JP2013051100A - Battery temperature control module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery temperature adjustment module capable of effectively adjusting the temperature without causing an increase in size.
In the battery temperature control module according to the present invention, the refrigerant is circulated in a space formed between a battery cell having a thick central portion with respect to a peripheral portion and a frame having a refrigerant passage. I decided to let them.
[Selection] Figure 7

Description

  The present invention relates to a battery temperature adjustment module capable of adjusting the temperature of a battery.

  Patent Document 1 discloses a battery temperature control module that cools an assembled battery by filling a cooling liquid into a container in which the assembled battery is housed and circulating the cooling liquid using a pump.

JP 2003-346924 A

  However, in the technique disclosed in Patent Document 1, since the entire assembled battery including the electrode tab portion is immersed in the coolant, the size of the module is increased, such as an increase in the size of the container and an increase in the flow rate of the coolant. There was a problem of inviting.

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a battery temperature adjustment module capable of effectively adjusting the temperature without causing an increase in size.

  In order to achieve the above object, in the battery temperature control module of the present invention, in a space formed between a battery cell having a thick central portion with respect to a peripheral portion and a frame having a refrigerant passage. It was decided to distribute the refrigerant.

  Therefore, since the space formed between the frame body and the entire battery cell is used without being immersed, the entire module can be downsized while the temperature of the battery is effectively controlled.

It is an external view of the module can provided with the battery temperature control module of Example 1. It is a disassembled perspective view of the module can of Example 1. FIG. FIG. 3 is an exploded perspective view of the battery cell of Example 1. It is AA sectional drawing of the module can of Example 1. FIG. FIG. 3 is an enlarged partial cross-sectional view of a B part of the module can of Example 1. It is CC sectional drawing of the module can of Example 1. FIG. It is DD sectional drawing of the module can of Example 1. FIG. It is DD sectional drawing of the module can of the modification 1. FIG. It is DD sectional drawing of the module can of the modification 2. FIG. It is a characteristic view showing the heat transfer performance per unit mass.

  FIG. 1 is an external view of a module can including the battery temperature control module according to the first embodiment. The module can (battery storage container) has a rectangular parallelepiped bottomed shape and includes a module can body portion 1 that houses the battery cell 8 therein, and a module can lid portion 6 that closes the module can body portion 1. The module can lid 6 is welded to the helicopter 7 of the module can body 1 by laser welding or the like after the battery cell 8 is accommodated in the module can body 1 to seal the module can. A through hole 6a for penetrating the plus electrode 2 and the minus electrode 3 is formed in the module can lid portion 6, and the substantially cylindrical plus electrode 2 and minus electrode 3 are formed so as to protrude from the through hole 6a. Is provided. For example, an O-ring or the like is provided in the through hole 6a to ensure liquid tightness.

  On the short side surface of the module can body 1, the inlet pipe 4 through which the coolant flows into the module can body 1 and the coolant after the heat is removed from the battery cell 8 accommodated in the module can body 1 flow out. And an outlet pipe 5 (distribution means). The cooling liquid is temperature-controlled by a temperature control system (not shown) and then returned to the module can at an appropriate temperature and flow rate. FIG. 2 is an exploded perspective view of the module can according to the first embodiment. The module can has a sealed can structure, and is structured to avoid the outflow of the cooling liquid to the outside.

  FIG. 3 is an exploded perspective view of the battery cell according to the first embodiment. The battery cell 8 is a plate-shaped laminate cell 9 having electrode tabs 15, and frame-shaped cell holders 10, 11, 12, 13, 14 (which are sized to cover the periphery of the laminate cell 9 ( Frame body) are alternately combined. The laminate cell 9 (battery cell) has a peripheral portion 9a that is crimped by a laminate pack, and a central portion 9b that is thicker than the peripheral portion 9a. The cell holders 10 to 14 are formed of an insulator such as resin, and current-carrying members 16 and 17 are selectively integrally formed at a portion that contacts the electrode tab 15. Thereby, the laminate cells 9 are electrically connected in series or in parallel. Details of the electrical connection method will be described later.

