JP5565306B2 - Cylindrical battery - Google Patents

Description

  The present invention relates to an electrode body in which a positive electrode plate and a negative electrode plate are overlapped with each other via a separator and wound in a columnar shape, a cylindrical battery case that accommodates the electrode body, and a safety valve provided in the battery case And a cylindrical battery.

  Conventionally, an electrode body in which a positive electrode plate and a negative electrode plate are overlapped with each other via a separator and wound into a columnar shape, a cylindrical battery case that accommodates the electrode body, and a safety valve provided in the battery case, There is known a cylindrical battery comprising: Among these, the safety valve is opened when gas is generated inside the battery due to battery abnormalities such as overcharge or internal short circuit, and the internal pressure of the battery case exceeds a predetermined valve opening pressure. Communicate. Thereby, the gas generated inside the battery is quickly exhausted to the outside of the battery.

  Such a safety valve is generally provided at the end of the battery case in the axial direction (case axial direction). That is, when the battery case is composed of, for example, a bottomed cylindrical case main body member and a plate-like case cover member that closes the opening of the case main body member, the safety valve is provided at the bottom of the case main body member or the case cover member. Provided. In addition, when the battery case is composed of, for example, a cylindrical case main body member that is open at both ends and plate-like case lid members that respectively close the openings at both ends of the case main body member, the safety valve has two cases. It is provided on either one of the lid members.

However, the end of the battery case in the axial direction of the battery case is provided with a positive electrode terminal or a negative electrode terminal in addition to the safety valve, and an electrolyte inlet, a current interruption mechanism, etc. are provided as necessary. There may be restrictions on the opening area when the valve is opened. On the other hand, if the safety valve is too small, it may be difficult to form the safety valve, or it may be difficult to quickly exhaust gas when the valve is opened.
In addition, when the gas is generated, the electrode body moves in the axial direction of the case, and the end of the electrode body in the winding axis direction or another member (such as a current collecting member) connected to this end is a safety valve. May be blocked from the inside, preventing the internal pressure from being properly applied to the safety valve. Then, even if the internal pressure of the battery exceeds the valve opening pressure, the safety valve may not open.

  In order to solve such a problem, it is conceivable to provide a safety valve in a case tube portion (case side wall portion) of the battery case. For example, Patent Literature 1 below discloses that a cylindrical case tube portion is provided with a low cleavage strength portion (corresponding to a safety valve) whose cleavage strength is lower than other portions (Patent Literature 1). (See the claims and FIGS. 1 and 2).

JP-A-10-269998

  If the safety valve is provided in the case cylinder as in Patent Document 1 described above, the size of the safety valve can be sufficiently ensured compared to the case where the safety valve is provided at the end of the battery case in the case axial direction. In addition, since it is not necessary to provide a safety valve at the end of the battery case in the axial direction of the battery case, the design (form and arrangement) of the positive or negative terminal, electrolyte inlet, current interruption mechanism, etc. provided at this end is free. There is an advantage that the degree becomes large.

  However, the electrode body may not only move in the case axis direction in the battery case as described above, but also a part of the electrode body that causes a battery reaction between the positive electrode plate and the negative electrode plate when gas is generated. (Hereinafter also referred to as an electrode body reaction part) may expand greatly in the radial direction of the winding axis. For this reason, even if the safety valve is provided in the case tube portion as in Patent Document 1, when the electrode body moves in the case axial direction and the electrode reaction portion expands in the radial direction, the safety valve is It may be blocked from the inside, preventing the internal pressure from being properly applied to the safety valve. Therefore, even when the safety valve is provided in the case tube portion, the safety valve may not open even if the internal pressure of the battery becomes equal to or higher than the valve opening pressure.

  The present invention has been made in view of the present situation, and provides a cylindrical battery that can reliably open a safety valve when the internal pressure of the battery becomes equal to or higher than a predetermined valve opening pressure. Objective.

One aspect of the present invention for solving the above problems is that an electrode body in which a positive electrode plate and a negative electrode plate are overlapped with each other via a separator and wound around in a cylindrical shape around a winding axis, and a case axis line A battery case having a cylindrical case tube portion extending along the electrode body and housing the electrode body in a form in which the winding shaft and the case axis line are parallel to each other; and provided in the battery case And a safety valve that opens when the internal pressure of the battery case becomes equal to or higher than a predetermined valve opening pressure, and communicates the inside and outside of the battery case. When the part that generates a battery reaction between the positive electrode plate and the negative electrode plate is an electrode body reaction part, the case cylinder part is the electrode body reaction of the electrode body in the axial direction along the case axis. On the outer side in the axial direction than the portion of the case axis In the direction, at least a part of the inner edge in the axial direction has a valve forming portion located radially inward from the outer peripheral surface of the electrode body reaction portion, and the safety valve is included in the battery case. Ri Na provided in the valve forming part of, the valve forming portion and the safety valve are cylindrical batteries are each flat.

  In this cylindrical battery, since the safety valve is provided in the valve forming portion of the case cylindrical portion, the size of the safety valve can be sufficiently secured as compared with the case where the safety valve is provided at the end portion in the case axial direction of the battery case. In addition, it is possible to increase the degree of freedom of the form and arrangement of the positive electrode terminal or the negative electrode terminal, the electrolyte solution injection port, the current interruption mechanism, and the like provided at the end of the battery case in the case axis direction.

