIG. 10, the electrode assembly 11 in this embodiment is formed by laminating a positive electrode 12 and a negative electrode 13 with a sheet-like separator 33 interposed therebetween. The positive electrode 12 has a first hole 123c and a second hole 123d in a positive electrode uncoated portion 12b provided along the side 122a. The first hole 123 c is located at a position close to the side 122 b of the positive electrode 12, more specifically at a position close to the corner 122 e of the positive electrode 12. The second hole 123d is at a position close to the side 122d of the positive electrode 12, more specifically at a position close to the corner 122g.

  The negative electrode 13 has a first hole 132c and a second hole 132d at a position close to the outer edge 131a. The separator 33 has a first hole 333c and a second hole 333d at a position close to the outer edge 233a. The first hole 132c of the negative electrode 13 and the first hole 333c of the separator 33 are positioned closer to the side 122b of the positive electrode 12 when the negative electrode 13 and the separator 33 are stacked with the positive electrode 12, in more detail. Is in a position close to the corner 122e of the positive electrode 12. The second hole 132d of the negative electrode 13 and the second hole 333d of the separator 33 are located close to the side 122d of the positive electrode 12, more specifically, close to the corner 122g. When the positive electrode 12, the negative electrode 13, and the separator 33 are stacked, the first holes 123c, 132c are located at positions where the first holes 123c, 132c, 333c and the second holes 123d, 132d, 333d overlap, respectively. , 333c and second holes 123d, 132d, 333d, respectively.

  Also in this embodiment, the negative electrode 13 and the separator 33 are large so as to cover either the front surface 12e or the back surface 12f of the positive electrode 12. For this reason, the 1st hole 132c and the 2nd hole 132d of the negative electrode 13 are located inside the boundary part of the negative electrode coating part 13a and the negative electrode uncoated part 13b. The first hole 333 c and the second hole 333 d of the separator 33 are also located inside the outer edge 233 a of the separator 33 so as to overlap the first hole 132 c and the second hole 132 d of the negative electrode 13. As a result, the first holes 123c, 132c, 333c and the second holes 123d, 132d, 333d are positioned to overlap each other.

  Then, light is projected onto the through-rows of the first holes 123c, 132c, and 333c and the through-holes of the second holes 123d, 132d, and 333d of the stacked body in the same manner as in the first embodiment, thereby stacking the layers. A shift inspection can be performed.

  Further, the positive electrode 12 of the present embodiment is not housed in the bag-shaped electrode housing separator as in the first embodiment. For this reason, when the stacking shift generated in the positive electrode 12 is large, at least one of the first hole 123c and the second hole 123d of the positive electrode 12 is blocked by the separator 33. Therefore, light projection is performed on the through-rows of the first holes 123c, 132c, 333c and the through-rows of the second holes 123d, 132d, 333d, together with the stacking deviation of the negative electrode 13 and the separator 33. The stacking deviation of the positive electrode 12 is also inspected.

Next, the operation of this embodiment will be described.
By projecting light to the through holes of the two holes such as the first holes 123c, 132c, 333c and the second holes 123d, 132d, 333d of the positive electrode 12, the negative electrode 13, and the separator 33, the first projection is performed. Depending on whether or not the holes 123c, 132c, 333c and the second holes 123d, 132d, 333d are penetrated to such a degree that light passes through, the lamination is performed with a small misalignment to the extent that there is no problem. Can be easily determined.

  In addition, two holes such as the first holes 123c, 132c, 333c and the second holes 123d, 132d, 333d are located at positions where the positive electrode 12, the negative electrode 13, and the separator 33 overlap when stacked. Whether the misalignment has occurred even if the misalignment is a linear misalignment due to the misalignment of each layer in the width direction or a misalignment due to the misalignment of each layer in the rotation direction. It can be suitably performed.

As described above, according to this embodiment, in addition to the effects (1), (3), (5), and (6) of the first embodiment, the following effects can be obtained. become.
(7) Since the positive electrode 12 has the first hole 123c and the second hole 123d in the positive electrode uncoated portion 12b, the electric capacity of the positive electrode 12 decreases with the formation of the first hole 123c and the second hole 123d. Can be suppressed. Further, it is possible to suppress the occurrence of a short circuit between the positive electrode 12 and the negative electrode 13 through the first holes 123c, 132c, 333c and the second holes 123d, 132d, 333d penetrating in a stacked state.

