Battery pack and energy storage system

Abstract

The invention relates to the technical field of energy storage, in particular to a battery pack and an energy storage system. The battery pack comprises a shell, a battery cell, a power converter and a heat conduction piece, the battery cell and the power converter are accommodated in the shell, and the power converter and the battery cell are arranged along a first direction; a heat insulation layer is arranged between the battery cell and the power converter, and a heat insulation layer is arranged between the battery cell and the heat conduction piece; the shell comprises a first side wall and a second side wall which are oppositely arranged along a second direction; the heat conduction part comprises a first heat conduction face and a second heat conduction face, the first heat conduction face faces the power converter in the first direction and is connected with the power converter, the second heat conduction face deviates from the battery cell in the second direction, the second heat conduction face is used for being connected with a radiator arranged outside the first side wall, and the second direction is perpendicular to the first direction. The risk of heat crosstalk between the power converter and the battery cell is low, and the heat dissipation effect of the battery pack can be improved.

Description

Technical Field

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

[0002] With the development of energy storage systems towards high energy and high integration, compared with traditional battery packs, the battery pack with a non-module structure has greater advantages.

[0003] The heat generated by the battery cells during charging and discharging will affect the charging and discharging process and the lifespan of the battery cells. For an energy storage system equipped with a power conversion module, there is also a risk of heat transfer and cross-heating between the heat dissipation of the power conversion module and the battery cells. Currently, the non-module battery pack uses a liquid cooling plate to cool the battery cells, and this cooling solution is not suitable for the household energy storage scenario. Summary of the Invention

[0004] This application provides a battery pack and an energy storage system, in which the heat dissipation of the battery cells and the power converter are isolated from each other, and the heat dissipation effect can be improved.

[0005] In a first aspect, this application provides a battery pack, which includes a housing, battery cells, a power converter, and a heat conducting member; the battery cells and the power converter are accommodated in the housing, and the power converter and the battery cells are arranged along a first direction; an insulating layer is provided between the battery cells and the power converter, and an insulating layer is provided between the battery cells and the heat conducting member; the housing includes a first side wall and a second side wall that are oppositely arranged along a second direction; the heat conducting member includes a first heat conducting surface and a second heat conducting surface, the first heat conducting surface faces the power converter along the first direction, the first heat conducting surface is connected to the power converter, the second heat conducting surface faces away from the battery cells along the second direction, and the second heat conducting surface is used to connect a radiator provided outside the first side wall, and the second direction is perpendicular to the first direction.

[0006] In the above battery pack, the power converter and the battery cells are thermally isolated by the insulating layer, which can prevent the higher-temperature power converter from baking the lower-temperature battery cells. The heat generated by the power converter can be absorbed by the heat conducting member through the first heat conducting surface of the heat conducting member, and the heat conducting member then transfers the heat to the externally provided radiator through the second heat conducting surface and exports it to the external environment. The direction of heat export of the second heat conducting surface is the second direction, avoiding the first direction in which the battery cells and the power converter are arranged, which can reduce the influence of the heat conduction of the power converter on the battery cells. The risk of cross-heating between the power converter and the battery cells and between the heat transfer link of the power converter and the heat transfer link of the battery cells can be reduced, and the heat dissipation effect of the battery pack can be improved.

[0007] In one embodiment, along the second direction, the surface of the battery cell facing away from the heat conducting member is connected to the inner surface of the second side wall. The battery cell is in thermally conductive contact with the inner wall of the housing to establish a heat transfer link. The heat generated by the battery cell can be transferred to the housing through direct contact, and then the heat is transferred to the external environment through natural convection and radiative convection between the housing and the external environment. There is a gap between the surface of the battery cell facing the heat conducting member and the first side wall, which can reduce the risk of heat crosstalk between the power converter and the battery cell and between the heat transfer link of the power converter and the heat transfer link of the battery cell.

[0008] In one embodiment, the battery pack further includes a radiator disposed outside the first side wall, and the radiator is connected to the second heat conducting surface. As a part of the structure of the battery pack, the radiator improves the heat dissipation performance of the battery pack itself.

[0009] In one embodiment, the heat conducting member is entirely accommodated in the housing, which is convenient for connecting the heat conducting member to the power converter; the second heat conducting surface is connected to the inner surface of the first side wall along the second direction, and the second heat conducting surface can be connected to the radiator through the first side wall.

[0010] In one embodiment, the housing includes a first outer shell and a second outer shell. The first outer shell and the second outer shell enclose a space for accommodating the battery cell and the power converter, and a heat insulation structure is provided at the connection between the first outer shell and the second outer shell; the first side wall is a part of the first outer shell, and the second side wall is a part of the second outer shell. By thermally isolating the first outer shell and the second outer shell, heat transfer between the heat conducting member and the battery cell through the housing is avoided.

[0011] In one embodiment, the battery pack further includes a battery cell bottom plate, insulating thermal conductive glue, and a heating element. The bottom of the battery cell is fixed to the battery cell bottom plate through the insulating thermal conductive glue; the heating element is fixed to the surface of the battery cell bottom plate facing away from the battery cell, and the heat insulation layer between the battery cell and the power converter is disposed between the heating element and the power converter. The battery cell bottom plate can provide support for the battery cell and play a role in heat equalization. The heating element is fixed to the battery cell bottom plate and is not easily detached, ensuring the heating effect. The insulating thermal conductive glue can play a role in temperature equalization and can also absorb the deformation generated by the battery cell.

[0012] In one embodiment, the battery cell further includes a surrounding frame and a top cover. The top cover and the battery cell bottom plate are opposite along the first direction, and the surrounding frame is disposed between the top cover and the battery cell bottom plate to form a space for accommodating the battery cell, and the insulating thermal conductive glue is filled between the outer peripheral surface of the battery cell and the surrounding frame. The top cover, the battery cell bottom plate, and the surrounding frame can provide encapsulation for the battery cell to protect the battery cell.

[0013] In one embodiment, the battery cell bottom plate is fixed to the housing. The battery cell bottom plate divides the internal space of the housing into a first chamber and a second chamber. The battery cell is accommodated in the first chamber, and the heating element and the power converter are accommodated in the second chamber. The battery cell bottom plate can be regarded as a part of the structure of the housing, providing a rigid support and heat equalization function for the battery cell.

[0014] In one embodiment, the first direction is the direction of gravity, and the power converter is disposed at the bottom of the battery cell; the heat conducting member has one or more internal flow channels, and each internal flow channel is filled with a phase change heat conducting working fluid; each internal flow channel includes a first flow channel segment parallel to the second direction and a second flow channel segment parallel to the first direction. The first flow channel segment faces the first heat conducting surface along the first direction, and the second flow channel segment faces the second heat conducting surface along the second direction. Heat is transferred between the first heat conducting surface and the second heat conducting surface through the phase change of the phase change heat conducting working fluid, and the heat of the power converter is transferred to the radiator.

[0015] In one embodiment, the heat conducting member includes one or more heat pipes, and the internal space of each heat pipe is an internal flow channel; the surface of each heat pipe facing the power converter along the first direction constitutes the first heat conducting surface, and the surface of each heat pipe facing away from the battery cell along the second direction constitutes the second heat conducting surface. The phase change heat conducting working fluid circulates in each heat pipe, and heat transfer can be achieved.

[0016] In one embodiment, the heat conducting member includes one or more heat pipes, a first heat conducting substrate and a second heat conducting substrate. The internal space of each heat pipe is an internal flow channel; the outer surface of each heat pipe facing the heat conducting member along the first direction is fixed to the first heat conducting substrate, and the surface of each heat pipe facing the heat conducting member along the second direction is fixed to the second heat conducting substrate; the surface of the first heat conducting substrate facing the power converter along the first direction is the first heat conducting surface, and the surface of the second heat conducting substrate facing away from the battery cell along the second direction is the second heat conducting surface. The heat conducting substrate can provide stable support for the heat conducting member and also combine multiple heat pipes together for convenient structural layout.

[0017] In one embodiment, the first heat conducting substrate includes one or more first receiving grooves, and the second heat conducting substrate includes one or more second receiving grooves; at least a part of each heat pipe is received in a first receiving groove, and a small part of each heat pipe is received in a second receiving groove. There is a larger heat conducting interface between the heat pipe and the heat conducting substrate, which can further improve the heat exchange efficiency.

[0018] In one embodiment, each heat pipe is bonded to the first heat conducting substrate and the second heat conducting substrate by heat conducting adhesive; alternatively, each heat pipe is welded to the first heat conducting substrate and the second heat conducting substrate. On the basis of ensuring heat conduction, the fixation between the heat pipe and the heat conducting substrate is more stable and reliable.

[0019] In one embodiment, the power converter includes a circuit board and a plurality of electronic components disposed on the circuit board; along the first direction, the height of any one of the electronic components is less than or equal to the distance between the first heat conducting surface and the circuit board, and each electronic component with a height less than the distance between the first heat conducting surface and the circuit board is thermally connected to the first heat conducting surface through a heat conducting adapter. The first heat conducting surface can absorb and transfer the heat of each electronic component to the heat conducting member, achieving a good heat conducting effect.