Moreover, at least a part of the inner edge in the axial direction of the valve forming portion is located radially inward from the outer peripheral surface of the electrode body reaction portion of the electrode body. For this reason, even when the electrode body is about to move toward the side where the valve forming portion is present in the case axial direction, for example, when gas is generated, at least the electrode body reaction portion is on the inner side in the axial direction of the valve forming portion. Since it is locked at the end edge, it is possible to reliably prevent the electrode body reaction part from moving to the inside in the radial direction of the valve forming part. For this reason, the safety valve provided in this valve formation part can be reliably prevented from being blocked by the electrode body reaction part from the inside in the radial direction, and the internal pressure not being properly applied to the safety valve. Therefore, in this cylindrical battery, when the battery internal pressure becomes equal to or higher than the valve opening pressure, the safety valve can be reliably opened.
Furthermore, in this cylindrical battery, the valve forming part and the safety valve are each flat. For this reason, compared with the case where the valve forming part or the safety valve has a curved surface such as an R shape, a safety valve with less variation in the valve opening pressure can be obtained.

  Furthermore, in the above-described cylindrical battery, the valve forming portion may be a cylindrical battery provided at a position away from an end edge in the axial direction of the case cylindrical portion.

  In this cylindrical battery, the valve forming portion is provided at a position away from the end edge in the axial direction of the case cylindrical portion. For this reason, the shape of the end portion in the axial direction of the battery case is not affected by the presence or absence of the valve forming portion. Therefore, the shape or arrangement of the positive electrode terminal or the negative electrode terminal provided at this end portion, the electrolyte injection port, the current interruption mechanism, etc. The degree of freedom can be increased.

1 is a longitudinal sectional view showing a lithium ion secondary battery according to Embodiment 1. FIG. It is a fragmentary perspective view which shows the vicinity of a valve formation part and a safety valve among the lithium ion secondary batteries which concern on Embodiment 1. FIG. FIG. 3 is a partial vertical cross-sectional view showing the vicinity of a valve forming unit and a safety valve in the lithium ion secondary battery according to Embodiment 1. FIG. 3 is a partial plan view illustrating a state in which the positive electrode plate and the negative electrode plate are overlapped with each other via a separator according to the first embodiment. It is explanatory drawing which shows a mode that a valve formation part and a safety valve are press-molded to a case main body member regarding the manufacturing method of the lithium ion secondary battery which concerns on Embodiment 1. FIG. It is explanatory drawing which shows a mode that the safety valve formed separately is joined to the valve formation part provided in the case main body member regarding another manufacturing method of the lithium ion secondary battery which concerns on Embodiment 1. FIG. It is a fragmentary longitudinal cross-section which shows the vicinity of a valve formation part and a safety valve among the lithium ion secondary batteries which concern on Embodiment 2. FIG. It is a fragmentary perspective view which shows the vicinity of a valve formation part and a safety valve among the lithium ion secondary batteries which concern on Embodiment 3. It is a fragmentary longitudinal cross-section which shows the vicinity of a valve formation part and a safety valve among the lithium ion secondary batteries which concern on Embodiment 3. FIG. 10 is an explanatory diagram showing an assembled battery according to Embodiment 4. 6 is a plan view showing a battery holder that constitutes an assembled battery according to Embodiment 4. FIG. FIG. 10 is a plan view showing a battery holder according to a modification of the fourth embodiment. FIG. 10 is an explanatory diagram showing a vehicle according to a fifth embodiment. It is explanatory drawing which shows the hammer drill which concerns on Embodiment 6. FIG.

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a lithium ion secondary battery (cylindrical battery) 100 according to the first embodiment. 2 and 3 show a configuration in the vicinity of the valve forming portion 115 and the safety valve 117 of the lithium ion secondary battery 100. FIG. FIG. 4 shows a state where the electrode body 120 constituting the lithium ion secondary battery 100 is developed.

  The lithium ion secondary battery 100 (hereinafter also simply referred to as the battery 100) is a cylindrical battery that is mounted on a vehicle such as a hybrid vehicle or an electric vehicle, or a battery using device such as a hammer drill. The battery 100 includes a cylindrical battery case 110, a cylindrical electrode body 120 having a cylindrical shape housed in the battery case 110, a positive electrode current collecting member 150 connected to the electrode body 120, and a negative electrode current collector. It is comprised from the member 160, the positive electrode terminal 155 fixed to the battery case 110, the negative electrode terminal 165, etc. (refer FIG. 1). In addition, a non-aqueous electrolyte solution 170 is injected into the battery case 110.

  Among these, the battery case 110 is made of metal (aluminum in the first embodiment). In the battery case 110, one side KA (upward in FIG. 1) in the case axis KX direction (hereinafter also simply referred to as one side KA) is open, while the other side KB in the case axis KX direction (in FIG. 1, (Bottom) (hereinafter also simply referred to as the other side KB) is composed of a bottomed cylindrical case body member 111 and a disk-like case lid member 113 that closes the opening 111h of the case body member 111. Yes.

  More specifically, the case main body member 111 includes a cylindrical case tube portion 111a extending from the one side tube end portion 111a1 to the other side tube end portion 111a2 along the case axis KX, and the other side of the case tube portion 111a. It consists of a disk-shaped case bottom 111b that closes the tube end 111a2. Further, the case lid member 113 is fixed by caulking to the one-side cylinder end 111a1 of the case cylinder 111a via a ring-shaped seal member 119.

