Battery pack and thermal management method

Abstract

The invention relates to a battery pack and a thermal management method. The battery pack comprises a battery module, wherein a heat conducting sheet is attached to at least part of the outer surface of the battery module; the battery module is accommodated in the box body; and the heat conduction bonding layer is arranged between the heat conduction sheet and the inner wall of the box body, the heat conduction sheet and the inner wall of the box body are bonded by the heat conduction bonding layer, and the heat conduction sheet is used for transferring heat generated by the battery module to the box body through the heat conduction bonding layer. According to the battery pack provided by the invention, the heat of the battery pack is quickly and uniformly conducted out of the box body by virtue of the light heat-conducting sheet with high heat-conducting property, so that the conduction efficiency of the heat on the surfaces of the battery cells is greatly improved. And meanwhile, the heat-conducting fins can uniformly disperse the heat of the batteries, so that local overheating can be effectively prevented, the problem of temperature uniformity in the batteries and the module is greatly improved, and the service life of the batteries is prolonged.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to a battery pack and a thermal management method. Background Art

[0002] With the rapid development of new energy vehicles, the performance and safety of power batteries have become key technical challenges. If the heat generated by the battery during operation cannot be effectively managed, it will affect the battery life and safety of use, so battery cooling technology came into being.

[0003] In the related technologies, battery cooling technologies include air cooling, liquid cooling, etc. These technologies have the following shortcomings in terms of heat dissipation efficiency and temperature uniformity. Air cooling system: The surface temperature of the battery cell is taken away by air flow. The poor thermal conductivity of air leads to poor heat dissipation, especially the battery cells inside the whole package are prone to local overheating. In addition, the temperature uniformity of the whole package of air cooling is poor, which affects the performance and life of the battery cell. Liquid cooling system: Compared with the air cooling system, the liquid has better thermal conductivity and can take away heat faster, but the liquid cooling plate is generally installed in the same box as the battery cell, which has the risk of leakage, and the liquid cooling plate is generally placed at the bottom or side of the box. The problem of single battery cell and uneven temperature of the whole package still exists.

[0004] However, the battery thermal management in the related art still has shortcomings in the uniformity of battery temperature when dissipating heat from the battery. Summary of the invention

[0005] In order to solve or partially solve the problems existing in the related art, the present application provides a battery pack and a thermal management method, which can solve the problem of temperature uniformity within the battery and the module, and achieve efficient and uniform heat dissipation of the battery and the battery cell.

[0006] A first aspect of the present application provides a battery pack, comprising:

[0007] A battery module, wherein a heat conductive sheet is attached to at least a portion of the outer surface of the battery module;

[0008] A box body, in which the battery module is accommodated;

[0009] The thermally conductive adhesive layer is disposed between the thermally conductive sheet and the inner wall of the box body. The thermally conductive adhesive layer bonds the thermally conductive sheet to the inner wall of the box body. The thermally conductive sheet is used to transfer the heat generated by the battery module to the box body via the thermally conductive adhesive layer.

[0010] Preferably, the battery module comprises a plurality of battery cells, the plurality of battery cells are arranged in sequence, the thermal conductive sheet is attached to at least a portion of the outer surface of the battery cells, and adjacent battery cells are separated by the thermal conductive sheet.

[0011] Preferably, the box body is square, and comprises end plates at both ends in the length direction, side plates at both sides in the width direction, bottom plates at both sides in the height direction, and an upper cover;

[0012] The battery cell is square in shape, has a first side surface in the length direction, and a second side surface in the width direction, the area of ​​the second side surface is smaller than the first side surface, and the thermal conductive sheet is attached to the first side surface and the bottom surface of the battery cell.

[0013] Preferably, the side plate is pressed against the second side surfaces of the multiple battery cells in the width direction, the end plate is pressed against the first side surfaces of the battery cells adjacent to the end plate, the bottom plate is pressed against the bottom surfaces of the multiple battery cells, and the upper cover is pressed against the top surfaces of the multiple battery cells.

