JP6493144B2 - Battery module - Google Patents

Description

  The present invention relates to a battery module.

  As a conventional battery module, for example, as in Patent Document 1, there is a battery module in which an array of battery cells held by a cell holder is sandwiched between end plates and a restraining load is applied. Further, for example, as in Patent Document 2, there is a battery module in which a temperature control member such as a heat radiating plate is arranged between adjacent battery cells to control the temperature of the battery cells.

  The temperature control member used in this Patent Document 2 has, for example, a plurality of ribs arranged in parallel with a predetermined interval on one surface of the base. The temperature control member is disposed between the battery cells so that each rib contacts the wall surface of the case of the adjacent battery cell. Thereby, a space surrounded by the base, the rib, and the battery cell is formed between the battery cells, and the space can be used as a flow path of the temperature control medium.

JP 2009-81056 A JP 2006-278330 A

  In the battery module as described above, temperature control of the battery cell during use is important. In particular, an electrode assembly incorporated in the case is located near the center of the battery cell when the array is viewed from the array direction, and sufficient securing of temperature control efficiency is required. Moreover, in the battery module as described above, the battery module may expand due to deterioration or the like. In a battery module of a type that applies a restraining load to an array of battery cells, the restraining load is continuously applied even when the battery cell is expanded. For this reason, the load added to the temperature control member arrange | positioned adjacent to a battery cell increases, and the failure | damage and deformation | transformation of a rib may arise. If the rib is damaged or deformed, the temperature control efficiency of the battery cell by the temperature control medium may be reduced.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a battery module that can sufficiently ensure the temperature control efficiency of the battery cell both when the battery cell is not expanded and when it is expanded. To do.

  In order to solve the above problems, a battery module according to an aspect of the present invention includes an array of battery cells, and a restraining member that applies a restraining load to the array in the battery cell array direction. The battery is provided with a temperature control member for each battery cell. The temperature control member has a plate-like base and a plurality of ribs arranged on one surface of the base, and the surface in the battery cell arrangement direction. The ribs are arranged so as to contact the battery cell, and in each of the plurality of ribs, at least a part of the side surface facing the center side of the rib arrangement direction is inclined outward from the center side of the rib arrangement direction. It is an inclined surface.

  In this battery module, in each of the plurality of ribs, at least a part of a side surface facing the center side in the rib arrangement direction is an inclined surface that is inclined outward from the center side in the rib arrangement direction. Thereby, the space | interval between ribs which pinches | interposes the center of the arrangement direction of a rib becomes wider than the space | interval between other ribs. Therefore, when the battery cell is not expanded, the flow path of the temperature control medium is formed near the center of the battery cell with a sufficient cross-sectional area, and the temperature control efficiency of the battery cell can be sufficiently ensured. In addition, when the battery cell expands, a part of the load applied from the battery cell side is received by the inclined surface toward the outside from the center side in the arrangement direction of the ribs. Can prevent damage and deformation. Therefore, the flow path of the temperature control medium is maintained even when the battery cell is expanded, and the temperature control efficiency of the battery cell can be sufficiently ensured.

  In each of the plurality of ribs, the entire side surface facing the center side in the rib arrangement direction may be an inclined surface that is inclined outward from the center side in the rib arrangement direction. In this case, when the battery cell is not expanded, the flow path of the temperature control medium is formed in the vicinity of the center of the battery cell with a sufficient cross-sectional area. Further, when the battery cell is expanded, a part of the load applied from the battery cell side is more reliably received from the central side in the arrangement direction of the ribs toward the outside by the inclined surface.

  Further, the inclination angle of the inclined surface with respect to the base may be larger as the rib is located at the center side in the arrangement direction of the ribs. When the battery cells expand, the vicinity of the center tends to expand more than the peripheral portion when viewed from the arrangement direction. Therefore, by setting the inclination angle of the inclined surface according to the tendency of expansion of the battery cell, damage and deformation of the rib during expansion of the battery cell can be suitably suppressed.

  Each battery cell contains an electrode assembly, each battery cell is held by a cell holder, and the temperature control member has a plurality of ribs in a region overlapping the electrode assembly when viewed from the arrangement direction of the array. May be attached to the cell holder so as to be disposed. Thereby, since the flow path of the temperature control medium is formed close to the electrode assembly with a certain positioning accuracy, the temperature control efficiency by the temperature control member can be improved.

