Battery pack, liquid cooling system, vehicle and energy storage system

Abstract

Embodiments of the present application provide a battery pack, a liquid cooling system, a vehicle and an energy storage system. The battery pack comprises a case and a plurality of battery cells; the plurality of battery cells are accommodated in the case or a closed space is formed between the cells and the case; the battery cells each comprise a cell body and an electrical connector arranged on the cell body; a first flow channel is formed between two adjacent battery cells or between the battery cells and the inner wall of the case, and the first flow channel is used for accommodating a heat exchange working medium; at least part of each cell body is immersed in the heat exchange working medium; and the area of contact between each electrical connector and the heat exchange working medium is zero. Therefore, the risk of ionization of the heat exchange working medium can be reduced.

Description

Battery packs, liquid cooling systems, vehicles and energy storage systems

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on December 19, 2023, with application number 202311762552.1, and priority to the Chinese patent application entitled “Battery Pack, Liquid Cooling System, Vehicle and Energy Storage System”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery pack, a liquid cooling system, a vehicle, and an energy storage system. Background Art

[0003] Currently, consumers are highly concerned about the rapid recharging capability of battery packs. For example, this is a primary consideration when purchasing new energy vehicles. Battery packs generate a significant amount of heat during fast charging. Liquid cooling plates are typically installed on battery packs to regulate the pack's temperature. The liquid cooling plate is connected to the battery pack's cells via thermally conductive adhesive. A heat exchange medium flows through the liquid cooling plate's internal channels, exchanging heat with the plate. The plate then exchanges heat with the battery pack's cells via the thermally conductive adhesive. This method of using liquid cooling plates to regulate the battery pack's temperature relies on two heat exchange processes within the plate. However, these two heat exchange processes in the plate result in significant heat loss, reducing the plate's heat exchange efficiency. As battery pack fast charging speeds increase, higher demands are placed on the battery pack's heat exchange capacity, which existing liquid cooling methods with liquid cooling plates struggle to meet. Furthermore, battery packs can experience thermal runaway due to factors such as collisions, generating significant amounts of heat. Liquid cooling with liquid cooling plates is unable to dissipate the significant heat generated by thermal runaway in a timely manner, and this heat accumulation can affect the safety and reliability of the battery pack. Summary of the Invention

[0004] The embodiments of the present application provide a battery pack, liquid cooling system, vehicle, and energy storage system that are beneficial for improving heat exchange efficiency and reducing the risk of ionization of the heat exchange medium.

[0005] In the first aspect, an embodiment of the present application provides a battery pack, comprising a case and a plurality of battery cells, wherein the plurality of battery cells are housed in the case or the battery cells and the case form a sealed space, the battery cell comprising a core body and an electrical connector provided on the core body, two adjacent battery cells or the battery cell and the inner wall of the case form a first flow channel, the first flow channel is used to accommodate a heat exchange medium, at least part of the core body is immersed in the heat exchange medium, the contact area between the electrical connector and the heat exchange medium is zero, and the electrical connector is a pole and / or a high-voltage conductive bus between the poles.

[0006] The poles include positive poles and negative poles. The high-voltage conductive bus between the poles refers to the high-voltage conductive bus connected between the positive pole of one battery cell and the negative pole of another battery cell.

[0007] The battery pack provided herein has a core that is at least partially immersed in a heat exchange medium. This means the battery pack utilizes an immersion-type liquid cooling solution, allowing the heat exchange medium to directly contact the core for heat exchange. Compared to liquid cooling solutions using liquid cooling plates, this increases the volume of the heat exchange medium in the battery pack, which helps improve the battery pack's heat exchange capacity and efficiency. Because the battery pack's heat exchange capacity and efficiency have been improved, it can effectively and promptly remove heat generated by the battery pack during fast charging or thermal runaway conditions, thereby improving the safety and reliability of the battery pack.

[0008] A first flow channel is formed between two adjacent battery cells / or a first flow channel is formed between the battery cells and the inner wall of the box, and at least part of the core is immersed in the heat exchange medium, that is, the battery pack of the present application adopts a semi-immersed liquid cooling solution. In this way, compared with the full immersion liquid cooling solution in which the entire box is filled with heat exchange medium, the semi-immersion liquid cooling solution reduces the volume of the heat exchange medium, which is beneficial to increase the rate of temperature rise or temperature drop of the heat exchange medium and shorten the time to reach the required temperature.

[0009] In addition, since the contact area between the electrical connector and the heat exchange medium is zero, liquid-electric separation is achieved, avoiding or reducing the risk of the heat exchange medium being ionized by the charged electrical connector, thereby improving the safety and reliability of the battery pack. If the heat exchange medium is ionized, it will destroy the insulation inside the battery pack, and there will be a risk of arcing and sparking inside the battery pack. If the heat exchange medium is ionized, it will change the physical properties of the heat exchange medium and affect the heat exchange efficiency between the heat exchange medium and the battery cell. In addition, electrical connectors are usually irregular in shape. Since the electrical connectors do not contact the heat exchange medium, the electrical connectors will not hinder the flow of the heat exchange medium, thereby effectively reducing the flow resistance of the heat exchange medium and improving the heat exchange uniformity of the battery pack.

[0010] According to the first aspect, in a possible implementation, the first flow channel includes a flat straight channel, the flat straight channel includes a first liquid inlet and a first liquid outlet, the flat straight channel extends along a first direction, the first liquid inlet of the flat straight channel is located at one end of the flat straight channel in the first direction for inputting heat exchange medium, and the first liquid outlet of the flat straight channel is located at the other end of the flat straight channel in the first direction for outputting heat exchange medium.

[0011] In this possible implementation, the straight flow channel can reduce the flow resistance of the heat exchange medium during the circulation process and improve the heat exchange uniformity of the battery pack.

[0012] According to the first aspect, in a possible implementation, the number of the flat and straight flow channels is at least two, and the at least two flat and straight flow channels are arranged along a second direction perpendicular to the first direction.

[0013] According to the first aspect, in a possible implementation, the first flow channel includes a curved flow channel, the curved flow channel includes a first liquid inlet and a first liquid outlet, the first liquid inlet of the curved flow channel is used to input the heat exchange medium, and the first liquid outlet of the curved flow channel is used to output the heat exchange medium.

[0014] In this possible implementation, the curved flow channel can improve the uniformity of the flow of the heat exchange medium between the battery cells.

[0015] According to the first aspect, in a possible implementation, the curved flow channel also includes a first part and a second part that are connected, the first part and the second part are arranged along the second direction, the first liquid inlet of the curved flow channel is arranged in the first part, and the first liquid outlet of the curved flow channel is arranged in the second part.

[0016] In this possible implementation, the first liquid inlet is arranged in the first part, the first liquid outlet is arranged in the second part, and the first part and the second part are arranged along the second direction. In this way, there is a distance between the first liquid inlet and the first liquid outlet in the second direction, which is beneficial to extending the heat exchange path of the heat exchange medium on the battery cell, and is beneficial to improving the heat exchange effect between the heat exchange medium and the battery cell.

[0017] According to the first aspect, in a possible implementation, the first liquid inlet of the curved flow channel is arranged at the first end of the first part in the first direction, the second end of the first part in the first direction is connected to the first end of the second part in the first direction, and the first liquid outlet of the curved flow channel is arranged at the second end of the second part in the first direction, and the first direction is perpendicular to the second direction.

