Battery pack

Abstract

The utility model relates to the technical field of energy storage equipment, in particular to a battery pack which comprises an outer shell and a module installed in the outer shell, the outer shell comprises an upper shell body and a lower shell body which are connected with each other, the module comprises a plurality of soft package battery cells, and the upper shell body is a cold plate in direct contact with the soft package battery cells. The utility model aims to provide a battery pack aiming at at least one technical problem related in the prior art.

Description

Technical Field

[0001] This application relates to the technical field of energy storage devices, and more particularly, to a battery pack. Background Art

[0002] With the continuous development of electric vehicles, the market share of electric vehicles is getting higher and higher. The cost of the battery pack greatly limits its popularization, and it is imperative to develop a battery pack with extremely low cost. In some types of existing battery packs, although some efforts have been made to simplify the structure of the battery pack, the effect of reducing the cost of the battery pack is not obvious. Utility Model Content

[0003] The purpose of this application is to provide a battery pack for at least one technical problem involved in the background art.

[0004] To achieve the above object, this application adopts the following technical solutions:

[0005] This application provides a battery pack, which includes a housing and a module installed in the housing. The housing includes an upper housing and a lower housing connected to each other. The module includes a plurality of soft-pack battery cells. The upper housing is a cold plate in direct contact with each of the soft-pack battery cells.

[0006] Optionally, the lower housing is a trough, the upper housing is plate-shaped, and the upper housing covers and is fixed to the notch of the lower housing.

[0007] The beneficial effect of this technical solution is that: compared with making the upper housing also adopt a trough structure, making the upper housing plate-shaped is easier to process the upper housing into a cold plate, or an existing plate-shaped cold plate can be directly used, further reducing the design and production costs.

[0008] Optionally, the soft-pack battery cell includes an aluminum-plastic film, and a strip-shaped weak part is formed on the aluminum-plastic film. The thickness of the film at the weak part is less than the thickness of the film at other positions on the aluminum-plastic film.

[0009] The beneficial effect of this technical solution is that: in this way, when the soft-pack battery cell is thermally out of control, it will first leak out directionally at the weak part. Compared with arranging other explosion-proof valves and other structures on the aluminum-plastic film, the structure of the soft-pack battery cell is more streamlined and the manufacturing cost is lower.

[0010] Optionally, the lower housing is a trough, the soft-pack battery cells in the module are arranged in sequence in a first direction, a support plate for supporting the module is installed in the lower housing, a diversion groove extending in the first direction is formed on the support plate, the weak part is disposed opposite to the diversion groove, an explosion-proof valve is provided on the housing, and the diversion groove is communicated with the explosion-proof valve.

[0011] The beneficial effects of this technical solution are as follows: In this way, when the gas in the soft-pack battery cell explodes, it can be received by the diversion grooves on the support plate and guided to the explosion-proof valve for discharge, so that the exploded gas is not likely to affect other soft-pack battery cells.

[0012] Optionally, the soft-pack battery cell includes a positive electrode tab and a negative electrode tab. The positive electrode tab and the negative electrode tab are the two ends of the soft-pack battery cell in the second direction. In the third direction, each soft-pack battery cell is hermetically connected to the support plate. The first direction, the second direction, and the third direction are perpendicular to each other in pairs.

[0013] The beneficial effects of this technical solution are as follows: In this way, the function of thermoelectric separation can be realized, so that the flue gas exploding from the soft-pack battery cell is not likely to enter other positions of the battery pack after entering the diversion groove, and thus is not likely to affect other positions of the battery pack, reducing the risk of arcing during thermal runaway of the battery pack. At the same time, since both the support plate and the upper housing are in direct contact with the soft-pack battery cell and both perform the functions of the side plates of the traditional soft-pack module, this enables the module itself not to be provided with a strengthening structure, but to use the lower housing and the upper housing as a cold plate to strengthen the module, integrating the functions of cooling, module protection, and module structure support into the upper housing, saving the side plates mentioned above, not only reducing the volume of the battery pack, but also reducing the manufacturing cost of the battery pack.

[0014] Optionally, the support plate is a plate member including a plurality of U-shaped structures.

[0015] The beneficial effects of this technical solution are as follows: By using a support plate including U-shaped structures, the bottom of the lower housing can be strengthened, and thus the protection effect on the module can be enhanced. Especially in the case of ball impact, it is more beneficial to protect the weak positions of the soft-pack battery cells.

