JP6737577B2 - Battery pack - Google Patents

Description

The present invention relates to an assembled battery.

In recent years, secondary batteries and fuel cells have been mainly developed from the viewpoint of environmental protection and fuel efficiency in the automobile industry. Since the output of each secondary battery is not so large, a desired number of stacked secondary batteries are formed into an assembled battery in order to allow the vehicle to travel. As a conventional technique relating to an assembled battery, Patent Document 1 discloses a cell subassembly in which a plurality of battery cells are stacked together by a pressure plate and a strip.

Special table 2012-515418 gazette

However, in Patent Document 1, the cell subassembly maintains a fixed state by a band-shaped body having a width dimension smaller than that of the cell assembly. Therefore, the stacked secondary batteries cannot be sufficiently held, and the cell assembly or the single battery may move from the direction orthogonal to the stacking direction depending on the magnitude of the external force, which may affect the battery performance.

It is an object of the present invention to provide an assembled battery that has improved reliability against impact even when an external force acts.

The present invention that achieves the above object is to stack a plurality of cells in the thickness direction, each cell including a battery body that includes a power generation element and is formed in a flat shape, and an electrode tab that is led out from the battery body, and to provide a space between adjacent cells. A battery group in which a heat radiating plate for radiating heat generated when the unit cell is used is arranged in at least one place, a pair of first cover members covering the battery group from both sides in the stacking direction of the unit cell, and the stacking direction intersecting with the stacking direction. And a pair of second cover members that cover the battery group from both sides in the direction intersecting the direction in which the electrode tab extends. The pair of second cover members are joined to the pair of first cover members when the battery group is pressed in the stacking direction by the pair of first cover members. Further, between at least one second cover member of the pair of second cover members and the heat dissipation plate, there is formed a restriction part for restricting movement of the heat dissipation plate in the plane direction in which the unit cells extend.
One of the second cover member and the heat dissipation plate is provided with a convex portion, the other is provided with a concave portion that abuts the convex portion, and the restriction portion is formed of the convex portion and the concave portion.
Further, the battery group has a spacer arranged at an end portion in a direction in which the unit cells extend flat and between adjacent unit cells in the stacking direction, and one of the second cover members has a mounting portion to be attached to the spacer. In addition, the spacer has a receiving portion to which the mounting portion of the one second cover member is mounted, and the restricting portion has the mounting portion mounted to the receiving portion, and the heat dissipation plate is pressed in the stacking direction together with the unit cells. It is formed between the one second cover member and the heat radiating plate via the spacer and the unit cell.

According to the assembled battery of the present invention, the pair of second cover members are joined to the pair of first cover members in a state where the battery group is pressed in the stacking direction by the pair of first cover members. Further, between at least one of the pair of second cover members and the heat radiating plate, there is formed a regulating portion for regulating the movement of the heat radiating plate in the plane direction in which the unit cells extend. Therefore, the regulation of the movement by the regulation portion can be applied not only to the heat sink but also to the battery group including the heat sink. Therefore, the movement of the battery group and the like can be suppressed even when an external force is input, and the reliability against impact can be improved.

It is a perspective view which shows the assembled battery which concerns on 1st Embodiment. 2(A) and 2(B) are a plan view and a side view showing the assembled battery of FIG. FIG. 2 is a perspective view showing a state where the upper stacking plate, the lower stacking plate, and the left and right side plates are disassembled from the battery pack shown in FIG. 1 and the entire laminate is exposed with a protective cover attached. It is a perspective view which removes a protective cover from the laminated body shown in FIG. 2 and decomposes|disassembles a laminated body into a battery group and a bus bar unit. It is a perspective view which decomposes|disassembles and shows the bus bar unit shown by FIG. A state in which the anode side electrode tab of the first cell sub-assembly (single cells connected in parallel for every three groups) and the cathode side electrode tab of the second cell sub-assembly (single cells connected in parallel for every three groups) are joined by a bus bar is decomposed FIG. FIG. 7A is a perspective view showing a state in which a pair of spacers (first spacer and second spacer) are attached to a unit cell, and FIG. 7B is a perspective view showing a pair of spacers (first spacer and first spacer). It is a perspective view showing the state where 2 spacers) were removed. It is a perspective view which shows a pair of spacer (1st spacer and 2nd spacer). It is sectional drawing which follows the 9-9 line of FIG.2(B). FIG. 10(A) is a perspective view showing a cross section of a main part of a state where a bus bar is joined to the electrode tabs of the stacked unit cells, and FIG. 10(B) is a side view showing FIG. is there. FIG. 10 is a partial cross-sectional view showing a heat dissipation plate and side plates at the same positions as in FIG. 9 in the battery pack according to the second embodiment. FIG. 10 is a partial cross-sectional view showing a heat dissipation plate and side plates at the same positions as in FIG. 9 in the battery pack according to the third embodiment. FIG. 10 is a partial cross-sectional view showing a heat dissipation plate, a side plate, a first spacer and a second spacer at the same position as in FIG. 9 in the battery pack according to the fourth embodiment. FIG. 13 is a partial cross-sectional view showing a modified example of FIG. 12.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description. The sizes and ratios of the respective members in the drawings may be exaggerated for convenience of explanation and may differ from the actual sizes and ratios. In the figure, the azimuths are indicated by the arrows indicated by X, Y, and Z. The direction of the arrow indicated by X indicates the direction that intersects the stacking direction of the unit cells 110 and is along the longitudinal direction of the unit cells 110. The direction of the arrow indicated by Y intersects with the stacking direction of the unit cells 110 and indicates the direction along the lateral direction of the unit cells 110. The direction of the arrow represented by Z indicates the stacking direction of the unit cells 110.

(First embodiment)
First, the assembled battery 100 of the first embodiment will be described with reference to FIGS. 1 to 10.