[0020] In one embodiment, the thermal conductive adapter is a combination of one or more of thermal conductive silicone grease, thermal conductive pad, thermal conductive glue, and solder.

[0021] In one embodiment, the first heat-conducting surface is connected to the surface of the power converter facing the battery cell. After being heated, the liquid phase-change heat-conducting medium in the heat-conducting member turns into a gas with lower density and moves upward, making it easier to transfer heat to the location of the second heat-conducting surface, which is beneficial to the internal circulation of the phase-change heat-conducting medium and has a better heat conduction effect. In a second aspect, the present application provides an energy storage system, which includes a base, a battery control unit, and one or more battery packs as provided in the first aspect; one or more battery packs are stacked on the base in sequence along a first direction, and the battery control unit is arranged at the top of the one or more battery packs, away from the top of the base, and the battery control unit is electrically connected to the power converter of each battery pack. Because the battery pack has a good heat dissipation effect, the energy storage system can play a better role in energy storage and power supply.

[0022] In one embodiment, the battery pack includes a plurality of battery packs, the plurality of battery packs are stacked in sequence along a first direction, and any two adjacent battery packs are connected via terminals.

[0023] In one embodiment, multiple battery packs are connected in parallel at high voltage, and the failure of any battery pack will not affect the normal use of other battery packs, with high reliability and availability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1a A schematic diagram of the structure of an energy storage system provided in an embodiment of the present application;

[0025] Figure 1b A schematic diagram of the structure of an energy storage system provided in an embodiment of the present application;

[0026] Figure 2 A schematic diagram of a circuit principle of an energy storage system provided in an embodiment of the present application;

[0027] Figure 3a A schematic diagram of a cross-sectional structure of a battery pack provided in an embodiment of the present application;

[0028] Figure 3b A schematic diagram of a cross-sectional structure of a battery pack provided in an embodiment of the present application;

[0029] Figure 4a A schematic diagram of the structure of a battery cell and a shell of a battery pack provided in an embodiment of the present application;

[0030] Figure 4b A schematic diagram of a heat transfer link of a battery cell of a battery pack provided in an embodiment of the present application;

[0031] Figure 5a Schematic diagram of the structure of a power converter, a housing, and a radiator for a battery pack provided by an embodiment of the present application;

[0032] Figure 5b Schematic diagram of the structure of a heat conducting member for a battery pack provided by an embodiment of the present application;

[0033] Figure 5c Schematic diagram of the heat transfer link of a power converter for a battery pack provided by an embodiment of the present application;

[0034] Figure 6 Schematic diagram of the cross-sectional structure of a battery pack provided by an embodiment of the present application;

[0035] Figure 7 Schematic diagram of the cross-sectional structure of a battery pack provided by an embodiment of the present application;

[0036] Figure 8a Schematic diagram of the cross-sectional structure of a battery pack provided by an embodiment of the present application;

[0037] Figure 8b Schematic diagram of the heat transfer link of a power converter for a battery pack provided by an embodiment of the present application;

[0038] Figure 9 Schematic diagram of the cross-sectional structure of a battery pack provided by an embodiment of the present application;

[0039] Figure 10 Schematic diagram of the cross-sectional structure of a battery pack provided by an embodiment of the present application;

[0040] Figure 11 Schematic diagram of a partial structure of a battery pack provided by an embodiment of the present application;

[0041] Figure 12a Schematic diagram of a partial structure of a battery pack provided by an embodiment of the present application;

[0042] Figure 12b Schematic diagram of the cross-sectional structure of a battery cell and a heating member for a battery pack provided by an embodiment of the present application;

[0043] Figure 13 Schematic diagram of the cross-sectional structure of a battery pack provided by an embodiment of the present application;

[0044] Figure 14a Schematic diagram of the structure of a power converter and a heat conducting member for a battery pack provided by an embodiment of the present application;

[0045] Figure 14b Schematic diagram of the structure of a power converter and a heat conducting member for a battery pack provided by an embodiment of the present application;

[0046] Figure 15aSchematic structural diagram of a heat conducting member of a battery pack provided by an embodiment of the present application;

[0047] Figure 15b Schematic structural diagram of a heat conducting member of a battery pack provided by an embodiment of the present application;

[0048] Figure 16a Schematic structural diagram of a heat conducting member of a battery pack provided by an embodiment of the present application;

[0049] Figure 16b Schematic structural diagram of a heat conducting member of a battery pack provided by an embodiment of the present application;

[0050] Figure 17a Schematic structural diagram of a heat conducting member of a battery pack provided by an embodiment of the present application;

[0051] Figure 17b Schematic structural diagram of a heat conducting member of a battery pack provided by an embodiment of the present application;

[0052] Figure 17c Schematic structural diagram of a heat conducting member of a battery pack provided by an embodiment of the present application;

[0053] Figure 18 Schematic structural diagram of a heat conducting member of a battery pack provided by an embodiment of the present application;

[0054] Figure 19a Schematic structural diagram of a heat conducting member of a battery pack provided by an embodiment of the present application;

[0055] Figure 19b Schematic structural diagram of a heat conducting member of a battery pack provided by an embodiment of the present application;

[0056] Figure 20a Schematic structural diagram of a heat conducting member of a battery pack provided by an embodiment of the present application;

[0057] Figure 20b Schematic structural diagram of a heat conducting member of a battery pack provided by an embodiment of the present application.

[0058] Reference numerals:

[0059] 10 - Battery pack; 20 - Base; 30 - Battery control unit;

[0060] 1 - Battery cell; 11 - Sub - battery cell; 2 - Power converter; 21 - Circuit board; 22 - Electronic component; 221 - Set electronic component; 23 - Thermal conduction adapter; 3 - Housing; 31 - First outer shell; 32 - Second outer shell; 4 - Heating element; 5 - Thermal conduction element; 51 - Internal flow channel; 52 - Substrate; 501 - Heat pipe; 502 - Thermal conduction substrate; 502a - First thermal conduction substrate; 502b - Second thermal conduction substrate; 6 - Radiator; 7 - Thermal insulation layer; 81 - Battery cell bottom plate; 82 - Insulating thermal conductive adhesive; 83 - Top cover; 84 - Enclosure;

[0061] A - Thermal conduction surface; B1 - First side wall; B2 - Second side wall; C1 - First accommodation groove; C2 - Second accommodation groove; D - Terminal; J - Gap; L1 - First flow channel segment; L2 - Second flow channel segment; M1 - First thermal conduction surface; M2 - Second thermal conduction surface; R1 - First chamber; R2 - Second chamber. Detailed implementation manners

[0062] With the progress of technology, energy storage systems are developing towards high energy and high integration. Currently, the relatively advanced cell - to - pack (CTP) generally uses structures such as steel belts or tapes to relatively simply combine and fix square batteries to form a battery cell. The battery cell is directly combined with the housing, which can reduce the use of end plates and partitions, further squeeze the space inside the battery pack, and has stronger integrity. Compared with traditional battery packs, the volume utilization rate of the cell - to - pack increases by 15% - 20%, the number of components decreases by 40%, the production efficiency increases by 50%, and the application can significantly reduce the manufacturing cost of energy storage batteries. Among them, the cell - to - pack bonds the battery cell array to the liquid - cooled bottom plate through a thermal conduction structure adhesive and conducts heat management through the liquid - cooled bottom plate. However, the application range of this solution is limited. The liquid - cooled bottom plate, as a complete liquid - cooling system, specifically includes parts such as a liquid - cooling plate, a liquid - cooling unit with a heater, liquid - cooling pipelines, a liquid - cooling plate, and a coolant. For household energy storage systems with a small energy per unit, their own energy storage capacity is small. Configuring a liquid - cooling system will significantly reduce the energy - volume density of the battery pack and also increase the product weight, affecting on - site installation. In addition, the cost brought by configuring a liquid - cooling system and the complex heat - flow and thermal - resistance design are not suitable for household energy storage systems. When the cell - to - pack includes a power conversion module, it is also necessary to consider the risk of heat transfer between the heat dissipation of the power conversion module and the battery cell.

[0063] Based on this, the embodiments of the present application provide a battery pack and an energy storage system, which isolate the heat - dissipation links of the battery cell and the power conversion module, prevent heat transfer between the two, and can effectively manage the heat of the battery pack.

[0064] In order to make the purpose, technical solutions, and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings.

[0065] The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to limit this application. As used in the specification and appended claims of this application, the singular forms "a", "an", "the", "above-mentioned", "said", and "this" are also intended to include expressions such as "one or more", unless the context clearly indicates otherwise.

[0066] Reference to "one embodiment" or "some embodiments" described in this specification means that a specific feature, structure, or characteristic described in connection with that embodiment is included in one or more embodiments of this application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc., which appear in different places in this specification, do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "comprising", "including", "having", and their variants mean "including but not limited to", unless otherwise specifically emphasized.