[0014] Preferably, there are a plurality of heat conducting sheets, and the plurality of heat conducting sheets include a first heat conducting sheet and a second heat conducting sheet.

[0015] The first heat conductive sheet includes a first attachment portion extending in the height direction of the battery module and a second attachment portion extending in the length direction; the second heat conductive sheet includes two first attachment portions extending in the height direction of the battery module and a second attachment portion extending in the length direction;

[0016] The battery core includes first battery cores respectively close to the two end plates and a plurality of second battery cores between two of the first battery cores;

[0017] The first attachment portion of the first heat conductive sheet is attached to the first side surface of the first battery core away from the end plate, and the second attachment portion of the first heat conductive sheet is attached to the bottom surface of the first battery core;

[0018] The two first attachment portions of the second heat conductive sheet are attached to two first side surfaces of the second battery core that are opposite to each other, and the second attachment portion of the second heat conductive sheet is attached to the bottom surface of the second battery core.

[0019] Preferably, a metal heat conducting member is embedded in the second attaching portion of the first heat conducting sheet and / or the second heat conducting sheet.

[0020] Preferably, an immersion cooling structure, a liquid cooling structure, an air cooling structure or a phase change material cooling structure is provided outside the box body for dissipating heat from the box body.

[0021] Preferably, the thermally conductive sheet is made of graphite or carbon nanotube composite material.

[0022] Preferably, the thermally conductive adhesive layer is a thermally conductive adhesive; or,

[0023] The material of the box is metal.

[0024] Preferably, the battery cell is a square battery cell, a cylindrical battery cell or a soft-pack battery cell.

[0025] A second aspect of the present application provides a thermal management method for a battery pack, comprising:

[0026] A heat conductive sheet is attached to at least a portion of the outer surface of the battery module;

[0027] A box is provided to accommodate the battery module;

[0028] A heat-conducting adhesive layer is provided between the heat-conducting sheet and the inner wall of the box body to bond the heat-conducting sheet to the inner wall of the box body, and the heat conducted from the battery module to the heat-conducting sheet is conducted to the box body via the heat-conducting adhesive layer.

[0029] Preferably, the box body is cooled by an immersion cooling structure; or,

[0030] Dissipate heat from the box through a liquid cooling structure; or,

[0031] Dissipate heat from the box through an air cooling structure; or

[0032] The box body is cooled by a phase change material cooling structure.

[0033] The technical solution provided by the present application may include the following beneficial effects: by attaching a heat conductive sheet to at least part of the outer surface of the battery module, accommodating the module in a box, and providing a combined design of a heat conductive adhesive layer between the heat conductive sheet and the inner wall of the box, the heat of the battery pack is quickly and evenly conducted to the outside of the box by means of a heat conductive sheet with high thermal conductivity and light weight, greatly improving the heat conduction efficiency of the battery cell surface. At the same time, the heat conductive sheet can evenly disperse the heat of the battery, effectively preventing local overheating, greatly improving the temperature uniformity problem in the battery and module, and extending the battery life.

[0034] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and other objects, features and advantages of the present application will become more apparent by describing in more detail the exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0036] Figure 1 is a schematic diagram of the structure of a battery pack shown in an embodiment of the present application;

[0037] Figure 2 It is a schematic diagram of the structure of the middle cell of the module in the battery pack shown in the embodiment of the present application;

[0038] Figure 3 is a schematic diagram of the structure of a box in a battery pack shown in an embodiment of the present application;

[0039] Figure 4a and Figure 4b is a schematic diagram of the structure of a heat conducting sheet in a battery pack shown in an embodiment of the present application;

[0040] Figure 5 is a schematic diagram of the structure of a liquid storage tank in a battery pack shown in an embodiment of the present application;

[0041] Figure 6 It is a flow chart of the thermal management method of the battery pack shown in the embodiment of the present application.

