Liquid-cooled battery pack and energy storage system

Abstract

The utility model provides a liquid-cooled battery pack and an energy storage system.The liquid-cooled battery pack comprises a cold plate, a plurality of battery cells, an equalization module and a radiator, the interior of the cold plate comprises a first cooling medium flow channel allowing a cooling medium to circulate, the battery cells are arranged on the cold plate, the equalization module comprises a DC / DC converter, and the first cooling medium flow channel is communicated with the first cooling medium flow channel. The equalization module is used for controlling the plurality of battery cells to be charged or discharged, the radiator is in contact with the equalization module so as to perform heat exchange with the equalization module, and the radiator is in contact with the cold plate so as to perform heat exchange with the cold plate. According to the liquid-cooled battery pack and the energy storage system provided by the embodiment of the invention, the heat dissipation requirement of the equalization module can be met, and the cooling efficiency of the battery pack is improved.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and more specifically, to a liquid-cooled battery pack and an energy storage system. Background Art

[0002] Currently, a battery pack with a balancing module is known. The DC / DC converter of the balancing module can adjust the current distribution between battery modules. Multiple battery packs with balancing modules can achieve energy balance between battery packs.

[0003] However, as the capacity of battery cells gradually increases, the energy density of the battery pack increases accordingly, and the power of the battery pack with a balancing module also increases accordingly, which poses higher challenges to the heat dissipation management of the balancing module and the thermal management architecture design of the battery pack.

[0004] Currently, battery packs with balancing modules cool the balancing modules by adopting natural heat dissipation, but the cooling efficiency is low and cannot meet the increasing heat dissipation demand. Therefore, how to improve the cooling efficiency of battery packs with balancing modules has become a problem that needs to be solved urgently. Utility Model Content

[0005] The present application provides a liquid-cooled battery pack and energy storage system, which can meet the heat dissipation requirements of the balancing module in the battery pack and improve the cooling efficiency of the balancing module of the battery pack.

[0006] In a first aspect, a liquid-cooled battery pack is provided, comprising a cold plate, a plurality of battery cells, a balancing module and a radiator, wherein the cold plate comprises a first cooling medium flow channel for circulating a cooling medium, the plurality of battery cells are arranged on the cold plate, the balancing module comprises a DC / DC converter, the balancing module is used to control the charging or discharging of the plurality of battery cells, the radiator contacts the balancing module to perform heat exchange with the balancing module, and the radiator contacts the cold plate to perform heat exchange with the cold plate.

[0007] The liquid-cooled battery pack provided in the embodiment of the present application is provided with a radiator which is in contact with the balancing module and the cold plate respectively. The radiator is cooled by the cooling medium flow channel of the cold plate, and then the balancing module in contact with the radiator is cooled, thereby improving the cooling efficiency of the balancing module. The power of the battery pack can continue to evolve with the large capacity of the battery cells, and the implementation cost and complexity are also low, which also helps to improve the stability of the battery pack and extend its service life.

[0008] In one of the implementations, the liquid-cooled battery pack also includes a cover body, the cover body and the cold plate form a first receiving cavity, the multiple battery cells and the balancing module are accommodated in the first receiving cavity, the radiator includes a first part located in the first receiving cavity, a first surface of the first part contacts the balancing module, and a second surface of the first part contacts the cold plate.

[0009] In the embodiment of the present application, the first part of the radiator located in the first receiving cavity of the battery pack contacts the balancing module and the cold plate respectively. The first part of the radiator used for contact is located in the first receiving cavity of the battery pack, which is conducive to maintaining a stable operating temperature and the transfer of cold air. In addition, it can also avoid external influences such as dust, thereby improving the service life and stability of the battery pack.

[0010] In one implementation manner, the heat sink includes heat dissipation teeth arranged on a third surface of the first part, and the third surface is a surface of the first part away from the balancing module in a direction perpendicular to the first surface.

