JP6500480B2 - Battery module - Google Patents

Description

  The present invention relates to a battery module.

  As a conventional battery module, there exists a battery module of patent document 1, for example. This conventional battery module includes a battery cell, a battery holder, and a laminated body in which end plates are laminated, a constraining band for constraining the laminated body in the laminating direction, and a plurality of elastic bodies having elasticity. It is done. The elastic body has elasticity in the stacking direction of the battery cells, and a plurality of elastic bodies are arranged in a dotted manner in a region where the battery cells and the battery holder face each other in the stacked body.

JP, 2009-81056, A

  By the way, in the battery module described above, there are cases where a temperature control member is interposed between the battery cells from the viewpoint of securing the temperature control efficiency of the battery cells. The temperature control member is configured, for example, by arranging a plurality of ribs at predetermined intervals on one surface side of a plate-like base. In this temperature control member, the space surrounded by the rib and the wall surface of the battery cell can be used as a flow path for the temperature control medium or the like by bringing the end of the rib into contact with the adjacent battery cell.

  However, when the above-mentioned temperature control member is interposed between battery cells, no flow path is formed for the battery cells located at the array end, and the temperature control efficiency of the battery cells located at the array end is located on the center side It may be inferior to the temperature control efficiency of a battery cell. Further, in the battery module, an elastic body such as rubber may be interposed between the array body and the end plate in order to prevent damage to the battery cell and the restraint member due to the restraint load. Such an elastic body can be a factor that reduces the temperature control efficiency of the battery cells located at the array end.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a battery module capable of sufficiently securing the temperature control efficiency of the battery cells located at the arrangement end.

  In order to solve the above-mentioned subject, a battery module concerning one side of the present invention is a battery module provided with a plurality of battery cells formed by storing an electrode assembly, and the battery cell held by a cell holder is a temperature control member And a restraint member for applying a restraint load to the arrangement in the direction of arrangement of the battery cells, wherein the temperature control member protrudes from the cell holder and contacts the adjacent battery cells Between one end side battery cell having a plurality of ribs and located at the array end opposite to the projecting direction of the ribs and the restraint member, it overlaps with the electrode assembly in the battery cell as viewed from the array direction of the array An elastic body is disposed in the area.

  In this battery module, an elastic body is disposed between the one end side battery cell positioned at the arrangement end in the direction opposite to the projecting direction of the rib and the restraint member. Since the ribs projecting from the cell holder holding the one end side battery cell are in contact with the adjacent battery cells, the flow path of the temperature control medium is not directly formed on the one end side battery cell. On the other hand, since the elastic body is disposed in a region overlapping with the electrode assembly in the battery cell when viewed from the arrangement direction of the array, in the region not overlapping with the electrode assembly, the elastic body is not pinched A space where the battery cell and the restraint member face each other is formed. Therefore, by using this space as the flow path of the temperature control medium, the temperature control efficiency of the battery cells located at the array end can be sufficiently secured.

  The elastic body may have a plurality of ribs in contact with the one end battery cell. In this case, when the rib of the elastic body contacts the one end side battery cell, the flow path of the temperature control medium can be formed between the elastic body and the one end side battery cell. Therefore, the temperature control efficiency of the battery cells located at the array end can be further sufficiently secured.

  Further, the other end battery cells positioned at the array end in the same direction as the projecting direction of the ribs may not be held by the cell holder, but may be held by the restraint member in a state of being positioned by the positioning portion. By omitting the cell holder for holding the other end battery cell, the number of arranged cell holders can be reduced. Moreover, since the other end side battery cell can be positioned to a restraint member, the attachment operation | work of a battery cell becomes easy.

  According to this battery module, the temperature control efficiency of the battery cells located at the array end can be sufficiently secured.

FIG. 2 is a schematic diagram illustrating an embodiment of a battery module. It is sectional drawing which shows the structure of the battery cell used for the battery module shown in FIG. It is the III-III sectional view taken on the line in FIG. It is the principal part expansion schematic of the one end side battery cell periphery in the battery module shown in FIG. It is the principal part expansion schematic of a periphery of the other end side battery cell in the battery module shown in FIG.