[0042] Reference numerals: module 110 ; battery cell 111 ; heat conductive sheet 120 ; housing 130 ; end plate 131 ; side plate 132 ; upper cover 133 ; heat conductive adhesive layer 140 ; ​​aerogel 150 ; liquid storage tank 160 ; liquid inlet 161 ; liquid outlet 162 . DETAILED DESCRIPTION

[0043] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0044] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0045] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0046] In the related art, battery cooling technologies include air cooling, liquid cooling, etc. These technologies have the following shortcomings in terms of heat dissipation efficiency and temperature uniformity. Air cooling system: The surface temperature of the battery cell is taken away by air flow. The poor thermal conductivity of air leads to poor heat dissipation, especially the battery cells inside the whole package are prone to local overheating. In addition, the temperature uniformity of the whole package of air cooling is poor, which affects the performance and life of the battery cell. Liquid cooling system: Compared with the air cooling system, the liquid has better thermal conductivity and can take away heat faster, but the liquid cooling plate is generally installed in the same box as the battery cell, which has the risk of leakage, and the liquid cooling plate is generally placed at the bottom or side of the box. The problem of uneven temperature of the single battery cell and the whole package still exists. When the battery thermal management in the related art dissipates heat from the battery, the uniformity of the battery temperature is still insufficient.

[0047] In view of the above problems, an embodiment of the present application provides a battery pack that can solve the problem of temperature uniformity within the battery and the module, and achieve efficient and uniform heat dissipation of the battery and the battery cell.

[0048] The technical solution of the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0049] Figure 1 It is a schematic diagram of the structure of a battery pack shown in an embodiment of the present application.

[0050] See also Figure 1 , the battery pack includes:

[0051] A battery module 110, wherein a heat conducting sheet 120 is attached to at least a portion of the outer surface of the battery module 110;

[0052] A box body 130 , in which the battery module 110 is accommodated;

[0053] The thermally conductive adhesive layer 140 is disposed between the thermally conductive sheet 120 and the inner wall of the box body 110 . The thermally conductive adhesive layer 140 bonds the thermally conductive sheet 120 to the inner wall of the box body 120 . The thermally conductive sheet 120 is used to transfer the heat generated by the battery module 110 to the box body 130 via the thermally conductive adhesive layer 140 .

[0054] The battery pack in this embodiment is a battery pack to be cooled or heated, and can achieve two-way management of cooling and heating. In high-temperature scenarios, the battery pack is cooled, and in low-temperature scenarios (such as low-temperature driving, low-temperature charging), the battery pack is heated.

[0055] The battery pack includes a battery module 110, and a heat conductive sheet 120 is attached to at least part of the outer surface of the battery module 110. The high thermal conductivity of the heat conductive sheet 120 can quickly transfer the heat of the battery module 110 to the surface of the heat conductive sheet 120. The heat conductive sheet 120 can evenly disperse the heat of the battery module, solving the problem of uneven heat dissipation.

[0056] The battery module 110 is accommodated in the housing 130 , and the heat conducted from the battery module 110 to the heat conductive sheet 120 can be transferred to the housing 130 .

[0057] A heat conductive adhesive layer 140 is provided between the heat conductive sheet 120 and the inner wall of the box 130, and the heat conductive adhesive layer 140 bonds the heat conductive sheet 120 to the inner wall of the box 120, so that the heat generated by the battery module 110 is transferred to the box 130 via the heat conductive adhesive layer 140. The heat of the battery pack can be transferred from "battery module → heat conductive sheet → heat conductive adhesive layer → box".

[0058] In an optional embodiment of the present application, the battery module 110 includes a plurality of battery cells 111 , which are arranged in sequence, and a thermal conductive sheet 120 is attached to at least a portion of the outer surface of the battery cells 111 , and adjacent battery cells 111 are separated by the thermal conductive sheet 120 .