[0018] In this possible implementation, the first part and the second part both extend along the first direction, the first direction is perpendicular to the second direction, and there is a distance between the first liquid inlet and the first liquid outlet in the first direction, which is beneficial to extending the heat exchange path of the heat exchange medium on the battery cell and improving the heat exchange effect between the heat exchange medium and the battery cell.

[0019] According to the first aspect, in a possible implementation, the curved flow channel also includes a third part, the first part, the third part, and the second part are arranged in sequence along the second direction, the first end of the third part in the first direction is connected to the second end of the first part, the second end of the third part in the first direction is connected to the first end of the second part, and the first end of the first part, the second end of the third part, and the first end of the second part are arranged in sequence in the second direction.

[0020] In this possible implementation, the curved flow channel is in an "S" shape.

[0021] According to the first aspect, in a possible implementation, the battery pack further includes a guide bar fixed between two adjacent battery cells, and the guide bar, the battery cells, and the inner wall of the box form a first flow channel.

[0022] In this possible implementation, the first flow channel is formed by the guide bar, the battery cell, and the inner wall of the box, resulting in a simple structure and easy manufacturing. Furthermore, the guide bar can support the battery cell when it expands, reducing the possibility of deformation of the battery cell and the first flow channel, reducing the impact of the battery cell's cyclic expansion on the first flow channel, and improving the uniformity of the heat exchange medium flowing through the first flow channel.

[0023] According to the first aspect, in one possible implementation, a second flow channel is provided on the inner wall of the box body, and the second flow channel is used to accommodate the heat exchange medium. The second flow channel includes a connected opening, a second liquid inlet and a second liquid outlet. The second liquid inlet is used to input the heat exchange medium, and the second liquid outlet is used to output the heat exchange medium. Each battery cell cover is provided on a corresponding opening.

[0024] In this possible implementation, since the second flow channel can also flow the heat exchange medium, this increases the heat exchange area between the heat exchange medium and the battery cell, thereby improving the heat exchange efficiency of the battery pack.

[0025] In addition, the first flow channel and the second flow channel may not be connected, and the heat exchange working fluid in the first flow channel and the heat exchange working fluid in the second flow channel do not circulate with each other, but can flow separately. Through the zoning design of the heat exchange working fluid, when the heat exchange working fluid leaks somewhere in the battery pack, for example, the bottom seal of the battery pack fails due to scraping of the entire vehicle, making the heat exchange working fluid in the first flow channel of the battery pack unable to work, the heat exchange working fluid in the second flow channel does not leak and can still play a thermal protection role, thereby improving the robustness of the liquid cooling system. In addition, the immersion heat exchange working fluid is restricted to flow in an orderly manner between the first side surface and the bottom surface of the battery cell, which can reduce the volume of the immersion heat exchange working fluid and reduce the risk of leakage outside the battery pack during long-term use.

[0026] According to the first aspect, in a possible implementation, the box includes a main body and multiple support pads, the multiple support pads are arranged at intervals on the inner wall of the main body, a second flow channel is formed between each adjacent support pad, and each battery cell is connected to the corresponding two adjacent support pads.

[0027] In this possible implementation, multiple support pads are spaced apart on the inner wall of the main body to form multiple secondary flow channels. This simplifies the flow channel structure, simplifies the production of the housing, and reduces the cost of manufacturing the battery pack. Furthermore, the support pads provide support when the battery cells expand, reducing the possibility of deformation of the battery cells and the secondary flow channels, and reducing the impact of cyclic expansion of the battery cells on the secondary flow channels, thereby improving the uniformity of the heat exchange medium flowing through the second flow channels.

[0028] According to the first aspect, in a possible implementation, the box includes a main body and a partition accommodated in the main body, the partition and the inner wall of the main body form a second flow channel and a receiving cavity that are separated and arranged, the partition is provided with multiple openings, and multiple battery cells are accommodated in the receiving cavity.

[0029] In this possible implementation, the second flow channel is directly formed by the separator and the main body, and multiple openings are provided on the separator. The flow channel structure is simple, which simplifies the preparation of the box and reduces the production cost of the battery pack.

[0030] According to the first aspect, in a possible implementation, the second flow channel extends along a first direction, and in the first direction, the length of the second flow channel is greater than the length of the battery cell, and an opening portion of the second flow channel is exposed outside the plurality of battery cells.

[0031] In this possible implementation, if a battery cell experiences thermal runaway and gas is ejected from the bottom of the battery cell, since the opening of the second flow channel is partially exposed outside the multiple battery cells, the gas passes through the second flow channel and is exhausted from the opening exposed in the second flow channel, thereby improving the smoothness of the thermal runaway exhaust, reducing the possibility of battery pack explosion, and thus improving the safety of the battery pack.

[0032] According to the first aspect, in a possible implementation, the box body is further provided with a connecting flow channel, and the connecting flow channel connects the first flow channel and the second flow channel.

[0033] In this possible implementation, the first flow channel and the second flow channel may also be connected via a connecting channel, so that the heat exchange medium flows between the first flow channel and the second flow channel, that is, the heat exchange medium forms an integrated flow in the battery pack.

[0034] According to the first aspect, in a possible implementation, the second liquid outlet is connected to the connecting flow channel; the heat exchange medium enters the first flow channel after passing through the second liquid inlet, the second liquid outlet, and the connecting flow channel.

[0035] According to the first aspect, in a possible implementation, the battery pack also includes a first current collector, a second current collector, a third current collector, a fourth current collector, a first multi-way valve and a second multi-way valve. The first current collector and the first flow channel are connected to the second current collector, and the third current collector, the second flow channel and the fourth current collector are connected; the first multi-way valve is connected to the first current collector and the third current collector, and the second multi-way valve is connected to the second current collector and the fourth current collector; the first multi-way valve and the second multi-way valve are connected, and the first multi-way valve and the second multi-way valve are used to control the conduction and closing of the third current collector, the fourth current collector, the first current collector and the second current collector.

[0036] In this possible implementation, a multi-way valve is used to control the flow of the heat exchange medium in the first and second flow channels, reducing the number of valves and pipelines required and increasing control flexibility. The first and second multi-way valves can be connected by a pipeline. This allows the heat exchange medium in the first and second flow channels to share a heat exchanger and pump, reducing the number of heat exchangers and pumps required and simplifying the structure of the liquid cooling system.

[0037] According to the first aspect, in one possible implementation, the battery pack includes a first operating mode and a second operating mode, and the battery pack can be switched between the first operating mode and the second operating mode by controlling the second multi-way valve and the first multi-way valve; when the battery pack is in the first operating mode, the heat exchange medium can flow in the first flow channel and the second flow channel; when the battery pack is in the second operating mode, the heat exchange medium can flow in one of the first flow channel and the second flow channel.

[0038] In this possible implementation, when the battery pack is in the first working mode, the heat exchange medium can flow in the first flow channel and the second flow channel, and the heat exchange medium in the first flow channel and the second flow channel can exchange heat with the battery cells. In this way, the volume of the heat exchange medium for heat exchange is larger, and the heat exchange capacity of the battery pack is strong, which is conducive to improving the heat exchange efficiency of the battery pack.

[0039] When the battery pack is in the second operating mode, the heat exchange medium in one of the first and second flow channels exchanges heat with the battery cells. This reduces the volume of the heat exchange medium, which helps increase the rate of temperature rise or fall. This allows the battery pack's operating mode to be selected based on the specific application scenario of the liquid cooling system, helping to reduce the system's energy consumption.