[0011] In the embodiment of the present application, the heat sink is provided with heat dissipation teeth in contact with the external environment, so that the heat sink can dissipate heat for the balancing module through dual heat dissipation methods of natural heat dissipation and cold plate heat dissipation, thereby improving the cooling efficiency.

[0012] In one implementation, the first part includes a first heat sink and a second heat sink, the first heat sink is perpendicular to the second heat sink, the second heat sink is arranged parallel to the cold plate, the first surface is the surface of the first heat sink facing the multiple battery cells, and the second surface is the surface of the second heat sink facing the cold plate.

[0013] The embodiment of the present application increases the contact area between the heat sink and the cold plate by setting the structure of the heat sink, thereby accelerating the heat dissipation speed and meeting the heat dissipation requirements of the balancing module.

[0014] In one implementation manner, the balancing module includes a shell, the shell is in contact with a fourth surface, and the fourth surface is a surface of the second heat dissipation plate away from the cold plate.

[0015] In the embodiment of the present application, the side of the shell facing the cold plate is arranged to exchange heat with the radiator, so that in addition to the surface of the balancing module in contact with the first surface of the radiator, the shell can also dissipate heat, further meeting the heat dissipation requirements of the balancing module.

[0016] In one of the implementations, the balancing module includes a shell, and the shell and the first surface of the first part form a second receiving cavity. The balancing module also includes a circuit board received in the second receiving cavity, and the circuit board is fixed to the shell. The DC / DC converter includes a plurality of circuit elements, and the plurality of circuit elements are arranged on the circuit board. The first surface of the first part includes a plurality of bosses protruding toward the plurality of circuit elements, and the plurality of bosses are received in the second receiving cavity and in contact with the plurality of circuit elements.

[0017] In the embodiment of the present application, the boss of the heat sink is in contact with the circuit element to achieve the purpose of heat dissipation of the balancing module and meet the heat dissipation requirements of the balancing module.

[0018] In one implementation manner, a side of the shell facing the cold plate contacts the cold plate, so that the cold plate and the balancing module perform heat exchange.

[0019] In the embodiment of the present application, the housing of the balancing module is arranged to contact the cold plate to perform heat exchange with the cold plate, thereby further cooling the balancing module and meeting the heat dissipation requirements of the balancing module.

[0020] In one implementation manner, the radiator includes a second cooling medium flow channel for the cooling medium to flow therethrough, and the second cooling medium flow channel is connected to the first cooling medium flow channel.

[0021] In the embodiment of the present application, a second cooling medium flow channel is provided inside the radiator, thereby expanding the range of heat dissipation and accelerating the heat dissipation of the balancing module.

[0022] In one implementation, the cold plate includes a bottom plate and a top plate, the bottom plate and the top plate are bonded together, the multiple battery cells and the heat sink are arranged on the top plate, a groove is formed on a surface of the bottom plate that is bonded to the top plate, and the groove and the top plate together form the first cooling medium flow channel.

[0023] The cold plate of the liquid-cooled battery pack provided in the embodiment of the present application has a simple structure and is easy to implement, and can meet the heat dissipation requirements of the balancing module of the liquid-cooled battery pack.

[0024] In one implementation, the cold plate further includes side beams and cross beams, the side beams surround the structure formed by connecting the bottom plate and the top plate, the cross beams are arranged on a side of the bottom plate away from the top plate, and both ends of the cross beams are respectively connected to the side beams.

[0025] In the embodiment of the present application, the structural performance of the cold plate is strengthened by arranging side beams and cross beams on the cold plate, thereby improving the stability of the cold plate.

[0026] In one implementation, the first cooling medium flow channel includes a first flow channel and a second flow channel, the first flow channel and the second flow channel are connected, the first flow channel is bent in a U-shape and distributed inside the cold plate, and the second flow channel is distributed side by side inside the cold plate along the bending direction of the first flow channel, the first flow channel is used for the cooling medium to flow into the first cooling medium flow channel, and the second flow channel is used for the cooling medium to flow out of the first cooling medium flow channel.