[0059] The box body 130 is square in shape, and includes end plates 131 arranged at both ends in the length direction, side plates 132 arranged at both sides in the width direction, bottom plates and an upper cover 133 arranged at both sides in the height direction;

[0060] The battery cell 111 is square in shape and has a first side surface in the length direction and a second side surface in the width direction. The area of ​​the second side surface is smaller than the first side surface. The thermal conductive sheet 120 is attached to the first side surface and the bottom surface of the battery cell 111 .

[0061] The side plate 132 is pressed against the second side surfaces of the battery cells 111 in the width direction, the end plate 131 is pressed against the first side surfaces of the battery cells 111 adjacent to the end plate, the bottom plate is pressed against the bottom surfaces of the battery cells 111, and the upper cover 133 is pressed against the top surfaces of the battery cells 111.

[0062] There are multiple heat conducting sheets 120, including a first heat conducting sheet and a second heat conducting sheet.

[0063] The first heat conductive sheet includes a first attachment portion extending in the height direction of the battery module and a second attachment portion extending in the length direction; the second heat conductive sheet includes two first attachment portions extending in the height direction of the battery module and a second attachment portion extending in the length direction;

[0064] The battery cell 111 includes a first battery cell respectively close to two end plates and a plurality of second battery cells between the two first battery cells;

[0065] The first attachment portion of the first heat conductive sheet is attached to the first side surface of the first battery cell away from the end plate, and the second attachment portion of the first heat conductive sheet is attached to the bottom surface of the first battery cell;

[0066] The two first attachment portions of the second heat conducting sheet are attached to the two first side surfaces of the second battery core that are opposite to each other, and the second attachment portion of the second heat conducting sheet is attached to the bottom surface of the second battery core.

[0067] A plurality of battery cells 111 are connected in series or in parallel according to actual needs, and are arranged in sequence to obtain a battery module 110. A heat conductive sheet 120 is attached to a portion of the outer surface of the battery cell 111. Adjacent battery cells 111 are separated by the heat conductive sheet 120. The heat conductive sheets 120 are pressed together by using aerogel 150, so that the battery module 110 has good pressing force. Figure 2 , which is a schematic structural diagram of the middle battery cell 111 of the battery module 110 .

[0068] like Figure 3 As shown, it is a schematic diagram of the box 130. The box 130 is a closed square box, including end plates 131 at both ends in the length direction, side plates 132 on both sides in the width direction, and bottom plates and upper covers 133 on both sides in the height direction. The battery module 110 can be encapsulated in the box 130. Among them, the materials of the end plates 131 and the side plates 132 can be the same or different, and the embodiment of the present application does not limit this. In addition, fins are provided on the outer surface of the box 130 to enhance heat exchange.

[0069] The battery cell 111 is square, and is provided with a first side surface in the length direction and a second side surface in the width direction. The area of ​​the second side surface is smaller than the first side surface. The thermal conductive sheet 120 is attached to the first side surface and the bottom surface of the battery cell 111. The thermal conductivity of the thermal conductive sheet 120 in the X and Y directions is high (2-5 times higher than that of aluminum). The high thermal conductivity of the thermal conductive sheet 120 in the X and Y directions can quickly transfer the heat from the first and second sides of the battery cell 111 to the surface of the thermal conductive sheet 120.

[0070] The side plate 132 of the box body 130 is pressed against the second side of the plurality of battery cells 111 in the width direction, the end plate 131 of the box body 130 is pressed against the first side of the battery cell 111 adjacent to the end plate 131, the bottom plate is pressed against the bottom surface of the plurality of battery cells 111, the heat conductive sheet 120 on the bottom surface of the battery cell 111 is pressed against the heat conductive adhesive layer 140, the heat conductive adhesive layer 140 is connected to the box body 130, and the upper cover is pressed against the top surface of the plurality of battery cells 111. Among them, the material of the box body 130 can be metal. The battery module 110 is tightly pressed against the end plate 131, the side plate 132, the bottom surface and the top surface 133, which not only ensures mechanical stability but also enhances heat conduction.