[0040] According to the first aspect, in a possible implementation, the first manifold, the second manifold, the third manifold, the fourth manifold, the first multi-way valve, and the second multi-way valve are all located in the housing.

[0041] In this possible implementation, the first manifold, the second manifold, the third manifold, the fourth manifold, the first multi-way valve and the second multi-way valve are all located inside the box, so that the first manifold, the second manifold, the third manifold, the fourth manifold, the first multi-way valve and the second multi-way valve can all be integrated into the battery pack. In this way, when the battery pack is assembled to a vehicle or other electrical equipment or an energy storage system, it is only necessary to make simple pipe connections to the heat exchanger, pump, etc. outside the battery pack.

[0042] According to the first aspect, in a possible implementation, the core body includes a top surface of the battery cell, a bottom surface of the battery cell and a side surface of the battery cell, the top surface of the battery cell and the bottom surface of the battery cell are arranged opposite to each other, the side surface of the battery cell is connected between the top surface of the battery cell and the bottom surface of the battery cell, the electrical connector is arranged on the top surface of the battery cell, the side surface of the battery cell includes two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to each other and in parallel, the two second side surfaces are arranged opposite to each other and in parallel, and the area of ​​the first side surface is greater than the area of ​​the second side surface; the first side surfaces of multiple battery cells are arranged in an array, and a first flow channel is formed between the first side surfaces of two adjacent battery cells.

[0043] In this possible implementation, since the first flow channel is formed between the side surfaces of two adjacent battery cells with larger areas, the contact area between the battery cells and the heat exchange medium is increased, thereby improving the heat exchange efficiency of the battery pack.

[0044] According to the first aspect, in some possible implementations, the second side surfaces of the plurality of battery cells are arranged in an array, and the second side surfaces of adjacent battery cells form a first flow channel.

[0045] According to the first aspect, in some possible implementations, a first flow channel is formed between the second side surface of the battery cell and the inner wall of the box.

[0046] In a second aspect, an embodiment of the present application further provides a liquid cooling system, comprising a heat exchanger, a pump, and a battery pack according to the first aspect, wherein the heat exchanger, the pump, and the first flow channel of the battery pack are connected by a pipeline.

[0047] Since the battery pack uses a semi-immersion liquid cooling solution to regulate temperature, it can reduce the energy consumption of the liquid cooling system while improving the heat exchange efficiency of the liquid cooling system.

[0048] In a third aspect, an embodiment of the present application further provides a vehicle, comprising a vehicle body and a liquid cooling system according to the second aspect, wherein the liquid cooling system is arranged on the vehicle body.

[0049] Because the battery pack uses a semi-immersion liquid cooling solution to regulate temperature, it improves the heat exchange efficiency of the liquid cooling system while reducing its energy consumption. Furthermore, the contact area between the electrical connector and the heat exchange medium is zero, achieving liquid-to-electric separation. This avoids or reduces the risk of the heat exchange medium being ionized by the charged electrical connector, thereby improving the safety and reliability of the battery pack and vehicle.

[0050] In a fourth aspect, an embodiment of the present application further provides an energy storage system, comprising the liquid cooling system of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] FIG1 is a schematic diagram of a vehicle provided in some embodiments of the present application;

[0052] FIG2 is a schematic structural diagram of a battery pack provided in some embodiments of the present application;

[0053] FIG3 is a schematic diagram of a partial structure of a battery pack provided in some embodiments of the present application;

[0054] FIG4 is a schematic diagram of a first flow channel of a battery pack provided in some embodiments of the present application;

[0055] FIG5 is a schematic diagram of a first flow channel of a battery pack provided in some embodiments of the present application;

[0056] FIG6 is a schematic diagram of a first flow channel formed by the inner wall of a battery pack and the second side surface of a battery cell according to some embodiments of the present application;

[0057] FIG7 is a schematic diagram of a battery pack provided by some embodiments of the present application, wherein the opening of the second flow channel exposes the battery cell;

[0058] FIG8 is a schematic diagram of a second flow channel formed by a main body and a separator of a battery pack provided in some embodiments of the present application;

[0059] FIG9 is a schematic diagram of a battery pack provided by some embodiments of the present application, wherein the cells are placed horizontally in a box;

[0060] FIG10 is a schematic diagram of piping of a liquid cooling system provided by some embodiments of the present application;

[0061] FIG11 is a schematic diagram of the flow of a heat exchange medium when the battery pack provided by some embodiments of the present application is in a first operating mode;

[0062] FIG12 is a schematic diagram of the flow of a heat exchange medium when the battery pack is in the first sub-mode according to some embodiments of the present application;

[0063] FIG13 is a schematic diagram of the flow of a heat exchange medium when the battery pack is in the second sub-mode according to some embodiments of the present application;

[0064] FIG14 is a schematic diagram showing that a first flow channel and a second flow channel of a battery pack provided in some embodiments of the present application are connected via a connecting flow channel. DETAILED DESCRIPTION

[0065] FIG1 is a schematic diagram of a vehicle provided in some embodiments of the present application. The vehicle includes a liquid cooling system 1 and a vehicle body 2. The liquid cooling system 1 is disposed on the vehicle body 2. The vehicle can be a new energy vehicle or a conventional vehicle.

[0066] The liquid cooling system 1 includes a battery pack 101, a heat exchanger 102, and a pump 103. The battery pack 101 is used to provide electrical energy. The battery pack 101, the heat exchanger 102, and the pump 103 are connected by pipes to form a heat exchange loop. The heat exchanger 102 is used to regulate the temperature of the battery pack 101. The pump 103 is used to drive the heat exchange medium to circulate in the heat exchange loop to achieve temperature regulation of the battery pack 101. The heat exchanger 102 may include an evaporator, a condenser, etc. It can be understood that the liquid cooling system 1 may also include other necessary or non-essential components such as a compressor.

[0067] It is understandable that the liquid cooling system 1 can also be applied to energy storage systems or other electrical equipment.

[0068] Please refer to Figure 2. The battery pack 101 includes a case 20 and a plurality of battery cells 40. The plurality of battery cells 40 can be accommodated in the case 20. The battery cell 40 includes a core 42 and an electrical connector 44 provided on the core 42. The electrical connector 44 can be a pole 442 and / or a high-voltage conductive bar 444. The pole 442 is protruding from the core 42 and is electrically connected to the core 42. The pole 442 includes a positive pole 4422 and a negative pole 4424. The positive pole 4422 of one battery cell 40 is electrically connected to the negative pole 4424 of another battery cell 40 through the high-voltage conductive bar 444. The negative pole 4424 of one battery cell 40 is electrically connected to the positive pole 4422 of another battery cell 40 through the high-voltage conductive bar 444. That is, the high-voltage conductive bar 444 refers to the high-voltage conductive bar between the poles 442.

[0069] In a battery pack 101 provided herein, two adjacent battery cells 40 or a battery cell 40 and the inner wall of the housing 20 form a first flow channel 201. The first flow channel 201 is used to accommodate a heat exchange medium 200. At least a portion of the battery cell 42 is immersed in the heat exchange medium 200, and the contact area between the electrical connector 44 and the heat exchange medium 200 is zero. It will be appreciated that in some embodiments, the multiple battery cells 40 may not be housed within the housing 20. Instead, the battery cells 40 and the housing 20 may form a sealed space, with the battery cells 40 and the inner wall of the housing 20 forming the first flow channel 201.