[0027] In the embodiment of the present application, the first cooling medium flow channel is distributed in a U-shaped manner, so as to increase the distribution range of the first cooling medium flow channel in the cold plate, improve the temperature consistency of the cold plate, and reduce the temperature difference between the battery cells, thereby helping to improve the temperature uniformity of the battery pack.

[0028] In one implementation, the cooling medium is a coolant, and the cold plate further includes a liquid inlet and a liquid outlet, the liquid inlet is connected to an end of the first flow channel away from the second flow channel, and the liquid outlet is connected to an end of the second flow channel away from the first flow channel.

[0029] In one implementation manner, the cooling medium is a phase change material.

[0030] In a second aspect, an energy storage system is provided, comprising a controller, a liquid cooling unit, and as in the first aspect and any one of the implementations of the first aspect, the liquid-cooled battery pack further comprises a battery management unit; the battery management unit is located in the liquid-cooled battery pack, and is used to collect temperature information of the multiple battery cells; the controller and the liquid cooling unit are located outside the liquid-cooled battery pack, and the controller is used to control the liquid cooling unit to start the circulation of the cooling medium in the cold plate according to the temperature information to dissipate heat from the liquid-cooled battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of a liquid-cooled battery pack provided in an embodiment of the present application.

[0032] Figure 2 is a schematic diagram of a balancing module applicable to an embodiment of the present application.

[0033] Figure 3 is a schematic top view of a cold plate applicable to an embodiment of the present application.

[0034] Figure 4 Schematic diagram of a cold plate suitable for use in an embodiment of the present application.

[0035] Figure 5 is a schematic diagram of a heat sink suitable for an embodiment of the present application.

[0036] Reference numerals:

[0037] 100-liquid-cooled battery pack; 10-cover; 20-cold plate; 201-first cooling medium flow channel; 30-battery module; 301-battery cell; 40-battery management unit; 50-balancing module; 501-housing; 502-radiator; 503-circuit element; 504-circuit board; 5021-boss; 5022-heat dissipation tooth; 202-side beam; 203-bottom plate; 204-top plate; 205-liquid inlet; 206-liquid outlet; 207-cross beam; 2011-first flow channel; 2012-second flow channel; 5023-first heat dissipation plate; 5024-second heat dissipation plate. DETAILED DESCRIPTION

[0038] A single lithium-ion battery is difficult to meet high power requirements, so we usually use multiple lithium-ion batteries in series and parallel. Due to the influence of the battery production technology level, even batteries of the same process and the same model will have inconsistencies in performance. At the same time, with the change of the use environment and the aggravation of the aging phenomenon, the difference between batteries will continue to increase, and eventually the performance of the battery will become worse and worse, and the number of times it can be used will become less and less. In addition, the overcharge and discharge behavior of the battery will also cause safety problems such as fire. Therefore, in order to ensure the safety and durability of the battery, a battery management unit must be established to monitor and control the battery in real time. The battery management unit can monitor the status of each battery cell in the battery module in real time, analyze their respective power, and achieve power balance of the battery cells in the battery module, ultimately preventing the battery pack from overcharging and over-discharging, and ensuring the safe operation of the battery pack.

[0039] Balancing technology refers to the use of external circuits to adjust the energy of the battery cells in the series-parallel battery module to reduce the inconsistency during the charging and discharging process. Since lithium-ion batteries have poor resistance to abuse, once overcharged or over-discharged, it will affect the performance and life of the battery, so balancing technology is indispensable in the application of lithium-ion battery packs. At present, lithium-ion battery pack balancing technology is roughly divided into passive balancing and active balancing. Passive balancing uses resistance discharge to consume excess power in the battery pack to achieve the purpose of balancing; active balancing uses DC / DC converters (including circuit elements such as capacitors, inductors and transformers) to transfer energy from high-energy battery packs to low-energy battery packs, thereby achieving balancing and effectively improving the problem of energy waste. The balancing module of the battery pack involved in this application uses active balancing.