In the battery case 110, the case cylinder portion 111a is provided with a later-described valve forming portion 115, and the valve forming portion 115 is further provided with a later-described safety valve 117 (see FIGS. 1 to 3).
In addition, a positive terminal 155 is fixed at the center of the case lid member 113 that forms the end of the one side KA of the battery case 110 (see FIG. 1). The positive electrode terminal 155 has a columnar shape with a male screw formed on the outer periphery, and protrudes from the case lid member 113 to the one side KA. The positive electrode terminal 155 is electrically connected to a positive electrode current collector 121m of an electrode body 120 described later via a case lid member 113 and a positive electrode current collector 150 described later.

  On the other hand, a negative electrode terminal 165 is fixed at the center of the case bottom 111b that forms the end of the other side KB of the battery case 110 (see FIGS. 1 to 3). Similarly to the positive electrode terminal 155, the negative electrode terminal 165 has a columnar shape with a male screw formed on the outer periphery, and protrudes from the case bottom 111b to the other side KB. The negative electrode terminal 165 is electrically connected to a negative electrode current collector 131m of the electrode body 120 described later via a case bottom 111b and a negative electrode current collector 160 described later.

  Next, the electrode body 120 will be described. The electrode body 120 has a cylindrical shape having a winding axis AX, and the winding axis AX and the case axis KX are parallel to each other. Further, in the first embodiment, the winding axis AX and the case axis KX. Are accommodated in the battery case 110 in a form that matches (see FIGS. 1 and 3). This electrode body 120 is obtained by winding a belt-like positive electrode plate 121 and a belt-like negative electrode plate 131 on each other via a belt-like separator 141 having air permeability (see FIG. 4) and winding around a winding axis AX. is there. In the electrode body 120, the central part in the winding axis AX direction that causes a battery reaction between the positive electrode plate 121 and the negative electrode plate 131 is an electrode body reaction part 120f described later.

  The positive electrode plate 121 has a positive electrode current collector foil 122 made of a strip-shaped aluminum foil as a core material. On both main surfaces of the positive electrode current collector foil 122, positive electrode active material layers 123 and 123 are strip-shaped in the longitudinal direction (left and right direction in FIG. 4) on a part of the width direction and extending in the longitudinal direction, respectively. Is provided. The positive electrode active material layers 123 and 123 are composed of a positive electrode active material, a conductive additive, and a binder.

  In the positive electrode plate 121, a belt-like portion where the positive electrode current collector foil 122 and the positive electrode active material layers 123 and 123 exist in the thickness direction of the positive electrode plate 121 is the positive electrode portion 121 w. The positive electrode part 121 w faces a negative electrode part 131 w (described later) of the negative electrode plate 131 via the separator 141 in a state where the electrode body 120 is configured. A portion where the positive electrode portion 121w and the negative electrode portion 131w face each other is an electrode body reaction portion 120f that causes a battery reaction between the positive electrode plate 121 and the negative electrode plate 131 in the electrode body 120.

  In addition, with the provision of the positive electrode portion 121w on the positive electrode plate 121, one end portion in the width direction (upward in FIG. 4) of the positive electrode current collector foil 122 extends in a band shape in the longitudinal direction and has its own thickness. The positive electrode current collector portion 121m has no positive electrode active material layer 123 in the direction. A part of the positive electrode current collector 121m in the width direction protrudes from the separator 141 in a spiral shape to one side SA in the winding axis AX direction, and is connected to the positive electrode current collector 150 (see FIG. 1). ).

  The positive electrode current collecting member 150 includes a current collecting plate portion 151 having a disk shape, and a lead portion extending from the current collecting plate portion 151 to one side KA in the case axis KX direction (one side SA in the winding axis AX direction). 153. Of the current collector plate 151, the positive electrode current collector 121m of the positive electrode plate 121 described above is joined to the main surface 151c on the other side KB in the case axis KX direction (the other side SB in the winding axis AX direction). . On the other hand, the lead part 153 is in contact with the main surface 113c of the other side KB (the other side SB) in the case lid member 113. Thereby, the positive electrode plate 121 (positive electrode current collector 121m) of the electrode body 120 and the positive electrode terminal 155 provided upright on the case lid member 113 are electrically connected.

  The negative electrode plate 131 has a negative electrode current collector foil 132 made of a strip-shaped copper foil as a core material. On both main surfaces of the negative electrode current collector foil 132, negative electrode active material layers 133 and 133 are band-like in the longitudinal direction (left and right direction in FIG. 4) on a part extending in the longitudinal direction and extending in the longitudinal direction. Is provided. The negative electrode active material layers 133 and 133 are composed of a negative electrode active material, a binder, and a thickener.

  In the negative electrode plate 131, a strip-shaped portion where the negative electrode current collector foil 132 and the negative electrode active material layers 133 and 133 are present in the thickness direction of the negative electrode plate 131 is the negative electrode portion 131w. The entire area of the negative electrode portion 131 w faces the separator 141 in a state where the electrode body 120 is configured. In addition, as a result of providing the negative electrode portion 131w on the negative electrode plate 131, one end portion (downward in FIG. 4) in the width direction of the negative electrode current collector foil 132 extends in a band shape in the longitudinal direction and has its own thickness. The negative electrode current collector portion 131m has no negative electrode active material layer 133 in the direction. A part of the negative electrode current collector 131m in the width direction protrudes from the separator 141 to the other side SB in the winding axis AX direction in a spiral shape and is connected to the negative electrode current collector 160 (FIG. 1 and FIG. 1). (See FIG. 3).