  Hereinafter, preferred embodiments of the battery module will be described in detail with reference to the drawings.

  FIG. 1 is a view showing an embodiment of a battery module. As shown in the figure, the battery module 1 includes an array 2 in which a plurality of battery cells 11 are arrayed, and an end plate (restraint member for applying a restraint load to the array 2 in the array direction of the battery cells 11 3) and an elastic body 4 interposed between the array body 2 and the end plate 3.

  Array 2 includes, for example, a plurality of (in this case, seven) battery cells 11. The battery cell 11 is, for example, a lithium ion secondary battery. For example, as shown in FIGS. 2 and 3, the battery cell 11 includes a hollow case 12 having, for example, a substantially rectangular parallelepiped shape, and an electrode assembly 13 accommodated in the case 12. The case 12 is formed of, for example, a metal such as aluminum, and, for example, an organic solvent-based or non-aqueous electrolyte solution is injected into the case 12. As shown in FIG. 2, the positive electrode terminal 15 and the negative electrode terminal 16 are disposed apart from each other on the top surface of the case 12. The positive electrode terminal 15 is fixed to one side in the width direction at 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 at the top surface of the case 12 via the insulating member 18 It is done.

  As shown in FIG. 3, the electrode assembly 13 is constituted of, for example, a positive electrode 21, a negative electrode 22, and a bag-like 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 separator 23, and in this state, the positive electrode 21 and the negative electrode 22 are alternately stacked via the separator 23.

  The positive electrode 21 has, for example, a metal foil 21 a made of aluminum foil and a positive electrode active material layer 21 b formed on both sides of the metal foil 21 a. The positive electrode active material layer 21 b is formed to include a positive electrode active material and a binder. Examples of the positive electrode active material include composite oxides, metallic lithium, sulfur and the like. The composite oxide includes, for example, at least one of manganese, nickel, cobalt and aluminum, and lithium. Further, a tab 21 c is formed at 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 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 a metal foil 22a made of, for example, copper foil, and a negative electrode active material layer 22b formed on both sides of the metal foil 22a. The negative electrode active material layer 22 b is formed to include a negative electrode active material and a binder. As the negative electrode active material, for example, graphite, highly oriented graphite, meso carbon micro beads, hard carbon, carbon such as soft carbon, alkali metals such as lithium and sodium, metal compounds, SiO x (0.5 ≦ x ≦ 1.5) Etc., boron-added carbon, and the like. Further, a tab 22 c is formed at the upper edge portion of the negative electrode 22 corresponding to the position of the negative electrode terminal 16. The tab 22 c extends upward from the upper edge of the negative electrode 22 and is connected to the negative electrode terminal 16 via the conductive member 25.

  The separator 23 is formed, for example, in a bag shape, and accommodates only the positive electrode 21 inside. Examples of materials for forming the separator 23 include porous films made of polyolefin resins such as polyethylene (PE) and polypropylene (PP), and woven or non-woven fabrics made of polypropylene, polyethylene terephthalate (PET), methyl cellulose and the like. The separator 23 is not limited to a bag but may be a sheet.

  The end plate 3 is, for example, a plate member made of metal. End plate 3 has, for example, an area larger than that of battery cell 11 as viewed in the arrangement direction, as shown in FIG. 1, and the outer edge portion of end plate 3 is larger than the outer edge portion of battery cell 11. In the state of projecting to the outside, the array 2 and the elastic body 4 are respectively disposed at both ends in the array direction. A plurality of bolts 5 are inserted through the outer edge portions of the end plates 3, 3. The nut 6 is screwed to the tip of each bolt 5 from the outside of the end plate 3, thereby sandwiching the battery cell 11 and the elastic body 4 into a unit and applying a restraining load.

