JP2014154484A - Battery and battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery, and the like, in which increase in the internal resistance can be suppressed when charge and discharge are repeated.SOLUTION: A battery 10 includes an electrode body 30 formed by winding a first electrode plate 31, a second electrode plate 41 and a separator 51 flatly. A gap SK1 communicating in the axial direction EH is provided between second edges 51f2 of the separator 51 on one side, and first edges 51f1 on one side are jointed entirely over the longitudinal direction KH so as to surround the edge 41 of EC of the second electrode plate 41 on one side. Furthermore, the battery 10 has a gap SK2 communicating in the axial direction EH between a second edge 51g2 of the separator 51 on the other end side and an adjacent second exposed part 41r, and the first edge 51g1 on the other side is joined to an adjacent second exposed part 41r entirely in the longitudinal direction KH.

Description

  The present invention provides a battery comprising an electrode body in which a belt-like first electrode plate and a belt-like second electrode plate are stacked on each other via a pair of belt-like separators and wound in a flat shape, and a battery case containing the electrode body. And an assembled battery including a plurality of the batteries.

Conventionally, an electrode body in which a strip-shaped first electrode plate (for example, a positive electrode plate) and a strip-shaped second electrode plate (for example, a negative electrode plate) are overlapped with each other via a pair of strip-shaped separators and wound flatly around an axis. There are known batteries comprising: Furthermore, as an active material layer (positive electrode active material layer or negative electrode active material layer) of an electrode plate, one that expands and contracts with charge / discharge is known. For example, when a negative electrode active material layer is formed using graphite particles as negative electrode active material particles, the graphite particles expand during the charging process and contract during the discharge process, so the negative electrode active material layer also expands during the charging process and contracts during the discharge process. To do.
In addition, as a prior art relevant to this invention, the battery (refer FIG. 1 etc. of patent document 1) of patent document 1 is mentioned.

Japanese Patent Laid-Open No. 9-320636

  As described above, the pore volume of the active material layer that expands and contracts with charge and discharge increases and decreases with charge and discharge. When the pore volume decreases, the electrolyte filled in the pores in the active material layer is discharged from the active material layer by the amount corresponding to the decrease in the pore volume, and further discharged outside the electrode body. On the other hand, when the pore volume increases, the electrolyte is absorbed into the active material layer from the outside of the electrode body by the amount corresponding to the increase in the pore volume.

In particular, in the compressed part of the electrode body that is compressed in the stacking direction when the battery is used, the electrolyte solution often goes in and out of the electrode body from the active material layer due to charge / discharge (especially when high rate discharge occurs) There are many). The reason is considered as follows. That is, for example, when the active material layer contracts during discharge, an external force due to compression is further applied to the contraction, so that the discharge amount of the electrolyte increases. On the other hand, when the active material layer expands during charging, the amount of electrolyte absorbed increases (the amount of electrolyte discharged during discharging increases, so the amount of electrolyte absorbed during charging also increases).
When such a battery is repeatedly charged and discharged, a concentration distribution is generated in the electrolyte solution as the electrolyte solution enters and exits from the active material layer (especially, the active material layer in the compressed portion of the electrode body) to the outside of the electrode body. The internal resistance increases, which is not preferable.

  This invention is made | formed in view of this present condition, Comprising: When charging / discharging is performed repeatedly, the battery which can suppress that internal resistance of a battery increases, and an assembled battery using this battery are provided. With the goal.

  One embodiment of the present invention for solving the above-described problems is a band-shaped first electrode plate having a first active material layer on a first electrode foil, and a porous material that expands and contracts with charge / discharge on the second electrode foil. A belt-like second electrode plate having a quality second active material layer is stacked on each other via a pair of belt-like separators and wound flatly around an axis, and the first electrode plate includes the first electrode plate The electrode foil has a first exposed portion that is exposed in a strip shape on one side in the axial direction along the axis, and the second electrode plate includes a first exposed portion in which the second electrode foil is exposed in a strip shape on the other side in the axial direction. An electrode body having two exposed portions; and a battery case that houses the electrode body, wherein the electrode body has the first active material layer and the second active material layer overlapping in the stacking direction with the separator interposed therebetween. A battery having a central winding part, wherein the product of the central winding part when the battery is used. A portion that is compressed in the direction is a central compressed portion, and a portion that is located on the one side of the central compressed portion is one of the edge portions of the separator that overlaps the first exposed portion and the stacking direction. One side first edge portion and the other portion as one side second edge portion, and the central compressed portion of the separator on the other side edge portion overlapping the second exposed portion in the stacking direction. When the part located on the other side of the part is the other side first edge part and the other part is the other side second edge part, the axial direction is between the one side second edge parts. The first side edge portions of the one side are joined together over the longitudinal direction of the separator so as to surround the one side edge of the second electrode plate, and the second side of the second side. A gap that extends in the axial direction between the end edge portion and the adjacent second exposed portion. And, respectively joined to a battery comprising the whole over the longitudinal direction on the second exposed part for Tonarizai said first edge portion the other side.

  In this battery, among the one side edge portions of the separator, the first side edge portions on the one side are joined together over the longitudinal direction of the separator to surround the one side edge of the second electrode plate. For this reason, when charging / discharging is performed, the electrolyte retained in the second active material layer in the central compressed portion does not flow out or inflow to the outside of the electrode body through the first side edges on one side. It is suppressed. Moreover, in this battery, the other side first edge portion of the other side edge portion of the separator is joined to the second exposed portion adjacent thereto in the longitudinal direction of the separator. For this reason, when charging / discharging is performed, the electrolytic solution retained in the second active material layer in the central compressed part passes outside the first end edge part and the second exposed part to the outside of the electrode body. Outflow and inflow of the water is suppressed. As described above, the electrolyte solution held in the second active material layer in the central compressed portion is prevented from flowing out and flowing into the outside of the electrode body in the axial direction. Therefore, in this battery, it can suppress that the internal resistance of a battery increases when charging / discharging is performed repeatedly.

  On the other hand, among the one side edge portions of the separator, the second side edge portions on the one side are not joined at least in part in the longitudinal direction of the separator, and the axial direction is between the second side edge portions on the one side. Therefore, the electrolytic solution can move in the axial direction through this gap. In addition, at least a part of the second side edge of the other side of the separator on the other side in the longitudinal direction is not joined to the second exposed part adjacent to the second side edge, and the second side edge of the other side is not joined. Since there is a gap in the axial direction between the second exposed portion and the second exposed portion, the electrolyte can move in the axial direction through this gap. For this reason, it can be set as the battery which impregnated the electrolyte solution in the electrode body (2nd active material layer) reliably.

In addition, as a mode in which a part of the electrode body (central compressed portion) is compressed in the stacking direction when the battery is used, the mode in which the central compressed portion is directly compressed by the elasticity of the battery case itself, Further, there may be mentioned a mode in which a spacer is interposed between the battery case and the electrode body, and the central compressed portion is indirectly compressed through this spacer. In addition, by pressing the battery case from the outside in the stacking direction, the central compressed portion is compressed by the battery case, and a spacer is interposed between the battery case and the electrode body, and the central cover is interposed via the spacer. The aspect which compresses a compression part is mentioned.
Moreover, as a joining form of separators, joining by heat welding or ultrasonic welding, joining using adhesive tapes, such as interposing a double-sided adhesive tape, joining by an adhesive agent, etc. are mentioned.
Moreover, joining of the separator and the second exposed portion of the second electrode plate includes joining using an adhesive tape such as interposing a double-sided adhesive tape, joining using an adhesive, and the like.

Further, in the battery described above, the central winding portion includes two curved end portions in which the first active material layer, the second active material layer, and the separator are bent into a semicylindrical shape and overlap each other, and The first active material layer, the second active material layer, and the separator overlap each other in a flat plate shape, and the central compressed portion is the flat plate. It is preferable that the battery is the entire part.