FIG. 1 is a perspective view showing an assembled battery 100 according to the first embodiment. 2(A) and 2(B) are a plan view and a side view showing the assembled battery of FIG. FIG. 3 shows a state in which the upper stacking plate 151, the lower stacking plate 152, and the left and right side plates 153 are disassembled from the battery pack 100 shown in FIG. 1 and the entire stack 100S with the protective cover 140 attached is exposed. It is a perspective view. FIG. 4 is a perspective view showing the laminated body 100S shown in FIG. 2 with the protective cover 140 removed and the laminated body 100S disassembled into a battery group 100G and a bus bar unit 130.

FIG. 5 is an exploded perspective view of the bus bar unit 130 shown in FIG. FIG. 6 shows the anode-side electrode tabs 113A of the first cell sub-assembly 100M (single cells 110 connected in parallel for every three sets) and the cathode-side electrode tabs 113K of the second cell sub-assembly 100N (single cells 110 connected in parallel for every three sets). It is a perspective view which decomposes|disassembles and shows the state joined by the bus bar 131 typically.

FIG. 7A is a perspective view showing a state in which a pair of spacers 120 (first spacer 121 and second spacer 122) are attached to the unit cell 110, and FIG. It is a perspective view showing the state where (the 1st spacer 121 and the 2nd spacer 122) was removed. FIG. 8 is a perspective view showing a pair of spacers 120 (first spacer 121 and second spacer 122). FIG. 9 is a sectional view taken along the line 9-9 of FIG.

FIG. 10(A) is a perspective view showing a cross section of a main part of a state where the bus bar 131 is joined to the electrode tab 113 of the stacked unit cells 110, and FIG. 10(B) shows FIG. 10(A) from the side. It is a side view.

In the state shown in FIG. 1, the front left side is referred to as the entire assembled battery 100 and the “front side” of each component, the back right side is referred to as the entire assembled battery 100 and the “rear side” of each component, and the right hand The front side and the back side on the left side are referred to as the “sides” on the left and right of the entire assembled battery 100 and each component.

As shown in FIG. 1 to FIG. 3, the assembled battery 100 is a laminated body including a battery group 100G in which a plurality of flat single cells 110 are stacked in the thickness direction and a heat sink 170 is arranged between the single cells 110. Having 100S. The assembled battery 100 further includes a protective cover 140 attached to the front surface side of the stacked body 100S, and a housing 150 that houses the stacked body 100S in a state in which each of the single cells 110 is pressed along the stacking direction of the single cells 110. With. As shown in FIG. 4, the stacked body 100S includes a battery group 100G and a bus bar unit 130 that is attached to the front surface side of the battery group 100G and integrally holds a plurality of bus bars 131. The protective cover 140 covers and protects the bus bar unit 130. As shown in FIG. 5, the bus bar unit 130 includes a plurality of bus bars 131 and a bus bar holder 132 that integrally mounts the plurality of bus bars 131 in a matrix. Of the plurality of bus bars 131, the anode side terminal 133 is attached to the anode side end, and the cathode side terminal 134 is attached to the cathode side end.

The assembled battery 100 according to the first embodiment will be outlined with reference to FIG. 3, FIG. 9 and FIG. 10B. A battery main body 110H including a power generation element 111 and formed in a flat shape, and electrodes derived from the battery main body 110H. A plurality of unit cells 110 each including a tab 113 are stacked in the thickness direction, and a heat dissipation plate 170 that dissipates heat generated when the unit cells 110 are used is disposed at at least one position between adjacent unit cells 110. The battery group 100G, an upper pressure plate 151 and a lower pressure plate 152 (corresponding to a pair of first cover members) that cover the battery group 100G from both sides in the stacking direction Z of the unit cell 110, intersect with the stacking direction Z, and A pair of side plates 153 (corresponding to a pair of second cover members) covering the battery group 100G from both sides in a direction intersecting the direction in which the electrode tabs 113 extend, and the pair of side plates 153 connect the battery group 100G to the upper pressing plate 151. And the lower pressure plate 152 and the upper pressure plate 151 and the lower pressure plate 152 are bonded to each other in a state of being pressed in the stacking direction Z. A restriction portion 180 that restricts the movement of the heat dissipation plate 170 in the plane direction XY in which the battery 110 extends is formed.

As shown in FIG. 6, the battery group 100G includes a first cell sub-assembly 100M including three electric cells 110 electrically connected in parallel and a second cell sub-assembly 100N including another three electric cells 110 electrically connected in parallel. And are connected in series by a bus bar 131.

The first cell sub-assembly 100M and the second cell sub-assembly 100N have the same configuration except the refraction direction of the tip portion 113d of the electrode tab 113 of the unit cell 110. Specifically, the second cell sub-assembly 100N is an inverted one of the unit cells 110 included in the first cell sub-assembly 100M. However, the bending direction of the tip portion 113d of the electrode tab 113 of the second cell sub-assembly 100N is aligned with the lower side of the stacking direction Z so as to be the same as the bending direction of the tip portion 113d of the electrode tab 113 of the first cell sub-assembly 100M. ing. Each unit cell 110 has a pair of spacers 120 (first spacer 121 and second spacer 122) attached thereto.

The unit cell 110 corresponds to, for example, a flat lithium ion secondary battery. As shown in FIG. 10(A), FIG. 10(B), etc., the unit cell 110 includes a battery main body 110H in which a power generation element 111 is sealed with a pair of laminate films 112, and a battery electrically connected to the power generation element 111. And a thin plate-shaped electrode tab 113 led out from the main body 110H.

The power generation element 111 is configured by stacking a plurality of positive and negative electrodes sandwiched by separators. The power generation element 111 receives power supply from the outside and is charged, and then supplies power while discharging to an external electric device.