(Third embodiment)
Hereinafter, a third embodiment in which the present invention is embodied in a secondary battery mounted on a vehicle (for example, an industrial vehicle or a passenger vehicle) will be described with reference to FIG.

  As shown in FIG. 11, the electrode assembly 11 in this embodiment is formed by laminating a positive electrode 12 and a negative electrode 13 via a sheet-like separator 33. Also in the present embodiment, the negative electrode 13 and the separator 33 are large so as to cover either the front surface 12e or the back surface 12f of the positive electrode 12. In this embodiment, the sizes of the separator 33 and the negative electrode 13 are different, and the separator 33 is larger than the negative electrode 13.

  The negative electrode 13 has a first hole 132e, a second hole 132f, and a third hole 132g at a position close to the outer edge 131a. The separator 33 has a first hole 333e, a second hole 333f, and a third hole 333g at a position close to the outer edge 233a.

  The first hole 132e and the second hole 132f of the negative electrode 13 and the first hole 333e and the second hole 333f of the separator 33 are formed on the positive electrode 12 when the negative electrode 13 and the separator 33 are laminated with the positive electrode 12. The positions are close to the side 122a. Further, the first hole 132e and the second hole 132f of the negative electrode 13 and the first hole 333e and the second hole 333f of the separator 33 are formed when the negative electrode 13 and the separator 33 are stacked with the positive electrode 12. 12 positive electrode tabs 12c are sandwiched. Further, the third hole 132g of the negative electrode 13 and the third hole 333g of the separator 33 are in positions close to the side 122c of the positive electrode 12 when the negative electrode 13 and the separator 33 are laminated with the positive electrode 12, respectively. .

  By being positioned in this way, the first hole 132e and the third hole 132g of the negative electrode 13 and the first hole 333e and the third hole 333g of the separator 33 are paired with each other in the pair of sides 122a, 122a, The positions are close to 122c. The first hole 132e and the second hole 132f of the negative electrode 13 and the first hole 333e and the second hole 333f of the separator 33 are formed on a pair of opposing sides 12g and 12h in the positive electrode tab 12c of the positive electrode 12. The positions are close to each other. Therefore, in the negative electrode 13 and the separator 33, the positions of the first holes 132e and 333e, the second holes 132f and 333f, and the third holes 132g and 333g are the two pairs of sides 12g, 12h, The position is close to 122a and 122c. And the negative electrode 13 and the separator 33 have 1st hole 132e, 333e, 2nd hole 132f, 333f, and 3rd hole 132g, 333g in the position which overlaps when they are laminated | stacked.

  In the same manner as in the first and second embodiments, the through holes of the first holes 132e and 333e, the through lines of the second holes 132f and 333f, and the through lines of the third holes 132g and 333g are used. By projecting light, it is possible to inspect stacking deviation.

  Further, the positive electrode 12 of the present embodiment is not housed in the bag-shaped electrode housing separator as in the first embodiment, and does not have a hole as in the second embodiment. Absent. For this reason, when the stacking deviation generated in the positive electrode 12 is large, at least one of the first hole 333e, the second hole 333f, and the third hole 333g of the separator 33 is blocked by the positive electrode 12. Accordingly, light is projected onto the through-rows of the first holes 132e and 333e, the through-rows of the second holes 132f and 333f, and the through-rows of the third holes 132g and 333g, whereby the negative electrode 13 and the separator In addition to the 33 stacking shift, the stacking shift of the positive electrode 12 is also inspected.

  In the negative electrode 13, the third hole 132 g is located near the side 122 c of the positive electrode 12 and opposed to the positive electrode tab 12 c when the negative electrode 13 is stacked with the positive electrode 12. In the negative electrode 13, the distance between the first hole 132e and the third hole 132g and the distance between the second hole 132f and the third hole 132g are set to be equal. Similarly to the negative electrode 13, in the separator 33, the distance between the first hole 333e and the third hole 333g and the distance between the second hole 333f and the third hole 333g are set to be equal. ing.

Next, the operation of this embodiment will be described.
The first hole 132e, 333e, the second hole 132f, 333f, and the third hole 132g, 333g of the negative electrode 13 and the separator 33 have a first hole by projecting light to the through-hole row of the three holes. 132e and 333e, the second holes 132f and 333f, and the third holes 132g and 333g have a small stacking deviation to the extent that there is no problem depending on whether or not light passes through the through-rows. It is possible to easily determine whether or not stacking can be performed in the state.