[0070] If the heat exchange medium fills the entire interior of the battery pack, the heat exchange medium is in direct contact with the entire battery cell for heat exchange, and the poles and the high-voltage conductive bars between the poles will be in direct contact with the heat exchange medium. On the one hand, since the heat exchange medium is in direct contact with the poles and / or high-voltage conductive bars on the battery cell, as the use time increases, the heat exchange medium is at risk of being ionized by high voltage. If the heat exchange medium is ionized, it will destroy the insulation inside the battery pack, and there will be a risk of arcing and sparking inside the battery pack. If the heat exchange medium is ionized, it will change the physical properties of the heat exchange medium and affect the heat exchange efficiency between the heat exchange medium and the battery cell. On the other hand, since the heat exchange medium fills the entire interior of the battery pack, the volume of the heat exchange medium is large, resulting in a low temperature rise rate of the battery pack when the battery cells in the battery pack need to be heated, or a low temperature drop rate of the battery pack when the battery cells in the battery pack need to be cooled. In this way, it takes a long time to reach the required operating temperature of the battery pack, which will increase the energy consumption of the vehicle.

[0071] In the battery pack 101 provided in the present application, at least a portion of the core 42 is immersed in the heat exchange medium 200. That is, the battery pack 101 adopts an immersion liquid cooling solution, so that the heat exchange medium 200 is in direct contact with the core 42 for heat exchange. Compared with the liquid cooling solution of the liquid cooling plate, this increases the volume of the heat exchange medium 200 in the battery pack 101, which is conducive to improving the heat exchange capacity and heat exchange efficiency of the battery pack 101. Since the heat exchange capacity and heat exchange efficiency of the battery pack 101 have been improved, the heat generated by the battery pack 101 during the fast charging process or thermal runaway can be effectively and promptly removed, thereby helping to improve the safety and reliability of the battery pack 101.

[0072] A first flow channel is formed between two adjacent battery cells 40 / or a first flow channel 201 is formed between the battery cell 40 and the inner wall of the box body 20, and at least part of the core body 42 is immersed in the heat exchange medium 200, that is, the battery pack 101 of the present application adopts a semi-immersed liquid cooling solution. In this way, the volume of the heat exchange medium 200 is reduced, which is beneficial to increase the rate of temperature rise or temperature drop of the heat exchange medium 200 and shorten the time to reach the required temperature.

[0073] Furthermore, since the contact area between the electrical connector 44 and the heat exchange medium 200 is zero, liquid-electric separation is achieved, thus avoiding the risk of the heat exchange medium 200 being ionized by the charged electrical connector 44. Furthermore, the electrical connectors 44, such as the poles 442 and the high-voltage conductive bus 444, are typically irregular in shape. Since the electrical connectors 44 do not contact the heat exchange medium 200, they do not hinder the flow of the heat exchange medium, thereby effectively reducing the flow resistance of the heat exchange medium 200 and improving the heat exchange uniformity of the battery pack 101.

[0074] The heat exchange medium 200 can be a coolant, such as water, ethylene glycol solution, propylene glycol solution, or fluorinated liquid. The heat exchange medium 200 can also include a gas. The working fluid can be a single component or a mixture of at least two heat exchange working fluids 200 (for example, a mixed liquid formed by mixing at least two coolants). The heat exchange working fluid 200 can maintain a single phase (i.e., no phase change) during flow, or it can be two-phase (i.e., transitioning between a liquid phase and a gas phase). It is understood that the desired type of heat exchange working fluid can be selected as needed.

[0075] In some embodiments of the present application, the housing 20 includes a main body 22 and a plurality of support pads 24. The main body 22 is configured to accommodate a plurality of battery cells 40. The plurality of support pads 24 are spaced apart on the bottom wall of the main body 22 and positioned within the main body 22 to support the plurality of battery cells 40. The main body 22 includes a top wall, a bottom wall, and side walls, with the top wall and the bottom wall disposed opposite each other. The side walls are connected between the bottom wall and the top wall.

[0076] Referring to FIG. 3 , the core 42 is generally cuboid in shape and includes a top surface 422, a bottom surface 424, and side surfaces 426. The top surface 422 and the bottom surface 424 are disposed opposite each other, and the side surfaces 426 are connected between the top and bottom surfaces 424. The electrical connector 44 is disposed on the top surface 422. The side surfaces 426 include two first side surfaces 4262 and two second side surfaces 4264. The two first side surfaces 4262 are disposed opposite and parallel to each other, and the two second side surfaces 4264 are disposed opposite and parallel to each other. The area of ​​the first side surfaces 4262 is greater than that of the second side surfaces 4264. The area of ​​the bottom surface 424 is smaller than that of the first side surfaces 4262. The first side surfaces 4262 of the plurality of battery cells 40 are arranged along the second direction Z, and at least one first flow channel 201 is defined between the first side surfaces 4262 of two adjacent battery cells 40. Because the first flow channel 201 is formed between the larger side surfaces of two adjacent battery cells 40, the contact area between the battery cells 40 and the heat exchange medium 200 is increased, thereby improving the heat exchange efficiency of the battery pack 101. For example, the dotted arrows in FIG3 indicate the flow direction of the heat exchange medium 200 in the battery pack 101.

[0077] In some embodiments of the present application, the two second side surfaces 4264 are arranged relative to each other along the first direction X, the top surface 422 of the battery cell and the bottom surface 424 of the battery cell are spaced apart along the second direction Z, the two first side surfaces 4262 are arranged relative to each other along the third direction Y, the first direction X is perpendicular to the third direction Y, the third direction Y is perpendicular to the second direction Z, and the first direction X is perpendicular to the second direction Z. The top surface 422 of the battery cell, the bottom surface 424 of the battery cell, and the bottom wall of the box body 20 are arranged along the second direction Z. That is, the battery cell 40 is placed vertically in the box body 20. It will be understood that the present application does not limit the shape of the core body 42 to a cube, and the core body 42 may also be other shapes, for example, a cylinder, etc. It will be understood that the first direction is different from the second direction, the second direction is different from the third direction, and the third direction is different from the first direction.

[0078] It can be understood that in the first direction X, the first side surfaces 4262 of the first and tail battery cells 40 among the multiple battery cells 40 can form a first flow channel 201 with the inner wall of the box body 20 to increase the contact area between the first and tail battery cells 40 among the multiple battery cells 40 and the heat exchange medium 200.

[0079] The battery pack 101 also includes a guide bar 50 (as shown in FIG4 ), which is fixed between two adjacent first side surfaces 4262. The guide bar 50, the battery cell 40, and the inner wall of the box body 20 form a first flow channel 201. The guide bar 50, the battery cell 40, and the inner wall of the box body 20 form the first flow channel 201, which has a simple structure and is easy to manufacture. In addition, the guide bar 50 can support the battery cell 40 when it expands, reduce the possibility of deformation of the battery cell 40 and the first flow channel 201, and improve the uniformity of the heat exchange medium when it flows in the first flow channel 201. It can be understood that the present application does not limit the number of first flow channels 201.