  In this battery, the central compressed part of the electrode body that is compressed when the battery is used is the entire flat plate part. For this reason, it is suppressed that the electrolyte solution hold | maintained at the 2nd active material layer in a flat plate part flows out inflow outside an electrode body about an axial direction. Therefore, it can suppress that the internal resistance of a battery increases when charging / discharging is performed repeatedly. On the other hand, since the electrolyte solution can move in the axial direction on one side and the other side of the curved end portion, a battery in which the electrolyte solution is reliably impregnated in the electrode body (in the second active material layer) can be obtained. .

  Further, in the battery described above, the central winding portion includes two curved end portions in which the first active material layer, the second active material layer, and the separator are bent into a semicylindrical shape and overlap each other, and The first active material layer, the second active material layer, and the separator overlap each other in a flat plate shape, and the central compressed portion is the flat plate. It is preferable that the battery is composed of a plurality of stretched central compressed parts that are located within the section and extend in the axial direction.

  In this battery, the central compressed part of the electrode body that is compressed when the battery is used consists of a plurality of elongated central compressed parts that are located in the flat plate part and extend in the axial direction. For this reason, it is suppressed that the electrolyte solution hold | maintained at the 2nd active material layer in an extending | stretching center to-be-compressed part flows out out of the electrode body, and flows in about an axial direction. Therefore, it can suppress that the internal resistance of a battery increases when charging / discharging is performed repeatedly. On the other hand, the electrolyte solution can move in the axial direction on one side and the other side of the flat plate portion other than the stretched central compressed portion and the curved end portion. Therefore, a battery in which the electrolytic solution is reliably impregnated in the electrode body (in the second active material layer) can be obtained.

  Moreover, another aspect is an assembled battery including a plurality of the batteries according to any one of the above, and is interposed between the batteries adjacent to each other in the stacking direction of the central compressed part, A plurality of spacers in contact with a contacted portion located in the stacking direction of the central compressed portion, and a plurality of the batteries and the spacers arranged in the stacking direction of the central compressed portion in the stacking direction. And a restraining member that restrains while pressing.

  Since this assembled battery uses the above-described battery, it is possible to suppress an increase in the internal resistance of the battery when charging and discharging are repeated.

In another aspect, a strip-shaped first electrode plate having a first active material layer on the first electrode foil, and a porous second active material layer that expands and contracts on charge and discharge on the second electrode foil. A band-shaped second electrode plate having a plurality of layers is laminated on each other via a pair of band-shaped separators and wound flatly around an axis, and the first electrode plate has the first electrode foil along the axis. An electrode body having a first exposed portion exposed in a strip shape on one side in the axial direction, and the second electrode plate having a second exposed portion in which the second electrode foil is exposed in a strip shape on the other side in the axial direction. And a battery case that houses the electrode body, and the electrode body has a central winding portion in which the first active material layer and the second active material layer overlap in the stacking direction via the separator. The central winding portion includes a semi-cylindrical shape in which the first active material layer, the second active material layer, and the separator are bent. And two curved end portions that overlap each other, and a flat plate portion that is located between the curved end portions and in which the first active material layer, the second active material layer, and the separator overlap each other in a flat plate shape. A portion of the separator that is positioned on the one side of the flat plate portion of the one side edge portion that overlaps the first exposed portion in the stacking direction as the first side edge portion, A portion located on the one side of the curved end portion is set as one second end edge portion, and the other end edge portion of the separator that overlaps with the second exposed portion in the stacking direction is the flat plate portion. When the part located on the other side is the other side first end edge part and the part located on the other side of the curved end part is the other side second edge part, the one side second end edge part Having a gap in the axial direction between the first end portions on the one side Joining the entire length of the separator to surround the one end edge of the second electrode plate, and between the other second end edge and the adjacent second exposed portion, The battery has a gap extending in the axial direction, and is joined to the second exposed portion adjacent to the other first end edge portion over the entire length direction.

  In this battery, among the one side edge portions of the separator, the first side edge portions on the one side are joined together over the longitudinal direction of the separator to surround the one side edge of the second electrode plate. For this reason, when charging / discharging is performed, the electrolyte solution held in the second active material layer in the flat plate portion is prevented from flowing out / inflowing to the outside of the electrode body through the first side edge portions on one side. The Moreover, in this battery, the other side first edge portion of the other side edge portion of the separator is joined to the second exposed portion adjacent thereto in the longitudinal direction of the separator. For this reason, when charging / discharging is performed, the electrolytic solution retained in the second active material layer in the flat plate portion flows out to the outside of the electrode body through the space between the other first end edge portion and the second exposed portion.・ Inflow is suppressed. As described above, the electrolyte solution held in the second active material layer in the flat plate portion is prevented from flowing out and flowing into the outside of the electrode body in the axial direction. Therefore, in this battery, it can suppress that the internal resistance of a battery increases when charging / discharging is performed repeatedly.

  On the other hand, among the one side edge portions of the separator, the second side edge portions on the one side are not joined at least in part in the longitudinal direction of the separator, and the axial direction is between the second side edge portions on the one side. Therefore, the electrolyte solution can move in the axial direction on one side of the curved end portion through the gap. In addition, at least a part of the second side edge of the other side of the separator on the other side in the longitudinal direction is not joined to the second exposed part adjacent to the second side edge, and the second side edge of the other side is not joined. Since there is a gap in the axial direction between the second exposed portion and the second exposed portion, the electrolyte can move in the axial direction on the other side of the curved end portion through this gap. For this reason, it can be set as the battery which impregnated the electrolyte solution in the electrode body (2nd active material layer) reliably.

  Moreover, another aspect is an assembled battery including a plurality of the above-described batteries, and is interposed between the batteries adjacent to each other in the stacking direction of the flat plate portion, and the stacking direction of the flat plate portion of the battery case. A plurality of spacers that are in contact with the contacted portion located in the plate, and a plurality of the batteries arranged in the stacking direction of the flat plate portion and a restraining member that presses and restrains the spacer in the stacking direction. It is an assembled battery.

  Since this assembled battery uses the above-described battery, it is possible to suppress an increase in the internal resistance of the battery when charging and discharging are repeated.

In another aspect, a strip-shaped first electrode plate having a first active material layer on the first electrode foil, and a porous second active material layer that expands and contracts on charge and discharge on the second electrode foil. A band-shaped second electrode plate having a plurality of layers is laminated on each other via a pair of band-shaped separators and wound flatly around an axis, and the first electrode plate has the first electrode foil along the axis. An electrode body having a first exposed portion exposed in a strip shape on one side in the axial direction, and the second electrode plate having a second exposed portion in which the second electrode foil is exposed in a strip shape on the other side in the axial direction. And a battery case that houses the electrode body, and the electrode body has a central winding portion in which the first active material layer and the second active material layer overlap in the stacking direction via the separator. The central winding portion includes a semi-cylindrical shape in which the first active material layer, the second active material layer, and the separator are bent. And two curved end portions that overlap each other, and a flat plate portion that is located between the curved end portions and in which the first active material layer, the second active material layer, and the separator overlap each other in a flat plate shape. The flat plate portion is divided into virtual first flat plate portions and second flat plate portions that alternately extend in a direction extending in the axial direction and connecting the curved end portions, and the first of the separators. Of the one side edge that overlaps the one exposed portion and the stacking direction, a portion located on the one side of the first flat plate portion is defined as a first side first edge portion, and the second flat plate portion or the curved end portion A portion located on the one side of the first side is defined as a second side edge on the one side, and the other side edge of the separator that overlaps the second exposed portion and the stacking direction on the other side of the first flat plate portion. The second flat plate portion is a portion located on the other side as the first edge portion on the other side. Alternatively, when the portion located on the other side of the curved end portion is the second side edge portion on the other side, the one side second edge portion has a gap leading to the axial direction, and the one side The first side edges are joined together over the length of the separator so as to surround the one side edge of the second electrode plate, and are adjacent to the second side edge of the other side. 2 is a battery having a gap extending in the axial direction between the two exposed portions and joining the second exposed portion adjacent to the second exposed portion adjacent to the other side in the longitudinal direction.