  The negative electrode current collecting member 160 includes a current collecting plate portion 161 having a disk shape, and a lead portion 163 extending from the current collecting plate portion 161 to the other side KB (the other side SB). The negative electrode current collector 131m of the negative electrode plate 131 described above is joined to the main surface 161c of the one side KA (one side SA) of the current collector plate 161. On the other hand, the lead part 163 is in contact with the main surface 111bc on the one side KA (one side SA) of the case bottom 111b of the case body member 111. Thereby, the negative electrode plate 131 (negative electrode current collector 131m) of the electrode body 120 and the above-described negative electrode terminal 165 provided upright on the case bottom 111b are electrically connected.

  The separator 141 is a porous film made of resin, specifically, polypropylene (PP) and polyethylene (PE), and has a strip shape.

Next, the valve formation part 115 and the safety valve 117 will be described (see FIGS. 1 to 3).
The valve forming portion 115 is provided in the case tube portion 111a of the battery case 110 described above, and forms a part of the case tube portion 111a. Specifically, the valve forming portion 115 is provided on the other side cylinder end 111a2 that forms the end of the other side KA in the case cylinder portion 111a, and the electrode body of the electrode body 120 in the case axis KX direction. It is located outside the reaction part 120f in the case axis line KX direction (the other side KB in the first embodiment).

In the radial direction of the case axis KX, the center of the inner edge 115f in the case axis KX direction of the valve forming unit 115 is located radially inward from the outer peripheral surface 120fm of the electrode body reaction unit 120f. Specifically, as shown in FIG. 3, the distance from the case axis KX to the inner edge 115f of the valve forming portion 115 is greater than the distance (radius) RA from the case axis KX to the outer peripheral surface 120fm of the electrode body reaction portion 120f. The valve forming portion 115 is provided in the case tube portion 111a so that the distance (shortest distance) BA is smaller.
Further, the valve forming portion 115 has a rectangular shape in plan view and a flat plate shape.

  A flat non-returnable safety valve 117 having a rectangular shape in a plan view is formed in the valve forming portion 115 over almost the entire area thereof. In the safety valve 117, a groove 117v forming a V-shaped groove is formed in a predetermined shape (plan view, a shape in which two Y-shaped lower ends are connected symmetrically). As a result, the safety valve 117 is opened when the internal pressure of the battery case 110 exceeds a predetermined valve opening pressure. Specifically, the groove 117v is used as a starting point for breaking and opening, and the inside and outside of the battery case 110 are communicated. Then, the gas generated inside the battery is quickly exhausted outside the battery.

  As described above, in the battery 100 according to the first embodiment, the positive electrode plate 121 and the negative electrode plate 131 are overlapped with each other via the separator 141 and wound around in a cylindrical shape around the winding axis AX. It has an electrode body 120 and a cylindrical case tube portion 111a extending along the case axis KX, and the electrode body 120 is accommodated in a form in which the winding axis AX and the case axis KX are parallel to each other. A cylinder provided with the battery case 110 and a safety valve 117 which is provided in the battery case 110 and opens when the internal pressure of the battery case 110 becomes equal to or higher than a predetermined valve opening pressure to communicate the inside and outside of the battery case 110. Type battery.

  And when the part which produces a battery reaction between the positive electrode plate 121 and the negative electrode plate 131 among the electrode bodies 120 is the electrode body reaction part 120f, the case cylinder part 111a has the electrode body 120 in the case axis KX direction. At least a part of the inner edge 115f in the case axis KX direction is radially inward from the outer peripheral surface 120fm of the electrode body reaction part 120f with respect to the radial direction of the case axis KX. It has the valve formation part 115 located. Moreover, the safety valve 117 is provided in the valve forming portion 115 of the battery case 110.

  In this battery 100, since the safety valve 117 is provided in the valve forming portion 115 of the case cylinder portion 111a, the safety valve 117 is provided at the end portion (the case lid member 113 or the case bottom portion 111b) of the battery case 110 in the case axis KX direction. In comparison with this, the size of the safety valve 117 can be sufficiently secured. In addition, it is possible to increase the form and the degree of arrangement of the positive electrode terminal 155 or the negative electrode terminal 165 provided at the end of the battery case 110 in the case axis KX direction.

  In addition, the valve forming portion 115 has a part of the inner edge 115 f in the case axis KX direction positioned radially inward from the outer peripheral surface 120 fm of the electrode body reaction portion 120 f of the electrode body 120. For this reason, even when the electrode body 120 tries to move toward the other side KB where the valve forming portion 115 exists in the direction of the case axis KX, at least the electrode body reaction portion 120f has the inner edge of the valve forming portion 115. Since it is latched by 115f, it can prevent reliably that the electrode body reaction part 120f moves to the radial inside of the valve formation part 115. FIG. For this reason, it is possible to reliably prevent the safety valve 117 provided in the valve forming portion 115 from being blocked by the electrode body reaction portion 120f from the inside in the radial direction so that the internal pressure is not properly applied to the safety valve 117. Therefore, in this battery 100, when the battery internal pressure becomes equal to or higher than the valve opening pressure, the safety valve 117 can be reliably opened.

  In the first embodiment, the valve forming part 115 and the safety valve 117 are provided on the other cylinder end 111a2 on the side where the negative electrode terminal 165 is present, of the case cylinder 111a of the case body member 111. On the other hand, the case main body member 111 is electrically connected to the negative electrode current collector 131m of the electrode body 120 via the negative electrode current collector member 160, so that the valve forming portion 115 and the safety valve 117 are connected to the negative electrode current collector of the electrode body 120. The electric potential is the same as that of the electric part 131m and the negative electrode current collecting member 160. Therefore, the current collector plate portion 161 of the electrode body 120 and the negative electrode current collector member 160 moves to the other side KB, and the negative electrode current collector portion 131m of the electrode body 120 or the current collector plate portion 161 of the negative electrode current collector member 160 is Even when it contacts the valve forming part 115 or the safety valve 117, there is no short circuit between them.

