JP2007280858A - Holding structure of secondary battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a holding structure of a secondary battery in which a flowing out of fluid from a fluid passage provided in a battery holder can be controlled. <P>SOLUTION: The holding structure of the secondary battery is provided with battery cells 33 and a plurality of battery holders 15p and 15q which are assembled to pinch battery cells and form a cooling air passage 120 to pass a cooling air. A plurality of battery holders 15p and 15q are provided with an internal face 25s facing the cooling air passage 120, an external face 25t facing an external space 110 in a rear side of the internal face 25s, and a pair of matching faces 51 and 52 which extend between the internal face 25s and the external face 25t and form a jointing part between a plurality of battery holders 15p and 15q. The pair of the matching faces 51 and 52 include an extended part 62 in a plane crossing a direction of connecting the inner face 25a with the external face 25t in a shortest distance. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention generally relates to a secondary battery holding structure, and more specifically, a secondary battery including a battery holder that holds a battery cell and in which an internal space in which a fluid flows is formed in the battery holder. Relates to the holding structure.

  Regarding a conventional secondary battery holding structure, for example, in Japanese Patent Application Laid-Open No. 2002-42753, a plurality of batteries whose outer peripheral surfaces are formed of a conductive material are stacked while ensuring insulation, and each battery is evenly distributed. A battery holder intended for cooling is disclosed (Patent Document 1). In Patent Document 1, an assembled battery is configured by alternately stacking batteries and battery holders. A battery holder that matches the outer periphery of the battery is formed on the outer edge of the battery holder. A plurality of batteries are sandwiched between battery holders of battery holders arranged on both sides of each battery. The battery holder forms a cooling air flow path between adjacent batteries.

Japanese Patent Application Laid-Open No. 2002-319383 discloses a battery module for the purpose of improving durability and battery life (Patent Document 2). Japanese Patent Application Laid-Open No. 2004-63352 discloses that a surface pressure is applied to a power generation element of a stacked battery from the outside of an exterior material, while suppressing generation of a gap between electrode plates. A battery module aimed at suppressing deterioration of battery performance by managing the battery with high accuracy is disclosed (Patent Document 3).
JP 2002-42753 A JP 2002-319383 A JP 2004-63352 A

  In the above-mentioned Patent Document 1, since a pair of battery holders are arranged so as to sandwich the battery, a joint is formed between the battery holders. However, with such a configuration, the cooling air may flow out from the cooling air flow path formed in the battery holder through the joint. In this case, the cooling efficiency of the battery decreases.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems and to provide a secondary battery holding structure that suppresses fluid from flowing out from a fluid passage formed in a battery holder.

  A secondary battery holding structure according to the present invention includes a battery cell and a plurality of battery holders that are combined with each other so as to sandwich the battery cell and form an internal space through which a fluid flows. The plurality of battery holders extend between the inner surface facing the internal space, the outer surface facing the outside of the inner space on the back side of the inner surface, and the inner surface and the outer surface to form a joint between the plurality of battery holders. And a mating surface. The pair of mating surfaces includes a first portion that extends in a plane that intersects the direction connecting the inner surface and the outer surface with the shortest distance.

  According to the secondary battery holding structure configured as described above, the pair of mating surfaces are compared with the case where the pair of mating surfaces extend in a plane in the direction connecting the inner surface and the outer surface with the shortest distance. The distance from the internal space along the outside to the outside of the internal space is set large. For this reason, when a gap is formed between the pair of mating surfaces, the pressure loss of the fluid flow from the internal space to the outside through the gap can be increased. Thereby, it can suppress that a fluid flows out outside the interior space.

  Moreover, the battery cell is clamped by a plurality of battery holders in a direction orthogonal to the direction connecting the inner surface and the outer surface with the shortest distance. According to the secondary battery holding structure configured as described above, it is assumed that the plurality of battery holders are pushed back by the expanded battery cells. In this case, a gap is formed between the pair of mating surfaces, and the gap extends in a direction in which the battery cell is sandwiched between the plurality of battery holders. Even in this case, as compared with the case where the pair of mating surfaces extend in the plane in the direction connecting the inner surface and the outer surface with the shortest distance, the spread of the gap can be suppressed to be small. Thereby, it can suppress that the outflow of a fluid expands by expansion | swelling of a battery cell.