[0080] The first flow channel 201 includes a straight and / or curved channel. As shown in Figure 4 , the first flow channel 201 includes a straight and curved channel, which includes a first liquid inlet 2011 and a first liquid outlet 2013. The straight and curved channel extends along a first direction X. The first liquid inlet 2011 of the straight and curved channel is located at one end of the straight and curved channel in the first direction X for inputting the heat exchange medium 200, and the first liquid outlet 2013 of the straight and curved channel is located at the other end of the straight and curved channel in the first direction X for outputting the heat exchange medium 200. The straight and curved channel can reduce the flow resistance of the heat exchange medium 200 during circulation, thereby improving the heat exchange uniformity of the battery pack 101.

[0081] Figure 4 exemplarily illustrates two flattened direct current channels, arranged along a third direction Y perpendicular to the first direction X. Increasing the number of flattened direct current channels improves the heat exchange between the heat exchange medium and the battery cells. It is understood that the number of flattened direct current channels can be one or at least two, and this application does not limit the number or arrangement of the flattened direct current channels.

[0082] In one embodiment, as shown in FIG5 , the first flow channel 201 includes a curved flow channel, which can improve the uniformity of the flow of the heat exchange medium 200 between the battery cells 40. The curved flow channel is generally S-shaped. The curved flow channel includes a first portion 2014, a second portion 2015, a third portion 2016, a first liquid inlet 2011, and a first liquid outlet 2013. The first portion 2014, the second portion 2015, and the third portion 2016 all extend along a first direction X. The first portion 2014, the third portion 2016, and the second portion 2015 are arranged along a third direction Y. The first direction X is perpendicular to the third direction Y. The first liquid inlet 2011 is provided at the first end of the first portion 2014 in the first direction X for inputting the heat exchange medium 200. The second end of the first portion 2014 in the first direction X is connected to the first end of the second portion 2015 in the first direction X. The first liquid outlet 2013 of the curved flow channel is located at the second end of the second portion 2015 in the first direction X, where the first direction X is perpendicular to the third direction Y. The first end of the first portion 2014, the second end of the third portion 2016, and the first end of the second portion 2015 are sequentially arranged in the third direction Y. The first portion 2014 can be located on a side of the first side 4262 close to the bottom surface 424 of the battery cell, and the second portion 2015 can be located on a side of the first side 4262 close to the top surface 422 of the battery cell.

[0083] It can be understood that the present application does not limit the shape of the curved flow channel. For example, the curved flow channel can be "C" or "Z" shaped.

[0084] In some embodiments of the present application, the battery cell 40 and the inner wall of the housing 20 form a first flow channel 201 for circulating the heat exchange medium 200. For example, as shown in FIG6 , the first flow channel 201 is formed between the second side surface 4264 of the battery cell 40 and the inner wall of the housing 20. It will be understood that the second side surfaces 4264 of multiple battery cells 40 can be arranged in an array, and the first flow channel 201 is formed between the second side surfaces 4264 of adjacent battery cells 40.

[0085] Please refer to Figures 2 and 3 again. A second flow channel 203 is provided on the inner wall of the housing 20. The second flow channel 203 is used to accommodate the heat exchange medium 200. The second flow channel 203 includes an opening 2031, a second liquid inlet 2033, and a second liquid outlet 2035 that are interconnected. The second liquid inlet 2033 is used to input the heat exchange medium 200. The second liquid outlet 2035 is used to output the heat exchange medium 200. Each battery cell 40 is covered on a corresponding opening 2031 to enable the battery cell 40 to exchange heat with the heat exchange medium 200 in the second flow channel 203. In some embodiments of the present application, the bottom surface 424 of the battery cell is covered on the corresponding opening 2031. The second flow channel 203 extends along the first direction X. Since the second flow channel 203 can also circulate the heat exchange medium, this increases the heat exchange area between the heat exchange medium 200 and the battery cell 40, thereby improving the heat exchange efficiency of the battery pack 101.

[0086] In some embodiments of the present application, the first flow channel 201 and the second flow channel 203 may not be interconnected, and the heat exchange medium 200 in the first flow channel 201 and the heat exchange medium 200 in the second flow channel 203 do not circulate with each other, but may flow separately. For example, the liquid cooling system 1 includes a first flow path and a second flow path that are independent of each other, each of which is provided with a heat exchanger 102, a pump 103, etc. The first flow channel 201 is located in the first flow path, and the second flow channel 203 is located in the second flow path. The heat exchange medium 200 in the first flow channel 201 circulates only in the first flow path where the first flow channel 201 is located and does not flow into the second flow channel 203. The heat exchange medium 200 in the second flow channel 203 circulates only in the second flow path where the second flow channel 203 is located and does not flow into the first flow channel 201. By designing the heat exchange medium 200 in a zoned manner, if a leak occurs somewhere in the battery pack 101, such as a vehicle scraping the bottom, causing the seal at the bottom of the battery pack 101 to fail and the heat exchange medium 200 leaking out of the second flow channel 203 of the battery pack 101, the heat exchange medium 200 within the first flow channel 201 remains intact and can still provide thermal protection, thereby improving the robustness of the liquid cooling system 1. Furthermore, the submerged heat exchange medium 200 is restricted to flow orderly within the first and second flow channels 201, 203, reducing the volume of the submerged heat exchange medium 200 and the risk of leakage outside the battery pack 101 during prolonged use.

[0087] In some embodiments of the present application, a second flow channel 203 is formed between each pair of adjacent support pads 24, and each battery cell 40 is connected to two corresponding adjacent support pads 24. The first side surfaces 4262 of the two battery cells 40 and the sides of the support pads 24 facing away from the main body 22 together form the first flow channel 201. By providing multiple support pads 24 spaced apart on the inner wall of the main body 22 to form multiple second flow channels 203, the structure is simplified, simplifying the preparation of the box 20 and reducing the production cost of the battery pack 101.

[0088] In some embodiments of the present application, referring to FIG. 7 , in the first direction X, the length of the second flow channel 203 is greater than the length of the battery cell 40, and a portion of the opening 2031 of the second flow channel 203 is exposed outside the multiple battery cells 40. If a battery cell 40 experiences thermal runaway, that is, the battery cell 40 expands and gas is ejected from the bottom surface 424 of the battery cell, since a portion of the opening 2031 of the second flow channel 203 is exposed outside the multiple battery cells 40, the gas passes through the second flow channel 203 and is exhausted from the exposed opening 2031 of the second flow channel 203, thereby improving the smoothness of the thermal runaway exhaust, reducing the possibility of explosion of the battery pack 101, and thus improving the safety of the battery pack 101.

[0089] The battery cell 40 also includes a battery cell explosion-proof valve 46. The battery cell explosion-proof valve 46 (as shown in FIG2 ) is disposed on the bottom surface 424 of the battery cell and is disposed toward the opening 2031. In other words, the orthographic projection of the battery cell explosion-proof valve 46 on the housing 20 along the second direction Z is located in the second flow channel 203. If a battery cell 40 experiences thermal runaway, the battery cell explosion-proof valve 46 on the thermal runaway battery cell 40 will spray gas into the corresponding second flow channel 203. Since the opening 2031 of the second flow channel 203 is partially exposed outside the plurality of battery cells 40, the gas passes through the second flow channel 203 and is exhausted from the opening 2031 exposed in the second flow channel 203, thereby improving the patency of the thermal runaway exhaust, further reducing the possibility of explosion of the battery pack 101, and thus improving the safety of the battery pack 101.