  Furthermore, in this Embodiment 1, the valve formation part 115 and the safety valve 117 are each flat form. For this reason, compared with the case where the valve formation part 115 or the safety valve 117 has curved surfaces, such as R shape, it can be set as the safety valve 117 with little variation in valve opening pressure.

Next, a method for manufacturing the battery 100 will be described.
First, the positive electrode plate 121 is manufactured. That is, a positive electrode current collector foil 122 made of a long aluminum foil is prepared. Then, a positive electrode active material paste containing a positive electrode active material, a conductive material, and a binder is applied to one main surface of the positive electrode current collector foil 122 while leaving a strip-like positive electrode current collector portion 121m extending in the longitudinal direction. By drying with hot air, a strip-like positive electrode active material layer 123 is formed. Similarly, the above-described positive electrode active material paste is applied to the main surface on the opposite side of the positive electrode current collector foil 122 while leaving the belt-like positive electrode current collector portion 121m, and dried with hot air. 123 is formed. Then, in order to improve an electrode density, the positive electrode active material layers 123 and 123 are compressed with a pressure roll. Thus, the positive electrode plate 121 is formed (see FIG. 4).

  Separately, the negative electrode plate 131 is manufactured. That is, a negative electrode current collector foil 132 made of a long copper foil is prepared. Then, a negative electrode active material paste containing a negative electrode active material, a binder and a thickener is applied to one main surface of the negative electrode current collector foil 132 while leaving a strip-shaped negative electrode current collector portion 131m extending in the longitudinal direction. Then, it is dried with hot air to form a strip-like negative electrode active material layer 133. Similarly, the negative electrode active material paste is applied to the main surface on the opposite side of the negative electrode current collector foil 132 while leaving the strip-shaped negative electrode current collector 131m, and dried with hot air to form a strip-shaped negative electrode active material layer. 133 is formed. Then, in order to improve an electrode density, the negative electrode active material layers 133 and 133 are compressed with a pressure roll. Thus, the negative electrode plate 131 is formed (see FIG. 4).

  Next, a long separator 141 is prepared, the positive electrode plate 121 and the negative electrode plate 131 are overlapped with each other via the separator 141 (see FIG. 4), and wound around the axis line AX using a winding core to obtain an electrode body. 120 is formed. Thereafter, in the electrode body 120, the positive electrode current collector 150 is welded to the positive electrode current collector 121m, and the negative electrode current collector 160 is welded to the negative electrode current collector 131m (see FIG. 1).

  Separately, a bottomed cylindrical case body member 111 is prepared, and a negative electrode terminal 165 is welded to the case bottom 111b. After that, as shown in FIG. 5, the valve forming portion 115 and the safety valve 117 are formed on the other side cylinder end portion 111a2 of the case cylinder portion 111a of the case body member 111 by press working using the upper mold GU and the lower mold GD. Are formed at the same time.

  At this time, in the first embodiment, since the valve forming portion 115 and the safety valve 117 are formed in a flat plate shape, the valve forming portion 115 and the safety valve 117 can be easily formed. That is, if the valve forming portion 115 or the safety valve 117 is formed in a curved plate shape such as an R shape, it is difficult to form a press die having a form corresponding to the curvature. Further, this tends to cause variations in the valve opening pressure of the safety valve that is press-molded. On the other hand, in this Embodiment 1, since the valve formation part 115 and the safety valve 117 are made into flat form, formation of a press die (upper mold GU and lower mold GD) is easy. In addition, the safety valve 117 with little variation in valve opening pressure can be press-molded, and the productivity of the battery 100 can be improved.

  Next, the electrode body 120 in which the positive current collecting member 150 and the negative current collecting member 160 are joined is inserted into the case body member 111 in which the safety valve 117 is formed (see FIG. 1). Then, the lead portion 163 of the negative electrode current collecting member 160 is welded to the case bottom portion 111 b of the case main body member 111. Thereafter, a non-aqueous electrolyte solution 170 is injected into the case body member 111. Thereafter, the case lid member 113 to which the negative electrode terminal 165 is welded is crimped and fixed via the seal member 119 so as to close the opening 111 h of the case main body member 111. Thus, the battery 100 is completed.

In the first embodiment, as described above, the case tube portion 111a is pressed to form the valve forming portion 115 and the safety valve 117. However, the method for forming the valve forming portion 115 and the safety valve 117 is not limited thereto. Absent.
For example, the case tube portion 111a is pressed to form the valve forming portion 116 having the opening 116h (see FIG. 6). On the other hand, a rectangular plate-shaped safety valve 118 having a groove 118v similar to the groove 117v of the safety valve 117 is formed separately. The safety valve 118 can be provided in the valve forming portion 116 by joining the safety valve 118 to the opening 116 h of the valve forming portion 116.

(Embodiment 2)
Next, a second embodiment will be described. In a lithium ion secondary battery (cylindrical battery) 200 (hereinafter also simply referred to as a battery 200) according to the second embodiment, the form of the valve forming portion 215 and the safety valve 217 (see FIG. 7) is related to the first embodiment. It differs from the form (refer FIGS. 1-3) of the valve formation part 115 and the safety valve 117 of the battery 100. FIG. Other than that, the second embodiment is the same as the first embodiment, and the description of the same parts as the first embodiment is omitted or simplified.