[0067] Figure 1a The structure of an energy storage system provided for the embodiments of this application is a household energy storage system. As Figure 1a shown, the energy storage system includes a base 20, a battery control unit (BCU) 30, and one or more battery packs 10. Each battery pack 10 is used to provide electrical energy, and the number of battery packs 10 affects the power storage capacity of the system. The one or more battery packs 10 are fixed to the base 20, and the base 20 can provide structural support for the one or more battery packs 10 to prevent the battery packs 10 from directly contacting the ground. The battery control unit 30 is disposed on the top of the top battery pack 10 among the one or more battery packs 10 that faces away from the base 20, and the battery control unit 30 is electrically connected to the one or more battery packs 10. The battery control unit 30 is a system power control module responsible for the communication between the system and the external system. Exemplarily, the battery control unit 30 can be used to receive upper-level control commands to control and schedule the power within the system.

[0068] For ease of understanding, a three-dimensional coordinate system is established for the energy storage system. As Figure 1a shown, the three-dimensional coordinate system includes a first direction Z, a second direction Y, and a third direction X that are perpendicular to each other in pairs. Among them, the first direction Z is the arrangement direction of the plurality of battery packs 10 and is also the direction perpendicular to the installation bottom surface when the energy storage system is installed.

[0069] As a structural illustration, when the energy storage system includes two or more battery packs 10, the multiple battery packs 10 are arranged adjacent to each other in sequence along the first direction, and it can be considered that the multiple battery packs 10 are stacked between the base 20 and the battery control unit 30 along the first direction.

[0070] In one embodiment, as Figure 1b shown, any two adjacent battery packs 10 are plugged together through the terminal D. Between two adjacent battery packs 10, one battery pack 10 includes a terminal D for serving as a male head, and the other adjacent battery pack 10 includes a terminal D for serving as a female head. The two battery packs 10 are plugged together through the terminal D serving as the male head and the terminal D serving as the female head. Between the two battery packs 10 that are electrically connected by the way of terminal plugging, the electrical connection reliability is higher, and the plugging of the terminal D can be automatically completed during the assembly process of the multiple battery packs 10 being aligned and stacked.

[0071] Taking a battery pack 10 arranged between two battery packs 10 as an example, terminals D for plugging the two battery packs 10 are respectively arranged at both ends of the battery pack 10 along the first direction Z. Taking a battery pack 10 arranged between the battery control unit 30 and a battery pack 10 as an example, terminals D for plugging the battery control unit 30 and terminals D for plugging the adjacent battery pack 10 are respectively arranged at both ends of the battery pack 10. Taking a battery pack 10 arranged between the base 20 and a battery pack 10 as an example, a terminal D for plugging the adjacent battery pack 10 is arranged on the side of the battery pack 10 facing the adjacent battery pack 10.

[0072] Combined with Figure 1a and Figure 1b shown, in one embodiment, each terminal D included in each battery pack 10 is arranged on one end face of the battery pack 10 perpendicular to the first direction Z, and the orthographic projection of each terminal D on the end face where it is located is within the range of the end face. After the adjacent battery packs 10 are assembled and plugged, the terminal D is not exposed. Compared with the traditional wire harness connection, the plugging connection of adjacent battery packs 10 has higher sealing performance, can improve the sealing level of the energy storage system to above IP65, and reduce the interference of the energy storage system by the external environment such as salt mist and condensation during daily working conditions.

[0073] In one embodiment, each terminal D included in each battery pack 10 is close to one side of the battery pack 10 along the third direction Y, which is convenient for the structural layout of the battery cells and the power converter in the battery pack 10. The terminals D included in the multiple battery packs 10 of the energy storage system are arranged along the first direction Z, and the circuit connections of the multiple battery packs 10 are located on one side of the entire energy storage system along the third direction Y, which is beneficial to the structural layout and electrical connection of the energy storage system.

[0074] Figure 2Illustrates the circuit architecture of the energy storage system provided by the embodiments of the present application. As Figure 2 shown, multiple battery packs 10 are electrically connected to the battery control unit 30 in a high-voltage parallel manner. Among them, each battery pack 10 includes a battery cell 1 and a power converter 2. The electrical energy of each battery cell 1 is collected after DC-DC conversion by the power converter 2, and then converted and output through the battery control unit 30. The failure of any one battery pack 10 will not affect the normal use of other battery packs 10, and it supports the mixed use of new and old battery packs 10, with high reliability and high availability. Each battery pack 10 does not require pre-charging during installation, which is convenient for application.

[0075] For each battery pack 10, the battery cell 1 generates Joule heat during charging and discharging. When the temperature of the battery cell 1 is too high, the charging and discharging efficiency of the battery cell 1 will decrease, and the high temperature will also accelerate the attenuation of the battery cell material, resulting in a shortened service life of the battery pack 10. The power converter 2 also generates heat during operation, and the temperature of the heat generated by the power converter 2 is different from the temperature of the heat generated by the battery cell 1. It is necessary to prevent the heat transfer of the two from occurring in series and affecting the heat management effect.

[0076] Figure 3a Shows a partial cross-sectional structural schematic diagram of a battery pack 10 provided by the embodiments of the present application. As Figure 3a shown, the battery pack 10 includes a battery cell 1, a power converter 2, a housing 3, a heat conducting member 5, and a radiator 6. The battery cell 1 and the power converter 2 are accommodated in the housing 3. The temperature of the power converter 2 during operation is generally higher than the temperature of the battery cell 1 during operation. In order to prevent the higher-temperature power converter 2 from baking the lower-temperature battery cell 1, the power converter 2 and the battery cell 1 are arranged along the first direction Z, and there is a gap between the power converter 2 and the battery cell 1. Among them, an insulating layer 7 is provided between the power converter 2 and the battery cell 1, and the insulating layer 7 can achieve thermal isolation between the power converter 2 and the battery cell 1. The housing 3 includes a first side wall B1 and a second side wall B2 that are oppositely arranged along the second direction Y, and the battery cell 1 is arranged between the first side wall B1 and the second side wall B2 along the second direction Y. The heat conducting member 5 includes a first heat conducting surface M1 and a second heat conducting surface M2. The first heat conducting surface M1 faces the power converter 2 along the first direction Z, and the first heat conducting surface M1 is connected to the power converter 2. The power converter 2 establishes a heat transfer link with the heat conducting member 5 through the first heat conducting surface M1. The second heat conducting surface M2 faces away from the battery cell 1 along the second direction Y, and the second heat conducting surface M2 is used to connect to a heat dissipation device outside the housing 3. The heat generated by the power converter 2 can be dissipated to the external heat dissipation device through the heat conducting member 5. The second heat conducting surface M2 is used to connect to a heat dissipation device arranged outside the first side wall B1, and the direction in which the second heat conducting surface M2 transfers heat to the radiator 6 avoids the first direction Z in which the battery cell 1 and the power converter 2 are arranged, reducing the risk of heat transfer between the heat transfer link of the battery cell 1 and the heat transfer link of the power converter 2, which can improve the heat dissipation effect of the battery pack 10.

[0077] Among them, the heat conducting member 5 can obtain the heat of the power converter 2. An insulating layer 7 is provided between the heat conducting member 5 and the battery cell 1, which can prevent the risk of cross-heat generation between the power converter 2 and the battery cell 1 and between the heat transfer link of the power converter 2 and the heat transfer link of the battery cell 1, and improve the heat dissipation effect. In order to achieve the heat insulation purpose, the insulating layer 7 is made of a material with a low thermal conductivity, and specifically may include one or a combination of more of PU foam, silicone foam, aerogel, and polytetrafluoroethylene plastic.

[0078] Figure 3b An example of a battery pack 10 including a radiator 6 is shown. As Figure 3b shown, the radiator 6 is disposed outside the first side wall B1 of the housing 3, which is convenient for the radiator 6 to exchange heat with the external environment and export the heat to the external environment. The heat exchange between the radiator 6 and the external environment includes natural convection and radiative convection.

[0079] Among them, the radiator 6 is exemplified as a natural convection radiator, which can dissipate heat by exchanging heat with the external environment through air flow. Specifically, the radiator 6 includes a plurality of heat dissipation fins arranged at intervals along the third direction X, and any two adjacent heat dissipation fins are parallel to each other. Each heat dissipation fin extends along the first direction Z, and a channel for air to flow is formed between any two adjacent heat dissipation fins and extends along the first direction Z. When the air in the upper and lower layers convects along the first direction Z, the air can pass through the plurality of channels formed by the plurality of heat dissipation fins of the radiator 6, and the air contacts the heat dissipation fins to exchange heat, achieving the purpose of heat dissipation.

[0080] For Figure 3b the radiator 6 therein, the height of the radiator 6 along the second direction Y is determined. The cross-sectional area of the radiator 6 perpendicular to the first direction Z is the cross-sectional area for the inlet and outlet air of the radiator 6, and can also be regarded as the heat exchange interface area between the radiator 6 and the external environment. The greater the amount of external air flow entering the radiator 6 along the first direction Z, the better the heat dissipation effect. When the dimension of the housing 3 along the third direction X is greater than the dimension along the first direction Z, the heat exchange interface area between the radiator 6 and the external environment is larger, and the amount of air flow entering the plurality of channels formed by the radiator 6 is larger, and the heat dissipation effect of the radiator 6 is better.