  According to the present invention, the temperature control efficiency of the battery cell can be sufficiently secured both when the battery cell is not expanded and when it is expanded.

It is the schematic which shows the battery module which concerns on 1st Embodiment. It is sectional drawing which shows the inside of a battery cell. It is the III-III sectional view taken on the line in FIG. It is a perspective view of a cell holder. It is a principal part expanded sectional view of a temperature control member. It is a principal part expanded sectional view of the temperature control member when expansion | swelling arises in the battery cell. It is a principal part expanded sectional view of the temperature control member of the battery module which concerns on 2nd Embodiment. It is a principal part expanded sectional view of the temperature control member when expansion | swelling arises in the battery cell. It is a principal part expanded sectional view of the temperature control member of the battery module which concerns on the modification of 1st Embodiment. It is a principal part expanded sectional view of the temperature control member of the battery module which concerns on the modification of 2nd Embodiment.

Hereinafter, preferred embodiments of a battery module according to one aspect of the present invention will be described in detail with reference to the drawings.
[First Embodiment]

  FIG. 1 is a schematic view showing the battery module according to the first embodiment. As shown in the figure, the battery module 1 includes an array body 2 in which battery cells 11 are arrayed, and a restraining member 3 that applies a restraining load to the array body 2 in the battery cell array direction. Yes. The battery module 1 is used as a battery of a vehicle such as a forklift.

  The array body 2 includes a plurality (seven bodies in the present embodiment) of battery cells 11. In the present embodiment, the battery cells 11 are arranged in a state of being held by the cell holder 31. The array body 2 includes an elastic body 8 and a temperature control member 41.

  The restraining member 3 includes, for example, a pair of end plates 4 and 4 and a fastening member 5 that fastens the end plates 4 and 4 together. The end plate 4 has, for example, a substantially rectangular plate shape having an area larger than that when the battery cell 11 is viewed from the arrangement direction, and the outer edge portion of the end plate 4 is outside the outer edge portion of the battery cell 11. Are arranged on both ends of the array body 2 in the array direction.

  The fastening member 5 is constituted by, for example, a long bolt 6 and a nut 7 screwed into the bolt 6. The bolt 6 is inserted through the end plate 4 at a position corresponding to the edge of the array 2 at the outer edge portion of the end plate 4, for example. When the nut 7 is screwed onto the tip of each bolt 6 from the outside of the end plate 4, the battery cell 11, the elastic body 8, and the temperature control member 41 are sandwiched and unitized and a restraining load is applied. .

  The elastic body 8 is a member used for the purpose of preventing the battery cell 11 and the end plate 4 from being damaged by a restraining load when the battery cell 11 is expanded. As shown in FIG. 1, the elastic body 8 is formed in a rectangular plate shape by, for example, urethane rubber sponge, and is disposed between the battery cell 11 and the end plate 4 on one end side in the arrangement direction. Examples of other forming materials of the elastic body 8 include ethylene propylene diene rubber (EPDM), chloroprene rubber, and silicon rubber. The elastic body 8 is not limited to rubber and may be a spring material or the like.

  The battery cell 11 which comprises the battery module 1 is a nonaqueous electrolyte secondary battery, such as a lithium ion secondary battery, for example. As shown in FIGS. 2 and 3, the battery cell 11 includes a hollow case 12 having a substantially rectangular parallelepiped shape, for example, and an electrode assembly 13 accommodated in the case 12.

  The case 12 is made of a metal such as aluminum. Further, for example, an organic solvent-based or non-aqueous electrolyte is injected into the case 12. As shown in FIG. 2, the positive terminal 15 and the negative terminal 16 are disposed on the top surface of the case 12 so as to be separated from each other. The positive electrode terminal 15 is fixed to one side in the width direction on the top surface of the case 12 via the insulating member 17, and the negative electrode terminal 16 is fixed to the other side in the width direction on the top surface of the case 12 via the insulating member 18. Has been.