  In this battery, among the one side edge portions of the separator, the first side edge portions on the one side are joined together over the longitudinal direction of the separator to surround the one side edge of the second electrode plate. For this reason, when charging / discharging is performed, the electrolyte solution held in the second active material layer in the first flat plate portion does not flow out or inflow to the outside of the electrode body between the first side edge portions on one side. It is suppressed. Moreover, in this battery, the other side first edge portion of the other side edge portion of the separator is joined to the second exposed portion adjacent thereto in the longitudinal direction of the separator. For this reason, when charging / discharging is performed, the electrolytic solution held in the second active material layer in the first flat plate portion is transferred to the outside of the electrode body through the space between the other first end edge portion and the second exposed portion. Outflow and inflow of the water is suppressed. As described above, the electrolyte solution held in the second active material layer in the first flat plate portion is prevented from flowing out and flowing into the outside of the electrode body in the axial direction. Therefore, in this battery, it can suppress that the internal resistance of a battery increases when charging / discharging is performed repeatedly.

  On the other hand, among the one side edge portions of the separator, the second side edge portions on the one side are not joined at least in part in the longitudinal direction of the separator, and the axial direction is between the second side edge portions on the one side. Therefore, the electrolyte solution can move in the axial direction on one side of the second flat plate portion and the curved end portion through the gap. In addition, at least a part of the second side edge of the other side of the separator on the other side in the longitudinal direction is not joined to the second exposed part adjacent to the second side edge, and the second side edge of the other side is not joined. Since there is a gap in the axial direction between the second exposed portion and the second exposed portion, the electrolyte can move in the axial direction on the other side of the second flat plate portion and the curved end portion through this gap. For this reason, it can be set as the battery which impregnated the electrolyte solution in the electrode body (2nd active material layer) reliably.

  Moreover, another aspect is an assembled battery including a plurality of the batteries described above, and is interposed between the batteries adjacent to each other in the stacking direction of the first flat plate portion, and the first flat plate portion of the battery case. The plurality of spacers that contact the contacted portion positioned in the stacking direction, and the plurality of batteries and the spacers arranged in the stacking direction of the first flat plate portion are restrained while pressing in the stacking direction. And a restraining member.

  Since this assembled battery uses the above-described battery, it is possible to suppress an increase in the internal resistance of the battery when charging and discharging are repeated.

1 is a perspective view of a battery according to Embodiment 1. FIG. 1 is a longitudinal sectional view of a battery according to Embodiment 1. FIG. 4 is an exploded perspective view of the lid member, the positive electrode terminal member, the negative electrode terminal member, and the like according to the first embodiment. FIG. It is explanatory drawing of an electrode body in connection with Embodiment 1. FIG. 4 is a partial enlarged cross-sectional view of a portion including a flat plate portion of an electrode body according to Embodiment 1. FIG. FIG. 4 is a partial enlarged cross-sectional view of a portion including a curved end portion of an electrode body according to the first embodiment. 2 is a side view of the assembled battery according to Embodiment 1. FIG. FIG. 10 is an explanatory diagram of an electrode body according to the second embodiment. 6 is a side view of an assembled battery according to Embodiment 2. FIG. It is explanatory drawing of an electrode body in connection with the comparative example 1. It is explanatory drawing of an electrode body in connection with the comparative example 2. It is explanatory drawing of an electrode body in connection with the comparative example 3. It is a graph which shows charging / discharging cycle life about each battery which concerns on Examples 1, 2 and Comparative Examples 1-3. It is a graph which shows the impregnation completion time of electrolyte solution about each battery which concerns on Examples 1, 2 and Comparative Examples 1-3.

(Embodiment 1)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a battery 10 according to the first embodiment. FIG. 3 shows the lid member 23, the positive terminal member 60, the negative terminal member 70, and the like of the battery case 20. Moreover, the electrode body 30 is shown in FIGS. Hereinafter, the battery thickness direction BH, the battery lateral direction CH, and the battery vertical direction DH of the battery 10 will be described as the directions shown in FIGS. 1 and 2. The axial direction EH, the electrode body thickness direction FH, and the electrode body width direction GH of the electrode body 30 will be described as the directions shown in FIGS. 2 and 4 to 6.

  The battery 10 is a rectangular and sealed lithium ion secondary battery mounted on a vehicle such as a hybrid vehicle or an electric vehicle. The battery 10 includes a rectangular battery case 20, a flat wound electrode body 30 accommodated in the battery case 20, a positive terminal member 60 and a negative terminal member 70 supported by the battery case 20, and the like. It is composed of Further, a non-aqueous electrolyte solution 27 is held in the battery case 20.

  Among these, the battery case 20 is made of metal (specifically, aluminum). The battery case 20 includes a bottomed rectangular tube-shaped case body 21 having a rectangular opening 21h only on the upper side, and a rectangular plate-shaped lid member 23 that seals the opening 21h of the case body 21. (See FIGS. 1 to 3). In the lid member 23, a non-returnable safety valve 23v is provided near the center in the longitudinal direction (battery lateral direction CH). In addition, a liquid injection hole 23 h that is used when injecting the electrolyte solution 27 into the battery case 20 is provided in the vicinity of the safety valve 23 v and is hermetically sealed by the sealing member 25.

  Moreover, the positive electrode terminal member 60 and the negative electrode terminal member 70 of the form extended outside from the inside of the battery case 20 are each fixedly installed in the vicinity of the both ends of the longitudinal direction among the cover members 23 (FIG. 1). (See FIG. 3). Specifically, each of the positive electrode terminal member 60 and the negative electrode terminal member 70 is connected to the electrode body 30 in the battery case 20, and passes through the lid member 23 and extends to the outside of the battery case 20. The members 61 and 71 are composed of crank-shaped second terminal members 62 and 72 which are disposed on the lid member 23 and fixed to the first terminal members 61 and 71 by crimping. The positive electrode terminal member 60 and the negative electrode terminal member 70 are disposed inside the lid member 23 (inside the case) together with metal fastening members 65 and 75 for fastening connection terminals outside the battery, such as bus bars and crimp terminals. The first insulating members 67 and 77 made of resin and the second insulating members 68 and 78 made of resin disposed outside the case 23 (outside the case) are fixed to the cover member 23.

  Next, the electrode body 30 will be described (see FIGS. 2 and 4 to 6). The electrode body 30 is housed in the battery case 20 in a state of being laid down so that its axis (winding axis) AX is parallel to the battery lateral direction CH (see FIG. 2). This electrode body 30 is formed by laminating a belt-like positive electrode plate (first electrode plate) 31 and a belt-like negative electrode plate (second electrode plate) 41 through a pair of separators 51 and 51 made of a porous resin. Then, it is wound around the axis AX and compressed into a flat shape (see FIGS. 4 to 6).

The positive electrode plate 31 has a strip-like positive electrode foil (first electrode foil) 32 made of aluminum as a core material. On the front surface and the back surface of the positive electrode electrode foil 32, a part of the width direction (right and left direction in FIGS. 4 to 6) (a portion on the right side in FIGS. 4 to 6) is placed in the longitudinal direction (FIG. 5). And the porous positive electrode active material layer (1st active material layer) 33 and 33 extended in strip | belt shape in the direction orthogonal to a paper surface in FIG. 6 is formed. The positive electrode active material layer 33 is formed of positive electrode active material particles, a conductive material, and a binder. In Embodiment 1, lithium-cobalt-nickel-manganese composite oxide is used as the positive electrode active material particles. Acetylene black (AB) is used as the conductive material, and polyvinylidene fluoride (PVDF) is used as the binder.