  In the cell holders 10 to 14, recesses 18 are formed at positions corresponding to the opening positions of the inlet pipe 4 and the outlet pipe 5. A flow hole 19 that penetrates to the laminate cell 9 side is formed at substantially the center of the bottom of the recess 18. A leaf spring 20 that presses and holds the laminate cell 9 toward the inner side in the stacking direction on the cell holders 10 and 14 (frame bodies positioned on the outer side in the stacking direction) positioned at both ends when the laminate cells 9 are stacked and combined. (Spring member) is integrally formed. The dimensions of the battery cell 8 obtained by stacking and combining the laminate cell 9 and the cell holders 10 to 14 are designed to be an interference fit to the module can body 1 so that pressurization is applied to the laminate cell 9. It is configured.

  FIG. 4 is a cross-sectional view of the module can of Example 1 taken along line AA. The plus electrode 2 and the energizing member 16 are integrated, and the energizing member 16 and the electrode tab 15 of the laminate cell 9 are laminated so as to be in electrical contact. The electrode tab 15 provided on the other end side of the laminate cell of the energizing member 16 is configured to contact the energizing member 17 and be electrically connected to the tab electrode of the adjacent laminate cell 9. Similarly, in the case of Example 1, four laminate cells 9 are connected in series and finally connected to the negative electrode 3.

  As described above, the cell holders 10 to 14 and the laminate cell 9 are stacked, and at the same time, electrical bonding is possible, and the number of parts and the number of assembly steps can be greatly reduced. Further, since only the positive electrode 2 and the negative electrode 3 penetrate from the module can, it is easy to ensure liquid tightness. Furthermore, the liquid tightness can be further improved by bonding the cell holders 10 to 14 and the module can with an adhesive or the like. The leaf spring 20 is integrally formed with the cell holders 10 and 14 at the ends, and is configured to press the laminate cell 9 when laminating.

  FIG. 5 is an enlarged partial cross-sectional view of part B of the module can according to the first embodiment. While the current-carrying member 17 and the electrode tab 15 of the laminate cell 9 are in electrical contact, the cell holders 10 to 14 are interposed so as to sandwich or cover the laminate weld end 21 (joint portion between the peripheral portion 9a and the electrode tab 15). Are stacked. Further, an electrically insulating filling adhesive 22 is filled and sealed so as to fill a gap between the cell holders 10 to 14 and the laminate weld end 21. Accordingly, the sealing property of the end portion of the laminate cell 9 can be reinforced by the filling adhesive 22, and the coolant passage 23 (between the frame body and the battery cell) is provided between the laminate cell 9 and the cell holders 10-14. Formed space). In addition, by using the filling adhesive 22, it is possible to design a dimension giving priority to the contact between the current-carrying members 16 and 17 and the electrode tab 15, and electrical connection can be easily ensured.

  6 is a cross-sectional view of the module can of Example 1 taken along the line CC. The coolant flowing in from the inlet pipe 4 cools the laminate cell 9 through the coolant passage 23 (see FIG. 5) and flows out from the outlet pipe 5. The coolant flows through the entire periphery of the edge of the laminate cell 9, and in the vicinity of the electrode tab 15. Although the coolant does not contact the central portion of the laminate cell 9, it can be cooled by the coolant directly contacting the peripheral portion of the laminate cell 9 because the laminate cell 9 has a large thermal conductivity in the plane direction. Further, by cooling the periphery of the electrode tab 15, it is possible to effectively cool with a small amount of liquid.