  As shown in FIG. 3, the electrode assembly 13 includes a positive electrode 21, a negative electrode 22, and a separator 23 disposed between the positive electrode 21 and the negative electrode 22. In the electrode assembly 13, the positive electrode 21 is accommodated in the bag-shaped separator 23, and the bag-shaped separator 23 and the negative electrode 22 in which the positive electrode 21 is accommodated are alternately stacked.

  The positive electrode 21 includes a metal foil 21a made of, for example, aluminum foil, and a positive electrode active material layer 21b formed on both surfaces of the metal foil 21a. The positive electrode active material layer 21b is formed including a positive electrode active material and a binder. Examples of the positive electrode active material include composite oxide, metallic lithium, and sulfur. The composite oxide includes, for example, at least one of manganese, nickel, cobalt, and aluminum and lithium. A tab 21 c is formed on the upper edge portion of the positive electrode 21 corresponding to the position of the positive electrode terminal 15. The tab 21 c extends upward from the upper edge portion of the positive electrode 21 and is connected to the positive electrode terminal 15 via the conductive member 24.

  On the other hand, the negative electrode 22 has, for example, a metal foil 22a made of copper foil and a negative electrode active material layer 22b formed on both surfaces of the metal foil 22a. The negative electrode active material layer 22b is formed including a negative electrode active material and a binder. Examples of the negative electrode active material include carbon such as graphite, highly oriented graphite, mesocarbon microbeads, hard carbon, and soft carbon, alkali metals such as lithium and sodium, metal compounds, SiOx (0.5 ≦ x ≦ 1.5 ) And the like, and boron-added carbon. A tab 22 c is formed at the upper edge of the negative electrode 22 in correspondence with the position of the negative electrode terminal 16. The tab 22 c extends upward from the upper edge portion of the negative electrode 22 and is connected to the negative electrode terminal 16 via the conductive portion 25.

  The separator 23 is formed in a bag shape, for example, and accommodates only the positive electrode 21 therein. Examples of the material for forming the separator 23 include a porous film made of a polyolefin resin such as polyethylene (PE) and polypropylene (PP), a woven fabric or a nonwoven fabric made of polypropylene, polyethylene terephthalate (PET), methylcellulose, and the like. The separator 23 is not limited to a bag shape, and a sheet shape may be used.

  Subsequently, the configuration of the cell holder 31 and the temperature control member 41 described above will be described in more detail.

  The cell holder 31 is a member that holds the battery cell 11. The cell holder 31 is formed of a resin material such as polypropylene, for example, and includes a frame body 32, a partition portion 33, a terminal accommodating portion 34, and a bolt guide portion 35 as shown in FIG. The frame 32 includes a bottom plate 36 and a pair of side plates 37 and 37 erected on the edge of the bottom plate 36 in the width direction. The partition portion 33 is a plate-like member provided substantially in parallel with the bottom plate 36. The partition 33 connects the side plates 37 and 37 at a position corresponding to the height of the case 12 of the battery cell 11. With such a configuration, when the battery cell 11 is fitted into the cell holder 31, the bottom surface 12 b of the case 12 and the side surface in the width direction are exposed with the side surface 12 a (see FIG. 3) in the arrangement direction of the case 12 exposed from the frame body 32. 12c (see FIG. 2) is held by the frame 32 of the cell holder 31.

  The terminal accommodating portion 34 is a portion that accommodates the positive electrode terminal 15 and the negative electrode terminal 16 of the battery cell 11. The terminal accommodating portion 34 is provided on the partition portion 33 and surrounds the positive electrode terminal 15 and the negative electrode terminal 16 when the battery cell 11 is fitted in the frame body 32. The bolt guide portion 35 is a portion through which the bolt 6 of the restraining member 3 is inserted. The bolt guide part 35 is provided in the partition part 33 and the bottom plate 36, respectively. The bolt guide portion 35 on the partition 33 side is provided adjacent to the inside of the terminal accommodating portion 34 on the partition 33. Further, the bolt guide portion 35 on the bottom plate 36 side is provided on the bottom surface side of the bottom plate 36 at the end in the width direction of the bottom plate 36.

  The temperature control member 41 is a member used for temperature control of the battery cell 11. As shown in FIGS. 1 and 4, the temperature control member 41 has a plate-like base 42 and a plurality of ribs 43 arranged on one surface side of the base 42. The base 42 is formed of a resin material such as polypropylene, for example, in a rectangular shape having substantially the same dimensions as the side surface 12 a in the arrangement direction of the case 12. Further, the thickness of the base 42 is substantially the same as the thickness of the partition portion 33 of the cell holder 31.