  The valve forming portion 215 and the safety valve 217 according to the second embodiment are also provided in the case tube portion 111a, not the end portion (the case lid member 113 or the case bottom portion 111b) of the battery case 110 in the case axis KX direction. However, in the first embodiment, the flat valve forming portion 115 and the safety valve 117 are provided in the case tube portion 111a in a form parallel to the case axis KX. On the other hand, the valve forming portion 215 and the safety valve 217 according to the second embodiment are similarly provided in a flat plate shape at the other-side tube end portion 111a2 of the case tube portion 111a, but at an angle θ with respect to the case axis KX. And the other side KB (to the left in FIG. 7) is located in the radially inner side.

  In addition, the valve formation part 215 which concerns on this Embodiment 2 is also the case axis line KX direction rather than the electrode body reaction part 120f of the electrode body 120 about the case axis line KX direction similarly to the valve formation part 115 which concerns on the said Embodiment 1. FIG. Located on the other side KB. Further, the valve forming portion 215 also has a center of the inner edge 215f in the case axis KX direction in the radial direction of the case axis KX, located radially inward from the outer peripheral surface 120fm of the electrode body reaction portion 120f. Specifically, a distance (shortest distance) BA from the case axis KX to the inner edge 215f of the valve forming portion 215 is larger than a distance (radius) RA from the case axis KX to the outer peripheral surface 120fm of the electrode body reaction portion 120f. Is smaller. Further, the safety valve 217 is formed with a groove 217v similar to the groove 117v of the safety valve 117 according to the first embodiment.

Also in the battery 200 according to the second embodiment, since the safety valve 217 is provided in the valve forming portion 215 of the case cylinder portion 111a, the size of the safety valve 217 can be sufficiently ensured. In addition, it is possible to increase the form and the degree of arrangement of the positive electrode terminal 155 or the negative electrode terminal 165 provided at the end of the battery case 110 in the case axis KX direction.
Further, the valve forming portion 215 has a part of the inner end edge 215f in the case axis KX direction positioned radially inside the outer peripheral surface 120fm of the electrode body reaction portion 120f of the electrode body 120. For this reason, similarly to the first embodiment, the safety valve 217 can be reliably prevented from being blocked by the electrode body reaction part 120f from the inside in the radial direction, and the internal pressure is not appropriately applied to the safety valve 217. Therefore, the battery 200 according to the second embodiment can also surely open the safety valve 217 when the battery internal pressure becomes equal to or higher than the valve opening pressure.

(Embodiment 3)
Next, a third embodiment will be described. In the lithium ion secondary battery (cylindrical battery) 300 (hereinafter also simply referred to as the battery 300) according to the third embodiment, the form of the valve forming portion 315 and the safety valve 317 (see FIGS. 8 and 9) is the present embodiment. 1 and 2 are different from the configurations of the valve forming portions 115 and 215 and the safety valves 117 and 217 of the batteries 100 and 200 according to FIGS. Other than that, the second embodiment is the same as the first and second embodiments, and the description of the same parts as the first and second embodiments is omitted or simplified.

  The valve forming portion 315 according to the third embodiment is also provided at the case cylinder portion 111a, not at the end portion (the case lid member 113 or the case bottom portion 111b) of the battery case 110 in the case axis KX direction. The portion 315 is provided at a position away from the outermost edge 111af of the other side KB of the case tube portion 111a (at a position spaced by a predetermined interval HA).

  However, this valve forming portion 315 is also on the other side in the case axis KX direction from the electrode body reaction portion 120f of the electrode body 120 in the case axis KX direction, like the valve forming portions 115 and 215 in the first and second embodiments. Located in KB. Further, the valve forming portion 315 also has a center of the inner edge 315f in the case axis KX direction in the radial direction of the case axis KX, located radially inward from the outer peripheral surface 120fm of the electrode body reaction portion 120f. Specifically, the distance (shortest distance) BA from the case axis KX to the inner edge 315f of the valve forming portion 315 is larger than the distance (radius) RA from the case axis KX to the outer peripheral surface 120fm of the electrode body reaction portion 120f. Is smaller. Further, the safety valve 317 is formed with a groove 317v similar to the grooves 117v and 217v of the safety valves 117 and 217 according to the first and second embodiments.

Also in the battery 300 according to the third embodiment, since the safety valve 317 is provided in the valve forming portion 315 of the case tube portion 111a, the size of the safety valve 317 can be sufficiently ensured. Moreover, the freedom degree of arrangement | positioning and form of the positive electrode terminal 155 or the negative electrode terminal 165 provided in the edge part of the case axis line KX direction of the battery case 110 can be enlarged.
In addition, the valve forming portion 315 has a part of the inner edge 315f in the case axis KX direction positioned radially inside the outer peripheral surface 120fm of the electrode body reaction portion 120f of the electrode body 120. For this reason, similarly to the first and second embodiments, the safety valve 317 can be prevented from being blocked by the electrode body reaction part 120f from the inside in the radial direction and the internal pressure is not appropriately applied to the safety valve 317. Therefore, the battery 300 of the third embodiment can also reliably open the safety valve 317 when the battery internal pressure becomes equal to or higher than the valve opening pressure.

  Furthermore, in the third embodiment, the valve forming portion 315 is provided at a position away from the edge 111af on the other side KB in the case axis KX direction of the case cylinder portion 111a. For this reason, since the form of the end of the other side KB of the battery case 110 (the case bottom 111b in the third embodiment) is not affected by the presence or absence of the valve forming portion 315, the terminal (this third embodiment) provided on the case bottom 111b. Then, the degree of freedom of arrangement and form of the negative electrode terminal 165) can be further increased.