  Preferably, the pair of mating surfaces oppose each other with a gap therebetween. According to the secondary battery holding structure configured as described above, by providing a gap in advance between the pair of mating surfaces, it is caused by variation in the shape of the battery cell or the battery holder, a change in the volume of the battery cell, or the like. The pair of mating surfaces can be prevented from contacting each other in a state where the battery cell is not sandwiched between the battery holders.

  Preferably, the first portion extends in a plane orthogonal to the direction connecting the inner surface and the outer surface with the shortest distance. According to the secondary battery holding structure configured as described above, even if the plurality of battery holders are pushed back to the expanded battery cell, the gap formed between the pair of mating surfaces is the first. It does not spread in the part. For this reason, it can suppress more effectively that the outflow of fluid by expansion of a battery cell expands.

  Preferably, the pair of mating surfaces further includes a second portion extending in a plane in a direction connecting the inner surface and the outer surface with the shortest distance. The size of the gap formed between the pair of mating surfaces is smaller in the first part than in the second part. According to the secondary battery holding structure configured as described above, the size of the gap formed between the pair of mating surfaces varies when the expansion or contraction of the battery cell is taken into consideration. In this case, the variation in the size of the gap is larger in the second portion than in the first portion. For this reason, it can suppress that a pair of mating surfaces contact mutually by setting the magnitude | size of a clearance gap so that it may become larger in a 2nd part rather than a 1st part. At the same time, the pressure loss of the fluid flow from the internal space toward the outside can be increased in the first portion where the gap is set smaller.

  Preferably, the first portion is formed to be bent so that the extending direction changes between the inner surface and the outer surface. According to the secondary battery holding structure configured as described above, when a gap is formed between the pair of mating surfaces, the pressure loss of the fluid flow from the internal space to the outside through the gap is further reduced. It can be increased effectively.

  The fluid flowing through the internal space is at least one of a refrigerant that cools the battery cell and a gas that is discharged from the battery cell. According to the secondary battery holding structure configured as described above, the cooling efficiency of the battery cells can be improved by suppressing the outflow of the refrigerant. Moreover, leakage of gas discharged from the battery cell can be suppressed.

  As described above, according to the present invention, it is possible to provide a secondary battery holding structure that suppresses fluid from flowing out from a fluid passage formed in the battery holder.

  Embodiments of the present invention will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are denoted by the same reference numerals.

(Embodiment 1)
FIG. 1 is a perspective view showing a battery pack to which a secondary battery holding structure according to Embodiment 1 of the present invention is applied. In the drawing, the case body that forms the exterior of the battery pack is depicted in perspective.

  Referring to FIG. 1, a battery pack 10 is mounted on a hybrid vehicle that uses an internal combustion engine such as a gasoline engine or a diesel engine and a rechargeable secondary battery as power sources. The battery pack 10 includes a battery cell 33 and a plurality of battery holders 15 that are combined with each other so as to sandwich the battery cell 33.

  The plurality of battery cells 33 include battery cells 33m and 33n. A set of battery cells 33m and 33n arranged in parallel is stacked in a predetermined direction (hereinafter referred to as a stacking direction of the battery cells 33). The plurality of battery cells 33 are electrically connected to each other in series by a bus bar (not shown). The battery cell 33 is formed from a lithium ion battery. The battery cell 33 is not particularly limited as long as it is a chargeable / dischargeable secondary battery, and may be, for example, a nickel metal hydride battery.

  Battery holders 15 are arranged between sets of battery cells 33m and 33n adjacent in the stacking direction of the battery cells 33, respectively. A plurality of battery holders 15 are arranged in the stacking direction of the battery cells 33 with the battery cells 33 sandwiched therebetween. End plates 40 and 41 are arranged on both sides of the plurality of battery holders 15 arranged side by side. The end plate 40 and the end plate 41 are coupled to each other by a restraining band 42 as a restraining member. The restraining band 42 applies a restraining force along the stacking direction of the battery cells 33 to the battery holder 15.

  With such a configuration, the plurality of battery holders 15 are integrally held by the restraining band 42. The battery cell 33 is sandwiched in the stacking direction of the battery cells 33 by two battery holders 15 arranged on both sides of the battery cell 33.