[0090] It will be understood that the present application does not limit the configuration of the second flow channel 203. In some embodiments of the present application, as shown in FIG8 , the housing 20 includes a main body 22 and a partition 26 housed within the main body 22. The partition 26 and the inner wall of the main body 22 define a second flow channel 203 and a receiving cavity 205, which are separated and arranged. The partition 26 is provided with a plurality of openings 2031. A plurality of battery cells 40 are housed within the receiving cavity 205, with the cell 40 covers positioned over the openings 2031. The battery pack 101 also includes a battery pack explosion-proof valve 53, which is disposed on the outer wall of the main body 22. The battery pack explosion-proof valve 53 is configured to eject gas from the second flow channel 203 when the gas pressure within the second flow channel 203 becomes excessive. When a battery cell 40 within the battery pack 101 experiences thermal runaway, gas ejected from the bottom surface 424 of the cell will flow into the second flow channel 203. When the gas pressure in the second flow channel 203 exceeds the range that the battery pack explosion-proof valve 53 can withstand, the battery pack explosion-proof valve 53 releases the gas in the second flow channel 203, thereby reducing the possibility of explosion of the battery pack 101 and improving the safety of the battery pack 101.

[0091] In some embodiments of the present application, as shown in FIG9 , a second side surface 4264 of the battery cell 40 can cover the opening 2031 of the corresponding second flow channel 203. The contact area between the electrical connector 44 of the battery cell 40 and the heat exchange medium 200 is zero, that is, the battery cell 40 is placed horizontally within the box 20. A battery cell explosion-proof valve 46 is provided on the top surface 422 of the battery cell, and the top surface 422 of the battery cell is arranged toward the side wall of the box 20. A second side surface 4264 of the battery cell 40 is provided on the side of the battery cell 40 that faces the support pad 24.

[0092] Referring to Figure 10 , in some embodiments of the present application, the battery pack 101 further includes a first manifold 61, a second manifold 62, a third manifold 63, a fourth manifold 64, a first multi-way valve 671, and a second multi-way valve 672. The first manifold 61, the first flow channel 201, and the second manifold 62 are connected to allow the heat exchange medium 200 to flow through each of the first flow channels 201. The third manifold 63, the second flow channel 203, and the fourth manifold 64 are connected to allow the heat exchange medium 200 to flow through each of the second flow channels 203. The first multi-way valve 671 is connected to the heat exchanger 102 outside the battery pack 101 via a pipeline, and the second multi-way valve 672 is connected to the pump 103 via a pipeline. The first multi-way valve 671 is connected to the first manifold 61 and the third manifold 63, and the second multi-way valve 672 is connected to the second manifold 62 and the fourth manifold 64. The first multi-way valve 671 and the second multi-way valve 672 are connected and are used to control the conduction and closing of the third manifold 63, the fourth manifold 64, the first manifold 61, and the second manifold 62. The multi-way valves are used to control the flow of the heat exchange medium 200 in the first flow channel 201 and the second flow channel 203, thereby reducing the number of valves and pipelines used and improving control flexibility.

[0093] The first multi-way valve 671 and the second multi-way valve 672 can be connected by a pipeline. In this way, the heat exchange medium 200 in the first flow channel 201 and the second flow channel 203 can share the heat exchanger 102 and pump 103, thereby reducing the number of heat exchangers 102 and pumps 103 used and simplifying the structure of the liquid cooling system 1. It will be understood that the box 20 or other structure within the battery pack 101 is provided with a connecting flow channel, and the first multi-way valve 671 is connected to the second multi-way valve 672 through the connecting flow channel.

[0094] In some embodiments of the present application, the first manifold 61, the second manifold 62, the third manifold 63, the fourth manifold 64, the first multi-way valve 671, and the second multi-way valve 672 are all located within the housing 20, so that the first manifold 61, the second manifold 62, the third manifold 63, the fourth manifold 64, the first multi-way valve 671, and the second multi-way valve 672 can all be integrated into the battery pack 101. In this way, when the battery pack 101 is assembled into an electrical device such as a vehicle or an energy storage system, only simple piping connections need to be made to the heat exchanger 102, the pump 103, and the like outside the battery pack 101. It is understandable that the first manifold 61, the second manifold 62, the third manifold 63, the fourth manifold 64, the first multi-way valve 671, and the second multi-way valve 672 can also be located outside the battery pack 101.

[0095] The battery pack 101 has a first operating mode (as shown in FIG. 11 ) and a second operating mode (as shown in FIG. 12 and FIG. 13 ). The battery pack 101 can switch between the first and second operating modes by controlling the opening and closing of each valve port in the first multi-way valve 671 and the second multi-way valve 672 . When the battery pack 101 is in the first operating mode, the pump 103 drives the heat exchange medium 200 to flow through the first and second flow channels 201 , 203 , exchanging heat with the battery cells 40 . When the battery pack 101 is in the second operating mode, the pump 103 drives the heat exchange medium 200 to flow through either the first or second flow channels 201 , 203 , exchanging heat with the battery cells 40 .

[0096] When the battery pack 101 is in the first operating mode, the heat exchange medium 200 can flow in the first flow channel 201 and the second flow channel 203. The heat exchange medium 200 in the first flow channel 201 and the second flow channel 203 can exchange heat with the battery cell 40. In this way, the volume of the heat exchange medium 200 performing heat exchange is relatively large, and the heat exchange capacity of the battery pack 101 is strong, which is conducive to improving the heat exchange efficiency of the battery pack 101. When the battery pack 101 is in the second operating mode, because the heat exchange medium 200 in one of the first flow channel 201 and the second flow channel 203 exchanges heat with the battery cell 40, the volume of the heat exchange medium 200 is relatively small, which is conducive to increasing the rate of temperature rise or temperature drop. In this way, the operating mode of the battery pack 101 can be selected according to the specific application scenario of the liquid cooling system 1, which is conducive to reducing the energy consumption of the liquid cooling system 1.

[0097] In some embodiments of the present application, the first multi-way valve 671 and the second multi-way valve 672 can both be four-way valves. The first multi-way valve 671 and the second multi-way valve 672 each include a first valve port 6711, a second valve port 6712, a third valve port 6713, and a fourth valve port 6714. The first valve port 6711 of the first multi-way valve 671 is connected to the first liquid inlet 2011 of the first manifold 61, the second valve port 6712 of the first multi-way valve 671 is connected to the second liquid inlet 2033 of the third manifold 63, the third valve port 6713 of the first multi-way valve 671 is connected to the fourth valve port 6714 of the second multi-way valve 672, and the fourth valve port 6714 of the first multi-way valve 671 is connected to the heat exchanger 102 via a pipeline. The first valve port 6711 of the second multi-way valve 672 is connected to the second manifold 62, the second valve port 6712 of the second multi-way valve 672 is connected to the fourth manifold 64, the third valve port 6713 of the second multi-way valve 672 is connected to the pump 103, and the fourth valve port 6714 of the second multi-way valve 672 is connected to the third valve port 6713 of the first multi-way valve 671. It is understood that the first multi-way valve 671 and the second multi-way valve 672 may also be other types of multi-way valves.