(Embodiment 4)
Next, a fourth embodiment will be described. The assembled battery 600 according to the fourth embodiment is obtained by connecting a plurality of lithium ion secondary batteries 100, 100,... According to the first embodiment (see FIG. 10).

The assembled battery 600 includes a plurality of batteries 100, 100,..., A pair of battery holders 610, 610, a plurality of restraining bolts 613, 613 and nuts 615, 615, a plurality of bus bars 620, 620,. 623, 623,...
The plurality of batteries 100, 100,... Are arranged in parallel to each other (so that the case axes KX, KX,... Are parallel to each other), and the adjacent batteries 100, 100 are opposite to each other. It is held between a pair of battery holders 610, 610 so that they face each other (so that the positive electrode terminal 155 and the negative electrode terminal 165 of the adjacent batteries 100, 100 face opposite sides).

Among these, the battery holder 610 has a rectangular plate shape as shown in FIG. The battery holder 610 is formed with a plurality of three types of openings (first opening 610h1, second opening 610h2, and third opening 610h3).
The first opening 610h1 forms a circular hole in plan view that is slightly larger than the diameter of the battery case 110. The first opening 610h1 is inserted with one side cylinder end 111a1 of the case cylinder 111a of the battery case 110, and the one side cylinder end 111a1 penetrates the battery holder 610 and protrudes from the battery holder 610. ing. Thereby, the battery 100 is held by the battery holder 610 at the one-side cylinder end 111a1 of the battery case 110.

  The second opening 610h2 is similar to the cross section of the other cylinder end 111a2 of the case cylinder 111a and the case bottom 111b in the battery case 110, and is slightly larger than this. That is, the second opening 610h2 is a notch-shaped hole having a string 610h2c and an arc (super arc) 610h2d. The other side cylinder end 111a2 of the battery case 110 is inserted into the second opening 610h2, and the other side cylinder end 111a2 penetrates the battery holder 610 and protrudes from the battery holder 610. Further, in this state, a part of the valve forming portion 115 provided on the other side cylinder end portion 111 a 2 and the entire safety valve 117 protrude outward from the battery holder 610.

  Accordingly, the battery 100 is held by the battery holder 610 at the other cylinder end portion 111 a 2 of the battery case 110. In addition, since the other cylindrical end 111a2 of the battery case 110 and the second opening 610h2 of the battery holder 610 are notched circular holes as described above, the battery 100 can be rotated around the case axis KX. Can be prevented. That is, when the battery 100 tries to rotate, the other cylinder end portion 111a2 provided with the valve forming portion 115 comes into contact with the second opening 610h2 of the battery holder 610 to prevent the battery 100 from rotating.

The third opening 610h3 has a circular shape in plan view, and a restraining bolt 613 is inserted therein. The pair of battery holders 610, 610 are fixed to each other by a plurality of restraining bolts 613, 613 and nuts 615, 615 with a plurality of batteries 100, 100,.
The bus bar 620 and the nut 623 electrically connect the adjacent positive electrode terminal 155 and the negative electrode terminal 165 of the adjacent batteries 100, 100. Thereby, the some battery 100,100, ... is connected in series.

  As described above, in the assembled battery 600 according to the fourth embodiment, the cross-sectional shape of the other cylinder end portion 111a2 of the battery case 110 is cut off as described above because the valve forming portion 115 is provided. It has a circular shape. In addition, the second opening 610h2 of the battery holder 610 that holds the other-side cylinder end 111a2 also has a cutout circle shape corresponding to the cross-sectional shape of the other-side cylinder end 111a2. For this reason, it is possible to reliably prevent the battery 100 from rotating around the case axis KX.

In the fourth embodiment, the shape of the second opening 610h2 of the battery holder 610 is similar to the cross section of the other-side cylinder end 111a2 of the battery case 110, but the shape of the second opening 610h2 can be changed as appropriate. .
For example, like the battery holder 612 shown in FIG. 12, a semicircular recess 610h2e may be provided in a part of the string 610h2c of the second opening 610h2. By providing such a recess 610h2e, gas can be reliably discharged from the safety valve 117 when the valve is opened, regardless of the presence of the battery holder 610.

(Embodiment 5)
Next, a fifth embodiment will be described. A vehicle 700 according to the fifth embodiment is equipped with the assembled battery 600 of the fourth embodiment having the lithium ion secondary battery 100 of the first embodiment, and drives the electric energy stored in the lithium ion secondary battery 100. It is used as all or part of the driving energy of the source (see FIG. 13).

The vehicle 700 is a hybrid vehicle on which the assembled battery 600 described above is mounted and driven using the engine 740, the front motor 720, and the rear motor 730 in combination. Specifically, the vehicle 700 includes a vehicle body 790, an engine 740, a front motor 720, a rear motor 730, a cable 750, and an inverter 760 attached thereto. Further, the vehicle 700 includes the above-described assembled battery 600 having a plurality of batteries 100, 100,... Therein, and the electric energy stored in the assembled battery 600 is used to drive the front motor 720 and the rear motor 730. We are using.
As described above, since the battery 100 can reliably open the safety valve 117 when the internal pressure becomes equal to or higher than the predetermined valve opening pressure, the safety of the vehicle 700 can be improved.