  Note that the restraining member that integrally holds the plurality of battery holders 15 is not limited to the restraining band 42, and may be, for example, a bolt that generates an axial force in the stacking direction of the battery cells 33. Further, the restraining member may be rubber, string, tape, or the like that generates a tightening force in the stacking direction of the battery cells 33.

  The battery cell 33 has a pair of side surfaces 33a facing opposite to each other. The side surface 33a is a surface having the largest area among the plurality of surfaces of the battery cell 33. The plurality of battery cells 33 are arranged so that the side surfaces 33 a face each other at positions adjacent to each other in the stacking direction of the battery cells 33.

  The battery pack 10 further includes an intake chamber 34 and an exhaust chamber 35. The intake chamber 34 and the exhaust chamber 35 are provided adjacent to the battery holder 15 in a direction orthogonal to the stacking direction of the battery cells 33. The intake chamber 34 and the exhaust chamber 35 extend in the stacking direction of the battery cells 33. The intake chamber 34 and the exhaust chamber 35 are arranged in the horizontal direction with the battery holder 15 in between. In order to keep the height low, the battery pack 10 adopts a cross-flow system in which cooling air is circulated in the horizontal direction.

  The plurality of battery holders 15 form a cooling air passage 120 through which cooling air flows between the intake chamber 34 and the exhaust chamber 35. The cooling air passage 120 is formed between each battery cell 33 adjacent in the stacking direction. The battery holder 15 has an opening 16 that allows the cooling air passage 120 and the intake chamber 34 to communicate with each other, and has an opening 17 that allows the cooling air passage 120 and the exhaust chamber 35 to communicate with each other.

  Cooling air introduced into the battery pack 10 from the inside of the vehicle flows into the cooling air passage 120 from the intake chamber 34 through the opening 16. The cooling air that has flowed into the cooling air passage 120 flows along the side surface 33a of the battery cell 33. During this time, the battery cell 33m is first cooled, and then the battery cell 33n is cooled. The cooling air whose temperature has been increased by heat exchange with the battery cell 33 is discharged from the cooling air passage 120 through the opening 17 to the exhaust chamber 35. Although FIG. 1 shows the case where cooling air flows in the same direction in the intake chamber 34 and the exhaust chamber 35, the cooling air may flow in directions opposite to each other.

  The battery holder 15 further forms an exhaust gas passage 130 through which the gas discharged from the battery cell 33 flows. The exhaust gas passage 130 extends along the stacking direction of the battery cells 33. The exhaust gas passage 130 is formed immediately above the battery cells 33m and 33n.

  FIG. 2 is a perspective view showing the battery holder in FIG. In the figure, the battery holder 15p and the battery holder 15q adjacent to each other in the stacking direction of the battery cells 33, and the battery cell 33 disposed between the battery holder 15p and the battery holder 15q are shown.

  With reference to FIG. 1 and FIG. 2, the battery holder 15 is formed of an insulating material. The battery holder 15 is made of, for example, a resin material such as polypropylene or a polymer of polypropylene. The battery holder 15 may be formed of a metal whose surface is coated with a resin. The battery holder 15 electrically insulates the battery cells 33 adjacent in the stacking direction.

  The battery holder 15 includes a base portion 21 interposed between battery cells 33 adjacent in the stacking direction, and side portions 22, 23, 24, and 25 formed on the periphery of the base portion 21. The base portion 21 has a substantially rectangular flat plate shape. The side parts 22, 23, 24 and 25 are respectively formed on the four sides of the base part 21. Openings 16 and 17 are formed in the side portions 24 and 25, respectively.

  The base portion 21 has a front surface 21a and a back surface 21b facing each other. The base portion 21 is formed with ribs 26 that protrude from the surface 21 a and extend from the intake chamber 34 toward the exhaust chamber 35. A plurality of ribs 26 are formed at intervals from each other. A space for allowing the cooling air to flow along the side surface 33 a of the battery cell 33 is secured between the plurality of adjacent ribs 26. In addition, it may replace with the rib 26 and may provide the boss | hub arrange | positioned in dot shape on the surface 21a, and may provide it combining the rib 26 and the boss | hub.

  In a state where the battery cell 33 is sandwiched, the battery holder 15p and the battery holder 15q are combined. At this time, the battery cell 33 is clamped in the stacking direction of the battery cells 33 by being pressed by the ribs 26 of the battery holder 15q and the back surface 21b of the battery holder 15p. A cooling air passage 120 is formed in a space surrounded by the side portions 22, 23, 24 and 25 of the battery holders 15p and 15q.