  The elastic body 4 is a member used for the purpose of preventing breakage of the battery cell 11 and the end plate 3 due to a restraint load when the battery cell 11 is expanded or the like. As shown in FIG. 1, the elastic body 4 is formed in a rectangular plate shape by a rubber sponge made of, for example, urethane, and the battery cell 11 at one end side in the arrangement direction (one end side battery cell 11A described later) and the end plate 3 Is placed between. The thickness of the elastic body 4 is equal to or greater than the thickness of the end plate 3. Examples of the material for forming the elastic body 4 include ethylene propylene diene rubber (EPDM), chloroprene rubber, silicone rubber and the like.

  Subsequently, the configurations of the array 2 and the elastic body 4 described above will be described in more detail.

  As shown in FIG. 1, a cell holder 31 is attached to the battery cell 11. The cell holder 31 has a frame 32 integrally molded of, for example, a resin. The frame 32 is fitted in the case 12 along the side surfaces of the case 12 of the battery cell 11 excluding the side surfaces in the arrangement direction of the battery cell 11.

  A temperature control member 33 is provided on one side of the frame 32 of the cell holder 31. The temperature control member 33 is formed of, for example, a resin such as polypropylene, and has a plate-like base 34 and a plurality of ribs 35 having a rectangular cross-section and formed at equal intervals on one surface side of the base 34. The temperature control member 33 has the base 34 as a cell holder 31 so that the other surface side without the rib 35 is in contact with the battery cell 11 and the rib 35 extends outward in the width direction of the battery cell 11 (the depth direction in FIG. 1). The cell holder 31 is attached by being fitted into the frame 32 of

  In the array body 2, the outward ribs 35 protrude outward from the frame 32, and the tips of the ribs 35 are in contact with the case 12 of the adjacent battery cell 11. Therefore, a space S1 surrounded by the base 34, the ribs 35 and 35, and the case 12 of the battery cell 11 is formed between the adjacent battery cells 11 and 11. The space S1 is used, for example, as a flow path through which a temperature control medium such as cooled air flows, and contributes to temperature control of the adjacent battery cells 11.

  By the way, in the configuration in which the outwardly directed ribs 35 are in contact with the adjacent battery cells 11, the battery cells 11 located at the array end opposite to the projecting direction of the ribs 35 (hereinafter referred to as "one end battery cell 11A)" Because there is no rib 35 in contact with the space 31. Therefore, no space S1 surrounded by the base 34, the ribs 35 and 35, and the case 12 of the battery cell 11 is formed for the one end battery cell 11A. In addition, since the elastic body 4 is disposed between the one end side battery cell 11A and the end plate 3, the arrangement of another member for forming the flow passage is also formed. In this case, the temperature control efficiency of the one end battery cell 11A may be inferior to the temperature control efficiency of the other battery cells 11 located on the center side.

  On the other hand, in the battery module 1, as shown in FIG. 4, the dimensions of the elastic body 4 are taken into consideration, and in the region overlapping the electrode assembly 13 in the battery cell 11 when viewed from the arrangement direction of the array 2 Four are arranged. More specifically, in the present embodiment, the elastic body 4 is a region where the positive electrode active material layer 21b and the negative electrode active material layer 22b face each other in the electrode assembly 13 when viewed from the arrangement direction of the array 2 (see FIG. 3) are arranged to overlap.

  In the present embodiment, the elastic body 4 is sized so as not to overlap with the tabs 21 c and 22 c and the conductive members 24 and 25. Therefore, the upper end 12a of the case 12 of the one end battery cell 11A projects beyond the upper end 4a of the elastic body 4 and opposes the end plate 3 with a constant distance. Therefore, a space S2 surrounded by the upper end 12a of the case 12 of the one end battery cell 11A, the upper end 4a of the elastic member 4 and the end plate 3 is formed between the one end battery cell 11A and the end plate 3 Ru.

  Further, in the present embodiment, the positive electrode 21 and the negative electrode 22 are spaced apart from the bottom surface of the case 12 by a constant distance (see FIGS. 2 and 3). Therefore, the lower end portion 12b of the case 12 of the one end battery cell 11A projects beyond the lower end portion 4b of the elastic body 4 and faces the end plate 3 at a constant distance. Therefore, a space S3 surrounded by the lower end 12b of the case 12 of the one end battery cell 11A, the lower end 4b of the elastic body 4 and the end plate 3 is formed between the one end battery cell 11A and the end plate 3 Ru.