[0071] The heat conducting sheet 120 may be provided in plurality, including a first heat conducting sheet and a second heat conducting sheet, wherein the first heat conducting sheet is L-shaped, such as Figure 4a As shown, it includes a first attachment portion extending along the height direction of the battery module and a second attachment portion extending along the length direction; the second heat conductive sheet is U-shaped, such as Figure 4bAs shown, it includes two first attachment parts extending in the height direction of the battery module and a second attachment part extending in the length direction. The multiple battery cells 111 include first battery cells respectively close to the two end plates and multiple second battery cells between the two first battery cells. The first attachment part of the first thermal conductive sheet is attached to the first side surface of the first battery cell away from the end plate, and the second attachment part of the first thermal conductive sheet is attached to the bottom surface of the first battery cell; the two first attachment parts of the second thermal conductive sheet are attached to the two first side surfaces opposite to each other of the second battery cell, and the second attachment part of the second thermal conductive sheet is attached to the bottom surface of the second battery cell. A metal thermal conductive part is embedded in the second attachment part of the first battery cell and the second battery cell, and the metal thermal conductive part is in contact with the bottom surface of the battery cell 111. The metal thermal conductive part can improve the thermal conductivity of the thermal conductive sheet 120 in the Z direction. By contacting the metal thermal conductive part with the bottom surface of the battery cell 111, it can be ensured that the heat at the bottom of the battery can also be quickly conducted away. The heat conducting sheet 120 is relatively light, and has relatively high thermal conductivity in the X and Y directions. The thermal conductivity is improved in the Z direction by embedding a metal heat conducting member, thereby ensuring high thermal conductivity in all directions of the heat conducting sheet 120. The length and width of the metal heat conducting member can be the same as the length and width of the bottom of the heat conducting sheet 120, and the thinner the better. The metal heat conducting member can be a metal foil, and the metal foil can be made of a material with high thermal conductivity, such as copper foil or aluminum foil.

[0072] The heat conducting sheet 120 may be graphite or carbon nanotube composite material. Graphite sheet can evenly disperse the heat of the battery. Carbon nanotube composite material is a new type of material with better thermal conductivity and lower density, which can improve the thermal conductivity of the battery pack and reduce the weight of the battery pack.

[0073] In an optional embodiment of the present application, the box body 130 is provided with an immersion cooling structure, a liquid cooling structure, an air cooling structure or a phase change material cooling structure outside the box body for dissipating heat from the box body.

[0074] Furthermore, the box 130 can also be cooled by an immersion cooling structure, a liquid cooling structure, an air cooling structure or a phase change material cooling structure. Preferably, an immersion cooling structure can be used for heat dissipation, such as Figure 5As shown, it is a schematic diagram of a liquid storage tank 160. The box body 130 is immersed in the liquid storage tank 160 filled with coolant. The liquid storage tank 160 is provided with a liquid inlet 161 and a liquid outlet 162. The liquid inlet 161 and the liquid outlet 162 can introduce coolant and flow out coolant. The coolant is in a flowing state in the liquid storage tank 160. When the heat of the battery pack is transferred to the box body 130, the coolant flows through the outer wall of the box body 130 to take away the heat. The battery module 110 is encapsulated in the box body 130 to avoid direct contact between the coolant and the battery cell 111, thereby reducing the risk of leakage. This immersion cooling method enables the coolant to exchange heat with the box body 130 efficiently and evenly, thereby reducing the maximum temperature and maximum temperature difference of the battery pack. In addition, the inner wall of the liquid storage tank 160 is also provided with fins to enhance heat exchange. By quickly transferring the heat conducted on the heat conductive sheet 120 to the box body 130, and then dissipating the heat through the coolant, an efficient thermal management system is formed. The heat of the battery can be evenly dispersed by the heat conductive sheet 120, and combined with the all-round contact of immersion cooling, local overheating can be effectively prevented, greatly improving the temperature uniformity problem in the battery and module, and extending the battery life. Furthermore, by realizing heat exchange between the battery cell and the coolant outside the box, the risk of damage to the battery cell caused by coolant leakage is avoided, the leakage problem is solved, and the safety of the battery is ensured. At the same time, there is no need to consider the problem of liquid leakage during subsequent battery maintenance, which is convenient for maintenance.