  FIG. 3 is a cross-sectional view of the battery pack taken along line III-III in FIG. Referring to FIGS. 2 and 3, cooling air passage 120 is formed inside battery holder 15 with side part 25 interposed therebetween, and external space 110 is formed outside battery holder 15. The side portion 25 has an inner surface 25s facing the cooling air passage 120, and an outer surface 25t facing the outer space 110 on the back side of the inner surface 25s. The inner surface 25s and the outer surface 25t extend in parallel to each other.

  The side portion 25 is formed with a pair of mating surfaces 51 and 52 that form a joint between the battery holders 15 adjacent to each other. The battery holder 15p has a mating surface 52 as one of a pair of mating surfaces, and the battery holder 15q combined with the battery holder 15p has a mating surface 51 as the other of the pair of mating surfaces. The pair of mating surfaces 51 and 52 extends between the inner surface 25s and the outer surface 25t.

  The pair of mating surfaces 51 and 52 face each other with a gap therebetween. In FIG. 3, the mating surface 52 of the battery holder 15p and the mating surface 51 of the battery holder 15q are opposed to each other with a gap 55 therebetween. The cooling air passage 120 and the external space 110 communicate with each other through the gap 55. The pair of mating surfaces 51 and 52 extend in parallel at positions facing each other. The pair of mating surfaces 51 and 52 extend in a direction surrounding the cooling air passage 120.

  The gap 55 is formed in consideration of the thickness of the battery cell 33, the variation in the shape of the battery holder 15, the volume change of the battery cell 33, and the like. With such a configuration, it is possible to prevent the mating surface 51 and the mating surface 52 from contacting each other in a state where the battery cell 33 is not sandwiched between the battery holders 15p and 15q. The battery holder 15p and the battery holder 15q may be combined in a state where the gap 55 is not formed and the pair of mating surfaces 51 and 52 are in close contact with each other. Even in this case, a gap may be formed between the pair of mating surfaces 51 and 52 due to the expansion of the battery cell 33.

  The pair of mating surfaces 51 and 52 has a portion 62 that extends in a plane that intersects the direction (direction indicated by the arrow 101) that connects the inner surface 25s and the outer surface 25t with the shortest distance. The direction connecting the inner surface 25s and the outer surface 25t with the shortest distance coincides with the direction from the cooling air passage 120 toward the external space 110. The direction connecting the inner surface 25s and the outer surface 25t with the shortest distance is orthogonal to the stacking direction of the battery cells 33, that is, the direction in which the battery cells 33 are sandwiched by the plurality of battery holders 15 (the direction indicated by the arrow 102). In the present embodiment, the portion 62 extends in a plane orthogonal to the direction connecting the inner surface 25s and the outer surface 25t with the shortest distance.

  The pair of mating surfaces 51 and 52 further includes a plurality of portions 61 extending as a second portion in a plane connecting the inner surface 25s and the outer surface 25t with the shortest distance. The plurality of portions 61 are provided adjacent to the cooling air passage 120 and the external space 110, respectively. The portion 62 is provided between the plurality of portions 61. The distance C between the pair of mating surfaces 51 and 52 in the portion 62 is smaller than the distance B between the pair of mating surfaces 51 and 52 in the portion 61.

  In FIG. 3, the pair of mating surfaces 51 and 52 formed on the side portion 25 is shown. Similarly, the side portions 22, 23 and 24 also have a pair of mating surfaces 51 and 62 having portions 61 and 62. 52 is formed. That is, the pair of mating surfaces 51 and 52 are formed so as to surround the periphery of the cooling air passage 120 except for the openings 16 and 17 that intake and exhaust the cooling air.

  FIG. 4 is a cross-sectional view of the battery pack taken along line IV-IV in FIG. With reference to FIG. 4, the exhaust gas passage 130 is formed between the battery cell 33 and the side portion 22. An exhaust gas passage 130 is formed inside the battery holder 15 across the side portion 22, and an external space 110 is formed outside the battery holder 15. The side portion 22 has an inner surface 22s facing the exhaust gas passage 130 and an outer surface 22t facing the external space 110 on the back side of the inner surface 22s. The inner surface 22s and the outer surface 22t extend in parallel to each other. A pair of mating surfaces 71 and 72 are further formed on the side portion 22. The pair of mating surfaces 71 and 72 extends between the inner surface 22s and the outer surface 22t. The exhaust gas passage 130 and the external space 110 communicate with each other through a gap 55 formed between the mating surface 71 and the mating surface 72.