  The negative electrode plate 41 has a strip-shaped negative electrode foil (second electrode foil) 42 made of copper as a core material. Of the front and back surfaces of the negative electrode foil 42, a longitudinal direction (FIG. 5) is provided on a part (left portion in FIGS. 4 to 6) in the width direction (the left-right direction in FIGS. 4 to 6). And the porous negative electrode active material layer (2nd active material layer) 43 and 43 extended in strip shape in the direction orthogonal to a paper surface in FIG. 6 is formed. The negative electrode active material layer 43 is formed of negative electrode active material particles, a binder, and a thickener. In the first embodiment, natural graphite is used as negative electrode active material particles, styrene butadiene rubber (SBR) is used as a binder, and carboxymethyl cellulose (CMC) is used as a thickener. Since the negative electrode active material particles (natural graphite particles) expand during the charging process and contract during the discharging process, the negative electrode active material layer 43 also expands during the charging process and contracts during the discharging process.

The positive electrode plate 31 has a positive electrode exposed portion (first exposed portion) 31r in which the positive electrode foil 32 is exposed in a strip shape on one side EC (leftward in FIGS. 2 and 4 to 6) in the axial direction EH. A part of the positive electrode exposed portion 31r protrudes from the separator 51 in a flat spiral shape toward the one side EC in the axial direction EH to form a positive electrode protruding wound portion 30c of the electrode body 30. The positive electrode exposed portion 31r is connected (welded) to the first terminal member 61 of the positive electrode terminal member 60 in the positive electrode protruding wound portion 30c.
Further, the negative electrode plate 41 has a negative electrode exposed portion (second exposed portion) 41r in which the negative electrode electrode foil 42 is exposed in a strip shape on the other side ED in the axial direction EH (rightward in FIGS. 2 and 4 to 6). . A part of the negative electrode exposed portion 41r protrudes in a flat spiral shape from the separator 51 toward the other side ED in the axial direction EH to form a negative electrode protruding wound portion 30d of the electrode body 30. The negative electrode exposed portion 41r is connected (welded) to the first terminal member 71 of the negative electrode terminal member 70 by the negative electrode protruding winding portion 30d.

  A portion located between the positive electrode protruding winding portion 30c and the negative electrode protruding winding portion 30d is a main body portion 30e of the electrode body 30 (see FIGS. 2 and 4 to 6). The main body 30e includes a central winding portion 30h, a one-side winding portion 30f located on one side EC in the axial direction EH of the central winding portion 30h, and the other side in the axial direction EH of the central winding portion 30h. It has the other side winding part 30g located in ED. Among these, the center winding part 30 h is a part where the positive electrode active material layer 33 and the negative electrode active material layer 43 overlap in the stacking direction JH with the separators 51, 51 interposed therebetween.

Further, the one-side wound part 30f and the positive electrode exposed part 31r of the positive electrode plate 31 and the one side edge part 51f of the separator 51 (positioned on one side EC of the separator 51 and overlap with the positive electrode exposed part 31r in the stacking direction JH). Part) is a part overlapping the stacking direction JH.
Further, the other side winding part 30g and the negative electrode exposed part 41r of the negative electrode plate 41 and the other side edge part 51g of the separator 51 (located on the other side ED of the separator 51 and overlap with the negative electrode exposed part 41r in the stacking direction JH). Part) is a part overlapping the stacking direction JH.

  Further, the center winding portion 30h includes a first curved end portion 30k, a second curved end portion 30m, and a flat plate portion 30n when viewed in the electrode body width direction GH (see FIGS. 2 and 4). Among these, the one side curved end portion 30k is located on one side GA (upward in FIGS. 2 and 4) in the electrode body width direction GH, and the positive electrode active material layer 33, the negative electrode active material layer 43, and the separator 51 are semicylindrical. It is a part which is bent into a shape and overlaps each other. The other side curved end 30m is located on the other side GB (lower side in FIGS. 2 and 4) in the electrode body width direction GH, and the positive electrode active material layer 33, the negative electrode active material layer 43, and the separator 51 are semicylindrical. It is a part which is bent into a shape and overlaps each other.

  The flat plate portion 30n is located between the one-side curved end portion 30k and the other-side curved end portion 30m, and the positive electrode active material layer 33, the negative electrode active material layer 43, and the separator 51 overlap each other in a flat plate shape. . In the first embodiment, the entire flat plate portion 30n is a central compressed portion that is compressed in the stacking direction JH (electrode body thickness direction FH) when the battery 10 is used, as will be described later.

Next, the separator 51 will be further described (see FIGS. 2 and 4 to 6). Of the one-side edge 51f of the separator 51 located in the one-side wound portion 30f, a portion located on the one-side EC in the axial direction EH of the flat plate portion (center compressed portion) 30n is designated as one-side first end. The other portion, that is, the portion located on the one side EC in the axial direction EH of the one-side curved end portion 30k and the other-side curved end portion 30m is defined as the one-side second end edge portion 51f2. .
Moreover, the part located in the other side ED of the axial direction EH of the flat plate part 30n among the other side edge part 51g of the separator 51 located in the other side winding part 30g is set as the other side first edge part 51g1. Other parts, that is, parts located on the other side ED in the axial direction EH of the one-side curved end part 30k and the other-side curved end part 30m are referred to as the other-side second end edge part 51g2.

  In this battery 10, one of the separators 51, 51, the first side edge portions 51 f 1 on the one side facing each other, are separated by a double-sided adhesive tape 53 made of polyimide in the longitudinal direction KH of the separator 51 (in FIG. 5, orthogonal to the paper surface). Are joined together as a whole, and surround the end edge 41f of the one side EC in the axial direction EH of the negative electrode plate 41 (see FIGS. 4 and 5). On the other hand, the second end edges 51f2 on the one side facing each other are not joined at all the sites in the longitudinal direction KH (around the axis AX), but form a gap SK1 that leads to the axis EH between them. (See FIG. 4 and FIG. 6).

  Further, of the separators 51 and 51, the other first side edge portions 51g1 adjacent to each other through the negative electrode exposed portion 41r of the negative electrode plate 41 are connected to the adjacent negative electrode exposed portion 41r by the double-sided adhesive tape 53. Each is joined to the whole over the longitudinal direction KH (refer FIG.4 and FIG.5). On the other hand, the other second end edge portions 51g2 adjacent to each other through the negative electrode exposed portion 41r are not joined to the adjacent negative electrode exposed portion 41r in all the portions in the longitudinal direction KH (around the axis AX), A gap SK2 leading to the axial direction EH is formed between the second side edge 51g2 and the negative electrode exposed portion 41r (see FIGS. 4 and 6).

  As described above, in the battery 10, the first first edge portions 51 f 1 of the one side edge portions 51 f of the separator 51 are joined to each other over the longitudinal direction KH of the separator 51, and the negative electrode plate 41. The edge 41f of the axial direction EH one side EC is enclosed. For this reason, when charging / discharging is performed, the electrolyte solution 27 held in the negative electrode active material layer 43 in the flat plate portion (center compressed portion) 30n is an electrode that passes between the first side edge portions 51f1 on one side. Outflow / inflow to the outside of the body 30 is suppressed. Further, in the battery 10, the other first end edge portion 51g1 of the other end edge portion 51g of the separator 51 is joined to the negative electrode exposed portion 41r adjacent thereto over the longitudinal direction KH of the separator 51 respectively. Yes. For this reason, when the charge / discharge is performed, the electrolyte solution 27 held in the negative electrode active material layer 43 in the flat plate portion 30n passes through the gap between the other first side edge portion 51g1 and the negative electrode exposed portion 41r. 30 Outflow / inflow to the outside is suppressed. In this way, the electrolyte solution 27 held in the negative electrode active material layer 43 in the flat plate portion 30n that is compressed during use is suppressed from flowing out / inflowing outside the electrode body 30 in the axial direction EH. Therefore, in this battery 10, it is possible to suppress an increase in the internal resistance of the battery 10 when charging and discharging are repeated.