  FIG. 7 is a cross-sectional view taken along the line DD of the module can according to the first embodiment. The coolant that has flowed in from the inlet pipe 4 recovers the pressure in the recessed portions 18 provided in the cell holders 10 to 14, and flows into the respective coolant passages 23 through the flow holes 19. Thereby, the cooling flow rate around the plurality of cells is equalized. In Example 1, the inlet pipe 4 and the outlet pipe 5 are provided vertically upward on the same side in order to ensure gas-liquid separation in the module can and to be compact. Therefore, the length 24 in the height direction of the cooling passage on the inlet pipe 4 and outlet pipe 5 side is formed shorter than the length 25 in the height direction of the cooling passage on the opposite side via the laminate cell 9. As a result, the lower part of the laminate cell 9 is cooled by passing through the vicinity of the electrode tab 15 rather than the coolant flow rate (see the flow indicated by the arrow A in FIG. 6) flowing out from the inlet pipe 4 to the outlet pipe 5 immediately. The coolant flow rate (refer to the flow indicated by arrow A in FIG. 6) in the path from cooling the tab 15 to the outlet pipe 5 is set to be larger.

[Modification 1]
Next, a first modification of the first embodiment will be described. Since the basic configuration is the same as that of the first embodiment, only different points will be described. FIG. 8 is a DD cross-sectional view of the module can of the first modification. In the module can of the first modification, a flow hole 26 (a passage through which the refrigerant flows) through which the cooling liquid flows into the space between the module can body 1 and the leaf spring 20 from the recess 18 that distributes the cooling liquid. Is different from the first embodiment. Thereby, the center part of the laminate cell 9 can be cooled, and the cooling performance is further improved. Here, if the amount of the coolant flowing into the cell central portion is too large, the flow rate of the coolant around the electrode tab may be lowered, so it is necessary to consider the balance with the increase in the heat transfer amount from the central portion. Therefore, the opening area of the circulation hole 26 is set smaller than that of the other circulation holes 19 so that these are comprehensively determined and the heat transfer performance is improved.

[Modification 2]
Next, Modification 2 will be described. Since the basic configuration is the same as that of the first embodiment, only different points will be described. FIG. 9 is a sectional view taken along the line DD of the module can of the second modification. In the module can of the second modification, a material having good thermal conductivity and flexibility (for example, a heat conductive gel material) is embedded in the space between the module can body 1 and the leaf spring 20. Is. As a result, it is possible to extract heat from the cell center without causing the coolant to flow as in the first modification, and it is possible to further improve the performance while maintaining the heat conduction performance around the electrode tab. .

Next, effects of the first embodiment, the first and second modifications, and the comparative example will be described with reference to the drawings. The comparative example is a type in which the entire battery cell is immersed in a refrigerant, and corresponds to that described in Patent Document 1. FIG. 10 is a characteristic diagram showing heat transfer performance per unit mass. The horizontal axis is the reciprocal of the mass, and the vertical axis is the heat transfer performance, which means that better characteristics are obtained toward the upper right in FIG. Here, effects of the first embodiment will be listed.
(A) The amount of coolant can be reduced.
Since the electrode tab 15 is covered with the cell holders 10 to 14, the coolant passage is reduced and the amount of coolant can be reduced. Since the cell holders 10 to 14 are formed of an insulator such as resin, the density is small with respect to the coolant.

(B) A lightweight coolant can be used.
In the prior art, since the electrode tab is also immersed in the liquid, it is necessary to use a highly insulating cooling liquid. As the highly insulating cooling liquid, a fluorine-based liquid can be mentioned, but the density is considerably high. On the other hand, in Example 1, since the electrode tab 15 is sealed, for example, lightweight oil such as silicon oil can be used. Silicon oil is about half as dense as fluorine-based liquids.

(C) The coolant flow rate around the electrode tab is improved.
In Example 1, since it is set as the structure which lets a cooling fluid flow through the peripheral part 9a of the lamination cell 9 so that especially the tab vicinity can be cooled intensively, the heat transfer coefficient here improves. In the prior art, since the whole is immersed, it is not always possible to secure a coolant flow rate at a location to be cooled, such as around the tab. In particular, since the parts are concentrated around the electrode tab and the structure is complicated, the coolant tends to stay.

(D) The thermophysical properties of the coolant are improved.
For the same reason as in (C) above, a coolant with high thermophysical properties can be used. Compared with fluorine-based coolant, the silicon oil system has large specific heat and thermal conductivity, and can improve the heat transfer coefficient.