[0016] Optionally, the module further includes a flexible circuit board and a plug-in. The positive electrode tabs of each soft-pack battery cell are directly connected to one flexible circuit board, and the negative electrode tabs of each soft-pack battery cell are directly connected to another flexible circuit board. The plug-in is fixed only at one end of the flexible circuit board in the first direction, and the first direction is the arrangement direction of each soft-pack battery cell.

[0017] The beneficial effects of this technical solution are as follows: In this way, the voltages of each soft-pack battery cell are collected through the flexible circuit board, replacing the traditional bus bar, streamlining the structure, reducing the size and manufacturing cost of the battery pack, and moreover, the tabs are made of relatively soft materials, which can absorb the dimensional changes caused by the compression and relaxation of the module.

[0018] Optionally, the module further includes sheet-shaped end plates. At one end of the module in the first direction is one sheet-shaped end plate, and at the other end of the module is another sheet-shaped end plate. The first direction is the arrangement direction of each soft-pack battery cell.

[0019] The beneficial effects of this technical solution are as follows: Compared with the existing end plates with complex structures and large thicknesses, the sheet-shaped end plates adopted in the embodiments of the present application have a smaller thickness and a simple structure. This not only reduces the space occupied by the end plates, improves the energy density of the battery pack, but also reduces the materials used for manufacturing the end plates and lowers the manufacturing cost.

[0020] Optionally, the module further includes an output pole base, and the output pole base is integrally formed with the sheet-shaped end plate.

[0021] The beneficial effects of this technical solution are as follows: In this way, an integrated design and molding of the end plate and the output pole base are achieved, integrating their functions together and reducing the manufacturing cost.

[0022] Optionally, the battery pack provided by the present application includes two modules, and the two modules are arranged in parallel within the housing.

[0023] The beneficial effects of this technical solution are as follows: This makes full use of the space formed by enclosing the upper housing and the lower housing. Compared with a structure where one housing corresponds to one module, the production cost is reduced.

[0024] The technical solution provided by the present application can achieve at least one of the following beneficial effects:

[0025] For the battery pack provided by the present application, by adopting soft-pack battery cells, the hard outer shell of the traditional battery cells is removed, reducing the manufacturing cost of a single battery cell. Since a battery pack generally uses multiple battery cells, the use of soft-pack battery cells in the battery pack can significantly reduce the manufacturing cost of the battery pack. And, by designing the upper housing as a cold plate, or designing the cold plate as the upper housing, compared with the existing structural form of a battery pack that includes both a cold plate and an upper housing, the number of parts used is reduced, thereby effectively reducing the manufacturing cost of the battery pack.

[0026] The additional technical features and their advantages of the present application will be more clearly described in the following description content, or can be understood through the specific practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the specific embodiments of the present application, the drawings required for use in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0028] Figure 1 It is an exploded structural schematic diagram of an embodiment of the battery pack provided by the embodiment of the present application;

[0029] Figure 2 Explosion structure schematic diagram of an embodiment of the module provided by the present application;

[0030] Figure 3 Stereo structure schematic diagram of an embodiment of the module provided by the present application;

[0031] Figure 4 Is Figure 3 Partial enlarged schematic diagram at position A in

[0032] Figure 5 Cross-sectional structure schematic diagram of an embodiment of the battery pack provided by the present application;

[0033] Figure 6 Is Figure 5 Partial enlarged schematic diagram at position B in

[0034] Figure 7 Bottom view structure schematic diagram of an embodiment of the soft package battery cell provided by the present application;

[0035] Figure 8 Is Figure 7 Partial enlarged schematic diagram at position C in

[0036] Figure 9 Stereo structure schematic diagram of an embodiment of the lower housing provided by the present application.

[0037] Reference numerals:

[0038] 01, upper housing; 02, module;

[0039] 03, BDU; 04, BMS;

[0040] 05, lower housing; 06, flexible circuit board;

[0041] 07, plug-in; 08, soft package battery cell;

[0042] 09, output pole base; 10, sheet end plate;

[0043] 11, foam; 12, positive pole tab;

[0044] 13, support plate; 14, diversion groove;

[0045] 15, negative pole tab; 16, weak part;

[0046] 17, explosion-proof valve. Detailed implementation manners

[0047] The technical solution of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the protection scope of the present application.

[0048] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0049] In the description of the present application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific situations.

[0050] As Figures 1 to 9 shown, the present application provides a battery pack, including a housing and a module 02 installed in the housing. The housing includes an upper housing 01 and a lower housing 05 connected to each other. The module 02 includes a plurality of soft-pack battery cells 08, and the upper housing 01 is a cold plate in direct contact with each of the soft-pack battery cells 08.