The laminate film 112 is formed by covering both sides of the metal foil with an insulating sheet. The pair of laminate films 112 covers the power generation element 111 from both sides in the stacking direction Z and seals the four sides thereof. As shown in FIGS. 7(A) and 7(B), the pair of laminate films 112 are arranged so that the anode-side electrode tab 113A and the cathode-side electrode 113a and the cathode-side electrode are directed outward from between the one ends 112a along the lateral direction Y. The tab 113K is led out.

As shown in FIGS. 7(A), 7(B), and 8, the laminate film 112 has a pair of connecting holes 112 e provided at both ends of one end 112 a along the lateral direction Y, and a first spacer. A pair of connecting pins 121i of 121 are inserted respectively. On the other hand, in the laminate film 112, the pair of connecting pins 122i are inserted into the pair of connecting holes 112e provided at both ends of the other end 112b along the lateral direction Y, respectively. The laminate film 112 is formed by bending both ends 112c and 112d along the longitudinal direction X upward in the stacking direction Z.

As shown in FIGS. 7(A) and 7(B), the electrode tab 113 includes an anode-side electrode tab 113A and a cathode-side electrode tab 113K. It extends toward the outside in a state of being separated from each other. The anode-side electrode tab 113A is made of aluminum in accordance with the characteristics of the components on the anode side in the power generation element 111. The cathode side electrode tab 113K is made of copper in accordance with the characteristics of the cathode side constituent member in the power generation element 111.

As shown in FIG. 10B, the electrode tab 113 is formed in an L shape from a base end portion 113c adjacent to the battery main body 110H to a tip end portion 113d. Specifically, the electrode tab 113 extends from the base end portion 113c along one of the longitudinal directions X. On the other hand, the tip portion 113d of the electrode tab 113 is formed by bending along the lower side in the stacking direction Z. The shape of the tip portion 113d of the electrode tab 113 is not limited to the L shape. The tip portion 113d of the electrode tab 113 is formed in a planar shape so as to face the bus bar 131. The electrode tab 113 may be formed in a U-shape by further extending the tip portion 113d and folding the extended portion along the base end portion 113c toward the battery main body 110H side. On the other hand, the base end portion 113c of the electrode tab 113 may be formed in a wavy shape or a curved shape.

As shown in FIGS. 10(A) and 10(B), the tip portion 113d of each electrode tab 113 is aligned and bent downward in the stacking direction Z in the single cell 110 in which a plurality of stacked sheets are stacked. Here, as shown in FIG. 6, the assembled battery 100 includes three unit cells 110 electrically connected in parallel (first cell sub-assemblies 100M) and another three unit cells 110 electrically connected in parallel (second cell). The cell sub-assembly 100N) is connected in series. Therefore, the top and bottom of the unit cell 110 are replaced for each of the three unit cells 110 so that the positions of the anode-side electrode tab 113A and the cathode-side electrode tab 113K of the unit cell 110 are crossed along the stacking direction Z. There is.

However, simply replacing the top and bottom of each of the three unit cells 110 causes the positions of the tip portions 113d of the electrode tabs 113 to vary in the vertical direction along the stacking direction Z. The tip portion 113d of 113 is adjusted and refracted so that the positions thereof are aligned.

In the first cell sub-assembly 100M shown in the lower part of FIG. 6, the anode side electrode tab 113A is arranged on the right side of the drawing, and the cathode side electrode tab 113K is arranged on the left side of the drawing. On the other hand, in the second cell sub-assembly 100N shown in the upper part of FIG. 6, the cathode side electrode tab 113K is arranged on the right side in the figure, and the anode side electrode tab 113A is arranged on the left side in the figure.

Thus, even if the arrangement of the anode-side electrode tab 113A and the cathode-side electrode tab 113K is different, the tip portion 113d of the electrode tab 113 of the unit cell 110 is bent downward along the stacking direction Z. Further, the tip portion 113d of each electrode tab 113 is arranged on the same surface side of the stacked body 100S as shown in FIG. 10(B). A double-sided tape 160 is attached to the unit cells 110 located on the upper surfaces of the first cell sub-assembly 100M and the second cell sub-assembly 100N, the double-sided tape 160 adhering to a laminated member laminated above.

As shown in FIG. 10B, the pair of spacers 120 (first spacer 121 and second spacer 122) are arranged between the stacked unit cells 110. As shown in FIGS. 7A and 7B, the first spacer 121 is arranged along one end 112a in the plane direction XY in which the flat unit cell 110 extends. As shown in FIGS. 7(A) and 7(B), the second spacer 122 is in the plane direction XY in which the flat unit cell 110 extends and the other end portion of the unit cell 110 opposite to the one end portion 112a. It is arranged along 112b. The second spacer 122 has a configuration in which the shape of the first spacer 121 is simplified. Each unit cell 110 has a pair of spacers 120 (first spacer 121 and second spacer 122) attached thereto, and then a plurality of cells are stacked in the stacking direction Z. The pair of spacers 120 (first spacer 121 and second spacer 122) are made of insulating reinforced plastics. Hereinafter, the configuration of the first spacer 121 will be described, and then the configuration of the second spacer 122 will be described in comparison with the configuration of the first spacer 121.

As shown in FIGS. 7A, 7B, and 8, the first spacer 121 is formed in an elongated rectangular parallelepiped shape along the short-side direction Y. The first spacer 121 includes mounting portions 121M and 121N at both ends in the longitudinal direction (transverse direction Y).

As shown in FIG. 10B, when the first spacer 121 is stacked in a state of being attached to the unit cell 110, the first spacer 121 and the upper surface 121a of the mounting portions 121M and 121N of the first spacer 121 and the first spacer 121a. The lower surfaces 121b of the mounting portions 121M and 121N of the other first spacer 121 arranged above the one spacer 121 come into contact with each other.