[0081] Refer to Figure 3a and Figure 3bAs shown, in some embodiments, a heat insulating layer 7 is provided between the battery cell 1 and the power converter 2 to isolate the heat transfer that may exist between the battery cell 1 and the power converter 2 along the first direction Z, and prevent heat transfer between the battery cell 1 and the power converter 2, which causes heat conduction between the battery cell 1 and the power converter 2. A portion of the heat conductive member 5 is provided along the first direction Z on the side of the power converter 2 away from the battery cell 1, and the heat insulating layer 7 between the battery cell 1 and the power converter 2 can also be used as a heat insulating layer between the heat conductive member 5 and the battery cell 1.

[0082] Refer to Figure 3a and Figure 3b As shown, in some embodiments, a thermal insulation layer 7 is provided between the power converter 2 and the housing 3 to isolate the heat transfer along the first direction Z that may exist between the power converter 2 and the housing 3, thereby preventing heat transfer from occurring between the power converter 2 and the housing 3 and causing heat conduction between the battery cell 1 and the power converter 2.

[0083] Refer to Figure 3a and Figure 3b As shown, in some embodiments, a thermal insulation layer 7 is provided on the surface of the heat conductor 5 along the second direction Y toward the battery cell 1 to isolate the heat transfer along the second direction Y that may exist between the heat conductor 5 and the battery cell 1, thereby preventing heat transfer between the battery cell 1 and the heat conductor 5 and causing heat conduction between the battery cell 1 and the power converter 2.

[0084] like Figure 3b In the battery pack 10 shown, in one embodiment, along the second direction Y, the surface of the battery cell 1 facing away from the heat conductor 5 is connected to the inner surface of the second side wall B2, and there is a gap between the surface of the battery cell 1 facing the heat conductor 5 and the first side wall B1, which can further reduce the risk of heat transfer between the heat conductor 5 and the battery cell 1. The battery cell 1 is connected to the inner wall of the shell 3, and a heat transfer link is established between the battery cell 1 and the shell 3. The heat generated by the battery cell 1 can be transferred to the shell 3 through direct contact, and then the heat is transferred to the external environment through natural convection and radiation convection between the shell 3 and the external environment.

[0085] With reference to the overall structure of the battery pack 10, along the second direction Y, the surface of the battery cell 1 facing away from the heat conducting member 5 is in fitting contact with the inner surface of the second side wall B2 of the housing 3. The direction of heat transfer from the battery cell 1 to the housing 3 is opposite to the direction of heat transfer from the second heat conducting surface M2 to the radiator 6, which can reduce the heat transfer risk between the battery cell 1 and the power converter 2. For the housing 3 with a regular structure, the first side wall B1 and the second side wall B2 have relatively consistent sizes and dimensions. In a specific setting, the battery cell 1 and the second heat conducting surface M2 are arranged to respectively correspond to two relatively large opposite side walls of the housing 3, which can increase the contact area between the battery cell 1 and the housing 3 and the heat conduction area between the second heat conducting surface M2 and the radiator 6, improving the heat dissipation effect. In a specific embodiment, the battery cell 1 and the second heat conducting surface M2 are configured to be respectively connected to two relatively large side walls of the housing 3 along the second direction Y. Compared with the traditional technology, the heat dissipation efficiency can be increased by about 30%.

[0086] Figure 3b In the exemplified structure, the heat conducting member 5 is entirely accommodated in the housing 3. Along the second direction Y, the battery cell 1 is connected to the inner surface of the second side wall B2 of the housing 3 in a fitting contact manner, and the second heat conducting surface M2 is connected to the inner surface of the first side wall B1 in a fitting contact manner. The radiator 6 is arranged on the outer surface of the first side wall B1 along the second direction Y. The radiator 6 and the second heat conducting surface M2 are relatively arranged on the inner and outer surfaces of the first side wall B1. The second heat conducting surface M2 can be connected to the radiator 6 through the first side wall B1 of the housing 3, thereby establishing a heat transfer link.

[0087] Combined Figure 3b , please refer to Figure 4a the schematic structural diagram of the battery cell 1 and the housing 3 shown. In a specific embodiment, one of the heat conducting surfaces A of the battery cell 1 parallel to the first direction Z is connected to the inner surface of the second side wall B2 of the housing 3 in a fitting contact manner, and the other surfaces of the battery cell 1 parallel to the first direction Z are not in contact with the housing 3. The heat conducting surface A is indicated by shading. The battery cell 1 is only connected to the housing 3 through the heat conducting surface A, and the battery cell 1 can directly conduct heat transfer with the housing 3 through the heat conducting surface A. In addition, the battery cell 1 is located in the housing 3, and the battery cell 1 can also form a heat transfer link of natural convection and radiative convection through the air between the battery cell 1 and the housing 3. Figure 4b That is, the heat transfer link of the battery cell 1 in the battery pack 10 is exemplified.

[0088] Combined Figure 3b , please refer to Figure 5aSchematic structural diagram of the power converter 2 shown, the heat conducting member 5, and the heat sink 6. In a specific embodiment, the first heat conducting surface M1 of the heat conducting member 5 faces the power converter 2 in the first direction Z, and the first heat conducting surface M1 is connected to the bottom surface of the power converter 2 in a manner of fitting contact in the first direction Z. The first heat conducting surface M1 and the second heat conducting surface M2 of the heat conducting member 5 are arranged at an angle. Exemplarily, the heat conducting member 5 is in an "L" shape, and the second heat conducting surface M2 is perpendicular to the first heat conducting surface M1. The first heat conducting surface M1 is perpendicular to the first direction Z, and the second heat conducting surface M2 is perpendicular to the second direction Y.

[0089] In an embodiment, the first direction Z is the gravity direction. Along the first direction Z, the second heat conducting surface M2 is higher than the first heat conducting surface M1. The heat transfer between the first heat conducting surface M1 and the second heat conducting surface M2 of the heat conducting member 5 is phase change heat transfer, that is, heat transfer is carried out between the first heat conducting surface M1 and the second heat conducting surface M2 through the phase change heat conducting medium whose property changes with temperature. As Figure 5b shown in the structure of the heat conducting member 5, the heat conducting member 5 has one or more internal flow channels 51, and each internal flow channel 51 is filled with a phase change heat conducting medium. Each internal flow channel 51 includes a first flow channel segment L1 parallel to the second direction Y and a second flow channel segment L2 parallel to the first direction Z. Specifically, the first flow channel segment L1 faces the first heat conducting surface M1 in the first direction Z, the orthographic projection of the first flow channel segment L1 on the outer surface of the heat conducting member 5 in the first direction Z overlaps at least partially with the first heat conducting surface M1, and the phase change heat conducting medium in the first flow channel segment L1 can exchange heat with the power converter 2 through the side wall where the first heat conducting surface M1 is located. The second flow channel segment L2 faces the second heat conducting surface M2 in the second direction Y, the orthographic projection of the second flow channel segment L2 on the outer surface of the heat conducting member 5 in the second direction Y overlaps at least partially with the second heat conducting surface M2, and the phase change heat conducting medium in the second flow channel segment L2 can exchange heat with the heat sink 6 through the side wall where the second heat conducting surface M2 is located.

[0090] Specifically, the phase change heat-conducting working fluid has two phases: liquid phase and gas phase. The density of the working fluid in the liquid phase is large, while the density of the working fluid in the gas phase is small. When the phase change heat-conducting working fluid exists in two phases and there is no structural obstruction, the horizontal height of the working fluid in the liquid phase is lower than that of the working fluid in the gas phase. During specific operation, due to gravity, the working fluid in the liquid phase in the heat-conducting member 5 is located in the first flow channel section L1. The working fluid in the liquid phase absorbs the heat of the power converter 2 through the first heat-conducting surface M1 and undergoes a phase change, which can change from the liquid phase to the gas phase. The gas-phase working fluid with a smaller density moves upward to the second flow channel section L2, transfers the heat to the radiator 6 through the second heat-conducting surface M2, and the heat is transferred to the environment via the radiator 6. The gas-phase working fluid is cooled and changes back to the liquid-phase working fluid, and then falls back to the first flow channel section L1 under the action of gravity, realizing the heat dissipation cycle of the phase change heat-conducting working fluid. During the state conversion process of the phase change heat-conducting working fluid with temperature change, the heat of the power converter 2 is absorbed by the liquid-to-gas phase change of the phase change heat-conducting working fluid in the first flow channel section L1, and the gas-to-liquid phase change of the phase change heat-conducting working fluid in the second flow channel section L2 can release and transfer the heat to the radiator 6. Figure 5c That is, the heat transfer link of the power converter 2 in the battery pack 10 is exemplified.