[0040] At present, the capacity of battery cells is getting larger and larger, and the energy density of a single box of energy storage systems is also greatly improved. It has now increased from 2MWh to 5MWh, and the corresponding battery packs are also evolving towards large size and high energy density. The battery pack PACK with a balancing module collects information from each battery module in the battery pack through the battery management unit. The host computer boundary control unit located outside the battery pack completes the information aggregation and formulates a balancing strategy. The balancing module controls the energy flow between battery packs through communication with the host computer boundary control unit, thereby realizing active balancing between battery packs and online charging of battery packs. The power of the balancing module also increases with the increase of the energy density of the battery pack, which poses higher challenges to the thermal management architecture design of the battery pack, the temperature uniformity of the battery cells, and the heat dissipation management of the balancing module.

[0041] A battery pack with a balancing module is usually cooled by natural heat dissipation. For example, a heat sink is connected to the high-temperature circuit components (such as a DC / DC converter) of the balancing module, and the heat dissipation teeth of the heat sink are arranged on the outside of the battery pack. The heat of the balancing module is dissipated into the external air by natural convection and radiation.

[0042] However, battery packs that use the natural heat dissipation method of the balancing module usually have low heat dissipation efficiency, especially in high temperature environments, where the circuit components of the balancing module are at risk of overheating, and there is a heat dissipation bottleneck due to the limitation of the structural size; as battery packs evolve towards large size and high energy density, insufficient heat dissipation by the natural heat dissipation method will therefore limit the capacity evolution of the battery pack. Therefore, the embodiments of the present application provide a liquid-cooled battery pack and energy storage system that can meet the heat dissipation requirements of the balancing module and improve the cooling efficiency of the battery pack.

[0043] The technical solution in this application will be described below in conjunction with the accompanying drawings.

[0044] Figure 1 is a schematic diagram of a liquid-cooled battery pack 100 provided in an embodiment of the present application. The liquid-cooled battery pack 100 includes at least one battery module 30 , a cold plate 20 , a balancing module 50 and a radiator 502 .

[0045] The cold plate includes a cooling medium flow channel 201 for the circulation of cooling medium (in Figure 4 At least one battery module 30 is placed on the cold plate 20, and the battery module 30 includes a plurality of battery cells 301, and the plurality of battery cells 301 are arranged along the length direction of the cold plate 20. When there are a plurality of battery modules 30 in the battery pack, the plurality of battery modules 30 are arranged along the width direction of the cold plate 20.

[0046] The balancing module 50 includes a DC / DC converter, which is used to adjust and control the charging or discharging process of multiple battery cells 301 in at least one battery module 30. The heat sink 502 is in contact with the balancing module 50 to perform heat exchange with the balancing module 50. The heat sink 502 is in contact with the cold plate to perform heat exchange with the cold plate.

[0047] It should be understood that the contact involved in the embodiments of the present application includes direct contact and indirect contact. For example, the heat sink 502 and the cold plate 20 can be in direct contact, or the heat sink 502 and the cold plate 20 can be in indirect contact, that is, insulating materials can be arranged between the heat sink 502 and the cold plate 20; similarly, the heat sink 502 and the balancing module 50 can be in direct contact, or other thermally conductive materials can be arranged between the heat sink 502 and the balancing module 50 to achieve indirect contact. The embodiments of the present application do not specifically limit this.

[0048] The battery pack provided in the embodiment of the present application is provided with a radiator which is in contact with the balancing module and the cold plate respectively. The radiator is cooled by the cooling medium flow channel of the cold plate, and then the balancing module in contact with the radiator is cooled, thereby meeting the heat dissipation demand for the balancing module and improving the cooling efficiency of the balancing module. The power of the battery pack can continue to evolve with the large capacity of the battery cells, the implementation cost and complexity are also low, and it also helps to improve the stability of the battery pack and extend its service life.