As shown in FIG. 8 and FIG. 10B, the first spacer 121 is provided at a position provided on the upper surface 121a of one first spacer 121 in order to perform relative positioning of the unit cells 110 that are stacked. The positioning pin 121c is fitted into a positioning hole 121d which is opened in the lower surface 121b of the other first spacer 121 and corresponds to the position of the positioning pin 121c.

As shown in FIG. 8, the first spacer 121 has a locating hole 121e for inserting a bolt connecting the plurality of assembled batteries 100 connected in the stacking direction Z, and a mounting portion along the stacking direction Z. It is opened to 121M and 121N, respectively.

As shown in FIG. 8, the first spacer 121 is formed such that a region between the mounting portions 121M and 121N is cut out from the upper side in the stacking direction Z. The cutout portion is provided with a first support surface 121g and a second support surface 121h along the longitudinal direction of the first spacer 121 (the lateral direction Y of the unit cell 110). The first supporting surface 121g is formed higher than the second supporting surface 121h in the stacking direction Z and is located on the unit cell 110 side.

As shown in FIGS. 7(A) and 7(B), the first spacer 121 supports the one end 112a of the laminate film 112 having the electrode tab 113 protruding by the first support surface 121g. doing. The first spacer 121 includes a pair of connecting pins 121i protruding upward from both ends of the first supporting surface 121g.

As shown in FIGS. 8 and 10(B), the first spacer 121 has a support portion 121j that contacts the electrode tab 113 from the opposite side of the bus bar 131 and supports the tip portion 113d of the electrode tab 113 of the single cell 110. , The side surface adjacent to the second supporting surface 121h and extending in the stacking direction Z. The support portion 121j of the first spacer 121 sandwiches the tip end portion 113d of the electrode tab 113 together with the bus bar 131 so that the tip end portion 113d and the bus bar 131 sufficiently come into contact with each other.

As shown in FIGS. 7 and 8, the second spacer 122 has a configuration in which the shape of the first spacer 121 is simplified. The second spacer 122 corresponds to a configuration in which a part of the first spacer 121 is removed along the lateral direction Y of the unit cell 110. Specifically, the second spacer 122 is configured by replacing the second support surface 121h and the first support surface 121g of the first spacer 121 with a support surface 122k. Specifically, like the first spacer 121, the second spacer 122 includes mounting portions 122M and 122N. The second spacer 122 is provided with a support surface 122k at a portion notched from the upper side in the stacking direction Z in the region between the mounting portions 122M and 122N. The support surface 122k mounts and supports the other end 112b of the laminate film 112. Like the first spacer 121, the second spacer 122 includes a positioning pin 122c, a positioning hole, a locate hole 122e, and a connecting pin 122i.

As shown in FIGS. 4 and 5, the bus bar unit 130 integrally includes a plurality of bus bars 131. The bus bar 131 is made of a metal having conductivity, and electrically connects the tip portions 113d of the electrode tabs 113 of different unit cells 110. The bus bar 131 is formed in a flat plate shape and stands up along the stacking direction Z.

The bus bar 131 is an anode side bus bar 131A that is laser-welded to the anode-side electrode tab 113A of one unit cell 110, and a cathode side that is laser-welded to the cathode-side electrode tab 113K of another unit cell 110 that is adjacent in the stacking direction Z. The bus bar 131K is joined and integrally configured.

As shown in FIG. 5, the anode-side bus bar 131A and the cathode-side bus bar 131K have the same shape and are each formed in an L shape. The anode-side bus bar 131A and the cathode-side bus bar 131K are stacked upside down. Specifically, the bus bar 131 joins the bent portion at one end of the anode side bus bar 131A along the stacking direction Z and the bent portion at one end of the cathode side bus bar 131K along the stacking direction Z, It is integrated. As shown in FIG. 5, the anode-side bus bar 131A and the cathode-side bus bar 131K include side portions 131c extending from one end in the lateral direction Y along the longitudinal direction X. The side portion 131c is joined to the bus bar holder 132.

The anode-side bus bar 131A is made of aluminum similarly to the anode-side electrode tab 113A. The cathode side bus bar 131K is made of copper similarly to the cathode side electrode tab 113K. The anode-side bus bar 131A and the cathode-side bus bar 131K made of different metals are bonded to each other by ultrasonic bonding.

As shown in FIG. 6, when the assembled battery 100 is configured by connecting three battery cells 110 in parallel to each other in series as shown in FIG. 6, the bus bar 131 includes the anode-side bus bar 131A, Laser welding is performed on the anode-side electrode tabs 113A of the three unit cells 110 that are adjacent to each other along the stacking direction Z. Similarly, the bus bar 131 laser-welds the cathode-side bus bar 131K to the cathode-side electrode tabs 113K of the three unit cells 110 that are adjacent to each other in the stacking direction Z.

However, among the bus bars 131 arranged in a matrix, the bus bar 131 located in the upper right of FIGS. 4 and 5 corresponds to the anode-side termination of the 21 unit cells 110 (3 parallel 7 series). It is composed of only the side bus bar 131A. The anode-side bus bar 131A is laser-bonded to the anode-side electrode tabs 113A of the uppermost three unit cells 110 of the battery group 100G. Similarly, among the bus bars 131 arranged in a matrix, the bus bar 131 located at the lower left of the drawings in FIGS. 4 and 5 corresponds to the cathode-side termination of the 21 single cells 110 (3 parallel 7 series), It is composed of only the cathode side bus bar 131K. The cathode-side bus bar 131K is laser-bonded to the cathode-side electrode tabs 113K of the three lowest unit cells 110 of the battery group 100G.

As shown in FIGS. 4 and 5, the bus bar holder 132 integrally holds a plurality of bus bars 131 in a matrix so as to face the electrode tabs 113 of each of the stacked unit cells 110. The bus bar holder 132 is made of resin having an insulating property and is formed in a frame shape.