(E) Anisotropy of thermal conductivity of laminate cell Since the laminate cell 9 is formed by laminating sheet-like electrodes inside, the thermal conductivity in the cell vertical direction with respect to the thermal conductivity in the cell plane direction. The rate is very low. Therefore, the area contribution of the cell peripheral part is larger than the area contribution of the cell central part (plane part). In Example 1, since the central part 9b is not immersed in the coolant, the heat transfer area is reduced as a whole, but the peripheral part 9a having a large contribution is intensively cooled.

That is, in the example, it is possible to realize an improvement in heat transfer performance and a reduction in weight as compared with the comparative example. Although not shown, since the space between the module can and the laminate cell 9 that was originally a waste space is used as the coolant passage, the size can be greatly reduced. Further, it is not necessary to use an expensive fluorine-based refrigerant and the amount of liquid can be reduced, so that the cost can be reduced.
In addition, since only the positive electrode portion and the negative electrode portion are used as the seal portion, and sealing is performed on both sides of the seal with the cell holders 10 to 14 and the seal with the module can, reliability can be ensured.

As described above, in the first embodiment, the following operational effects can be obtained.
(1) A laminate cell 9 (battery cell) having a peripheral portion 9a and a thick central portion 9b with respect to the peripheral portion 9a, a refrigerant passage 19, and a plurality of coverings of the peripheral portion 9a of the laminate cell 9 The cell holders 10 to 14 (frame body) and the cell holders 10 to 14 are stacked, and the laminate cell 9 is disposed therebetween, and between the cell holders 10 to 14 and the laminate cell 9 through the refrigerant passage of the cell holders 10 to 14. An inlet pipe 4 and an outlet pipe 5 (circulation means) for circulating the refrigerant in the formed space were provided.
Therefore, since the space formed between the cell holders 10 to 14 is used without immersing the entire laminate cell 9, the refrigerant flow rate can be suppressed, and the entire module can be reduced in size while effectively regulating the battery temperature. Can be achieved.

(2) The laminate cell 9 has the electrode tab 15 in the peripheral portion 9a, and the cell holders 10 to 14 are formed of an insulating material and cover the joint portion between the peripheral portion 9a and the electrode tab 15. Laminated.
Therefore, it is possible to avoid electrical contact between the laminate cell 9 and the refrigerant while effectively controlling the temperature of the laminate cell 9.

(3) Since the cell holders 10 to 14 have the current-carrying member 16 at a position where they overlap in the stacking direction of the electrode tab 15 and the cell holders 10 to 14, the electrode tabs are joined separately after the laminate cell 9 and the cell holders 10 to 14 are stacked. Such a process can be eliminated, and the assembly workability can be improved.

(4) It has a module can (battery storage container) for storing the laminate cell 9 and the cell holders 10 to 14, and a part of the energization member 16 protrudes from the module can.
Therefore, it is possible to prevent leakage of the refrigerant to the outside while facilitating electrical connection between the laminate cell 9 housed inside the module can and the outside of the module can.

(5) The cell holders 10 and 14 located on the outer side in the stacking direction have a leaf spring 20 (spring member) that pressurizes the laminate cell 9 toward the inner side in the stacking direction.
Therefore, it is not necessary to separately provide a member for suppressing the expansion of the laminate cell 9, and a reduction in the number of parts can be achieved.

(6) The central portion 9b of the laminate cell 9 is in contact with the central portion 9b of the adjacent laminate cell 9.
Therefore, the refrigerant can be circulated only in the periphery of the laminate cell, and the amount of the refrigerant can be reduced while ensuring the temperature control performance.

  (7) The refrigerant is a liquid. Therefore, the heat exchange efficiency between the laminate cell 9 and the refrigerant can be improved by using the liquid refrigerant.