  Further, when the three holes such as the first holes 132e and 333e, the second holes 132f and 333f, and the third holes 132g and 333g are positioned at the position where the negative electrode 13 and the separator 33 overlap when stacked, Whether the stacking shift is a linear shift caused by shifting each layer in the width direction or a rotation shift caused by shifting each layer in the rotation direction is suitable for determining whether a stacking shift has occurred. Can be done.

As described above, according to this embodiment, in addition to the effects (1), (3), (5), and (6) of the first embodiment, the following effects can be obtained. become.
(8) The first holes 132e and 333e and the second holes 132f and 333f are respectively located at two positions sandwiching the positive electrode tab 12c, and the third holes 132g and 333g are provided with the positive electrode tab 12c in the positive electrode 12. It is in a position close to the side 122c facing the side 122a. According to the first holes 132e and 333e, the second holes 132f and 333f, and the third holes 132g and 333g, it is possible to more easily determine that the stacking can be performed in a state in which the stacking deviation is small to the extent that there is no problem. Can do.

In addition, the said embodiment can also be implemented with the following forms which changed this suitably.
(Circle) the 1st protrusion part 331 of the 1st separator 31 and the 2nd protrusion part 332 of the 2nd separator 32 are not limited to the protrusion degree of 1st Embodiment. However, the holes 132 a and 132 b of the negative electrode 13, the holes 331 a and 331 b of the first separator 31, and the holes 332 a and 332 b of the second separator 32 so as to fit within the extent of the protrusions of the first protrusion 331 and the second protrusion 332. It is necessary to set the size of each.

In the first embodiment, a part of the first separator 31 and the second separator 32 may have a shape protruding from a part of the side of the positive electrode 12.
In the first embodiment, the negative electrode 13, the first separator 31, and the second separator 32 may be different in size. However, the negative electrode 13, the first separator 31, and the second separator 32 are stacked with the positive electrode 12, and at least a part of the protruding portion 132, the first protruding portion 331, and the second protruding portion 332 are: The directions protruding from the sides 122a, 122b, 122c, 122d of the positive electrode 12 need to be the same.

  (Circle) the protrusion part 132 of the negative electrode 13 is not limited to the protrusion degree of 1st Embodiment. However, the sizes of the holes 132 a and 132 b of the negative electrode 13, the holes 331 a and 331 b of the first separator 31, and the holes 332 a and 332 b of the second separator 32 must be set so as to fit within the extent of the protrusion 132. There is.

  In the first embodiment, a part of the negative electrode 13 may protrude in the same direction as the first protruding portion 331 of the first separator 31 and the second protruding portion 332 of the second separator 32.

  In the first embodiment, the joint portion 40 may not be provided on the entire outer edges 231a and 232a of the first separator 31 and the second separator 32. That is, as long as the positive electrode 12 can be accommodated inside the first separator 31 and the second separator 32, for example, the joint portion 40 may be partially provided on the opposite sides of the first separator 31 and the second separator 32.

  In the first embodiment, holes 331a, 331b, 332a, 332b may be provided in regions where the joint portions 40 of the first separator 31 and the second separator 32 are not provided. Moreover, in the form which does not provide the junction part 40 in each outer edge 231a, 232a of the 1st separator 31 and the 2nd separator 32, it is a junction part among each outer edge 231a, 232a of the 1st separator 31 and the 2nd separator 32. Holes 331a, 331b, 332a, and 332b may be provided in regions where 40 is not provided.

  The first separator 31 and the second separator 32 are joined by welding at the joint 40. The first separator 31 and the second separator 32 may be joined by joining other than welding, such as an adhesive tape, an adhesive, stitching, and a stapler.

  In the first embodiment, all the holes 331 a, 331 b, 332 a, 332 b of the negative electrode 13, the first separator 31, and the second separator 32 are located close to the side 122 a of the positive electrode 12. Etc., it may be in a position close to any of the four sides 122a, 122b, 122c, 122d of the positive electrode 12. In short, all the holes 331a, 331b, 332a, 332b may be provided in the protruding portion 132 of the negative electrode 13, the first protruding portion 331 of the first separator 31, and the second protruding portion 332 of the second separator 32. For example, the position can be set freely.