As shown in FIG. 5, the bus bar holders 132 are arranged in a pair along the stacking direction Z so as to be located on both sides in the longitudinal direction of the first spacer 121 supporting the electrode tab 113 of the unit cell 110. Each of the columns 132a is provided. The pair of support columns 132a are fitted to the side surfaces of the mounting portions 121M and 121N of the first spacer 121. The pair of support columns 132a are L-shaped when visually recognized in the stacking direction Z, and are formed in a plate shape extending along the stacking direction Z. The bus bar holder 132 is provided with a pair of auxiliary support columns 132b that are erected in the stacking direction Z and are spaced from each other so as to be located near the center of the first spacer 121 in the longitudinal direction. The pair of auxiliary support columns 132b are formed in a plate shape extending along the stacking direction Z.

As shown in FIG. 5, the bus bar holder 132 includes insulating portions 132c that project between the adjacent bus bars 131 along the stacking direction Z. The insulating portion 132c is formed in a plate shape extending along the lateral direction Y. Each insulating portion 132c is horizontally provided between the column portion 132a and the auxiliary column portion 132b. The insulating portion 132c prevents discharge by insulating between the bus bars 131 of the unit cells 110 that are adjacent to each other in the stacking direction Z.

The bus bar holder 132 may be configured by joining a column part 132a, an auxiliary column part 132b, and an insulating part 132c, which are formed independently of each other, to each other, or the column part 132a, the auxiliary column part 132b, and an insulating part 132c are integrally formed. It may be formed by molding.

As shown in FIGS. 4 and 5, the anode side terminal 133 corresponds to the anode side end of the battery group 100G configured by alternately stacking the first cell sub-assemblies 100M and the second cell sub-assemblies 100N.

As shown in FIGS. 4 and 5, the anode-side terminal 133 is joined to the anode-side bus bar 131A located in the upper right of the figure among the bus bars 131 arranged in a matrix. The anode-side terminal 133 is made of a conductive metal plate, and when viewed along the lateral direction Y, the one end 133b and the other end 133c are arranged along the stacking direction Z with reference to the central portion 133a. It consists of shapes that are refracted in different directions. The one end 133b is joined to the anode-side bus bar 131A by a laser or the like. The other end 133c connects an external input/output terminal to a hole 133d (including a screw groove) opened at the center thereof.

As shown in FIGS. 4 and 5, the cathode side terminal 134 corresponds to the cathode side end of the battery group 100G configured by alternately stacking the first cell sub-assemblies 100M and the second cell sub-assemblies 100N. As shown in FIGS. 4 and 5, the cathode-side terminal 134 is joined to the cathode-side bus bar 131K located at the lower left of the figure among the bus bars 131 arranged in a matrix. The cathode side terminal 134 has the same configuration as the anode side terminal 133.

As shown in FIGS. 1, 3 and 4, the protective cover 140 covers the busbar unit 130 to short-circuit the busbars 131 with each other, or the busbar 131 comes into contact with an external member to short-circuit or leak electricity. To prevent Further, the protective cover 140 exposes the anode side terminal 133 and the cathode side terminal 134 to the outside, and charges and discharges the power generation element 111 of each unit cell 110. The protective cover 140 is made of insulating plastic.

As shown in FIG. 4, the protective cover 140 is formed in a flat plate shape and is arranged upright along the stacking direction Z. The protective cover 140 has a shape in which the upper end 140b and the lower end 140c of the side surface 140a are bent along the longitudinal direction X, and is fitted into the bus bar unit 130.

As shown in FIGS. 3 and 4, the side surface 140 a of the protective cover 140 is a rectangular hole slightly larger than the anode side terminal 133 at a position corresponding to the anode side terminal 133 provided in the bus bar unit 130. The first opening 140d is provided. Similarly, the side surface 140 a of the protective cover 140 has a second opening 140 e formed of a rectangular hole slightly larger than the cathode side terminal 134 at a position corresponding to the cathode side terminal 134 provided in the bus bar unit 130. There is.

As shown in FIGS. 1 and 2B, the housing 150 houses the battery group 100G in a state of being pressed along the stacking direction. The upper pressure plate 151 and the lower pressure plate 152 apply an appropriate surface pressure to the power generation element 111 by sandwiching and pressing the power generation element 111 of each of the cells 110 included in the battery group 100G. In other words, the height of the battery group 100G in the assembled battery 100 is the same as the height when the unit cells 110 are stacked by the upper pressing plate 151 and the lower pressing plate 152 in the same load as the battery group 100G. The height is lower than the height.

As shown in FIGS. 1 and 3, the upper pressure plate 151 is arranged above the battery group 100G in the stacking direction Z. The upper pressing plate 151 has a pressing surface 151a protruding downward along the stacking direction Z at the center. The pressing surface 151a presses the power generation element 111 of each unit cell 110 downward. The upper pressure plate 151 includes holding portions 151b extending along the longitudinal direction X from both sides along the lateral direction Y. The holding portion 151b covers the placement portions 121M and 121N of the first spacer 121 or the placement portions 122M and 122N of the second spacer 122. A locating hole 151c communicating with the positioning hole 121d of the first spacer 121 or the positioning hole 122d of the second spacer 122 along the stacking direction Z is opened at the center of the holding portion 151b. A bolt that connects the assembled batteries 100 to each other is inserted into the locate hole 151c. The upper pressure plate 151 is made of a metal plate having a sufficient thickness. As shown in FIG. 3, the upper pressure plate 151 also has a bent portion 151d as a joint with the side plate 153, which is formed by bending both ends in the lateral direction Y intersecting the stacking direction Z.