[0049] In some embodiments, the liquid-cooled battery pack 100 also includes a battery management unit 40, which is used to control the charging and discharging of the battery cells 301 in the battery module 30 or monitor the status of the battery cells 301. The battery management unit 40 corresponds to the battery module 30 one by one. The battery management unit 40 is located between the battery module 30 and the balancing module 50, and is arranged on one side of the battery module 30 along the length direction of the cold plate 20. The battery management unit 40 is electrically connected to the battery module 30 and the balancing module 50.

[0050] In some embodiments, the electrical connection between the battery management unit and the battery module and the balancing module 50 includes an electrical connection and / or a communication connection. For example, the battery management unit 40 is connected to each battery module 30 via a wire or a wiring harness to transmit data and control signals. The connection method may also be a plug or an electrical interface, which is not specifically limited in the embodiments of the present application. Similarly, the battery management unit 40 and the balancing module 50, and the balancing module 50 and the battery module 30 may also be connected via wires, wiring harnesses or electrical interfaces.

[0051] In some embodiments, Figure 1As shown, the balancing module 50 is not in direct contact with the battery management unit 40, and a first space is formed between the balancing module 50 and the battery management unit 40, which can reduce possible interference and fault propagation, simplify module maintenance and replacement, and improve the stability and safety of the liquid-cooled battery pack 100.

[0052] In some embodiments, Figure 1 As shown, the liquid-cooled battery pack 100 also includes a cover body 10, which includes two surfaces arranged oppositely along the width direction of the cold plate 20, two surfaces arranged oppositely along the length direction of the cold plate 20, and one of the surfaces along the height direction of the cold plate 20. The cover body 10 is covered on the cold plate 20, and together with the cold plate 20, forms a first receiving cavity. The battery module 30, the battery management unit 40 and the balancing module 50 are accommodated in the first receiving cavity. The embodiment of the present application cools the radiator 502 through the cold plate 20, and the temperature of the receiving cavity also decreases accordingly. The battery management unit 40 in the receiving cavity and close to the balancing module 50 is also cooled accordingly, which effectively reduces the working ambient temperature of the battery management unit 40 and indirectly improves the measurement accuracy.

[0053] In some embodiments, the heat sink 502 includes a first portion located in the first receiving cavity, a first surface of the first portion of the heat sink 502 is connected to the balancing module 50 , and a second surface of the first portion of the heat sink 502 is connected to the cold plate 20 .

[0054] In some embodiments, the balancing module 50 or the battery module 30 is connected to the cold plate 20 via structural adhesive. The structural adhesive may be made of a material with good thermal conductivity, such as polyurethane thermal conductive adhesive, silicone grease, silicone, metal thermal conductive adhesive, or carbon nanotubes may be mixed with other polymer materials, etc. The balancing module 50 may also be connected to the cold plate 20 via welding, but the embodiments of the present application are not limited thereto.

[0055] Figure 2 is a schematic diagram of a balancing module 50 provided in an embodiment of the present application, combined with Figure 2 The following explanation is given.

[0056] In some embodiments, the balancing module 50 also includes a shell 501, the shell 501 includes two surfaces opposite to each other along the width direction of the cold plate, two surfaces opposite to each other along the height direction of the cold plate, and one surface arranged along the length direction of the cold plate. The first part of the radiator 502 and the shell 501 are arranged along the length direction of the cold plate 20, and the shell 501 is connected to the first surface of the first part of the radiator 502, so that the shell 501 and the first surface form a second receiving cavity.

[0057] The balancing module 50 further includes a circuit board 504 received in the second receiving cavity. The circuit board 504 is fixed on the housing 501 . The DC / DC converter includes a plurality of circuit elements 503 . The circuit elements 503 are disposed on the circuit board 504 .

[0058] A plurality of bosses 5021 are disposed on the first surface of the first portion of the heat sink 502, and the plurality of bosses 5021 are received in the second receiving cavity and contact the plurality of circuit elements 503. For example, the plurality of bosses 5021 contact the plurality of circuit elements 503 one by one; or each boss 5021 contacts the plurality of circuit elements 503; or the plurality of bosses 5021 contact the high-temperature element in the circuit elements 503; or the plurality of bosses 5021 also contact other circuit elements on the circuit board 504, and the embodiment of the present application is not limited thereto.