  On the other hand, among the one side edge portions 51f of the separator 51, the second side edge portions 51f2 on the one side are not joined at least at a part (all portions in the first embodiment) in the longitudinal direction KH of the separator 51. In addition, a gap SK1 leading to the axial direction EH is provided between the first second end edges 51f2. For this reason, the electrolyte solution 27 can move in the axial direction EH on the one side EC of the one side curved end portion 30k and the other side curved end portion 30m through the gap SK1 between the one side second end edge portions 51f2. Also, the negative electrode exposed portion in which at least a part of the second side edge portion 51g2 of the other side edge portion 51g2 of the separator 51 in the other side edge portion 51g2 (all portions in the first embodiment) is adjacent thereto. There is a gap SK2 that communicates in the axial direction EH between the second end edge portion 51g2 on the other side and the negative electrode exposed portion 41r without being joined to 41r. Therefore, the electrolyte solution 27 can move in the axial direction EH at the other side ED of the one side curved end 30k and the other side curved end 30m through the gap SK2 between the other second end edge 51g2 and the negative electrode exposed portion 41r. . Therefore, the battery 10 in which the electrolytic solution 27 is reliably impregnated in the electrode body 30 (in the negative electrode active material layer 43) can be obtained.

  Next, a method for manufacturing the battery 10 will be described. First, the electrode body 30 is formed. That is, a positive electrode plate 31, a negative electrode plate 41, and a pair of separators 51, 51 are prepared, the positive electrode plate 31 and the negative electrode plate 41 are overlapped with each other via the separators 51, 51, and are wound around the axis AX using a winding core. Turn. At that time, using the double-sided adhesive tape 53, the separators 51, 51 are joined to each other and become the first side edge portion 51f1 adjacent to each other, and the negative electrode exposed portion 41r of the negative electrode plate 41 is interposed therebetween. Next, the adjacent first side edge portions 51g1 are joined to the adjacent negative electrode exposed portion 41r. Thereafter, this is compressed into a flat shape to form the electrode body 30 (see FIG. 4).

  Separately, the lid member 23, the first terminal members 61 and 71, the second terminal members 62 and 72, the fastening members 65 and 75, the first insulating members 67 and 77, and the second insulating members 68 and 78, Prepare each. And using these, the positive electrode terminal member 60 and the negative electrode terminal member 70 are respectively fixed to the lid member 23 (see FIG. 3). Thereafter, the positive electrode terminal member 60 and the negative electrode terminal member 70 are welded to the electrode body 30.

  Next, after preparing the case main body 21 and accommodating the electrode body 30 in the case main body 21, the case main body 21 and the lid member 23 are welded to form the battery case 20 (see FIGS. 1 and 2). Thereafter, the electrolytic solution 27 is injected into the battery case 20 from the injection hole 23 h, and the electrolytic solution 27 is impregnated in the electrode body 30. At that time, as described above, the electrolyte solution 27 is disposed in the axial direction EH through the gap SK1 between the first side second edge portions 51f2 and the gap SK2 between the second side second edge portion 51g2 and the negative electrode exposed portion 41r. Since it can move, the negative electrode active material layer 43 can be impregnated quickly and reliably with the electrolytic solution 27. Thereafter, the liquid injection hole 23 h is hermetically sealed with the sealing member 25. Thereafter, the battery is subjected to initial charging and various inspections. Thus, the battery 10 is completed.

  Next, an assembled battery 100 using the battery 10 will be described (see FIG. 7). The assembled battery 100 includes a plurality of batteries 10 arranged in a row, a plurality of spacers 130 interposed between adjacent batteries 10, and a restraining member 110 that restrains the batteries 10 and the spacers 130 while pressing them. Prepare. In FIG. 7, the description of the positive electrode terminal member 60 and the negative electrode terminal member 70 of the battery 10 is omitted.

The plurality of batteries 10 are arranged in the battery thickness direction BH (electrode body thickness direction FH, stacking direction JH of the flat plate portion 30n) via spacers 130, and adjacent batteries 10 are connected to each other by a bus bar (not shown). They are electrically connected in series.
The spacer 130 has a rectangular plate shape slightly smaller than the case wide side surface 20c of the battery case 20, and is formed of resin. The spacer 130 corresponds to an area including the rectangular contacted portion 20t (see FIG. 1) located in the stacking direction JH of the flat plate portion (center compressed portion) 30n in the case wide side surface 20c of the battery case 20. It touches.
The alternately arranged batteries 10 and spacers 130 are restrained by the restraining member 110 while being pressed and compressed in the battery thickness direction BH. Thereby, the flat plate part 30n of the electrode body 30 accommodated in the battery 10 is also compressed in the electrode body thickness direction FH (lamination direction JH of the flat plate part 30n).

  The restraining member 110 has a pair of end plates 111, four restraining bands 113, and eight fastening bolts 115. The end plate 111 has a rectangular plate shape and is disposed on both sides of the batteries 10 and the spacers 130 arranged in a row. The restraint band 113 has a cylindrical shape and is disposed between the pair of end plates 111 to connect the end plates 111 to each other. The fastening bolt 115 is inserted through a through hole (not shown) provided in the end plate 111, and fastens the end 113 t of the restraining band 113 to the end plate 111.

  Since this assembled battery 100 uses the battery 10 described above, it is possible to suppress an increase in the internal resistance of the battery 10 when charging and discharging are repeated.

(Embodiment 2)
Next, a second embodiment will be described. The battery 210 according to the second embodiment is different from the electrode body 30 of the battery 10 according to the first embodiment in the form of the electrode body 230 (see FIG. 8). 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 electrode body 230 according to the second embodiment is wound in a flat shape using the positive electrode plate 31, the negative electrode plate 41, and the separator 51 that are the same as those of the first embodiment. The joining form of the separator 51 and the negative electrode exposed part 41r of the negative electrode plate 41 is different from that of the first embodiment.
Specifically, in the same manner as in the first embodiment, the electrode body 230 includes a positive electrode protruding winding portion 230c in which the positive electrode exposed portion 31r forms a flat spiral shape and a negative electrode protruding winding in which the negative electrode exposed portion 41r forms a flat spiral shape. It consists of a part 230d and a main body part 230e located between them. Among these, the main body portion 230e includes the central winding portion 230h, the one side winding portion 230f located on one side EC in the axial direction EH thereof, and the axial direction EH of the central winding portion 230h, as in the first embodiment. And the other side winding part 230g located on the other side ED. Further, the central winding portion 230h is divided into two curved end portions (one curved end portion 230k and the other curved end portion 230m) and a flat plate portion 230n positioned between them as in the first embodiment. .

  Of these, the flat plate portion 230n extends in the axial direction EH, and is striped and alternately present in the electrode body width direction GH (the direction connecting the curved end portions 230k and 230m), and the five virtual first flat plate portions 230n1 and four It is divided into a second flat plate portion 230n2. Among these, as will be described later, the first flat plate portion 230n1 is a central compressed portion (stretched central compressed portion) that is compressed in the stacking direction JH (electrode body thickness direction FH) when the battery 10 is used. is there.

Of the one side edge portion 51f of the separator 51 located in the one side winding portion 230f, a portion located on the one side EC in the axial direction EH of each first flat plate portion (stretched central compressed portion) 230n1, Each of the first side edge portions 51f3 is one side, and the other portion, that is, a portion located on one side EC in the axial direction EH of the second flat plate portion 230n2, the one side curved end portion 230k or the other side curved end portion 230m. , Respectively, are referred to as one side second end edge portion 51f4.
Moreover, the part located in the other side ED of the axial direction EH of each 1st flat plate part 230n1 among the other side edge parts 51g of the separator 51 located in the other side winding part 230g, respectively is the other side 1st. The other edge, that is, the second flat plate portion 230n2, the one-side curved end portion 230k or the other-side curved end portion 230m, which is located on the other side ED in the axial direction EH, is defined as the end edge portion 51g3. Let it be 2 edge part 51g4.

  In this battery 210, the first side edge portions 51 f 3 on one side of the separators 51, 51 that are adjacent to each other are joined to each other in the longitudinal direction KH of the separator 51 by the double-sided adhesive tape 55. 41, the edge 41f of the axial direction EH one side EC of 41 is enclosed (refer FIG.8 and FIG.5). On the other hand, the one-side second end edge portions 51f4 that face each other and are adjacent to each other are not joined at all the portions in the longitudinal direction KH (around the axis line AX), but form a gap SK1 that leads to the axial direction EH between them. (See FIGS. 8 and 6).