As shown in FIGS. 1 and 3, the lower pressurizing plate 152 has the same configuration as the upper pressurizing plate 151, and the upper pressurizing plate 151 is arranged in the upside down state. The lower pressurizing plate 152 is arranged below the battery group 100G in the stacking direction Z. The lower pressing plate 152 presses the power generation element 111 of each unit cell 110 upward by the pressing surface 152a protruding upward along the stacking direction Z. As shown in FIG. 3, the lower pressurizing plate 152 also has a bent portion 152d as a joint portion with the side plate 153, which is formed by bending both ends in the lateral direction Y intersecting the stacking direction Z.

As shown in FIGS. 1 and 3, the pair of side plates 153 has an upper portion so that the upper pressure plate 151 and the lower pressure plate 152, which press the battery group 100G from above and below in the stacking direction Z, do not separate from each other. The relative positions of the pressure plate 151 and the lower pressure plate 152 are fixed. The side plate 153 is made of a metal plate as shown in FIGS. 3 and 9, and stands up along the stacking direction Z. As shown in FIG. 9, the pair of side plates 153 has a convex portion 153e that protrudes in a convex shape in a plan view from the stacking direction Z, and a concave portion 153f that is formed by recessing on the surface opposite to the convex portion 153e. Prepare As will be described later, the recess 153f is in contact with the protrusion 171 of the heat dissipation plate 170, and forms a restriction part 180 for restricting the movement of the heat dissipation plate 170 and the battery group 100G between the recess 153f and the heat dissipation plate 170. The pair of side plates 153 are arranged outside the bent portion 151d of the upper pressure plate 151 and the bent portion 152d of the lower pressure plate 152. The pair of side plates 153 are joined to the upper pressure plate 151 and the lower pressure plate 152 by laser welding from both sides in the lateral direction Y of the battery group 100G. As shown in FIG. 2(B), each side plate 153 has a linear weld portion 153c formed by seam welding or the like along the longitudinal direction X with respect to a portion of the upper end 153a that is in contact with the upper pressure plate 151. Several places (corresponding to the joint) are formed. Similarly, each side plate 153 has a linear weld portion 153d (corresponding to a joint portion) formed by seam welding or the like along the longitudinal direction X with respect to a portion of the lower end 153b that is in contact with the lower pressure plate 152. It is formed in several places. The pair of side plates 153 covers and protects both sides of the battery group 100G in the lateral direction Y.

The heat dissipation plate 170 is arranged between the unit cells 110 forming the battery group 100G. The heat radiating plate 170 is used to radiate the heat mainly generated during charging/discharging of the battery group 100G to the outside. As shown in FIGS. 3 and 4, the heat dissipation plate 170 has a portion projecting outward from the unit cell 110 when viewed in plan from the stacking direction Z, and is in contact with the side plate 153. As a result, the heat generated inside is transferred to the outside and radiated. As shown in FIG. 9, the heat dissipation plate 170 has a convex portion 171 that protrudes outward from two sides of the rectangular outer periphery and is in contact with the concave portion 153f of the side plate 153 when viewed in a plan view from the stacking direction Z.

As shown in FIG. 9, the convex portion 171 contacts the concave portion 153f of the side plate 153 to suppress movement of the heat sink 170 in the XY plane, particularly in the longitudinal direction X in which the electrode tab 113 extends when an external force acts. The restriction portion 180 is formed. Further, as described above, the upper pressure plate 151, the lower pressure plate 152, and the side plate 153 are joined in a state where the battery group 100G is pressed in the stacking direction Z. Therefore, the protrusion 171 of the heat dissipation plate 170 and the recess 153f of the side plate 153 are in contact with each other so that not only the heat dissipation plate 170 but also the battery group 100G is prevented from moving.

In FIG. 9, the convex portion 171 of the heat radiating plate and the convex portion 153e and the concave portion 153f of the side plate 153 are provided at two places on the upper and lower sides in FIG. However, as long as the movement of the heat sink 170 can be suppressed and the movement of the battery group 100G can be suppressed, the positions and the numbers of the protrusions 171, the protrusions 153e, and the recesses 153f are not limited to those in FIG. The heat sink 170 is made of metal such as aluminum having a relatively high thermal conductivity.

The assembled battery 100 according to the above-described first embodiment has the following operational effects. In the first embodiment, the pair of side plates 153 are joined to the upper pressure plate and the lower pressure plate 152 while the battery group 100G is pressed in the stacking direction Z by the upper pressure plate 151 and the lower pressure plate 152. Further, between the side plate 153 and the heat dissipation plate 170, there is formed a restriction portion 180 that restricts the movement of the heat dissipation plate 170 in the plane direction XY in which the unit cell 110 extends.

With this configuration, the restriction of the movement of the heat dissipation plate 170 by the restriction unit 180 can be applied to the battery group 100G. Therefore, the movement of the battery group 100G and the like can be suppressed even when an external force is input, and the reliability of the assembled battery 100 against a shock can be improved.

Further, the concave portion 153f of the side plate 153 and the convex portion 171 of the heat dissipation plate 170 are in contact with each other in the longitudinal direction X in which the electrode tab 113 extends, in the XY plane. Even if the electrode tab 113 is joined to the bus bar 131 or the like, it may not be particularly fixed to the housing 150. Even in such a case, by configuring as described above, it is possible to suppress the movement of the battery group 100G and the like in the longitudinal direction X, which is likely to move, and improve the reliability of the assembled battery 100 against a shock.

Further, in the present embodiment, the restriction portion 180 can be configured by specifically aligning the concave portion 153f provided on the side plate 153 with the convex portion 171 formed on the heat dissipation plate 170.