[0051] In the battery pack provided by the present application, by adopting the soft-pack battery cells 08, the hard outer shell of the traditional battery cells is removed, reducing the manufacturing cost of a single battery cell. Since a battery pack generally uses a plurality of battery cells, the use of soft-pack battery cells 08 in the battery pack can significantly reduce the manufacturing cost of the battery pack; and, by designing the upper housing 01 as a cold plate, or designing the cold plate as the upper housing 01, compared with the existing structure of the battery pack that includes both a cold plate and an upper housing 01, the number of parts used is reduced, thereby effectively reducing the manufacturing cost of the battery pack.

[0052] Optionally, the lower housing 05 is a trough, and the upper housing 01 is plate-shaped. The upper housing 01 covers and is fixed to the notch of the lower housing 05. Compared with making the upper housing 01 also have a trough structure, making the upper housing 01 plate-shaped is easier to process the upper housing 01 into a cold plate, or an existing plate-shaped cold plate can be directly used, further reducing the design and production costs.

[0053] Optionally, the soft-pack battery cell 08 includes an aluminum-plastic film, and strip-shaped weak parts 16 are formed on the aluminum-plastic film. The film thickness of the weak parts 16 is smaller than the film thickness at other positions on the aluminum-plastic film. In this way, when the soft-pack battery cell 08 undergoes thermal runaway, it will first leak out directionally at the weak parts 16. Compared with arranging other explosion-proof valves and other structures on the aluminum-plastic film, the structure of the soft-pack battery cell 08 is more concise and the manufacturing cost is lower. In the embodiment of the present application, the weak parts 16 can be realized by engraving strip-shaped grooves on the outer wall of the aluminum-plastic film. It can be understood that the weakness in the weak parts 16 means that the strength at the weak parts 16 is weaker than the strength at other positions on the aluminum-plastic film.

[0054] Optionally, the lower housing 05 is a trough, and the soft-pack battery cells 08 in the module 02 are arranged in sequence in the first direction. A support plate 13 for supporting the module 02 is installed in the lower housing 05. A diversion groove 14 extending in the first direction is formed on the support plate 13. The weak parts 16 are arranged opposite to the diversion groove 14. An explosion-proof valve 17 is arranged on the outer shell, and the diversion groove 14 is communicated with the explosion-proof valve 17. In this way, when the gas in the soft-pack battery cell 08 explodes, it can be received by the diversion groove 14 on the support plate 13 and guided to the explosion-proof valve 17 for discharge, so that the exploded gas is not likely to affect other soft-pack battery cells 08. In the embodiment of the present application, preferably, adjacent soft-pack battery cells 08 are isolated by foam 11 to prevent heat diffusion. Moreover, when the soft-pack battery cells 08 are installed in the lower housing 05, the reduced size of the compressed module 02 can be achieved by compressing the foam 11, thereby facilitating the assembly of the module 02 into the lower housing 05.

[0055] Optionally, the pouch cell 08 includes a positive electrode tab 12 and a negative electrode tab 15. The positive electrode tab 12 and the negative electrode tab 15 are at both ends of the pouch cell 08 in the second direction. In the third direction, each pouch cell 08 is hermetically connected to the support plate 13. The first direction, the second direction, and the third direction are perpendicular to each other pairwise. In this way, the function of thermoelectric separation can be realized, so that the flue gas bursting out from the pouch cell 08 is not easy to enter other positions of the battery pack after entering the diversion groove 14, and thus it is not easy to affect other positions of the battery pack, reducing the risk of arcing when the battery pack is out of control thermally. At the same time, since both the support plate 13 and the upper shell 01 are in direct contact with the pouch cell 08 and both perform the functions of the side plates of the traditional pouch module 02, this enables the module 02 itself not to be provided with a strengthening structure, but to use the lower shell 05 and the upper shell 01 as a cold plate to strengthen the module 02, integrating the functions of cooling, protection of the module 02, and structural support of the module 02 into the upper shell 01, saving the side plates mentioned above, not only reducing the volume of the battery pack, but also reducing the manufacturing cost of the battery pack.

[0056] Optionally, the support plate 13 is a plate member including a plurality of U-shaped structures. By adopting the support plate 13 including U-shaped structures, the bottom of the lower shell 05 can be strengthened, and further the protection effect on the module 02 can be enhanced. Especially in the case of ball impact, it is more beneficial to protect the weak positions of the pouch cell 08.