  The ribs 43 are integrally formed with the base 42 by a resin material such as polypropylene as with the base 42. The rib 43 has, for example, a substantially rectangular cross section, and extends from one end side to the other end side in the width direction of the base 42. The thickness of the rib 43 is substantially the same as the thickness of the base 42, and the ribs 43 are arranged substantially parallel to the height direction of the base 42 with an interval corresponding to the thickness.

  As shown in FIG. 4, the temperature control member 41 is attached inward with respect to the cell holder 31 in advance so that the rib 43 faces the space surrounded by the frame body 32 (the holding space for the battery cells 11). Yes. In the state where the battery cell 11 is fitted in the frame body 32 of the cell holder 31, as shown in FIG. 5, the front end surface 43a of the rib 43 provided substantially parallel to the base 42 is in contact with the side surface 12a of the case 12, A rectangular space surrounded by the side surface 12 a of the case 12, the base 42, and the ribs 43, 43 is formed along the extending direction of the ribs 43. The space is used as a flow path S through which a temperature control medium such as cooling air flows.

  The base 42 and the rib 43 of the temperature control member 41 may be formed integrally with the cell holder 31. The temperature control member 41 is preferably attached to the cell holder 31 so that the ribs 43 are disposed in a region overlapping the electrode assembly 13 when viewed from the arrangement direction of the array 2. More specifically, the ribs 43 are arranged so as to overlap the opposing region (see FIG. 3) of the positive electrode active material layer 21b and the negative electrode active material layer 22b in the electrode assembly 13 when viewed from the arrangement direction of the array 2. It is suitable.

  Here, each of the plurality of ribs 43 described above has an inclined surface in which at least a part of the side surface facing the center side in the arrangement direction of the ribs 43 is inclined outward from the center side in the arrangement direction of the ribs 43. . More specifically, in the present embodiment, as shown in FIG. 5, the cross-sectional shape of the rib 43 is a substantially parallelogram shape. The side surface 43b facing the center side in the arrangement direction of the ribs 43 is inclined with an inclination angle θ with respect to the normal line of the base 42, and the entire surface is inclined toward the outside from the center side in the arrangement direction of the ribs 43. K.

  Further, the side surface 43c facing the center side in the arrangement direction of the ribs 43 is also inclined with an inclination angle θ with respect to the normal line of the base 42, as in the side surface 43b, and the entire surface is centered in the arrangement direction of the ribs 43. The inclined surface is inclined from the side toward the outside. In the present embodiment, the inclination angle θ is, for example, 5 ° to 30 °, and the inclination angles θ of the inclined surfaces K of all the ribs 43 are equal to each other.

  The ribs 43 located on one side of the central line L in the arrangement direction of the ribs 43 protrude from the base 42 in a state inclined from the central line L side to the one side, and the ribs 43 are arranged on the central line L in the arrangement direction of the ribs 43. Each of the ribs 43 located on the other side protrudes from the base 42 while being inclined from the center line L side to the other side. The cross-sectional shape of the flow path S (S1) between the ribs 43 and 43 is a parallelogram that is substantially the same as the cross-sectional shape of the rib 43.

  On the other hand, the cross-sectional shape of the flow path S (S2) between the ribs 43 adjacent to each other across the center line L is an isosceles trapezoidal shape that extends from the base 42 toward the side surface 12a of the case 12 in the battery cell 11. I am doing. Therefore, the interval between the adjacent ribs 43, 43 across the center line L is wider than the interval between the other ribs 43, 43, and the cross-sectional area of the flow path S2 is larger than the cross-sectional area of the flow path S1. Is also getting bigger. Therefore, when the battery cell 11 is not expanded, the flow path S2 of the temperature control medium is formed in the vicinity of the center of the battery cell 11 with a sufficient cross-sectional area, and the temperature control efficiency of the battery cell 11 can be sufficiently secured.