[0098] In some embodiments of the present application, when the battery pack 101 is in the first working mode, please refer to Figure 11, the first valve port 6711 of the first multi-way valve 671, the second valve port 6712 of the first multi-way valve 671, the third valve port 6713 of the first multi-way valve 671, the fourth valve port 6714 of the first multi-way valve 671, the first valve port 6711 of the second multi-way valve 672, the second valve port 6712 of the second multi-way valve 672, the third valve port 6713 of the second multi-way valve 672, and the fourth valve port 6714 of the second multi-way valve 672 are all opened, that is, the four valve ports of the first multi-way valve 671 and the second multi-way valve 672 are all opened, the first manifold 61 and the second manifold 62 are both connected, the third manifold 63 and the fourth manifold 64 are both connected, and the heat exchange medium 200 is circulated or flowing in the first flow channel 201 and the second flow channel 203. The heat exchange medium 200 in the first flow channel 201 and the second flow channel 203 exchanges heat with the battery cell 40. In this way, the area of ​​the heat exchange medium 200 flowing in the battery pack 101 is larger, which is beneficial to increasing the heat exchange capacity of the battery pack 101.

[0099] In some embodiments of the present application, the second operating mode includes a first sub-mode and a second sub-mode. When the battery pack 101 is in the first sub-mode, please refer to FIG12 , the first valve port 6711 of the first multi-way valve 671, the third valve port 6713 of the first multi-way valve 671, the first valve port 6711 of the second multi-way valve 672, and the third valve port 6713 of the second multi-way valve 672 are all open, and the second valve port 6712 of the first multi-way valve 671, the third valve port 6713 of the first multi-way valve 671, the second valve port 6712 of the second multi-way valve 672, and the fourth valve port 6713 of the second multi-way valve 672 are all open. 14 are all closed, so that the first valve port 6711 of the first multi-way valve 671 and the fourth valve port 6714 of the first multi-way valve 671 are connected, the first valve port 6711 of the second multi-way valve 672 and the third valve port 6713 of the second multi-way valve 672 are connected, and the third collecting pipe 63 and the fourth collecting pipe 64 are both closed, so that the heat exchange medium 200 can circulate or flow in the first collecting pipe 61, the first flow channel 201, and the second collecting pipe 62, and the heat exchange medium 200 does not circulate in the second flow channel 203.

[0100] Please refer to FIG13 . When the battery pack 101 is in the second sub-mode, the second valve port 6712 of the first multi-way valve 671, the fourth valve port 6714 of the first multi-way valve 671, the second valve port 6712 of the second multi-way valve 672, and the third valve port 6713 of the second multi-way valve 672 are all open, and the first valve port 6711 of the first multi-way valve 671, the third valve port 6713 of the first multi-way valve 671, the first valve port 6711 of the second multi-way valve 672, and the fourth valve port 6714 of the first multi-way valve 671 are all open. 14 are all closed, so that the second valve port 6712 of the first multi-way valve 671 and the fourth valve port 6714 of the first multi-way valve 671 are connected, the second valve port 6712 of the second multi-way valve 672 and the third valve port 6713 of the second multi-way valve 672 are connected, and the first collecting pipe 61 and the second collecting pipe 62 are both closed, so that the heat exchange medium 200 can circulate or flow in the third collecting pipe 63, the second flow channel 203, and the fourth collecting pipe 64, and the heat exchange medium 200 does not circulate in the first flow channel 201.

[0101] The liquid cooling system 1 can have multiple working scenarios, such as fast charging scenario, low temperature starting scenario, and discharge scenario. Different control strategies can be used to control the pump 103, heat exchanger 102, first multi-way valve 671, second multi-way valve 672 and other components in the liquid cooling system 1, so that the liquid cooling system 1 can work in different working scenarios. When the liquid cooling system 1 is in the fast charging scenario, the battery pack 101 is fast charged. Since the heat generated by the battery pack 101 during fast charging is very large, the battery pack 101 is controlled to be in the first working mode, and the heat exchange medium 200 circulates in both the first flow channel 201 and the second flow channel 203, thereby increasing the heat exchange area between the battery cell 40 and the heat exchange medium 200, and improving the heat exchange efficiency and heat exchange capacity of the battery pack 101.

[0102] In a low-temperature startup scenario, for example, when the temperature of the battery pack 101 is below -15 degrees Celsius, the liquid cooling system 1 controls the heat exchanger 102 or heater to heat the heat exchange medium 200, which then heats the battery cells 40. If the volume of the heat exchange medium 200 is too large, the temperature rise rate of the heat exchange medium 200 will be slow, which will increase the low-temperature startup time. In this case, the battery pack 101 can be selected to operate in the second operating mode, that is, the heat exchange medium 200 flows through one of the first flow channel 201 and the second flow channel 203. In this way, since the volume of the circulating heat exchange medium 200 is smaller, the temperature rise rate can be increased, which helps to reduce the duration of the low-temperature startup. Because the area of ​​the first side surface 4262 is larger than the area of ​​the battery cell bottom surface 424, the second sub-mode of the second operating mode can be selected to further reduce the volume of the heat exchange medium 200 and increase the temperature rise rate.

[0103] In some discharge scenarios, the liquid cooling system 1 is used. For example, in a low-heat discharge scenario where the heat generated by the discharging battery cell 40 per unit time is no greater than a preset value, or in a short-time discharge scenario where the discharge duration of the battery cell 40 is no greater than a preset duration, the battery pack 101 does not generate much heat. The battery pack 101 can be in the first operating mode, and the heat exchanger 102 can not actively cool the heat exchange medium 200. The pump 103 is controlled to drive the heat exchange medium 200 to circulate in the first flow channel 201 and the second flow channel 203. The heat exchange medium 200 circulates to cool the battery cell 40 of the battery pack 101, thereby saving active cooling energy. The preset value and preset duration can be set according to the different characteristics of the battery cell 40.

[0104] In some embodiments of the present application, the first flow channel 201 and the second flow channel 203 can also be connected to each other so that the heat exchange medium 200 can flow between the first flow channel 201 and the second flow channel 203, that is, the heat exchange medium 200 forms an integrated flow within the battery pack 101. As shown in Figure 14, the battery pack 101 is also provided with a connecting flow channel 207, which connects the first flow channel 201 and the second flow channel 203. The second liquid outlet 2035 of the second flow channel 203 is connected to the connecting flow channel 207. The heat exchange medium 200 enters the first flow channel 201 after passing through the second liquid inlet 2033, the second liquid outlet 2035, and the connecting flow channel 207. It is understood that the connecting flow channel 207 can be a flow channel formed on the housing 20, or it can be set on a pipe or structural member connected between the first flow channel 201 and the second flow channel 203. The present application does not limit the method of achieving communication between the first flow channel 201 and the second flow channel 203.

[0105] It can be understood that the present application does not limit the circulation method of the heat exchange medium 200 in the battery pack 101. For example, in some possible implementations, the first liquid outlet 2013 of the first flow channel 201 is connected to the connecting flow channel; the heat exchange medium 200 enters the second flow channel 203 after passing through the first liquid inlet 2011, the first liquid outlet 2013, and the connecting flow channel 207.

[0106] It should be understood that expressions such as "include" and "may include" used in this application indicate the existence of the disclosed functions, operations, or constituent elements, and do not limit one or more additional functions, operations, and constituent elements. In this application, terms such as "include" and / or "have" may be interpreted as indicating specific characteristics, numbers, operations, constituent elements, components, or combinations thereof, but may not be interpreted as excluding the existence or possibility of adding one or more other characteristics, numbers, operations, constituent elements, components, or combinations thereof.