[0091] Combined Figure 3b With the structure of the battery pack 10 shown, in order to further prevent heat transfer between the battery cell 1 and the power converter 2, the housing 3 is divided into two parts, so that the part of the housing 3 connected to the battery cell 1 and the part of the housing 3 connected to the second heat-conducting surface M2 are thermally isolated from each other. As Figure 6 shown, the housing 3 is separated into a first outer housing 31 and a second outer housing 32 at two positions G. The first outer housing 31 and the second outer housing 32 can be connected to form the housing 3. After the first outer housing 31 and the second outer housing 32 are enclosed and connected, a space for accommodating the battery cell 1 and the power converter 2 can be formed. The first outer housing 31 and the second outer housing 32 are thermally isolated and connected. Specifically, a heat insulation structure can be provided at the connection between the first outer housing 31 and the second outer housing 32. The above-mentioned first side wall B1 is a part of the first outer housing 31, and the second side wall B2 is a part of the second outer housing 32. The heat insulation structure at the connection between the first outer housing 31 and the second outer housing 32 can interrupt the heat conduction between the first side wall B1 and the second side wall B2.

[0092] Exemplarily, as Figure 6As shown, the connection position G between the first housing 31 and the second housing 32 is filled with a heat-insulating material, which can connect the first housing 31 and the second housing 32 while preventing heat conduction between the first housing 31 and the second housing 32. The battery cell 1 is connected to a part of the second side wall B2 of the second housing 32, and the second heat-conducting surface M2 of the heat-conducting member 5 is connected to a part of the first side wall B1 of the first housing 31. Among them, the first heat-conducting surface M1 faces a part of the second housing 32 along the first direction Z, and a heat-insulating layer 7 is provided between the first heat-conducting surface M1 and the second housing 32. The heat-insulating layer 7 can prevent heat conduction between the first heat-conducting surface M1 and the first housing 31, and further transfer it to the battery cell 1 through the second side wall B2, causing cross-heating between the heat conduction of the battery cell 1 and the power converter 2.

[0093] As Figure 7 shown in another battery pack 10, the housing 3 is also divided into a first housing 31 and a second housing 32 that are thermally isolated from each other. The battery cell 1 is connected to a part of the inner wall of the second housing 32, and the second heat-conducting surface M2 and the radiator 6 are oppositely arranged on the inner and outer surfaces of the first side wall B1 of the first housing 31. Different from Figure 6 the housing 3 shown, the connection position G between the first housing 31 and the second housing 32 is different. The first heat-conducting surface M1 of the heat-conducting member 5 faces a part of the first housing 31 along the first direction Z. At this time, the heat-insulating layer 7 between the two can be omitted, and the first heat-conducting surface M1 can directly contact the first housing 31, without causing cross-heating between the heat conduction of the battery cell 1 and the power converter 2.

[0094] In some embodiments, as Figure 8a shown, a part of the heat-conducting member 5 is located inside the housing 3 to connect the power converter 2, and another part is located outside the housing 3 to connect the radiator 6. Specifically, the part of the heat-conducting member 5 used to form the first heat-conducting surface M1 is arranged inside the housing 3 to connect with the power converter 2, and the part of the heat-conducting member 5 used to form the second heat-conducting surface M2 is arranged outside the housing 3, and the radiator 6 is fixed to the second heat-conducting surface M2. Specifically, the first heat-conducting surface M1 is located at the bottom of the battery cell 1 along the first direction Z. An insulating layer 7 is provided between the first heat-conducting surface M1 and the battery cell 1, and another insulating layer 7 is provided between the first heat-conducting surface M1 and the bottom of the housing 3. The part of the heat-conducting member 5 located in the housing 3 is fixed to the outer surface of the first side wall B1, so that the second heat-conducting surface M2 faces away from the outer surface of the first side wall B1 along the second direction Y. The second heat-conducting surface M2 is directly connected to the radiator 6, and a direct heat link can be established between the two to achieve heat conduction.

[0095] As Figure 8a shown, in order to prevent the second heat-conducting surface M2 from directly connecting with the first side wall B1 of the housing 3 to cause cross-heating between the heat conduction of the battery cell 1 and the power converter 2, an insulating layer 7 can be provided between the heat-conducting member 5 and the housing 3 along the second direction Y. Or, it can also refer toFigure 6 or Figure 7 As shown, the structure of the housing 3 is thermally insulated, so that the second side wall B2 and the first side wall B1 of the housing 3 connected to the battery cell 1 are thermally isolated from each other, preventing heat transfer between the battery cell 1 and the power converter 2 through thermal conduction.

[0096] In Figure 8a In the battery pack 10 shown, the first heat-conducting surface M1 of the heat-conducting member 5 is located inside the housing 3, and the second heat-conducting surface M2 is located outside the housing 3. The first heat-conducting surface M1 and the second heat-conducting surface M2 are structurally continuous. It can be considered that the heat-conducting member 5 passes through the housing 3. At the position where the heat-conducting member 5 passes through the housing 3, structures such as sealant and sealing ring can be used for sealing to ensure the sealing performance inside the housing 3.

[0097] Figure 8b Illustrated Figure 8a The heat transfer link of the power converter 2 in the battery pack 10 shown, compared with Figure 5b the heat transfer link shown, the heat-conducting part of the housing 3 is omitted in this heat transfer link.

[0098] In one embodiment, as Figure 9 shown, the first heat-conducting surface M1 of the heat-conducting member 5 is connected to the power converter 2 along the first direction Z. Compared with Figure 3b the structure of the battery pack 10 shown, the difference is that the first heat-conducting surface M1 is connected to the surface of the power converter 2 facing the battery cell 1. An insulating layer 7 is provided between the battery cell 1 and the first heat-conducting surface M1 to prevent heat transfer between the power converter 2 and the battery cell 1. An insulating layer 7 is provided between the power converter 2 and the bottom of the housing 3 to prevent heat transfer between the power converter 2 and the battery cell 1 through the housing 3.

[0099] As Figure 9 shown, when the heat-conducting member 5 selects a phase-change working medium for heat transfer, the first heat-conducting surface M1 is located above the power converter 2 along the first direction Z. The liquid phase-change heat-conducting working medium in the heat-conducting member 5 becomes a gas with a smaller density and moves upward when heated, which is more conducive to heat transfer to the position where the second heat-conducting surface M2 is located, facilitating the internal circulation of the phase-change heat-conducting working medium and achieving better heat conduction effect.

[0100] In another embodiment, as Figure 10As shown in the figure, the heat conducting member 5 is located outside the housing 3. The first heat conducting surface M1 of the heat conducting member 5 is connected to the outer surface of the bottom of the housing 3 along the first direction Z. The power converter 2 is connected to the inner surface of the bottom of the housing 3 along the first direction Z. The power converter 2 can achieve heat conduction with the first heat conducting surface M1 through the bottom of the housing 3. In order to prevent heat transfer between the power converter 2 and the battery cell 1 through the housing 3, the housing 3 is also divided into a first outer housing 31 and a second outer housing 32 that are thermally isolated from each other. The battery cell 1 is connected to the second side wall B2 of the second outer housing 32, and the second heat conducting surface M2 is connected to the outer surface of the first side wall B1 of the first outer housing 31. An insulating structure is provided at the position G where the first outer housing 31 and the second outer housing 32 are connected.

[0101] For the need to keep the battery cell 1 warm in a low-temperature environment, the heating components configured in the current household energy storage system are attached to the battery cell 1. Due to the influence of the self-balance and assembly error of the battery cell 1, and the expansion generated during the service process of the battery cell 1, the heating components cannot be well attached to the battery cell 1, which affects the heat transfer effect.

[0102] Based on this, the battery pack 10 provided in the embodiment of the present application further includes a battery cell bottom plate 81, an insulating thermal conductive adhesive 82, and a heating element 4, as Figure 11 shown. Among them, the top of the battery cell 1 has a power terminal d. The power terminal d includes a positive electrode and a negative electrode. This is only an exemplary illustration here. The bottom of the battery cell 1 is fixed to the battery cell bottom plate 81 through the insulating thermal conductive adhesive 82. The battery cell bottom plate 81 has a high hardness and is not easily deformed, and can provide sufficient strength support for the battery cell 1. The insulating thermal conductive adhesive 82 has a higher elastic deformation, and the shape deformation that occurs during the use of the battery cell 1 can be absorbed by the insulating thermal conductive adhesive 82, and the overall battery cell 1 can maintain a relatively regular shape.

[0103] As Figure 11As shown, the heating element 4 is fixed to the surface of the battery cell bottom plate 81 facing away from the battery cell 1. The heating element 4 generates heat to heat the battery cell 1 in a low-temperature environment, so as to ensure that the battery cell 1 can be maintained within an appropriate temperature range in a low-temperature environment, realizing normal electric energy storage and electric energy supply. The battery cell bottom plate 81 can provide good support for the heating element 4, and the heating element 4 is more closely and firmly attached to the battery cell bottom plate 81, and it is not easy for the battery cell bottom plate 81 to deform and cause the heating element 4 to separate from the battery cell bottom plate 81. Since the insulating thermal conductive adhesive 82 can absorb the deformation generated during the use of the battery cell 1, it will not affect the stability of the combination of the heating element 4 and the battery cell bottom plate 81, and will not generate air pockets or gaps that affect the heating temperature rise efficiency and uniformity, enabling the heating element 4 to normally perform the heating function. Specifically, the first direction Z is the direction perpendicular to the horizontal plane when the battery pack 10 is assembled, the top plate and the bottom of the battery cell 1 face each other in the first direction Z, and the heating element 4 can heat the battery cell 1 from the bottom of the battery cell 1. In some embodiments, the heating element 4 is a heating film, and specifically, one or a combination of silicone, polyimide heating film, positive temperature coefficient thermistor heating film, etc. can be selected.