(Second embodiment)
Next, the assembled battery according to the second embodiment will be described. FIG. 11 is a partial cross-sectional view showing the heat dissipation plate and the side plate at the same position as in FIG. 9 in the battery pack according to the second embodiment. The second embodiment is different from the first embodiment only in the configurations of the side plate and the heat dissipation plate that form the housing 150, and is the same in the other respects, and therefore a description of the same configuration will be omitted.

In the second embodiment, as shown in FIG. 12, the heat dissipation plate 270 has an engaging portion 271 that engages with the side plate 253 in order to connect with the side plate 253 on at least one side of the rectangular shape when viewed in a plan view from the stacking direction Z. Have. On the other hand, the side plate 253 has an engaged portion 253h having a hole for being hooked by the engaging portion 271 of the heat dissipation plate 270 at a position at any height in the stacking direction Z, in other words, being engaged. .. The engaging portion 271 is inserted through the hole portion of the engaged portion 253h and the hole portion of the engaged portion 253h, and is disposed outside the side plate 253 so as to form an outer wall surface of the side plate 253. And an outer placement portion 273 that contacts. The engaging portion 271 and the engaged portion 253h form a restriction portion 280.

Next, the function and effect of the assembled battery according to the second embodiment will be described. As described above, according to the battery pack according to the second embodiment, the restriction portion 280 is provided on the heat dissipation plate 270 and the engagement portion 271 of the side plate 253, and is engaged with the engagement portion 271 of the heat dissipation plate 270. And the engaged portion 253h thus formed. Therefore, similarly to the first embodiment, the movement of the heat dissipation plate 270 can be restricted and the movement of the battery group 100G and the like can be restricted to improve the reliability of the assembled battery against a shock.

(Third Embodiment)
Next, the assembled battery according to the third embodiment will be described. FIG. 12 is a partial cross-sectional view showing the heat dissipation plate and the side plate at the same position as in FIG. 9 in the battery pack according to the third embodiment. The third embodiment is different from the first embodiment only in the configurations of the side plate and the heat dissipation plate that configure the housing 150, and is the same in the other respects, and therefore a description of the same configuration will be omitted.

In the third embodiment, the side plate 353 and the heat dissipation plate 370 are integrally fixed by a connecting member 354 as shown in FIG. The side plate 353 is provided with an insertion hole 353i for inserting the connecting member 354. The connecting member 354 is provided outside the insertion hole 353h and an insertion portion 354h that is inserted through the insertion hole 353i of the side plate 353, and a pressing portion 354i that contacts the side plate 353 and presses the side plate 353 toward the heat dissipation plate 370. And a pressing portion 354j that is embedded in the heat dissipation plate 370 and presses the heat dissipation plate 370 toward the side plate 353. The heat dissipation plate 370 has an attachment portion 371 for attaching the connecting member 354 without dropping it. The mounting portion 371 is configured such that the cross section on the inner side than the entrance is larger.

The pressing portion 354j includes a portion having a larger cross section than the insertion portion 354h. The connecting member 354 is made of an elastically deformable member such as resin, and the pressing portion 354j contracts and deforms to pass through the insertion hole 353i and enter the mounting portion 371. It is expanded and deformed to a certain degree. This prevents the connecting member 354 from falling off. In the connecting member 354, the pressing portion 354i presses the side plate 353 against the heat dissipation plate 370, and the pressing portion 354j presses the heat dissipation plate 370 against the side plate 353, whereby the heat dissipation plate 370 and the side plate 353 are integrally fixed. The restricting portion 380 includes a connecting member 354, an insertion hole 353i of the side plate 353, and a mounting portion 371 of the heat dissipation plate 370. The side plate 353 and the heat dissipation plate 370 are in contact with each other in the lateral direction Y.

Next, the function and effect of the assembled battery according to the third embodiment will be described. As described above, in the third embodiment, the connection member 354 is configured to be inserted into the insertion hole 353i of the side plate 353 and attached to the attachment portion 371 of the heat dissipation plate 370. Therefore, similarly to the first and second embodiments, it is possible to restrict the movement of the heat dissipation plate 370 and the movement of the battery group 100G, etc., and improve the reliability of the assembled battery against impact.

(Fourth Embodiment)
Next, the assembled battery according to the fourth embodiment will be described. FIG. 13 is a cross-sectional view showing the heat dissipation plate, the side plate, the first spacer, and the second spacer at the same position as in FIG. 9 in the battery pack according to the fourth embodiment. The fourth embodiment is different from the first embodiment only in the configurations of the side plate, the heat dissipation plate, the first spacers, and the second spacers that configure the housing 150, and is otherwise the same, and thus the description of the similar configuration is omitted.

In the fourth embodiment, the side plate 453 has a mounting portion 453g for mounting on the first spacer 421 and the second spacer 422, as shown in FIG. The mounting portion 453g is configured by bending an end portion of the side plate 453 in the longitudinal direction X.

As shown in FIG. 13, the first spacer 421 and the second spacer 422 have receiving portions 421k and 422k for mounting the mounting portion 253g of the side plate 453 in addition to the configuration of the first embodiment. The receiving portions 421k and 422k are configured by grooves into which the mounting portions 453g that are the end portions of the side plate 453 can be inserted. However, it is not limited to this as long as the attachment portion 453g can be attached to restrict the movement of the heat dissipation plate 470. The mounting portion 453g contacts the receiving portions 421k and 422k in the longitudinal direction X in which the electrode tab 113 extends. The attachment portion 453g of the side plate 453 and the receiving portions 421k and 422k of the first spacer 421 and the second spacer 422 constitute the restriction portion 480.

Here, as shown in FIG. 13, the heat radiating plate 470 and the mounting portion 453g of the side plate 453 are in a state in which a gap is provided when no external force acts. In the present embodiment, particularly when an external force is applied, the heat dissipation plate 470 and the like come into contact with the attachment portion 453g, and the restriction portion 480 restricts the movement of the heat dissipation plate 470 and the battery group 100G in the longitudinal direction X in which the electrode tab 113 extends. ing.