(8) In the first modification, the cell holders 10 and 14 located on the outer side in the stacking direction have a passage through which a refrigerant flows between the leaf spring 20 and the module can.
Therefore, since heat removal from the central portion 9b can be expected, the heat transfer performance is improved as compared with the first embodiment. Here, since the flow rate to the central portion 9b can be reduced so that the refrigerant flow rate at the peripheral portion of the electrode tab 15 does not drop significantly, the central portion 9b is secured while ensuring the heat transfer performance of the electrode tab 15. Heat transfer path from can be added. In addition, although it increases compared with Example 1 about mass, since the liquid quantity of an electrode tab peripheral part can be reduced and a lightweight cooling fluid can be used, weight reduction is possible rather than a comparative example.

(9) In the second modification, a member having thermal conductivity and flexibility is provided between the leaf spring 20 and the module can.
Therefore, since the heat transfer path from the central portion 9b can be added while maintaining the coolant flow rate around the electrode tab, the heat transfer performance can be improved as compared with the first modification. On the other hand, a flexible heat transfer body generally has a high density, and its mass is larger than that of the first modification. However, by using a fluorine-based coolant, it is possible to reduce the weight as compared with the comparative example having a large amount of coolant.

  (10) The inner dimension of the module can is set to be an interference fit with respect to the outer dimension of the battery cell 8. Therefore, the electrical connection between the current-carrying members 16 and 17 and the electrode tab 15 in the battery cell 8 and the sealing property between the insulating cell holders 10 to 14 can be ensured.

  (11) An electric insulating filling adhesive 22 is filled and sealed so as to fill a gap between the cell holders 10 to 14 and the laminate weld end 21. Thereby, the sealing property of the end part of the laminate cell 9 can be reinforced by the filling adhesive 22. In addition, by using the filling adhesive 22, it is possible to design a dimension giving priority to the contact between the current-carrying members 16 and 17 and the electrode tab 15, and electrical connection can be easily ensured.

  As mentioned above, although this invention was demonstrated based on the Example and the modification, not only the said embodiment but another structure is also included in this invention. For example, in the embodiment, the cooling of the battery cell 8 has been mainly described.

DESCRIPTION OF SYMBOLS 1 Module can body part 2 Positive electrode 3 Negative electrode 4 Inlet pipe 5 Outlet pipe 6 Module can lid part 6a Through-hole 8 Battery cell 9 Laminate cell 9a Peripheral part 9b Center part 10, 11, 12, 13, 14 Cell holder 15 Electrode tab 16, 17 Current-carrying member 20 Leaf spring 22 Filling adhesive 23 Coolant passage

Claims (9)

A battery cell having a peripheral part and a central part thick with respect to the peripheral part;
A plurality of frames having a refrigerant passage and covering the periphery of the battery cell;
A circulation means for laminating the plurality of frames, arranging battery cells therebetween, and circulating a refrigerant in a space formed between the frame and the battery cells via a refrigerant passage of the frame; ,
A battery temperature control module comprising: The battery temperature control module according to claim 1,
The battery cell has an electrode tab on the periphery,
The frame body is formed of an insulating material and is laminated so as to cover a joint portion between the peripheral portion and the electrode tab. The battery temperature control module according to claim 2,
The battery body temperature regulation module, wherein the frame body has a current-carrying member at a position overlapping in the stacking direction of the electrode tab and the frame body. In the battery temperature control module according to claim 3,
A battery storage container for storing the battery cell and the frame;
A battery temperature control module, wherein a part of the energization member protrudes from the battery storage container. The battery temperature control module according to any one of claims 1 to 4,
The battery temperature control module, wherein the frame body positioned on the outer side in the stacking direction includes a spring member that pressurizes the battery cells toward the inner side in the stacking direction. The battery temperature control module according to claim 5,
The battery temperature control module, wherein the frame body located on the outer side in the stacking direction has a passage through which a refrigerant flows between the spring member and the battery storage container. The battery temperature control module according to claim 5,
A battery temperature control module comprising a member having thermal conductivity and flexibility between the spring member and the battery storage container. The battery temperature control module according to any one of claims 1 to 7,
The battery temperature control module, wherein a central portion of the battery cell is in contact with a central portion of an adjacent battery cell. The battery temperature control module according to any one of claims 1 to 8,
The battery temperature control module, wherein the refrigerant is a liquid.

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