[0104] In one embodiment, the insulating thermal conductive adhesive 82 can be selected from one or a combination of modified silicone, polyurethane adhesive, acrylic adhesive, etc.

[0105] In one embodiment, as Figure 12a shown, the battery pack 10 further includes a top cover 83 and a surrounding frame 84. The battery cell bottom plate 81 and the top cover 83 face each other in the first direction Z. The surrounding frame 84 is disposed between the top cover 83 and the battery cell bottom plate 81 to form a space for accommodating the battery cell 1. The battery cell 1 is accommodated in the battery cell bottom plate 81, the insulating thermal conductive adhesive 82 is filled between the outer peripheral surface of the battery cell 1 and the surrounding frame 84, and the power terminal d of the battery cell 1 exposes the top of the battery cell 1 and does not contact the battery cell bottom plate 81 of the top cover 83. In the battery cell 1 shown in Figure 12a shown, the top cover 83, the surrounding frame 84 and the battery cell bottom plate 81 can encapsulate the battery cell 1 and the insulating thermal conductive adhesive 82. The insulating thermal conductive adhesive 82 wraps the bottom and the outer peripheral surface of the battery cell 1, and conducts the heat generated by the battery cell 1 to the battery cell bottom plate 81 through a large contact area. There is a heat transfer link with good thermal conductivity between the battery cell 1 and the battery cell bottom plate 81. It should be understood that in this embodiment, the battery cell 1 can transfer heat through a part of the surrounding frame 84 connected to the housing 3.

[0106] In some embodiments, during the preparation and assembly of the battery cell 1, the insulating thermal conductive adhesive 82 can be filled between the battery cell 1 and the battery cell bottom plate 81 in a potting manner.

[0107] As Figure 12bAs shown, the battery cell 1 includes a plurality of sub - battery cells 11, which are arranged in an array. The bottom of each sub - battery cell 11 is fixed to the battery cell bottom plate 81 through an insulating thermal conductive adhesive 82, and adjacent sub - battery cells 11 can be isolated by structures such as foam. Taking the plurality of sub - battery cells 11 as a whole structure as a reference, the insulating thermal conductive adhesive 82 is filled between the bottom of the plurality of sub - battery cells 11 and the battery cell bottom plate 81, and between the outer peripheral surface of the plurality of sub - battery cells 11 and the surrounding frame 84. When the heating element 4 heats the plurality of sub - battery cells 11 through the battery cell bottom plate 81, the heat generated by the heating element 4 can be more evenly transferred to the plurality of sub - battery cells 11 through the battery cell bottom plate 81 and the temperature - equalizing effect of the insulating thermal conductive adhesive 82, which can ensure that the temperature rise of different sub - battery cells 11 tends to be consistent and there will be no large temperature difference inside one battery cell 1.

[0108] In some other embodiments, as Figure 13 shown, the battery cell 1 includes the battery cell 1, the battery cell bottom plate 81, and the insulating thermal conductive adhesive 82. The battery cell bottom plate 81 is fixed to the housing 3 of the battery pack 10 and divides the internal space of the housing 3 into a first chamber R1 and a second chamber R2 along the first direction Z. The battery cell 1 is accommodated in the first chamber R1, and the heating element 4 and the power converter 2 are accommodated in the second chamber R2. Specifically, each sub - battery cell 11 included in the battery cell 1 is adhesively fixed to the battery cell bottom plate 81 through the insulating thermal conductive adhesive 82, and the battery cell bottom plate 81 can provide stable support for the battery cell 1. The heating element 4 is connected to the battery cell bottom plate 81 to achieve heat conduction, and the heat of the heating element 4 can be transferred to the battery cell 1 through the battery cell bottom plate 81. In order to prevent heat conduction between the heating element 4 and the power converter 2, a heat insulation layer 7 is provided between the heating element 4 and the power converter 2, and the heat insulation layer 7 is exemplarily fixed to the side of the heating element 4 facing away from the battery cell bottom plate 81. For the convenience of illustration, other structures of the battery pack 10 are omitted here.

[0109] Figure 13 In the battery pack 10 shown, the battery cell bottom plate 81 can jointly provide encapsulation for the battery cell 1 of the battery cell 1 with the housing 3, or the battery cell bottom plate 81 can also be realized through a part of the structure of the housing 3 itself. The battery cell bottom plate 81 can provide the effects of support and temperature equalization for the battery cell 1. When the heating element 4 heats the battery cell 1 through the battery cell bottom plate 81, the heat generated by the heating element 4 can be more evenly transferred to different positions of the battery cell 1 through the battery cell bottom plate 81 and the temperature - equalizing effect of the insulating thermal conductive adhesive 82, which can ensure that the temperature rise of different sub - battery cells 11 tends to be consistent and there will be no large temperature difference inside one battery cell 1.

[0110] Figure 14a and Figure 14b illustrate partial structures of the power converter 2 and the heat conducting member 5 in the battery pack 10. Figure 14a It shows that the first heat conducting surface M1 of the heat conducting member 5 is connected to the surface of the power converter 2 facing the battery cell 1 along the first direction Z to establish a heat transfer link,Figure 14b It is shown that the first heat-conducting surface M1 of the heat-conducting member 5 is connected to the surface of the power converter 2 facing away from the battery cell 1 along the first direction Z to establish a heat transfer link.

[0111] like Figure 14a and Figure 14b As shown, the power converter 2 includes a circuit board 21 and one or more electronic components 22. Each electronic component 22 generates heat during operation, and a heat conductor 5 is required to transfer the heat to the heat sink 6 for heat dissipation. The heat conductor 5 is thermally connected to each electronic component 22. When the power converter 2 includes two or more electronic components 22, there may be a height difference between the heights of different electronic components 22 along the first direction Z. The distance between the first heat-conducting surface M1 and the circuit board 21 along the first direction Z is greater than or equal to the height of the highest electronic component 22, so as to avoid interference between the assembly of the heat conductor 5 and the power converter 2. The electronic component 221 with the highest height along the first direction Z among the multiple electronic components 22 is set, and the assembly and connection between the heat conductor 5 and the power converter 2 can be based on the set electronic component 221 as a reference.

[0112] When the distance between the first heat-conducting surface M1 and the circuit board 21 along the first direction Z is equal to the height of the set electronic component 221 , each electronic component 22 may be connected to the first heat-conducting surface M1 via the heat-conducting adapter 23 .

[0113] When the distance between the first heat conducting surface M1 and the circuit board 21 along the first direction Z is greater than the height of the set electronic component 221 , the first heat conducting surface M1 is connected to the set electronic component 221 , and other electronic components 22 can be connected to the first heat conducting surface M1 through the heat conducting adapter 23 .

[0114] For each electronic component 22 connected to the first heat-conducting surface M1 through the heat-conducting adapter 23, along the first direction Z, the sum of the height of the electronic component 22 and the height of the heat-conducting adapter 23 is the distance between the first heat-conducting surface M1 and the circuit board 21. The heat-conducting adapter 23 can be in the form of heat-conducting silica gel, heat-conducting pad, heat-conducting glue, etc.

[0115] The heat conducting member 5 provided in the embodiment of the present application is used to conduct the heat generated by the power converter 2 to the heat sink 6. Based on the basic structure of the heat conducting member 5 including the first heat conducting surface M1 and the second heat conducting surface M2 in an "L" shape, there are many specific implementation methods of the heat conducting member 5. Next, the specific structure of the heat conducting member 5 will be exemplified.

[0116] In some embodiments, Figure 15a and Figure 15bAs shown, the heat conducting member 5 includes two heat conducting substrates 502 and one or more heat pipes 501. Exemplarily, the two heat conducting substrates 502 are arranged at an angle, and along the first direction Z, one heat conducting substrate 502 is higher than the other heat conducting substrate 502. Each heat pipe 501 is bent. Taking one heat pipe 501 as an example, the heat pipe 501 is bent into an "L" shape and is fixed to the two heat conducting substrates 502 on both sides of the bending position respectively. Exemplarily, the two heat conducting substrates 502 are the first heat conducting substrate 502a and the second heat conducting substrate 502b respectively. The first heat conducting substrate 502a is lower than the second heat conducting substrate 502b along the first direction Z. The first heat conducting substrate 502a is used to connect with the power converter 2, and the second heat conducting substrate 502b is used to connect with the radiator 6. Specifically, each heat pipe 501 is fixed to the first heat conducting substrate 502a along the first direction Z toward the outer surface of the heat conducting member 5, and each heat pipe 501 is fixed to the second heat conducting substrate 502b along the second direction Y toward the surface of the heat conducting member 5. Wherein, the surface of the first heat conducting substrate 502a along the first direction Z toward the power converter 2 is the first heat conducting surface M1, and the surface of the second heat conducting substrate 502b along the second direction Y away from the battery cell 1 is the second heat conducting surface M2.