(Embodiment 6)
Next, a sixth embodiment will be described. A battery using device 800 according to the sixth embodiment includes the lithium ion secondary battery 100 according to the first embodiment and uses the lithium ion secondary battery 100 as at least one energy source (see FIG. 14).

The battery using device 800 is a hammer drill equipped with a battery pack 810 including the battery 100 according to the first embodiment. In the battery using device 800, a battery pack 810 is accommodated in a bottom 821 of a main body 820, and the battery pack 810 is used as an energy source for driving a drill.
As described above, since the battery 100 can reliably open the safety valve 117 when the internal pressure becomes equal to or higher than the predetermined valve opening pressure, the safety of the battery using device 800 can be improved. .
In addition, although the battery using device 800 is mounted with the battery 100 according to the first embodiment, the battery 200 or the battery 300 according to the second or third embodiment may be mounted instead.

In the above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to the above-described first to sixth embodiments, and it is needless to say that the present invention can be appropriately modified and applied without departing from the gist thereof. Yes.
For example, in Embodiments 1 to 6 described above, the battery case 110 has a cylindrical cylindrical case 111a, but is not limited thereto. For example, the case cylinder part 111a can be in the form of an elliptic cylinder or a square cylinder.

  In the first to sixth embodiments, the battery case 110 is exemplified by the bottomed cylindrical case body member 111 and the case lid member 113 that closes the opening 111h of the case body member 111. Not limited to. For example, the battery case 110 may be formed of a cylindrical case main body member that is open at both ends, and a case lid member that closes the openings at both ends of the case main body member.

  In the first to sixth embodiments, only one valve forming portion 115, 215, and 315 is provided in the case tube portion 111a of the battery case 110, and only one safety valve 117, 217, and 317 is provided. A plurality of forming portions and safety valves may be provided. For example, a plurality of valve forming portions can be provided on the case tube portion 111a, and one or more safety valves can be provided on each of them. Moreover, only one valve formation part can be provided in the case cylinder part 111a, and a plurality of safety valves can be provided therein. Further, a plurality of valve forming portions and safety valves may be provided in the circumferential direction of the case tube portion 111a, or a plurality of valve forming portions and safety valves may be provided in the case axis KX direction.

  In the first to sixth embodiments, the valve forming portions 115, 215, 315 and the safety valves 117, 217, 317 are simultaneously formed by one press working, but each is divided into two or more pressing steps. It may be formed. That is, in the first pressing step, only the valve forming portion 115 or the like is formed on the case tube portion 111a, and then a second pressing step is separately performed to further form the safety valve 117 or the like in the valve forming portion 115 or the like. You can also

  Moreover, in the said Embodiment 5, although the hybrid vehicle was illustrated as the vehicle 700 carrying the lithium ion secondary battery 100 of this invention, it is not restricted to this. Examples of the vehicle on which the lithium ion secondary battery according to the present invention is mounted include an electric vehicle, a plug-in hybrid vehicle, a hybrid railway vehicle, a forklift, an electric wheelchair, an electric assist bicycle, and an electric scooter.

  Moreover, although the hammer drill was illustrated as the battery use apparatus 800 which mounts the lithium ion secondary battery 100 of this invention etc. in the said Embodiment 6, it is not restricted to this. Examples of battery-powered devices on which the lithium ion secondary battery according to the present invention is mounted include, for example, personal computers, mobile phones, battery-powered electric tools, uninterruptible power supply devices, and other household appliances and office devices driven by batteries. And industrial equipment.

100, 200, 300 Lithium ion secondary battery (cylindrical battery)
110 Battery case 111 Case main body member 111a Case cylinder part 111af (on the other side of the case cylinder part) 111b Case bottom part 113 Case cover member 115, 116, 215, 315 Valve formation part 115f, 215f, 315f (Valve formation part Inner edges 117, 118, 217, 317 (in the axial direction) Safety valve 117v, 118v, 217v, 317v (Safety valve) Groove 120 Electrode body 120f Electrode body reaction section 120fm (electrode body reaction section) outer peripheral surface 121 Positive electrode plate 131 Negative electrode Plate 141 Separator 155 Positive electrode terminal 165 Negative electrode terminal 170 Non-aqueous electrolyte 600 Battery pack 700 Vehicle 800 Battery-operated device AX Winding axis SA (in the winding axis direction) One side SB (in the winding axis direction) The other side KX Case axis KA (case axial direction) one side KB (case axial direction) other side

Claims (2)

An electrode body in which a positive electrode plate and a negative electrode plate are overlapped with each other via a separator and wound in a cylindrical shape around a winding axis;
A battery case having a cylindrical case tube portion extending along the case axis, and housing the electrode body in a form in which the winding shaft and the case axis are parallel to each other;
A safety valve that is provided in the battery case and opens when the internal pressure of the battery case becomes equal to or higher than a predetermined valve opening pressure, and communicates the inside and outside of the battery case;
A cylindrical battery comprising:
When the portion of the electrode body that generates a battery reaction between the positive electrode plate and the negative electrode plate is an electrode body reaction part,
The case tube portion is
In the axial direction along the case axis, at least a part of the inner edge in the axial direction of the electrode in the radial direction of the case axis is outside the electrode body reaction part of the electrode body. Having a valve forming part located radially inside the outer peripheral surface of the body reaction part,
The safety valve, Ri Na provided in the valve forming part of the battery case,
The valve forming part and the safety valve are each a flat battery. The cylindrical battery according to claim 1,
The annuloplasty part is
A cylindrical battery provided at a position away from an end edge in the axial direction of the case cylindrical portion.

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