  Therefore, in the battery module 1, by arranging the elastic bodies 4 in the array 2, the battery cells 11 and the end plate 3 are protected against the restraint load, and between the end plate 3 and the one end battery cell 11A. By using the spaces S2 and S3 as the flow paths through which the temperature control medium flows, the temperature control efficiency of the one end battery cell 11A can be sufficiently secured.

  Further, as shown in FIG. 4, in the present embodiment, the elastic body 4 has a plurality of ribs 36 having a rectangular cross section formed at equal intervals on the contact surface side with the one end side battery cell 11A. The ribs 36 are arranged to extend in the width direction (the depth direction in FIG. 4) of the battery cell 11. The tip of the rib 36 abuts on the case 12 of the one end battery cell 11A, thereby forming a space S4 surrounded by the elastic body 4, the ribs 36 and 36, and the case 12 of the one end battery cell 11A. Similar to the temperature control member 33, by using the space S4 as a flow path through which the temperature control medium flows, the temperature control efficiency of the one end battery cell 11A can be further sufficiently secured.

  On the other hand, as shown in FIG. 5, the battery cells 11 (hereinafter referred to as “other-end battery cells 11 B”) located at the array end in the same direction as the projecting direction of the ribs 35 of the temperature control member 33 It has not been held. The end plate 3 in contact with the other end battery cell 11B is provided with a positioning portion 37 for positioning the other end battery cell 11B. The positioning portion 37 is a rectangular frame formed of, for example, metal or resin according to the dimensions of the case of the other-end battery cell 11B, and is integrally provided on the end plate 3. The other end battery cell 11B is held by the end plate 3 in a state of being fitted into the positioning portion 37.

  According to such a configuration, the number of arranged cell holders 31 can be reduced by omitting the cell holder for holding the other end side battery cell 11B, so that the cost of the battery module 1 can be reduced. In addition, since the other end side battery cell 11B can be easily positioned on the end plate 3 simply by fitting the battery cell 11B into the frame, the battery cell 11 can be easily assembled.

  The present invention is not limited to the above embodiment. For example, in the above embodiment, the end plates 3 and 3 are fastened by the bolt 5 and the nut 6 to apply a restraint load to the array 2 and the elastic body 4. A plate or the like may be connected, and both ends of the restraining band may be fastened to the end plates 3 and 3 with bolts or the like to apply a restraining load to the array 2 and the elastic body 4.

  Further, in the above embodiment, although the rib 35 of the temperature control member 33 and the rib 36 of the elastic body 4 both extend in the width direction of the battery cell 11, the ribs 35 and 36 have the height of the battery cell 11. It may extend in the longitudinal direction (vertical direction in FIG. 1). Also, the ribs 36 of the elastic body 4 may not necessarily be provided.

  DESCRIPTION OF SYMBOLS 1 ... battery module, 2 ... arrangement body, 3 ... end plate (restraint member), 4 ... elastic body, 11 ... battery cell, 11A ... one end side battery cell, 11B ... other end side battery cell, 13 ... electrode assembly, 31 ... cell holder, 33 ... temperature control member, 35 ... rib, 36 ... rib, 37 ... positioning part.

Claims (3)

A battery module comprising a plurality of battery cells formed by housing an electrode assembly, comprising:
An array formed by arranging the battery cells held by the cell holder via a temperature control member;
And a constraining member for applying a constraining load to the array in the array direction of the battery cells,
The temperature control member has a plurality of ribs projecting from the cell holder and contacting adjacent battery cells,
In a region overlapping with the electrode assembly in the battery cell as viewed from the arrangement direction of the array only between the one end side battery cell positioned at the array end opposite to the projecting direction of the rib and the restraint member Battery module in which an elastic body is disposed.   The battery module according to claim 1, wherein the elastic body has a plurality of ribs in contact with the one end side battery cell.   The other end battery cell positioned at the array end in the same direction as the projecting direction of the rib is not held by the cell holder, but is held by the restraint member in a state of being positioned by the positioning portion. The battery module of 2.

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