  Further, of the separators 51 and 51, the other first end edge portions 51g3 adjacent to each other through the negative electrode exposed portion 41r of the negative electrode plate 41 are connected to the adjacent negative electrode exposed portion 41r by the double-sided adhesive tape 55. They are joined to each other over the longitudinal direction KH (see FIGS. 8 and 5). On the other hand, the other second end edge portions 51g4 adjacent to each other via the negative electrode exposed portion 41r are not joined to the adjacent negative electrode exposed portion 41r in all the portions in the longitudinal direction KH (around the axis line AX). A gap SK2 that communicates in the axial direction EH is formed between the second side edge 51g4 and the negative electrode exposed portion 41r (see FIGS. 8 and 6).

  As described above, in the battery 210 of the second embodiment, the first side edge portions 51f3 on the one side among the one side edge portions 51f of the separator 51 are joined together over the longitudinal direction KH of the separator 51, and the negative electrode plate 41 is joined. The edge 41f of one side EC of the axial direction EH is surrounded. For this reason, when charging / discharging is performed, the electrolyte solution 27 held in the negative electrode active material layer 43 in the first flat plate portion (center compressed portion) 230n1 passes between the first side first edge portions 51f3. In addition, outflow / inflow to the outside of the electrode body 230 is suppressed. Further, in the battery 210, the other first end edge 51g3 of the other end edge 51g of the separator 51 is joined to the negative electrode exposed part 41r adjacent thereto over the longitudinal direction KH of the separator 51 as a whole. Yes. For this reason, when the charging / discharging is performed, the electrolyte solution 27 held in the negative electrode active material layer 43 in the first flat plate portion 230n1 passes between the first edge portion 51g3 on the other side and the negative electrode exposed portion 41r. Outflow / inflow to the outside of the electrode body 230 is suppressed. In this way, the electrolyte solution 27 held in the negative electrode active material layer 43 in the first flat plate portion 230n1 that is compressed during use is suppressed from flowing out / inflowing outside the electrode body 230 in the axial direction EH. Therefore, in this battery 210, it is possible to suppress an increase in the internal resistance of the battery 210 when charging and discharging are repeated.

  On the other hand, among the one side edge portions 51f of the separator 51, the second side edge portions 51f4 on the one side are not joined at least at a part of the longitudinal direction KH of the separator 51 (all portions in the second embodiment). In addition, a gap SK1 leading to the axial direction EH is provided between the first second end edges 51f4. For this reason, the electrolyte solution 27 moves in the axial direction EH on the one side EC of the second flat plate portion 230n2, the one side curved end portion 230k, and the other side curved end portion 230m through the gap SK1 between the one side second edge portions 51f4. it can. Also, the negative electrode exposed portion in which at least a part of the second side edge portion 51g4 of the other side edge portion 51g4 of the separator 51 in the longitudinal direction KH (all portions in the first embodiment) is adjacent thereto. There is a gap SK2 that communicates in the axial direction EH between the second end edge portion 51g2 on the other side and the negative electrode exposed portion 41r without being joined to 41r. For this reason, in the axial direction EH at the other side ED of the second flat plate portion 230n2, the one side curved end portion 230k, and the other side curved end portion 230m through the gap SK2 between the other side second end edge portion 51g4 and the negative electrode exposed portion 41r. The electrolytic solution 27 can move. Therefore, the battery 210 in which the electrolytic solution 27 is reliably impregnated in the electrode body 230 (in the negative electrode active material layer 43) can be obtained.

Next, an assembled battery 300 using the battery 210 will be described (see FIG. 9). The assembled battery 300 includes a plurality of batteries 210, a plurality of spacers 330, and a restraining member 110. Among these, the restraining member 110 is the same as that of the first embodiment.
On the other hand, the spacer 330 is different in form from the spacer 130 according to the first embodiment. Specifically, the spacer 330 has a rectangular plate-like plate-like portion 331 and a plurality of convex portions 333 protruding from the plate-like portion 331, and the cross section has a comb-tooth shape.

  In the spacer 330, the plate-shaped portion 331 is in contact with one battery 210 of the adjacent batteries 210, and each convex portion 333 is in contact with the other battery 210. Specifically, each convex portion 333 is a belt-shaped contacted portion 20u located in the stacking direction JH of the first flat plate portion (central compressed portion) 230n1 in the case wide side surface 20c of the battery case 20 (FIG. 1). Contact). Since the batteries 210 and the spacers 330 arranged in a row are pressed and compressed in the battery thickness direction BH by the restraining member 110, the first flat plate portion 230n1 of the electrode body 230 accommodated in the battery 210 is also in the electrode body thickness direction. Compressed to FH (stacking direction JH of first flat plate portion 230n1). In addition, a plurality of cooling paths RK through which a cooling medium flows is formed between the spacer 330 and the battery 210 by the contact of each convex portion 333 with the battery case 20.

  Since this assembled battery 300 uses the battery 210 described above, it is possible to suppress an increase in the internal resistance of the battery 210 when charging and discharging are repeated.

(Examples and Comparative Examples)
Next, the results of tests performed to verify the effects of the batteries 10 and 210 according to the first and second embodiments will be described. As Example 1, a battery 10 according to Embodiment 1 and an assembled battery 100 using the same were prepared. In the battery 10, as described above, of the one side edge portions 51 f of the separator 51, the first side edge portions 51 f 1 on the one side are joined together over the longitudinal direction KH of the separator 51, and While surrounding the edge 41f of the side EC, the first second edge portions 51f2 are not joined to each other in the longitudinal direction KH. Of the other side edge 51g of the separator 51, the other side first edge 51g1 is joined to the negative electrode exposed part 41r adjacent thereto across the longitudinal direction KH, while the other side second edge The part 51g2 is not joined to the negative electrode exposed part 41r adjacent to all the parts in the longitudinal direction KH.

  As Example 2, a battery 210 according to Embodiment 2 and an assembled battery 300 using the battery 210 were prepared. In the battery 210, as described above, the first side edge portions 51f3 of the one side of the one side edge portion 51f of the separator 51 are joined together over the longitudinal direction KH of the separator 51, and While surrounding the edge 41f of the side EC, the one-side second end edge portions 51f4 are not joined to each other in the longitudinal direction KH. Of the other side edge 51g of the separator 51, the other side first edge 51g3 is joined to the negative electrode exposed part 41r adjacent thereto over the entire longitudinal direction KH, while the other side second edge The part 51g4 is not joined to the adjacent negative electrode exposed part 41r at all the sites in the longitudinal direction KH.

  On the other hand, as Comparative Example 1, a battery having the electrode body 730 shown in FIG. 10 and an assembled battery using the battery were prepared. In the battery electrode body 730, the one side edge portions 51 f of the separator 51 are not joined to each other in the longitudinal direction KH of the separator 51. Further, the other edge 51g of the separator 51 is not joined to the negative electrode exposed portion 41r adjacent to the separator 51 in all the portions of the separator 51 in the longitudinal direction KH. Other than that was the same as the battery 10 and the assembled battery 100 of Example 1 (Embodiment 1).

  Moreover, as Comparative Example 2, a battery having the electrode body 830 shown in FIG. 11 and an assembled battery using the battery were prepared. In the battery electrode body 830, the one end edge portions 51 f of the separator 51 are joined to each other in the longitudinal direction KH of the separator 51 using the double-sided adhesive tape 57. Moreover, about the other side edge part 51g of the separator 51, all the parts of the longitudinal direction KH of the separator 51 are joined to the negative electrode exposed part 41r adjacent to this using the double-sided adhesive tape 57. Other than that was the same as the battery 10 and the assembled battery 100 of Example 1.