  The pair of mating surfaces 71 and 72 have a portion 82 that extends in a plane that intersects the direction connecting the inner surface 22s and the outer surface 22t with the shortest distance (the direction indicated by the arrow 103). The direction connecting the inner surface 22s and the outer surface 22t with the shortest distance coincides with the direction from the exhaust gas passage 130 toward the external space 110. In the present embodiment, the portion 82 extends in a plane orthogonal to the direction connecting the inner surface 22s and the outer surface 22t with the shortest distance. The direction connecting the inner surface 22s and the outer surface 22t with the shortest distance is orthogonal to the direction in which the battery cell 33 is sandwiched between the plurality of battery holders 15 (the direction indicated by the arrow 102). The pair of mating surfaces 71 and 72 further includes a plurality of portions 81 extending as a second portion in a plane connecting the inner surface 22s and the outer surface 22t with the shortest distance.

  The secondary battery holding structure according to the first embodiment of the present invention is combined with each other so as to sandwich the battery cell 33 and the battery cell 33, and the cooling air as the internal space through which the cooling air and the exhaust gas are circulated. And a plurality of battery holders 15 forming the passage 120 and the exhaust gas passage 130. The plurality of battery holders 15 include an inner surface 25s facing the cooling air passage 120, an outer surface 25t facing the outer space 110 as the outer side of the cooling air passage 120 on the back side of the inner surface 25s, and the inner surface 25s and the outer surface 25t. A pair of mating surfaces 51 and 52 extending and forming joints between the battery holders 15 are provided. The pair of mating surfaces 51 and 52 includes a portion 62 as a first portion that extends in a plane that intersects the direction connecting the inner surface 25s and the outer surface 25t with the shortest distance.

  The plurality of battery holders 15 extend between the inner surface 22s facing the exhaust gas passage 130, the outer surface 22t facing the outer space 110 as the outer side of the exhaust gas passage 130 on the back side of the inner surface 22s, and the inner surface 22s and the outer surface 22t. And a pair of mating surfaces 71 and 72 that form joints between the battery holders 15. The pair of mating surfaces 71 and 72 includes a portion 82 extending in a plane that intersects the direction connecting the inner surface 22s and the outer surface 22t with the shortest distance.

  According to the secondary battery holding structure according to Embodiment 1 of the present invention configured as described above, the pair of mating surfaces 51 and 52 are in the plane in the direction connecting the inner surface 25s and the outer surface 25t with the shortest distance. The creepage distance of the gap 55 between the cooling air passage 120 and the external space 110 can be set larger than in the case of extending in FIG. Thereby, the pressure loss of the cooling air flow from the cooling air passage 120 toward the external space 110 through the gap 55 is increased, and leakage of the cooling air in the cooling air passage 120 can be suppressed.

  Further, when the mating surface 51 and the mating surface 52 are separated in the direction indicated by the arrow 102 due to the expansion of the battery cell 33, the width of the gap 55 does not change in the portion 62. Therefore, as shown in FIG. 3, the distance C in the portion 62 can be set smaller than the distance B in the portion 61, and the pressure loss of the cooling air flow is effectively reduced in the portion 62 in which the gap 55 is set smaller. Can be increased.

  For the same reason, it is possible to increase the pressure loss of the exhaust gas flow from the exhaust gas passage 130 to the external space 110 through the gap 55, and to prevent the exhaust gas in the exhaust gas passage 130 from leaking. Further, in the present embodiment, since separate members such as sponge and butyl tape are not used in order to ensure the airtightness of the cooling air passage 120 and the exhaust gas passage 130, an assembling process and parts costs are not increased.

  In addition, the structure of a battery pack is not limited to the form shown in FIG. In the battery pack 10 shown in FIG. 1, a cross flow method in which cooling air flows in the horizontal direction is employed, but a vertical flow method in which cooling air flows in the vertical direction may be employed. Moreover, the form which laminates | stacks the some battery cell 33 is not limited to the form shown in FIG. In the battery pack 10 shown in FIG. 1, there are a plurality of battery cells in the flow direction of the cooling air, but only one battery cell may exist, or three or more battery cells may exist in the flow direction of the cooling air. May be arranged.