  When the battery cell 11 expands due to deterioration or overcharge, the side surface 12a of the case 12 in the battery cell 11 is curved so as to protrude outward with respect to the arrangement direction of the battery cell 11, as shown in FIG. While expanding. The expansion amount of the side surface 12a of the case 12 is the largest in the vicinity of the center line L, and tends to be smaller toward the end portion side of the side surface 12a. Even when the battery cell 11 is expanded, the restraint member 3 continues to apply the restraining load to the array 2. For this reason, the load added to the temperature control member 41 arrange | positioned adjacent to the battery cell 11 increases.

  On the other hand, in the battery module 1, as described above, each of the plurality of ribs 43 of the temperature control member 41 has the entire side surface 43 b facing the center side in the arrangement direction of the ribs 43 in the center in the arrangement direction of the ribs 43. The inclined surface K is inclined from the side toward the outside. Thereby, when the battery cell 11 is expanded, a part of the load applied from the battery cell 11 side is swept away from the center side in the arrangement direction of the ribs 43 by the inclined surface K. Breakage and deformation of the rib 43 can be suppressed as compared with the case where there is no rib (that is, the rib 43 is formed in a simple rectangular cross section). Accordingly, the flow path S of the temperature control medium is maintained even when the battery cell 11 is expanded, and the temperature control efficiency of the battery cell 11 can be sufficiently ensured.

  In addition, if the rib 43 is deformed by the load, a part of the load applied from the battery cell 11 side is applied from the center side in the arrangement direction of the rib 43 to the outside by the inclined surface K. The ribs 43 are deformed so as to fall toward the outside in the arrangement direction. Since the ribs 43 and 43 adjacent to each other with the center line L interposed therebetween are deformed so as to fall in opposite directions, even when the battery cell 11 expands, the flow path S2 of the temperature control medium has a sufficient cross-sectional area. The temperature control efficiency of the battery cell 11 can be sufficiently secured.

  In the present embodiment, in each of the plurality of ribs 43, the entire side surface 43 b facing the center side in the arrangement direction of the ribs 43 is an inclined surface K that is inclined outward from the center side in the rib arrangement direction. For this reason, when the battery cell 11 is not expanded, the flow path S2 of the temperature control medium is further formed in the vicinity of the center of the battery cell with a sufficient cross-sectional area. Further, when the battery cell 11 is expanded, a part of the load applied from the battery cell 11 side is more reliably received by the inclined surface K from the center side in the arrangement direction of the ribs 43 toward the outside.

In the present embodiment, an electrode assembly 13 is accommodated in each battery cell 11, and each battery cell 11 is held by a cell holder 31. The temperature control member 41 is attached to the cell holder 31 so that a plurality of ribs 43 are arranged in a region overlapping the electrode assembly 13 when viewed from the arrangement direction of the array. Thereby, since the flow path S of the temperature control medium is formed close to the electrode assembly 13 with a certain positioning accuracy, the temperature control efficiency by the temperature control member 41 can be improved.
[Second Embodiment]

  FIG. 7 is an enlarged cross-sectional view of a main part of the temperature control member of the battery module according to the second embodiment. As shown in the figure, in the battery module 51 according to the second embodiment, only a part of the side surface 43b facing the center side in the arrangement direction of the ribs 43 is inclined outward from the center side in the arrangement direction of the ribs 43. It is different from the first embodiment in that it has an inclined surface K.

  More specifically, in the battery module 51, the inclined surface K is provided only on the front end side of the side surface 43 b facing the center side in the arrangement direction of the ribs 43. The inclination angle θ of the inclined surface K with respect to the normal line of the base 42 is, for example, 5 ° to 30 °. The side surface 43 c facing the base end side of the side surface 43 b and the outside in the arrangement direction of the ribs 43 is substantially perpendicular to the base 42.

  Even in such a configuration, as in the first embodiment, the interval between the adjacent ribs 43 and 43 across the center line L is wider than the interval between the other ribs 43 and 43, The cross-sectional area of S2 is larger than the cross-sectional area of the flow path S1. Therefore, when the battery cell 11 is not expanded, the flow path S2 of the temperature control medium is formed in the vicinity of the center of the battery cell 11 with a sufficient cross-sectional area, and the temperature control efficiency of the battery cell 11 can be sufficiently ensured.