  Further, as Comparative Example 3, a battery having the electrode body 930 shown in FIG. 12 and an assembled battery using the battery were prepared. In the battery electrode body 930, only a part of the portion located on the one side EC of the flat plate portion (center compressed portion) is not joined between the one side edge portions 51 f of the separator 51, and The parts in the longitudinal direction KH are joined together using a double-sided adhesive tape 59. On the other hand, with respect to the other side edge 51g of the separator 51, all the parts in the longitudinal direction KH of the separator 51 are joined to the negative electrode exposed part 41r adjacent thereto using a double-sided adhesive tape 59. Other than that was the same as the battery 10 and the assembled battery 100 of Example 1.

  Next, for each of the assembled batteries of Examples 1 and 2 and Comparative Examples 1 to 3, a “charge / discharge cycle test” was performed to investigate the charge / discharge cycle life. Specifically, each battery was first charged to SOC 60%. Then, at an environmental temperature of 25 ° C., each battery was discharged at 30 C for 10 seconds and then rested for 10 seconds. Thereafter, the battery was charged at 7.5C for 40 seconds and then rested for 10 seconds. This charging / discharging was made into 1 cycle, and charging / discharging was repeated until the battery voltage at the time of 30C discharge reached 2.0V. And the number of cycles required until the battery voltage at the time of 30 C discharge reached 2.0 V was defined as the charge / discharge cycle life. The results are shown graphically in FIG. In addition, in FIG. 13, the charging / discharging cycle life of each battery is shown on the basis of the charging / discharging cycle life of the battery of Comparative Example 1 (100%).

  As can be seen from FIG. 13, the batteries of Examples 1 and 2 and Comparative Example 2 had a longer charge / discharge cycle life than the battery of Comparative Example 1. In particular, the batteries of Example 1 and Comparative Example 2 have a long charge / discharge cycle life. On the other hand, the battery of Comparative Example 3 had a shorter charge / discharge cycle life than the battery of Example 1.

  The reason is considered as follows. In the batteries of Examples 1 and 2 and Comparative Example 2, at least one portion of the one side edge portion 51f of the separator 51 located on one side EC of the central compressed portion of the electrode body (one side first edge portion). , The separators 51 are joined together over the longitudinal direction KH. Further, in the other side edge 51g of the separator 51, at least at a portion (the other side first edge) of the center compressed portion of the electrode body located on the other side ED, the separator 51 is the negative electrode 41 (negative electrode exposed). Part 41r) is joined entirely over the longitudinal direction KH. For this reason, the electrolyte solution 27 held in the negative electrode active material layer 43 in the central compressed part that is compressed during charging and discharging is suppressed from flowing out and flowing into the outside of the electrode body in the axial direction EH. Thereby, it can be considered that when the charge / discharge cycle test is performed, the increase in the internal resistance of the battery can be suppressed, and the charge / discharge cycle life is prolonged.

The reason why the battery of Example 2 has a shorter charge / discharge cycle life than the batteries of Example 1 and Comparative Example 2 is that the battery of Example 2 is more electrolyte solution than the battery of Example 1 and Comparative Example 2. This is because 27 cannot be held in the electrode body 230.
In addition, the reason why the battery of Comparative Example 3 has a shorter charge / discharge cycle life than the battery of Example 1 is because there is a portion where the separator is not joined despite the central compressed portion. This is because the liquid retention is reduced as compared with the battery.

  Next, for each of the batteries of Examples 1 and 2 and Comparative Examples 1 to 3, the impregnation from the time when the electrolytic solution 27 was injected into the battery case 20 until the impregnation into the electrode body was completed at the time of battery production. The completion time was investigated. Whether or not the impregnation into the electrode body has been completed is determined by disassembling the battery that has passed a predetermined time from the injection, and by positive electrode plate 31 (positive electrode active material layer 33) and negative electrode plate 41 (negative electrode active material layer 43). Judgment was made based on whether or not the whole was wet with the electrolyte solution 27. The results are shown graphically in FIG. In FIG. 14, the impregnation completion time of each battery is shown with the impregnation completion time of the battery of Comparative Example 2 as a reference (100%).

As can be seen from FIG. 14, the battery of Comparative Example 1 has the shortest time for impregnation with the electrolyte, and in the order of the battery of Example 2, the battery of Example 1, the battery of Comparative Example 3, and the battery of Comparative Example 2, The time for completion of impregnation with electrolyte was increased.
The reason is considered as follows. That is, in the battery of Comparative Example 1, the one side edge portions 51f of the separator 51 are not joined to each other in the longitudinal direction KH of the separator 51, and the other side edge portion 51g is separated from the separator 51. Are not joined to the adjacent negative electrode exposed portion 41r at all the sites in the longitudinal direction KH. For this reason, since the electrolytic solution 27 can move in the axial direction EH at all sites around the axial line AX of the electrode body, it is considered that the impregnation of the electrolytic solution 27 is completed in the shortest time.

  On the other hand, in each battery of Example 1 and Comparative Examples 2 and 3, one side edge portions 51f of the separator 51 are joined in part or all of the longitudinal direction KH of the separator 51, and the other side end. The edge portion 51g is joined to the negative electrode exposed portion 41r adjacent in part or all of the longitudinal direction KH of the separator 51. For this reason, since the movement of the electrolytic solution 27 in the axial direction EH is suppressed partly around the axis AX of the electrode body, it is considered that the completion time of impregnation of the electrolytic solution 27 is longer than that of the battery of Comparative Example 1. In addition, in the order of Example 2, Example 1, Comparative Example 3, and Comparative Example 2, the number of bonding sites between the separators 51 or the bonding site between the separator 51 and the negative electrode exposed portion 41r increases. It is considered that the movement time of 27 in the axial direction EH is suppressed, and the impregnation completion time of the electrolyte solution 27 is extended.

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 and second 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 the first and second embodiments, the first side second edge portions 51f2 and 51f4 of the separator 51 are not joined at all in the longitudinal direction KH of the separator 51. However, the first side second edge portions 51f2 and 51f4 are not illustrated. You may join each other in the part. Moreover, in Embodiment 1, 2, the case where the whole (all site | parts) of the said longitudinal direction KH of the other side 2nd edge part 51g2, 51g4 of the separator 51 was not joined to the adjacent negative electrode exposed part 41r was illustrated. However, you may join a part of other side 2nd edge 51g2, 51g4 to the negative electrode exposed part 41r which adjoins. However, even in these cases, the wider the portion that is not joined, the easier the electrolytic solution 27 moves in the axial direction EH, so that the electrolytic solution 27 can be more reliably impregnated in the electrode body during battery manufacture.

  Further, in the first and second embodiments, the case where the battery case 20 is compressed by the battery case 20 by pressing the battery case 20 from the outside in the stacking direction JH of the middle parts 30n and 230n1 is exemplified. However, it is not limited to this. For example, a spacer may be disposed inside the battery case, and the central compressed parts 30n and 230n1 may be compressed via the spacer. Alternatively, the central compressed parts 30n and 230n1 can be compressed directly or via a spacer disposed inside the battery case due to the elasticity of the battery case itself.

In the first and second embodiments, the separators 51 (the first side first edge portions 51f1 and 51f3) are joined to each other using the double-sided adhesive tapes 53 and 55, but the present invention is not limited to this. For example, the separators 51 may be joined by heat welding or ultrasonic welding, or the separators 51 may be joined using an adhesive.
In the first and second embodiments, the separator 51 (the other side first edge portion 51g1, 51g3) is joined to the negative electrode exposed portion 41r of the negative electrode plate 41 using the double-sided adhesive tapes 53, 55. Not limited. For example, the separator 51 may be bonded to the negative electrode exposed portion 41r using an adhesive.