  The present invention can also be applied to a fuel cell hybrid vehicle (FCHV) or an electric vehicle (EV) using a fuel cell and a secondary battery as drive sources. In the hybrid vehicle in the present embodiment, the internal combustion engine is driven at the fuel efficiency optimum operating point, whereas in the fuel cell hybrid vehicle, the fuel cell is driven at the power generation efficiency optimum operating point. The use of the secondary battery is basically the same for both hybrid vehicles.

  FIG. 5 is a cross-sectional view showing a first modification of the pair of mating surfaces in FIG. Referring to FIG. 5, in this modification, the pair of mating surfaces 51 and 52 has an angle other than 90 ° with respect to a direction (direction shown by an arrow 101) connecting the inner surface 25 s and the outer surface 25 t with the shortest distance. It has the part 63 extended in the plane which cross | intersects (alpha). The portion 63 is formed from the cooling air passage 120 to the external space 110.

  FIG. 6 is a cross-sectional view showing the displacement of the pair of mating surfaces in FIG. 5 when the battery cell expands. FIG. 7 is a cross-sectional view showing the displacement of a pair of mating surfaces for comparison when the battery cell expands. In FIG. 7, a pair of mating surfaces 51 and 52 are shown extending in a plane in a direction connecting the inner surface 25s and the outer surface 25t with the shortest distance.

  With reference to FIGS. 6 and 7, it is assumed that the mating surface 52 moves away from the mating surface 51 by a distance N in the stacking direction of the battery cells 33 due to the expansion of the battery cell 33. The angle α in FIG. 5 is 45 °.

In this case, in the comparative example shown in FIG. 7, the cross-sectional area of the gap 55 is increased by N × (the length in the direction perpendicular to the paper surface). On the other hand, in the pair of mating surfaces 51 and 52 in FIG. 6, the cross-sectional area of the gap 55 increases by N / (2 ^1/2 ) × (length in the direction perpendicular to the paper surface). The increase amount can be suppressed smaller than the comparative example shown in FIG. Therefore, according to the modification shown in FIG. 5, when the battery cell 33 expand | swells, it can suppress effectively that the leakage of cooling air expands.

  FIG. 8 is a cross-sectional view showing a second modification of the pair of mating surfaces in FIG. Referring to FIG. 8, in the present modification, the pair of mating surfaces 51 and 52 are configured by a plurality of portions 62 and a plurality of portions 61. The portions 61 and 62 are alternately arranged from the cooling air passage 120 toward the external space 110.

  FIG. 9 is a cross-sectional view showing a third modification of the pair of mating surfaces in FIG. Referring to FIG. 9, in this modification, the pair of mating surfaces 51 and 52 extend in a plane intersecting at an angle other than 90 ° with respect to the direction connecting the inner surface 25s and the outer surface 25t with the shortest distance. It consists of the existing part 63m and the part 63n. The part 63m and the part 63n extend in different directions. The part 63m and the part 63n intersect at an angle of 90 ° or less. The pair of mating surfaces 51 and 52 are formed by bending at the boundary between the portion 63m and the portion 63n. With such a configuration, the pressure loss of the cooling air flow flowing through the gap 55 can be further effectively increased.

  FIG. 10 is a cross-sectional view showing a fourth modification of the pair of mating surfaces in FIG. Referring to FIG. 10, in the present modification, the pair of mating surfaces 51 and 52 are configured by a plurality of portions 63 and a portion 62. The portions 63 and 62 are alternately arranged from the cooling air passage 120 toward the external space 110.

  The above-described effect of suppressing leakage of cooling air can be obtained in the same manner by the modification described above. Moreover, you may apply the structure of a pair of mating surfaces 51 and 52 shown in each modification to a pair of mating surfaces 71 and 72 shown in FIG.

(Embodiment 2)
FIG. 11 is a cross-sectional view showing a secondary battery holding structure according to Embodiment 2 of the present invention. In FIG. 11, the same position as the cross-sectional position showing each modification example in the first embodiment is shown. The secondary battery holding structure in the present embodiment has basically the same structure as the secondary battery holding structure in the first embodiment. Hereinafter, the description of the overlapping structure will not be repeated.