[0107] In addition, in this application, the expression "and / or" includes any and all combinations of the associated listed words. For example, the expression "A and / or B" may include A, may include B, or may include both A and B.

[0108] In this application, expressions including ordinal numbers such as "first" and "second" may modify various elements. However, such elements are not limited by the above expressions. For example, the above expressions do not limit the order and / or importance of the elements. The above expressions are only used to distinguish one element from other elements. For example, a first user device and a second user device indicate different user devices, even though the first user device and the second user device are both user devices. Similarly, without departing from the scope of this application, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0109] When a component is referred to as being "connected" or "accessed" to another component, it should be understood that the component is not only directly connected to or accessed to the other component, but also that another component may exist between the component and the other component. On the other hand, when a component is referred to as being "directly connected to" or "directly accessed" to another component, it should be understood that no component exists between them.

[0110] The above descriptions are merely specific embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any modifications or substitutions that can be readily conceived by a person skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A battery pack, characterized in that: It includes a box body and multiple battery cells, wherein the multiple battery cells are accommodated in the box body or the battery cells and the box body form a sealed space, the battery cell includes a core body and an electrical connector arranged on the core body, two adjacent battery cells or the battery cell and the inner wall of the box body form a first flow channel, the first flow channel is used to accommodate a heat exchange medium, at least part of the core body is immersed in the heat exchange medium, the contact area between the electrical connector and the heat exchange medium is zero, and the electrical connector is a pole and / or a high-voltage conductive bar between the poles.

2. The battery pack according to claim 1, characterized in that: The first flow channel includes a flat flow channel, which includes a first liquid inlet and a first liquid outlet. The flat flow channel extends along a first direction. The first liquid inlet of the flat flow channel is located at one end of the flat flow channel in the first direction for inputting heat exchange medium, and the first liquid outlet of the flat flow channel is located at the other end of the flat flow channel in the first direction for outputting heat exchange medium.

3. The battery pack according to claim 2, characterized in that: The number of the flat and straight channels is at least two, and the at least two flat and straight channels are arranged along a second direction perpendicular to the first direction.

4. The battery pack according to any one of claims 1 to 3, characterized in that: The first flow channel includes a curved flow channel, and the curved flow channel includes a first liquid inlet and a first liquid outlet. The first liquid inlet of the curved flow channel is used to input heat exchange medium, and the first liquid outlet of the curved flow channel is used to output heat exchange medium.

5. The battery pack according to claim 4, characterized in that: The curved flow channel also includes a first part and a second part that are connected to each other. The first part and the second part are arranged along a second direction. The first liquid inlet of the curved flow channel is arranged at the first part, and the first liquid outlet of the curved flow channel is arranged at the second part.

6. The battery pack according to claim 5, characterized in that: The first liquid inlet of the curved flow channel is arranged at the first end of the first part in the first direction, the second end of the first part in the first direction is connected to the first end of the second part in the first direction, the first liquid outlet of the curved flow channel is arranged at the second end of the second part in the first direction, and the first direction is perpendicular to the second direction.

7. The battery pack according to claim 6, characterized in that: The curved flow channel also includes a third part, the first part, the third part, and the second part are arranged in sequence along the second direction, the first end of the third part in the first direction is connected to the second end of the first part, the second end of the third part in the first direction is connected to the first end of the second part, and the first end of the first part, the second end of the third part, and the first end of the second part are arranged in sequence in the second direction.

8. The battery pack according to any one of claims 2 to 7, characterized in that: The battery pack further includes a guide bar fixed between two adjacent battery cells, and the guide bar, the battery cells, and the inner wall of the box form the first flow channel.

9. The battery pack according to any one of claims 1 to 8, characterized in that: A second flow channel is provided on the inner wall of the box body, and the second flow channel is used to accommodate a heat exchange medium. The second flow channel includes a connected opening, a second liquid inlet and a second liquid outlet. The second liquid inlet is used to input the heat exchange medium, and the second liquid outlet is used to output the heat exchange medium. Each of the battery cell covers is provided on a corresponding one of the openings.

10. The battery pack according to claim 9, characterized in that: The box body includes a main body and a plurality of support pads, wherein the plurality of support pads are arranged at intervals on the inner wall of the main body, the second flow channel is formed between every two adjacent support pads, and each of the battery cells is connected to corresponding two adjacent support pads.

11. The battery pack according to claim 9, characterized in that: The box body includes a main body and a partition contained in the main body, the partition and the inner wall of the main body form a second flow channel and a receiving cavity that are separated and arranged, the partition is provided with a plurality of the openings, and a plurality of the battery cells are contained in the receiving cavity.

12. The battery pack according to any one of claims 9 to 11, characterized in that: The second flow channel extends along a first direction. In the first direction, a length of the second flow channel is greater than a length of the battery core, and an opening portion of the second flow channel is exposed outside the plurality of battery cores.

13. The battery pack according to any one of claims 9 to 12, characterized in that: The box body is also provided with a connecting flow channel, and the connecting flow channel connects the first flow channel and the second flow channel.

14. The battery pack according to any one of claims 9 to 11, characterized in that: The battery pack further includes a first current collector, a second current collector, a third current collector, a fourth current collector, a first multi-way valve and a second multi-way valve, the first current collector and the first flow channel are connected to the second current collector, the third current collector, the second flow channel and the fourth current collector are connected; the first multi-way valve is connected to the first current collector and the third current collector, and the second multi-way valve is connected to the second current collector and the fourth current collector; The first multi-way valve and the second multi-way valve are connected, and the first multi-way valve and the second multi-way valve are used to control the conduction and closing of the third header, the fourth header, the first header, and the second header.

15. The battery pack according to claim 14, characterized in that: The battery pack includes a first working mode and a second working mode, and the battery pack can be switched between the first working mode and the second working mode by controlling the second multi-way valve and the first multi-way valve; When the battery pack is in the first working mode, the heat exchange medium can flow in the first flow channel and the second flow channel; When the battery pack is in the second operating mode, the heat exchange medium can flow in one of the first flow channel and the second flow channel.

16. The battery pack according to claim 15, characterized in that: The first header, the second header, the third header, the fourth header, the first multi-way valve and the second multi-way valve are all located in the housing.

17. The battery pack according to any one of claims 1 to 16, characterized in that: The core body includes a top surface of the battery cell, a bottom surface of the battery cell and a side surface of the battery cell, the top surface of the battery cell is arranged opposite to the bottom surface of the battery cell, the side surface of the battery cell is connected between the top surface of the battery cell and the bottom surface of the battery cell, the electrical connector is arranged on the top surface of the battery cell, the side surface of the battery cell includes two first side surfaces and two second side surfaces, the two first side surfaces are arranged opposite to and in parallel, the two second side surfaces are arranged opposite to and in parallel, and the area of ​​the first side surface is greater than the area of ​​the second side surface; The first side surfaces of the plurality of battery cells are arranged in an array, and the first side surfaces of two adjacent battery cells form a first flow channel.

18. A liquid cooling system, characterized in that: It comprises a heat exchanger, a pump and a battery pack according to any one of claims 1 to 17, wherein the heat exchanger, the pump and the first flow channel of the battery pack are connected by a pipeline.

19. A vehicle, characterized in that: It comprises a vehicle body and a liquid cooling system according to claim 18, wherein the liquid cooling system is arranged on the vehicle body.

20. An energy storage system, characterized in that: Comprising a liquid cooling system according to claim 18.

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