[0117] The cross-section of the heat pipe 501 perpendicular to the length direction can be circular, elliptical, oblate, square, etc. The internal space of the heat pipe 501 forms an internal flow channel for filling a phase change heat conducting working medium, and this flow channel extends along the length direction of the heat pipe 501 to both ends of the heat pipe 501.

[0118] Each heat conducting substrate 502 can fix multiple heat pipes 501, provide stable support for each heat pipe 501, and also combine multiple heat pipes 501 together, facilitating the structural layout. In order to strengthen the stability of the connection between the heat pipe 501 and the heat conducting substrate 502 and the effectiveness of heat conduction, the heat pipe 501 can be fixed to the heat conducting substrate 502 by means of thermal grease bonding or welding, so as to achieve good thermal interface contact between the heat pipe 501 and the heat conducting substrate 502 and ensure good heat transfer effect. On the basis of ensuring the heat conduction efficiency, the connection between the heat pipe 501 and the heat conducting substrate 502 is also more stable and reliable.

[0119] Refer to Figure 15a and Figure 15b As shown, the first heat conducting substrate 502a is used to connect with the power converter 2, and the second heat conducting substrate 502b is used to connect with the radiator 6. According to the relative position of the power converter 2 relative to the first heat conducting surface M1 along the first direction Z, the position of the first heat conducting substrate 502a relative to the heat pipe 501 can be adjusted adaptively so that the first heat conducting substrate 502a connects with the power converter 2. When the power converter 2 is located below the first heat conducting surface M1 along the first direction Z, the first heat conducting substrate 502a is as Figure 15ais shown fixed to the bottom of the heat pipe 501. When the power converter 2 is located at the top of the first heat conduction surface M1 along the first direction Z, the first heat conduction substrate 502a is as Figure 15b shown fixed above the heat pipe 501.

[0120] Combined Figure 16a with Figure 16b as shown, in order to more firmly fix the heat pipe 501 to the two heat conduction substrates 502, the first heat conduction substrate 502a includes one or more first receiving grooves C1, and the second heat conduction substrate 502b includes one or more second receiving grooves C2. Each heat pipe 501 is at least partially received in one first receiving groove C1, and each heat pipe 501 is at least partially received in one second receiving groove C2.

[0121] In some embodiments, as Figure 16a shown, a first receiving groove C1 capable of receiving the heat pipe 501 is formed by grooving on the surface of the first heat conduction substrate 502a for connecting the heat pipe 501. Specifically, a first receiving groove C1 can be opened for each heat pipe 501, or a first receiving groove C1 can be opened integrally for multiple heat pipes 501. During assembly, each heat pipe 501 can be at least partially received in the first receiving groove C1, and the first receiving groove C1 can partially wrap the outer peripheral surface of a section of the heat pipe 501 located in the first receiving groove C1. Along the thickness direction of the first heat conduction substrate 502a, the radial dimension of the heat pipe 501 is greater than the depth of the first receiving groove C1. It can be considered that a part of each heat pipe 501 is semi-buried and fixed to the first heat conduction substrate 502a. Correspondingly, a second receiving groove C2 capable of receiving the heat pipe 501 is formed by grooving on the surface of the second heat conduction substrate 502b for connecting the heat pipe 501. Specifically, a second receiving groove C2 can be opened for each heat pipe 501, or a second receiving groove C2 can be opened integrally for multiple heat pipes 501. During assembly, each heat pipe 501 can be at least partially received in the second receiving groove C2, and the second receiving groove C2 can partially wrap the outer peripheral surface of a section of the heat pipe 501 located in the first receiving groove C1. Along the thickness direction of the second heat conduction substrate 502b, the radial dimension of the heat pipe 501 is greater than the depth of the second receiving groove C2. It can be considered that a part of each heat pipe 501 is semi-buried and fixed to the second heat conduction substrate 502b.

[0122] In some embodiments, as Figure 16bAs shown, blind holes or through holes for the heat pipes 501 to extend into are formed in the first heat-conducting substrate 502a to form a first receiving groove C1 capable of accommodating the heat pipes 501. Specifically, a first receiving groove C1 can be provided for each heat pipe 501, or a first receiving groove C1 can be formed integrally for multiple heat pipes 501. During assembly, each heat pipe 501 can be at least partially received in the first receiving groove C1, and the first heat-conducting substrate 502a can circumferentially wrap the outer peripheral surface of the section of the heat pipe 501 located in the first receiving groove C1. Along the thickness direction of the first heat-conducting substrate 502a, the radial dimension of the heat pipe 501 is less than or equal to the radial dimension of the first receiving groove C1. It can be considered that a part of each heat pipe 501 is buried and fixed in the first heat-conducting substrate 502a. Correspondingly, blind holes or through holes for the heat pipes 501 to extend into are formed in the second heat-conducting substrate 502b to form a second receiving groove C2 capable of accommodating the heat pipes 501. Specifically, a second receiving groove C2 can be provided for each heat pipe 501, or a second receiving groove C2 can be formed integrally for multiple heat pipes 501. During assembly, each heat pipe 501 can be at least partially received in the second receiving groove C2, and the second heat-conducting substrate 502b can circumferentially wrap the outer peripheral surface of the section of the heat pipe 501 located in the second receiving groove C2. Along the thickness direction of the second heat-conducting substrate 502b, the radial dimension of the heat pipe 501 is less than or equal to the radial dimension of the second receiving groove C2. It can be considered that a part of each heat pipe 501 is buried and fixed in the second heat-conducting substrate 502b.

[0123] It should be understood that, as Figure 16b shown, when each heat pipe 501 is received in the first heat-conducting substrate 502a, either of the two surfaces of the first heat-conducting substrate 502a along the first direction Z can be used as the first heat-conducting surface M1.

[0124] As Figures 17a to 17c shown, in some embodiments, the two first heat-conducting substrates 502a and the second heat-conducting substrate 502b included in the heat-conducting member 5 can have an integral structure. It can be considered that the heat-conducting member 5 includes an "L"-shaped substrate 52 and one or more "L"-shaped heat pipes 501. Each heat pipe 501 is fixedly connected to the "L"-shaped substrate 52 in a shape-matching manner. With the "L"-shaped substrate 52 as a reference, the first heat-conducting substrate 502a is the partial structure of the substrate 52 perpendicular to the first direction Z, and the second heat-conducting substrate 502b is the partial structure of the substrate 52 perpendicular to the second direction Y.

[0125] As Figure 17aAs shown, as an example, the substrate 52 is a metal structural member. Each heat pipe 501 is fixed to the first heat-conducting substrate 502a along the surface facing the power converter 2 in the first direction X, and each heat pipe 501 is fixed to the second heat-conducting substrate 502b along the surface facing away from the battery cell 1 in the second direction Y. Among them, a gap J is reserved between the bent portion of each heat pipe 501 and the bent portion of the substrate 52 to reduce the assembly difficulty.

[0126] As Figure 17b shown, as an example, the substrate 52 is a metal structural member. The surface of the first heat-conducting substrate 502a facing away from the first heat-conducting surface M1 in the first direction Z is provided with one or more receiving grooves for receiving and fixing one or more heat pipes 501, and the surface of the heat-conducting substrate 502 facing away from the second heat-conducting surface M2 in the second direction Y is provided with one or more receiving grooves for receiving and fixing one or more heat pipes 501. Each heat pipe 501 is at least partially received in the receiving groove of the first heat-conducting substrate 502a, and each heat pipe 501 is at least partially received in the receiving groove of the second heat-conducting substrate 502b. Among them, a gap J can be reserved between the bent portion of each heat pipe 501 and the bent portion of the substrate 52 to reduce the assembly difficulty.

[0127] As Figure 17c shown, as an example, the substrate 52 is a metal structural member, different from Figure 17b that the bent portion of each heat pipe 501 can be integrally attached and fixed to the bent portion of the substrate 52.

[0128] In some other embodiments, as Figure 18 shown, the heat-conducting member 5 includes one or more heat pipes 501, and each heat pipe 501 is in the form of an extruded plate or a flat plate heat pipe. Taking one heat pipe 501 as an example, the heat pipe 501 is bent into an "L" shape to form a first heat-conducting surface M1 and a second heat-conducting surface M2 on both sides of the bent portion respectively. The cross-section of the heat pipe 501 perpendicular to the length direction can be a flat long strip shape, etc. The heat pipe 501 has a flow channel filled with a phase change heat-conducting working fluid, and the flow channel extends along the extension direction of the heat pipe 501 to both ends of the heat pipe 501. The one or more heat pipes 501 can be independently used as the heat-conducting member 5, and a part of each heat pipe 501 is used to connect the power converter 2 in the first direction Z, and a part of each heat pipe 501 is used to connect the radiator 6 in the second direction Y.