  In the first embodiment, the first separator 31 and the second separator 32 may be larger than the negative electrode 13. However, the size of the negative electrode 13 needs to be large enough to have the protruding portion 132.

In the first embodiment, the positive electrode 12 may also have a hole. However, the hole of the positive electrode 12 is desirably located in the positive electrode uncoated portion 12b.
○ In the second embodiment, it is assumed that all the holes 123c, 123d, 132c, 132d, 333c, and 333d of the positive electrode 12, the negative electrode 13, and the separator 33 are located close to the side 122a of the positive electrode 12. However, it may be located at other positions. However, when the positive electrode 12, the negative electrode 13, and the separator 33 are stacked, the positions of the holes 123c, 123d, 132c, 132d, 333c, and 333d are positions corresponding to the positive electrode uncoated portion 12b in the positive electrode 12. Need to be.

  In the second embodiment, the negative electrode 13 and the separator 33 are not limited to be large so as to cover either the front surface 12e or the back surface 12f of the positive electrode 12, and are, for example, the same size as the positive electrode 12 It may be a size.

  In the first embodiment and the second embodiment, each layer of the laminate may have three or more holes. However, since the number of holes is increased as the number of holes is increased, it is desirable that the number of holes formed in each layer is two in terms of suppressing the increase in the number of processes.

In the second embodiment, the separator 33 may be larger than the negative electrode 13.
In the third embodiment, the holes 132e, 132f, 132g of the negative electrode 13 and the holes 333e, 333f, 333g of the separator 33 are not limited to the form illustrated in FIG. For example, each of the negative electrode 13 and the separator 33 may have four holes, and the holes may be located close to the four sides 122a, 122b, 122c, and 122d of the positive electrode 12. Even in such a form, the positive electrode 12 can be in a position close to two opposing sides 122a, 122b, 122c, and 122d. Further, the holes of the negative electrode 13 and the separator 33 may have other positional relationships. However, all the holes of the negative electrode 13 and the separator 33 are formed in the protruding portion 132 of the negative electrode 13 shown in FIG. 3 or the first portion shown in FIG. 4 of the outer edge 131a of the negative electrode 13 and the outer edge 233a of the separator 33. As long as the holes of the negative electrode 13 and the separator 33 are provided in regions corresponding to the first protruding portion 331 of the separator 31 and the second protruding portion 332 of the second separator 32, the positions thereof can be freely set. .

  In the third embodiment, each layer of the laminate may have four or more holes. However, since the number of holes is increased as the number of holes is increased, it is desirable that the number of holes formed in each layer is three in terms of suppressing the increase in the number of processes.

In the third embodiment, the separator 33 and the negative electrode 13 may have the same size.
In the above embodiment, the diameter (X + α) of the holes formed in each layer of the laminate is not limited to a size such as 1 mm, and can be freely set according to the allowable degree of misalignment. is there.

  In the above embodiment, the shape of the holes formed in each layer of the laminate is not limited to a circle, and may be other shapes such as a rectangle. However, it is desirable to adopt a circular shape in terms of workability of the hole.

  In the said embodiment, as shown in FIG.5 and FIG.6, when the several sheets were laminated | stacked, the case where the test | inspection of a lamination | stacking deviation was performed was illustrated. The inspection of the stacking deviation can be performed as follows even in a state where one sheet such as the negative electrode 13 is stacked. That is, for example, when an inspection plate provided with a mark such as a hole is provided at the same position in the stacking direction of the negative electrode 13 and the electrode assembly 11, and when one negative electrode 13 is stacked on the inspection plate, the negative electrode 13 By checking the positional relationship between the holes and the marks on the inspection plate, the stacking deviation can be inspected.

  In the above embodiment, the stacking deviation inspection may be performed separately from the stacking operation. For example, every time a predetermined number of sheets (or more than a predetermined number) are stacked, the stacking operation may be interrupted to check the stacking deviation. Further, the stacking deviation may be inspected in a state where the stacking of the electrode assemblies 11 is completed.

  In the above-described embodiment, it is also possible to employ inspection methods other than light projection, such as a method of inspecting stacking deviation by directly passing a member such as a needle through the hole of each layer of the stacked body. Depending on the inspection method employed, it is necessary to set the hole size to an optimum size, such as the value of the hole diameter (X + α) of each layer.