10, 210 Battery 20 Battery case 20t, 20u Contacted portion 27 Electrolyte 30, 230 Electrode body 30c, 230c Positive electrode winding portion 30d, 230d Negative electrode protruding winding portion 30e, 230e Main body portion 30f, 230f One side winding Parts 30g, 230g other side winding part 30h, 230h central winding part 30k, 230k one side curved end part 30m, 230m other side curved end part 30n flat plate part (central compressed part)
230n flat plate portion 230n1 first flat plate portion (central compressed portion, extended central compressed portion)
230n2 2nd flat plate part 31 Positive electrode plate (1st electrode plate)
31r Positive electrode exposed portion (first exposed portion)
32 Positive electrode foil (first electrode foil)
33 Positive electrode active material layer (first active material layer)
41 Negative electrode plate (second electrode plate)
41f End edge 41r (one side of the negative electrode plate in the axial direction) negative electrode exposed portion (second exposed portion)
42 Negative electrode foil (second electrode foil)
43 Negative electrode active material layer (second active material layer)
51 Separator 51f One side edge 51f1, 51f3 One side first edge 51f2, 51f4 One side second edge 51g The other side edge 51g1, 51g3 The other side first edge 51g2, 51g4 The other side first 2 edge portions 53, 55 double-sided adhesive tape 100, 300 battery pack 110 restraining member 130, 330 spacer AX axis (winding axis)
EH Axial direction EC (Axial direction) One side ED (Axial direction) Other side FH Electrode body thickness direction GH Electrode body width direction JH Laminating direction KH (Separator) longitudinal direction SK1, SK2 Gap

Claims (8)

A strip-shaped first electrode plate having a first active material layer on the first electrode foil, and a strip-shaped second electrode having a porous second active material layer that expands and contracts with charge / discharge on the second electrode foil. The first electrode plate is formed in a strip shape on one side in the axial direction along the axis. The first electrode plate is laminated in a flat shape around the axis. An electrode body having a second exposed portion where the second electrode foil is exposed in a strip shape on the other side in the axial direction;
A battery case for housing the electrode body,
The electrode body is a battery having a central winding portion in which the first active material layer and the second active material layer overlap in the stacking direction via the separator,
Of the central winding portion, a portion compressed in the stacking direction when the battery is used is a central compressed portion,
Of the one side edge portion of the separator that overlaps the first exposed portion in the stacking direction, a portion located on the one side of the central compressed portion is defined as a first side first edge portion, and the other portion Is the second edge on one side,
Of the separator, the other side edge that overlaps with the second exposed part in the stacking direction is a part located on the other side of the central compressed part as the other side first edge part, and the other part Is the second edge on the other side,
There is a gap in the axial direction between the one side second end portions, and the one side first end portions are joined together over the longitudinal direction of the separator, and the second electrode plate Surrounding one side edge,
There is a gap communicating in the axial direction between the second edge portion on the other side and the second exposed portion adjacent to the second exposed portion, and the second exposed portion adjacent to the first edge portion on the other side has the gap Batteries formed by joining the whole in the longitudinal direction. The battery according to claim 1,
The central winding part is
Two curved ends where the first active material layer, the second active material layer and the separator are bent into a semi-cylindrical shape and overlap each other;
The first active material layer, the second active material layer, and the separator are located between the curved ends, and have a flat plate portion that overlaps with each other in a flat plate shape,
The central compressed portion is a battery that is the entire flat plate portion. The battery according to claim 1,
The central winding part is
Two curved ends where the first active material layer, the second active material layer and the separator are bent into a semi-cylindrical shape and overlap each other;
The first active material layer, the second active material layer, and the separator are located between the curved ends, and have a flat plate portion that overlaps with each other in a flat plate shape,
The central compressed portion is a battery including a plurality of extended central compressed portions that are located in the flat plate portion and extend in the axial direction. An assembled battery comprising a plurality of the batteries according to any one of claims 1 to 3,
A plurality of spacers interposed between the batteries adjacent to each other in the stacking direction of the central compressed portion, and abutting against the contacted portion located in the stacking direction of the central compressed portion of the battery case;
An assembled battery comprising: a plurality of the batteries arranged in the stacking direction of the central compressed portion; and a restraining member that restrains the spacer while pressing the spacers in the stacking direction. A strip-shaped first electrode plate having a first active material layer on the first electrode foil, and a strip-shaped second electrode having a porous second active material layer that expands and contracts with charge / discharge on the second electrode foil. The first electrode plate is formed in a strip shape on one side in the axial direction along the axis. The first electrode plate is laminated in a flat shape around the axis. An electrode body having a second exposed portion where the second electrode foil is exposed in a strip shape on the other side in the axial direction;
A battery case for housing the electrode body,
The electrode body has a central winding portion in which the first active material layer and the second active material layer overlap in the stacking direction via the separator,
The central winding part is
Two curved ends where the first active material layer, the second active material layer and the separator are bent into a semi-cylindrical shape and overlap each other;
A battery having a flat plate portion that is located between the curved end portions, and the first active material layer, the second active material layer, and the separator overlap each other in a flat plate shape,
Of the one side edge that overlaps the first exposed portion and the stacking direction of the separator, a portion located on the one side of the flat plate portion is defined as one side first edge, and the curved end portion The part located on one side is the one side second edge,
Of the separator, the portion located on the other side of the flat plate portion of the other side edge portion overlapping the second exposed portion in the stacking direction is set as the other side first edge portion, and the curved end portion When the portion located on the other side is the other side second edge,
There is a gap in the axial direction between the one side second end portions, and the one side first end portions are joined together over the longitudinal direction of the separator, and the second electrode plate Surrounding one side edge,
There is a gap communicating in the axial direction between the second edge portion on the other side and the second exposed portion adjacent to the second exposed portion, and the second exposed portion adjacent to the first edge portion on the other side has the gap Batteries formed by joining the whole in the longitudinal direction. An assembled battery comprising a plurality of the batteries according to claim 5,
A plurality of spacers that are interposed between the batteries adjacent to each other in the stacking direction of the flat plate portion, and are in contact with a contacted portion of the battery case located in the stacking direction of the flat plate portion;
An assembled battery comprising: a plurality of the batteries arranged in the stacking direction of the flat plate portion; and a restraining member that restrains the spacers while pressing the spacers in the stacking direction. A strip-shaped first electrode plate having a first active material layer on the first electrode foil, and a strip-shaped second electrode having a porous second active material layer that expands and contracts with charge / discharge on the second electrode foil. The first electrode plate is formed in a strip shape on one side in the axial direction along the axis. An electrode body having a second exposed portion where the second electrode foil is exposed in a strip shape on the other side in the axial direction;
A battery case for housing the electrode body,
The electrode body has a central winding portion in which the first active material layer and the second active material layer overlap in the stacking direction via the separator,
The central winding part is
Two curved ends where the first active material layer, the second active material layer and the separator are bent into a semi-cylindrical shape and overlap each other;
A battery having a flat plate portion that is located between the curved end portions, and the first active material layer, the second active material layer, and the separator overlap each other in a flat plate shape,
The flat plate portion is divided into virtual first flat plate portions and second flat plate portions that extend alternately in a direction extending in the axial direction and connecting the curved end portions,
Of the separator, one of the side edges that overlap the first exposed portion in the stacking direction is a portion located on the one side of the first flat plate portion as a first side first edge portion, and the second flat plate. Or a portion located on the one side of the curved end portion as one side second end portion,
Of the separator, the portion located on the other side of the first flat plate portion of the other end edge portion overlapping the second exposed portion in the stacking direction is set as the other first end edge portion, and the second flat plate When the portion located on the other side of the curved portion or the curved end is the other side second edge,
There is a gap in the axial direction between the one side second end portions, and the one side first end portions are joined together over the longitudinal direction of the separator, and the second electrode plate Surrounding one side edge,
There is a gap communicating in the axial direction between the second edge portion on the other side and the second exposed portion adjacent to the second exposed portion, and the second exposed portion adjacent to the first edge portion on the other side has the gap Batteries formed by joining the whole in the longitudinal direction. An assembled battery comprising a plurality of the batteries according to claim 7,
A plurality of spacers interposed between the batteries adjacent to each other in the stacking direction of the first flat plate portion, and abutting against a contacted portion located in the stacking direction of the first flat plate portion in the battery case;
An assembled battery comprising: a plurality of the batteries arranged in the stacking direction of the first flat plate portion; and a restraining member that restrains the spacers while pressing the spacers in the stacking direction.

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