[0129] Figure 19a and Figure 19bThe exemplary heat conducting member 5 includes two heat conducting substrates 502 and one or more of the above heat pipes 501. Exemplarily, the two heat conducting substrates 502 are a first heat conducting substrate 502a and a second heat conducting substrate 502b. The first heat conducting substrate 502a is lower than the second heat conducting substrate 502b along a first direction Z. The first heat conducting substrate 502a is used to connect to the power converter 2, and the second heat conducting substrate 502b is used to connect to the radiator 6. Each heat pipe 501 is fixed to the surface of the first heat conducting substrate 502a facing the power converter 2 along the first direction Z, and the surface of the first heat conducting substrate 502a facing the power converter 2 along the first direction Z constitutes a first heat conducting surface M1. Each heat pipe 501 is fixed to the surface of the second heat conducting substrate 502b facing away from the battery cell 1 along a second direction Y, and the surface of the second heat conducting substrate 502b facing away from the battery cell 1 constitutes a second heat conducting surface M2.

[0130] Taking one heat pipe 501 as an example, along the thickness direction of the heat pipe 501, the first heat conducting substrate 502a can be disposed on at least one of the two surfaces of the heat pipe 501, and the second heat conducting substrate 502b can be disposed on at least one of the two surfaces of the heat pipe 501. The heat pipe 501 can be used to connect to the power converter 2, and the first heat conducting substrate 502a can also be used to connect to the power converter 2. The heat pipe 501 can be used to connect to the radiator 6, and the second heat conducting substrate 502b can also be used to connect to the radiator 6. Taking the two heat conducting substrates 502 being respectively used for thermally connecting the power converter 2 and the radiator 6 as an example, the first heat conducting substrate 502a is used for thermally connecting to the power converter 2, and the second heat conducting substrate 502b is used for thermally connecting to the radiator 6. According to the relative position of the power converter 2 relative to the first heat conducting surface M1 along the first direction Z, the position of the first heat conducting substrate 502a relative to the heat pipe 501 is adjusted. When the power converter 2 is located at the bottom of the first heat conducting surface M1 along the first direction Z, the first heat conducting substrate 502a is fixed below the heat pipe 501 as Figure 19a shown. When the power converter 2 is located above the first heat conducting surface M1 along the first direction Z, the first heat conducting substrate 502a is fixed to the top plate of the heat pipe 501 as Figure 19b shown.

[0131] To enhance the stability of the connection between the heat pipe 501 and the heat conducting substrate 502 and the effectiveness of heat conduction, the heat pipe 501 can be fixed to the heat conducting substrate 502 by means of thermal grease bonding or welding, so that good thermal interface contact is achieved between the heat pipe 501 and the heat conducting substrate 502, ensuring a good heat transfer effect.

[0132] In some embodiments, it is also possible to form a receiving groove for receiving the heat pipe 501 by grooving on the surface of the heat conducting substrate 502, so that the heat pipe 501 is fixed to the heat conducting substrate 502 in a semi-embedded manner, further increasing the contact area of the heat pipe 501 for connecting to the heat conducting substrate 502 and improving the heat transfer efficiency, which is not shown here.

[0133] As shown in Figure 20a and Figure 20b In some embodiments, the two heat-conducting substrates 502 included in the heat-conducting member 5 may have an integral structure. It can be considered that the heat-conducting member 5 includes an "L"-shaped substrate 52 and one or more "L"-shaped heat pipes 501. Each heat pipe 501 is fixedly connected to the substrate 52 in a shape-matching manner. Each heat pipe 501 is fixedly connected to the "L"-shaped substrate 52 in a shape-matching manner. With the "L"-shaped substrate 52 as a reference, the first heat-conducting substrate 502a is a partial structure of the substrate 52 perpendicular to the first direction Z, and the second heat-conducting substrate 502b is a partial structure of the substrate 52 perpendicular to the second direction Y.

[0134] As shown in Figure 20a As an example, the substrate 52 is a metal structural member. Each heat pipe 501 is fixed to the first heat-conducting substrate 502a along the surface facing the power converter 2 in the first direction X, and each heat pipe 501 is fixed to the second heat-conducting substrate 502b along the surface facing away from the battery cell 1 in the second direction Y. Among them, a gap J is reserved at the bending part of each heat pipe 501 and the bending part of the substrate 52 to reduce the assembly difficulty.

[0135] As shown in Figure 20b As an example, the substrate 52 is a metal structural member. Different from the structure shown in Figure 20a the bending part of the substrate 52 is shape-matching with the bending part of each heat pipe 501, so that each heat pipe 501 can be fixedly attached to the bending part of the substrate 52 more completely.

[0136] It should be understood that the battery pack 10 provided by the embodiments of the present application and the energy storage system including the battery pack 10 can be applied to household energy storage. In some scenarios, it can also be combined and applied to other energy storage scenarios.

[0137] The above are only the specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present application, and all should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A battery pack, characterized in that: The battery pack includes a shell, a battery cell, a power converter and a heat conductor; The battery cell and the power converter are accommodated in the housing, and the power converter and the battery cell are arranged along a first direction; A heat insulation layer is provided between the battery core and the power converter, and a heat insulation layer is provided between the battery core and the heat conducting member; The housing comprises a first side wall and a second side wall which are arranged opposite to each other along a second direction; The heat conducting member includes a first heat conducting surface and a second heat conducting surface, the first heat conducting surface is toward the power converter along the first direction, the first heat conducting surface is connected to the power converter, the second heat conducting surface is away from the battery core along the second direction, the second heat conducting surface is used to connect to a heat sink arranged outside the first side wall, and the second direction is perpendicular to the first direction.

2. The battery pack according to claim 1, characterized in that: Along the second direction, a surface of the battery core facing away from the heat conductive member is connected to an inner surface of the second side wall, and a gap exists between a surface of the battery core facing the heat conductive member and the first side wall.

3. The battery pack according to claim 1 or 2, characterized in that: The battery pack further includes a radiator disposed outside the first side wall, and the radiator is connected to the second heat conducting surface.

4. The battery pack according to any one of claims 1 to 3, characterized in that: The heat conducting member is entirely contained in the housing; The second heat conducting surface is connected to the inner surface of the first side wall along the second direction.

5. The battery pack according to claim 4, characterized in that: The housing comprises a first housing and a second housing, the first housing and the second housing are enclosed to form a space for accommodating the battery cell and the power converter, and a heat insulation structure is provided at the connection between the first housing and the second housing; The first side wall is a part of a first housing, and the second side wall is a part of the second housing.

6. The battery pack according to any one of claims 1 to 5, characterized in that: The battery pack further comprises a battery cell bottom plate, an insulating thermally conductive adhesive, and a heating element, wherein the bottom of the battery cell is fixed to the battery cell bottom plate by the insulating thermally conductive adhesive; The heating element is fixed on the surface of the battery cell bottom plate facing away from the battery cell, and the heat insulation layer between the battery cell and the power converter is arranged between the heating element and the power converter.

7. The battery pack according to claim 6, characterized in that: The battery cell bottom plate is fixed to the shell, and the battery cell bottom plate separates the internal space of the shell into a first chamber and a second chamber. The battery cell is accommodated in the first chamber, and the heating element and the power converter are accommodated in the second chamber.

8. The battery pack according to any one of claims 1 to 7, characterized in that: The first direction is the direction of gravity, and the power converter is arranged at the bottom of the battery cell; The heat conducting member has one or more internal flow channels, each of which is filled with a phase-change heat conducting medium; Each of the internal flow channels includes a first flow channel section parallel to the second direction and a second flow channel section parallel to the first direction. The first flow channel section is opposite to the first heat conducting surface along the first direction, and the second flow channel section is opposite to the second heat conducting surface along the second direction.

9. The battery pack according to claim 8, characterized in that: The heat conducting member includes one or more heat pipes, and the internal space of each heat pipe is an internal flow channel; The surface of each heat pipe along the first direction facing the power converter constitutes the first heat conduction surface, and the surface of each heat pipe along the second direction away from the battery core constitutes the second heat conduction surface.

10. The battery pack according to claim 8, characterized in that: The heat-conducting member includes one or more heat pipes, a first heat-conducting substrate and a second heat-conducting substrate, and the internal space of each heat pipe is one of the internal flow channels; Each of the heat pipes is fixed to the first heat-conducting substrate along the first direction toward the outer surface of the heat-conducting member, and each of the heat pipes is fixed to the second heat-conducting substrate along the second direction toward the surface of the heat-conducting member; A surface of the first heat-conducting substrate along the first direction facing the power converter is the first heat-conducting surface, and a surface of the second heat-conducting substrate along the second direction away from the battery core is the second heat-conducting surface.

11. The battery pack according to claim 10, characterized in that: The first heat-conducting substrate includes one or more first containing grooves, and the second heat-conducting substrate includes one or more second containing grooves; Each of the heat pipes is at least partially accommodated in one of the first accommodating grooves, and each of the heat pipes is at least partially accommodated in one of the second accommodating grooves.

12. The battery pack according to any one of claims 8 to 11, characterized in that: The first heat-conducting surface is connected to a surface of the power converter facing the battery core.

13. An energy storage system, characterized in that: The energy storage system comprises a base, a battery control unit and one or more battery packs according to any one of claims 1 to 12; The one or more battery packs are stacked on the base in sequence along the first direction, and the battery control unit is arranged at the top of the one or more battery packs, facing away from the top of the base, and the battery control unit is electrically connected to the power converter of each battery pack.

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