[0057] Optionally, the module 02 further includes a flexible circuit board 06 and a plug 07. The positive electrode tabs 12 of each pouch cell 08 are directly connected to one flexible circuit board 06, and the negative electrode tabs 15 of each pouch cell 08 are directly connected to another flexible circuit board 06. The plug 07 is fixed only at one end of the flexible circuit board 06 in the first direction, and the first direction is the arrangement direction of each pouch cell 08. In this way, the voltage of each pouch cell 08 is collected through the flexible circuit board 06, replacing the traditional bus bar, streamlining the structure, reducing the size and manufacturing cost of the battery pack, and moreover, the tabs are made of relatively soft materials, which can absorb the dimensional changes caused by the compression and relaxation of the module 02. In the embodiment of the present application, the flexible circuit board 06 is preferably welded to the tabs.

[0058] Optionally, the module 02 further includes a sheet-shaped end plate 10. At one end of the module 02 in the first direction is one sheet-shaped end plate 10, and at the other end of the module 02 is another sheet-shaped end plate 10, and the first direction is the arrangement direction of each pouch cell 08. Compared with the existing end plates with complex structures and larger thicknesses, the sheet-shaped end plate 10 adopted in the embodiment of the present application has a smaller thickness and a simple structure, not only reducing the space occupied by the end plate, improving the energy density of the battery pack, but also reducing the materials used for manufacturing the end plate and reducing the manufacturing cost.

[0059] Optionally, the module 02 further includes an output pole base 09, and the output pole base 09 is integrally formed with the sheet-shaped end plate 10. In this way, the integrated design and molding of the end plate and the output pole base 09 are achieved, enabling the integration of their functions and reducing the manufacturing cost. In the embodiment of the present application, the sheet-shaped end plate 10 and the output pole base 09 are integrally formed by an injection molding method.

[0060] Optionally, the battery pack provided in the embodiment of the present application includes two of the modules 02, and the two modules 02 are arranged in parallel within the housing. This makes full use of the space formed by the enclosure of the upper housing 01 and the lower housing 05, and reduces the production cost compared to one housing corresponding to one module 02.

[0061] In the embodiment of the present application, the battery pack further includes a BDU 03 (battery pack disconnect unit) and a BMS 04 (battery management system) installed within the housing.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. Battery pack, characterized in that, It includes a housing and a module installed inside the housing. The housing includes an upper housing and a lower housing connected to each other. The module includes a plurality of soft-pack battery cells. The upper housing is a cold plate in direct contact with each of the soft-pack battery cells. The lower housing is a trough, and the upper housing is plate-shaped. The upper housing covers and is fixed to the notch of the lower housing. The soft-pack battery cell includes an aluminum plastic film, and a strip-shaped weak part is formed on the aluminum plastic film. The thickness of the film at the weak part is less than the thickness of the film at other positions on the aluminum plastic film. The lower housing is a trough. The soft-pack battery cells in the module are arranged in sequence in a first direction. A support plate for supporting the module is installed in the lower housing. A diversion groove extending in the first direction is formed on the support plate. The weak part is arranged opposite to the diversion groove. An explosion-proof valve is arranged on the housing, and the diversion groove is communicated with the explosion-proof valve.

2. The battery pack according to claim 1, characterized in that, The soft-pack battery cell includes a positive pole ear and a negative pole ear. The positive pole ear and the negative pole ear are the two ends of the soft-pack battery cell in a second direction. In a third direction, each of the soft-pack battery cells is hermetically connected to the support plate. The first direction, the second direction, and the third direction are perpendicular to each other pairwise.

3. The battery pack according to claim 1, characterized in that, The support plate is a plate member including a plurality of U-shaped structures.

4. The battery pack according to any one of claims 1 to 3, characterized in that, The module further includes a flexible circuit board and a plug-in. The positive pole ears of each of the soft-pack battery cells are directly connected to one of the flexible circuit boards, and the negative pole ears of each of the soft-pack battery cells are directly connected to the other flexible circuit board. The plug-in is fixed only at one end of the flexible circuit board in the first direction. The first direction is the arrangement direction of each of the soft-pack battery cells.

5. The battery pack according to any one of claims 1 to 3, characterized in that, The module further includes a sheet-shaped end plate. One end of the module in the first direction is one of the sheet-shaped end plates, and the other end of the module is the other sheet-shaped end plate. The first direction is the arrangement direction of each of the soft-pack battery cells.

6. The battery pack according to claim 5, characterized in that, The module further includes an output pole base, and the output pole base is integrally formed with the sheet-shaped end plate.

7. The battery pack according to any one of claims 1 to 3, characterized in that, It includes two of the modules, and the two modules are arranged side by side inside the housing.

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