[0075] Furthermore, the battery cell in this embodiment may be a square shell battery cell, a cylindrical battery cell, a soft pack battery cell or the like.

[0076] The embodiment of the present application provides a battery pack, which is designed by attaching a heat conductive sheet to at least part of the outer surface of the battery module, accommodating the module in a box, and providing a heat conductive adhesive layer between the heat conductive sheet and the inner wall of the box, and using a heat conductive sheet with high thermal conductivity and light weight to quickly and evenly conduct the heat of the battery pack to the outside of the box, greatly improving the heat conduction efficiency of the battery cell surface. At the same time, the heat conductive sheet can evenly disperse the heat of the battery, effectively preventing local overheating, greatly improving the temperature uniformity problem in the battery and module, and extending the battery life.

[0077] Figure 6 1 is a flow chart of a thermal management method for a battery pack shown in an embodiment of the present application. The method is applied to the battery pack of the above embodiment.

[0078] See also Figure 6 , the method comprising:

[0079] Step 601, attaching a heat conductive sheet to at least a portion of the outer surface of the battery module;

[0080] A thermal conductive sheet is attached to the outer surface of the battery module of the battery pack. The high thermal conductivity of the thermal conductive sheet can quickly transfer the heat of the battery module to the surface of the thermal conductive sheet. The thermal conductive sheet can evenly disperse the heat of the battery module, solving the problem of uneven heat dissipation.

[0081] Step 602, configuring a box body, and accommodating the battery module in the box body;

[0082] The battery module is housed in the box, and the heat conducted from the battery module to the heat conductive sheet can be transferred to the box.

[0083] Step 603, a thermally conductive adhesive layer is provided between the thermally conductive sheet and the inner wall of the box body to bond the thermally conductive sheet to the inner wall of the box body, and the heat conducted from the battery module to the thermally conductive sheet is conducted to the box body via the thermally conductive adhesive layer.

[0084] A heat-conducting adhesive layer is provided between the heat-conducting sheet and the inner wall of the box, and the heat-conducting adhesive layer bonds the heat-conducting sheet to the inner wall of the box, so that the heat generated by the battery module is transferred to the box through the heat-conducting adhesive layer. The heat of the battery pack can be transferred from "battery module → heat-conducting sheet → heat-conducting adhesive layer → box".

[0085] In an optional embodiment, the heat of the box is dissipated through an immersion cooling structure; or, the heat of the box is dissipated through a liquid cooling structure; or, the heat of the box is dissipated through an air cooling structure; or, the heat of the box is dissipated through a phase change material cooling structure.

[0086] Furthermore, the box body can also be cooled, and an immersion cooling structure, a liquid cooling structure, an air cooling structure or a phase change material cooling structure can be used for heat dissipation.

[0087] The embodiment of the present application provides a thermal management method for a battery pack, which is designed by attaching a thermal conductive sheet to at least part of the outer surface of the battery module, accommodating the module in a box, and providing a thermal conductive adhesive layer between the thermal conductive sheet and the inner wall of the box. The heat of the battery pack is quickly and evenly conducted to the outside of the box by means of a thermal conductive sheet with high thermal conductivity and light weight, greatly improving the conduction efficiency of heat on the surface of the battery cell. At the same time, the thermal conductive sheet can evenly disperse the heat of the battery, effectively preventing local overheating, greatly improving the temperature uniformity problem in the battery and module, and extending the battery life.