  Referring to FIG. 11, in the present embodiment, inner surface 25 s and outer surface 25 t do not extend in parallel to the stacking direction of battery cells 33, that is, the direction in which battery cells 33 are sandwiched by a plurality of battery holders 15. The pair of mating surfaces 51 and 52 have a portion 63 that extends in a plane that intersects at an angle other than 90 ° with respect to the direction connecting the inner surface 25s and the outer surface 25t with the shortest distance (the direction indicated by the arrow 101). The pair of mating surfaces 51 and 52 extend in a plane orthogonal to the direction in which the battery cell 33 is sandwiched between the plurality of battery holders 15.

  FIG. 12 is a cross-sectional view showing a battery pack for comparison with the battery pack in FIG. Referring to FIG. 12, in this comparative example, a pair of mating surfaces 51 and 52 extend within a plane in the direction connecting the inner surface 25s and the outer surface 25t with the shortest distance (the direction indicated by arrow 101).

  As can be seen by comparing the battery packs in FIGS. 11 and 12, in the present embodiment in which the pair of mating surfaces 51 and 52 have the portion 63, the gap 55 between the cooling air passage 120 and the external space 110 Creepage distance can be set larger. For this reason, similarly to Embodiment 1, it can suppress that the cooling air in the cooling air channel | path 120 leaks out.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a perspective view which shows the battery pack to which the holding structure of the secondary battery in embodiment of this invention was applied. It is a perspective view which shows the battery holder in FIG. It is sectional drawing of the battery pack along the III-III line | wire in FIG. It is sectional drawing of the battery pack along the IV-IV line in FIG. It is sectional drawing which shows the 1st modification of a pair of mating surface in FIG. It is sectional drawing which shows the displacement of a pair of mating surface in FIG. 5 when a battery cell expand | swells. It is sectional drawing which shows the displacement of a pair of mating surface for the comparison when a battery cell expand | swells. It is sectional drawing which shows the 2nd modification of a pair of mating surface in FIG. It is sectional drawing which shows the 3rd modification of a pair of mating surface in FIG. It is sectional drawing which shows the 4th modification of a pair of mating surface in FIG. It is sectional drawing which shows the holding structure of the secondary battery in Embodiment 2 of this invention. It is sectional drawing which shows the battery pack for comparing with the battery pack in FIG.

Explanation of symbols

  15, 15p, 15q battery holder, 33 battery cells, 51, 52, 71, 72 a pair of mating surfaces, 55 gap, 61, 62, 63, 63m, 63n, 81, 82 part, 110 external space, 120 cooling air passage , 130 Exhaust gas passage.

Claims (7)

A battery cell;
A plurality of battery holders that are combined with each other so as to sandwich the battery cells and form an internal space through which fluid flows, and
The plurality of battery holders extend between the inner surface facing the inner space, the outer surface facing the outside of the inner space on the back side of the inner surface, and the inner surface and the outer surface. A pair of mating surfaces forming a joint between them,
The pair of mating surfaces include a first battery holding structure including a first portion extending in a plane intersecting a direction connecting the inner surface and the outer surface with the shortest distance.   The secondary battery holding structure according to claim 1, wherein the battery cell is sandwiched by the plurality of battery holders in a direction orthogonal to a direction connecting the inner surface and the outer surface with a shortest distance.   The secondary battery holding structure according to claim 2, wherein the pair of mating surfaces face each other with a gap therebetween.   4. The secondary battery holding structure according to claim 2, wherein the first portion extends in a plane orthogonal to a direction connecting the inner surface and the outer surface with a shortest distance. 5. The pair of mating surfaces further includes a second portion extending in a plane in a direction connecting the inner surface and the outer surface with the shortest distance,
5. The secondary battery according to claim 2, wherein a size of a gap formed between the pair of mating surfaces is smaller in the first portion than in the second portion. Retaining structure.   The secondary battery according to claim 1, wherein the first portion is formed to be bent so that a direction in which the first portion extends between the inner surface and the outer surface changes. Holding structure.   The secondary battery according to any one of claims 1 to 6, wherein the fluid flowing through the internal space is at least one of a refrigerant that cools the battery cell and a gas that is discharged from the battery cell. Retaining structure.

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