Next, the function and effect of the assembled battery according to the fourth embodiment will be described. In the fourth embodiment, the restricting portion 480 attaches the mounting portion 453g of the side plate 453 to the receiving portion 421k of the first spacer 421 and the receiving portion 422k of the second spacer 422 to move especially in the longitudinal direction X in the plane direction XY. regulate. With this, not only the movement of the heat dissipation plate 470 but also the movement of the battery group 100G and the like can be restricted as in the first embodiment, and the reliability of the assembled battery against impact can be improved.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. FIG. 14 is a sectional view showing a modified example of FIG. In the third embodiment, the heat dissipation plate 370 and the side plate 353 are in contact with each other in the lateral direction Y, but the present invention is not limited to this.

If the movement of the heat dissipation plate 370 with respect to the side plate 353 can be restricted, the connecting member 355 can be configured as follows. As shown in FIG. 14, the connecting member 355 is provided outside the insertion portion 355h that inserts through the insertion hole 353i of the side plate 353, and contacts the side plate 353 so that the side plate 353 faces the heat dissipation plate 370. And a pressing portion 355j that is embedded in the heat dissipation plate 370 and that presses the heat dissipation plate 370 toward the side plate 353, and a separating portion 355k that separates the side plate 353 and the heat dissipation plate 370.

The insertion portion 355h is the same as the insertion portion 354h of the connecting member 354, the pressing portion 355i is the same as the pressing portion 354i, and the pressing portion 355j is the same as the pressing portion 354j, so description thereof will be omitted. Like the connecting member 354, the connecting member 355 is made of an elastically deformable material such as resin.

The separating portion 355k is formed in a shape larger than the insertion hole 353h of the side plate 353, and can be passed through the insertion hole 353h by reducing and deforming the separating portion 355k and the pressing portion 355j. However, once passing through the insertion hole 353i, the separating portion 355k and the pressing portion 355j cannot pass through the insertion hole 353h again unless a considerable amount of force is applied by the pressing portion 355j. Also by configuring the connecting member 355 as described above, the movement of the heat dissipation plate 370 with respect to the side plate 353 can be restricted and the movement of the unit cells 110 and the like can be restricted, and the reliability of the assembled battery against impact can be improved.

The heat dissipation plates 170, 270, 370, and 470 in the first to fourth embodiments may be joined to the side plates 153, 253, 353, and 453 with an adhesive tape or an adhesive. With this configuration, it is possible to prevent or suppress the generation of sound due to the contact between the heat dissipation plate and the side plate.

100 sets of batteries,
100G battery group,
110 cells,
110H battery body,
111 power generation element,
113 electrode tab,
221 first spacer,
222 Second spacer,
221k, 222k receiving part,
151 upper pressure plate (first cover member),
152 lower pressure plate (first cover member),
153, 253, 353, 453 Side plates (a pair of second cover members),
153f recess,
253g mounting part,
353h hole,
454 connecting member,
170, 270, 370, 470 heat sink,
171 convex part,
371 hook,
180,280,380,480 Regulators,
X longitudinal direction (direction in which the electrode tab extends),
Z Stacking direction.

Claims (3)

A plurality of unit cells each having a flat battery body including a power generation element and an electrode tab led out from the battery body are stacked in the thickness direction, and the unit cell is provided at least at one location between adjacent unit cells. A battery group in which a heat dissipation plate that dissipates heat generated when the battery is used is arranged,
A pair of first cover members that cover the battery group from both sides in the stacking direction of the unit cells;
A pair of second cover members that cross the stacking direction and cover the battery group from both sides in a direction that intersects the direction in which the electrode tab extends,
The pair of second cover members are joined to the pair of first cover members in a state where the battery group is pressed in the stacking direction by the pair of first cover members,
Wherein between the at least one of the second cover member of the pair of second cover member and the heat radiating plate, the Ri Na form a restricting portion for restricting movement of the heat radiating plate in the planar direction of extension of the unit cells,
One of the one second cover member and the heat dissipation plate has a convex portion, and the other has a concave portion that abuts the convex portion,
The restriction unit is an assembled battery including the convex portion and the concave portion . A plurality of unit cells each having a flat battery body including a power generation element and an electrode tab led out from the battery body are stacked in the thickness direction, and the unit cell is provided at least at one location between adjacent unit cells. A battery group in which a heat dissipation plate that dissipates heat generated when the battery is used is arranged,
A pair of first cover members that cover the battery group from both sides in the stacking direction of the unit cells;
A pair of second cover members that cross the stacking direction and cover the battery group from both sides in a direction that intersects the direction in which the electrode tab extends,
The pair of second cover members are joined to the pair of first cover members in a state where the battery group is pressed in the stacking direction by the pair of first cover members,
When there is an input between at least one second cover member of the pair of second cover members and the heat dissipation plate in the plane direction in which the unit cell extends , at least in the direction in which the electrode tab extends It has a regulation part that regulates the movement of the heat sink.
The battery group is connected to the unit cell at an end portion in a direction in which the unit cell extends flat , and has a spacer arranged between the unit cells adjacent in the stacking direction,
The one second cover member is attached to the spacer and includes an attachment portion extending in a direction intersecting the direction in which the electrode tab extends ,
The spacer has a receiving portion to which the attachment portion of the one second cover member is attached,
The restricting portion has the attachment portion attached to the receiving portion, and the heat dissipation plate is pressed in the stacking direction together with the unit cells, so that the one second cover member is interposed via the spacer and the unit cell. Batteries formed between the. The electrode tab extends in one direction in the plane direction,
The assembled battery according to claim 1, wherein the one second cover member and the heat dissipation plate are in contact with each other in a direction in which the electrode tab extends .