[0088] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A battery pack, characterized in that: include: A battery module, wherein a heat conductive sheet is attached to at least a portion of the outer surface of the battery module; A box body, in which the battery module is accommodated; The thermally conductive adhesive layer is disposed between the thermally conductive sheet and the inner wall of the box body. The thermally conductive adhesive layer bonds the thermally conductive sheet to the inner wall of the box body. The thermally conductive sheet is used to transfer the heat generated by the battery module to the box body via the thermally conductive adhesive layer.

2. The battery pack according to claim 1, characterized in that: The battery module includes a plurality of battery cells, which are arranged in sequence. The heat conductive sheet is attached to at least a portion of the outer surface of the battery cells, and adjacent battery cells are separated by the heat conductive sheet.

3. The battery pack according to claim 2, characterized in that: The box body is square in shape, and comprises end plates at both ends in the length direction, side plates at both sides in the width direction, bottom plates at both sides in the height direction, and an upper cover; The battery cell is square in shape, has a first side surface in the length direction, and a second side surface in the width direction, the area of ​​the second side surface is smaller than the first side surface, and the thermal conductive sheet is attached to the first side surface and the bottom surface of the battery cell.

4. The battery pack according to claim 3, characterized in that: The side plate is pressed against the second side surfaces of the plurality of battery cells in the width direction, the end plate is pressed against the first side surfaces of the battery cells adjacent to the end plate, the bottom plate is pressed against the bottom surfaces of the plurality of battery cells, and the upper cover is pressed against the top surfaces of the plurality of battery cells.

5. The battery pack according to claim 3, characterized in that: There are multiple heat conducting sheets, and the multiple heat conducting sheets include a first heat conducting sheet and a second heat conducting sheet. The first heat conductive sheet includes a first attachment portion extending in the height direction of the battery module and a second attachment portion extending in the length direction; the second heat conductive sheet includes two first attachment portions extending in the height direction of the battery module and a second attachment portion extending in the length direction; The battery core includes first battery cores respectively close to the two end plates and a plurality of second battery cores between two of the first battery cores; The first attachment portion of the first heat conductive sheet is attached to the first side surface of the first battery core away from the end plate, and the second attachment portion of the first heat conductive sheet is attached to the bottom surface of the first battery core; The two first attachment portions of the second heat conductive sheet are attached to two first side surfaces of the second battery core that are opposite to each other, and the second attachment portion of the second heat conductive sheet is attached to the bottom surface of the second battery core.

6. The battery pack according to claim 3, characterized in that: The second attachment portion of the first heat conducting sheet and / or the second heat conducting sheet is embedded with a metal heat conducting member.

7. The battery pack according to claim 1, characterized in that: The box body is provided with an immersion cooling structure, a liquid cooling structure, an air cooling structure or a phase change material cooling structure for dissipating heat from the box body.

8. The battery pack according to any one of claims 1 to 7, characterized in that: The heat conducting sheet is made of graphite or carbon nanotube composite material.

9. The battery pack according to any one of claims 1 to 7, characterized in that: The thermally conductive adhesive layer is a thermally conductive adhesive; or, The material of the box is metal.

10. The pool package according to claim 2, characterized in that: The battery cell is a square battery cell, a cylindrical battery cell or a soft-pack battery cell.

11. A thermal management method for a battery pack according to any one of claims 1 to 10, characterized in that: include: A heat conductive sheet is attached to at least a portion of the outer surface of the battery module; A box is provided to accommodate the battery module; A heat-conducting adhesive layer is provided between the heat-conducting sheet and the inner wall of the box body to bond the heat-conducting sheet to the inner wall of the box body, and the heat conducted from the battery module to the heat-conducting sheet is conducted to the box body via the heat-conducting adhesive layer.

12. The method according to claim 11, characterized in that Dissipate heat from the box through an immersion cooling structure; or, Dissipate heat from the box through a liquid cooling structure; or, Dissipate heat from the box through an air cooling structure; or The box body is cooled by a phase change material cooling structure.

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