Further, when the battery cell 11 expands, as shown in FIG. 8, a part of the load applied from the battery cell 11 side is received from the center side in the arrangement direction of the ribs 43 toward the outside by the inclined surface K. Therefore, breakage and deformation of the rib 43 can be suppressed as compared with the case where the inclined surface K is not present (that is, the rib 43 is formed in a simple rectangular cross section). Accordingly, the flow path S of the temperature control medium is maintained even when the battery cell 11 is expanded, and the temperature control efficiency of the battery cell 11 can be sufficiently ensured. Since the ribs 43 and 43 adjacent to each other with the center line L interposed therebetween are deformed so as to fall in opposite directions, even when the battery cell 11 expands, the flow path S2 of the temperature control medium has a sufficient cross-sectional area. The temperature control efficiency of the battery cell 11 can be sufficiently secured.
[Modification]

  The present invention is not limited to the above embodiment. For example, in the first embodiment described above, the inclination angles θ of the inclined surfaces K of all the ribs 43 are equal to each other. However, as shown in FIG. 9, the inclination angle θ of the inclined surface K with respect to the normal of the base 42 is The rib 43 located on the center side in the arrangement direction of the ribs 43 may be larger. As shown in FIG. 10, also in the second embodiment, the inclination angle θ of the inclined surface K with respect to the normal line of the base 42 is larger as the rib 43 located on the center side in the arrangement direction of the ribs 43. Good. When the battery cell 11 expands, the vicinity of the center tends to expand more than the peripheral portion when viewed from the arrangement direction. Therefore, by setting the inclination angle θ of the inclined surface K according to the expansion tendency of the battery cell 11, breakage and deformation of the rib 43 during expansion of the battery cell 11 can be suitably suppressed.

  In both the first embodiment and the second embodiment, the tip surfaces 43a of all the ribs 43 are substantially parallel to the base 42, but the side surface 12a of the case 12 when the battery cell 11 is expanded. Corresponding to the shape, the front end surface 43a of each rib 43 may be along a virtual curved surface that becomes concave toward the base 42 side. In this case, the load received by each rib 43 when the battery cell 11 expands can be made uniform, and breakage and deformation of the rib 43 when the battery cell 11 expands can be suitably suppressed.

  DESCRIPTION OF SYMBOLS 1,51 ... Battery module, 2 ... Array, 3 ... Restraint member, 11 ... Battery cell, 12a ... Side surface, 13 ... Electrode assembly, 31 ... Cell holder, 41 ... Temperature control member, 42 ... Base, 43 ... Rib, 43b: side surface, K: inclined surface, θ: inclination angle.

Claims (5)

An array of battery cells;
A restraining member for applying a restraining load in the arrangement direction of the battery cells to the array body,
The array is provided with a temperature control member for each battery cell,
The temperature control member has a plate-like base and a plurality of ribs arranged on one surface of the base, and the ribs are in contact with the battery cells so that the ribs are in contact with the side surfaces in the arrangement direction of the battery cells. Arranged,
In each of the plurality of ribs, at least a part of the side surface facing the center side in the arrangement direction of the ribs is an inclined surface that is inclined outward from the center side in the arrangement direction of the ribs ,
The battery module is configured such that an inclination angle of the inclined surface with respect to the base increases as the rib is located closer to the center side in the arrangement direction of the ribs .   2. The battery module according to claim 1, wherein in each of the plurality of ribs, the entire side surface facing the center side in the arrangement direction of the ribs is an inclined surface inclined outward from the center side in the arrangement direction of the ribs. .   2. In each of the plurality of ribs, only a part of a side surface facing the center side in the arrangement direction of the ribs is an inclined surface that is inclined outward from the center side in the arrangement direction of the ribs. Battery module. Each battery cell contains an electrode assembly,
Each battery cell is held by a cell holder,
Wherein the temperature control member, any one of claim 1 to 3, wherein the plurality of ribs in a region overlapping with the electrode assembly when viewed from the arrangement direction of the array is attached to the cell holder to be arranged The battery module as described. Of the plurality of ribs, the rib located on one side from the center in the arrangement direction of the ribs protrudes from the base in a state inclined from the center side to the one side,
The rib is any one of claims 1-4 projecting from said base in an inclined on the other side from the center side positioned on the other side from the center of the arrangement direction of the ribs of the plurality of ribs The battery module according to item.

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