In the above-described embodiment, it is possible to adopt the stacking displacement inspection method of the above-described form for the notch by forming a notch in each layer instead of the hole.
In the above embodiment, the positive electrode 12 has the positive electrode coating portion 12a on which the active material is applied on both the front and back surfaces, but may have the positive electrode coating portion 12a only on one surface of the positive electrode 12. . At this time, it is necessary to laminate the positive electrode 12 so that the positive electrode coating part 12a faces the negative electrode coating part 13a.

  In the above embodiment, the negative electrode 13 has the negative electrode coating portion 13a on which the active material is coated on both the front and back surfaces, but may have the negative electrode coating portion 13a only on one surface of the negative electrode 13. . At this time, it is necessary to laminate the negative electrode 13 so that the negative electrode coating portion 13a faces the positive electrode coating portion 12a.

  The secondary battery 10 is a lithium ion secondary battery, but is not limited thereto, and may be another secondary battery. In short, any ion may be used as long as ions move between the positive electrode active material layer and the negative electrode active material layer and transfer charge.

  The present invention may be embodied in a power storage device such as an electric double layer capacitor.

  DESCRIPTION OF SYMBOLS 10 ... Secondary battery, 11 ... Electrode assembly, 12 ... Positive electrode, 13 ... Negative electrode, 30 ... Electrode storage separator, 31 ... 1st separator, 32 ... 2nd separator, 40 ... Joining part, 122a, 122b, 122c , 122d ... side, 132 ... protruding portion, 132a, 331a, 332a ... first hole, 132b, 331b, 332b ... second hole, 331 ... first protruding portion, 332 ... second protruding portion.

Claims (8)

In a power storage device including an electrode assembly in which a positive electrode, a first separator and a second separator sandwiching the positive electrode, and a negative electrode are laminated,
The first separator has a first protrusion that covers one surface of the positive electrode and a part of which protrudes from at least a part of the positive electrode;
The second separator has a second protruding portion that covers the other surface of the positive electrode and partially protrudes in the same direction as the first protruding portion,
Has a joint between the first protruding portion and the second protruding portion are joined,
The negative electrode has a shape that covers one surface of the positive electrode and a part of which protrudes in the same direction as the first protruding portion and the second protruding portion,
The first separator, the second separator, and the negative electrode have two holes at positions that overlap when they are stacked,
The hole is close to two opposite sides of the positive electrode when the positive electrode is stacked, and close to a corner on a diagonal line of the positive electrode when the positive electrode is stacked near it is,
The power storage device, wherein the first separator and the second separator have the hole in the joint . A power storage device including a positive electrode, a negative electrode, and a separator, and including an electrode assembly in which the positive electrode and the negative electrode are stacked via the separator,
The positive electrode, the negative electrode, and the separator each have two holes at positions that overlap when they are stacked,
The hole is close to two opposite sides of the positive electrode when the positive electrode is stacked, and close to a corner on a diagonal line of the positive electrode when the positive electrode is stacked And a power storage device. The positive electrode has a coated part on which an active material is coated and an uncoated part on which the active material is not coated,
The power storage device according to claim 2 , wherein the positive electrode has the hole in the uncoated portion. The power storage device according to any one of claims 1 to 3 , wherein the power storage device is a secondary battery. A method for inspecting a stacking deviation of the positive electrode, the negative electrode, and the separator in an electrode assembly in which a positive electrode and a negative electrode are stacked via a separator,
The positive electrode, the negative electrode , and the separator each have two holes at positions that overlap when they are stacked,
The hole is close to two opposite sides of the positive electrode when the positive electrode is stacked, and close to a corner on a diagonal line of the positive electrode when the positive electrode is stacked And
As a requirement for determining that no misalignment has occurred when at least one of the negative electrode and the separator is laminated, the fact that the misalignment does not occur is performed. Stacking deviation inspection method. The stacking shift inspection method according to claim 5 , wherein a stacking shift inspection is performed in a state where a predetermined number or more of the positive electrode, the negative electrode, and the separator are stacked. The stacking deviation inspection method according to claim 5 or 6 , wherein the stacking deviation inspection of the electrode assembly is performed by projecting light onto the through-rows of the holes and receiving light transmitted through the through-holes of the holes. The stacking deviation inspection according to claim 7 , wherein the stacking deviation of the electrode assembly is inspected by projecting light onto the through-hole rows of the holes during the stacking of the positive electrode, the negative electrode, and the separator. Method.