[0059] In some embodiments, an opening is provided on one side of the cover 10, and the heat sink 502 further includes a heat sink tooth 5022 located outside the first receiving cavity. The heat sink tooth 5022 of the heat sink 502 passes through the opening of the cover to exchange heat with the air outside the battery pack. The heat sink tooth 5022 contacts the first portion to exchange heat with the first portion.

[0060] like Figure 2 As shown, the heat dissipation teeth 5022 are arranged on the third surface of the radiator 502, and are exposed to the outside of the liquid-cooled battery pack 100 through the opening of the cover 10, and the third surface of the radiator 502 covers the opening of the cover 10. In the embodiment of the present application, the heat dissipation teeth 5022 are arranged in the radiator 502 to exchange heat with the outside of the liquid-cooled battery pack 100, thereby realizing dual heat dissipation of natural heat dissipation and liquid cooling, meeting the heat dissipation requirements of the balancing module, and further improving the heat dissipation efficiency of the balancing module.

[0061] In some embodiments, the first portion of the heat sink and the heat dissipation teeth may be an integrated structure or a separate structure, which is not specifically limited in the embodiments of the present application.

[0062] In some embodiments, Figure 2 As shown, the balancing module 50 further includes a communication interface, which is used to communicate with the battery management unit 40 so as to monitor and control the status of the entire battery pack.

[0063] Circuit elements 503 may include switching tubes (MOSFET or BJT), inductors, capacitors, diodes and controllers, etc. The switching tube opens or closes the current path through switching action, thereby controlling the voltage conversion. The inductor is used to store and release energy, the capacitor is used to store charge and smooth the output voltage, the diode is used to control the flow direction of the current, and the controller or regulator is used to control the operation mode of the entire DC / DC converter.

[0064] In some embodiments, the first part of the radiator 502 includes a first heat dissipation plate 5023 and a second heat dissipation plate 5024, the first heat dissipation plate 5023 is perpendicular to the second heat dissipation plate 5024, the first surface is the surface of the first heat dissipation plate 5023 facing the multiple battery cells, and the second surface is the surface of the second heat dissipation plate 5024 facing the cold plate.

[0065] For example, combined with Figure 5 As shown in (a), the radiator 502 is L-shaped, the first heat sink 5023 and the second heat sink 5024 are both rectangular, and the connecting surface of the first heat sink 5023 and the second heat sink 5024 is located at the edge of the surface of the second heat sink 5024 facing the first heat sink 2023.

[0066] Combination Figure 5 As shown in (b), the heat sink 502 is T-shaped, the first heat sink 5023 and the second heat sink 5024 are both rectangular, and the connecting surface of the first heat sink 5023 and the second heat sink 5024 is located in the middle of the surface of the second heat sink 5024 facing the first heat sink 5023.

[0067] Combination Figure 5 As shown in (c), the radiator 502 is irregular, the first heat sink 5023 is irregular in shape, the second heat sink 5024 is rectangular, and a side of the first heat sink 5023 facing the second heat sink coincides with a side of the second heat sink 5024 facing the first heat sink, but the embodiments of the present application are not limited to this.

[0068] The embodiment of the present application increases the contact surface between the heat sink 502 and the cold plate 20 by providing a heat sink structure, thereby improving the heat dissipation effect of the cold plate 20 on the balancing module 50 .

[0069] In some embodiments, the first heat sink 5023 is perpendicular to the second heat sink 5024, the first surface is the surface of the first heat sink 5023 facing the multiple battery cells, the second surface is the surface of the second heat sink 5024 facing the cold plate, the fourth surface is the surface of the second heat sink 5024 away from the cold plate, and the shell 501 of the balancing module 50 contacts the fourth surface. In the embodiment of the present application, the side of the shell facing the cold plate is arranged to exchange heat with the radiator, so that in addition to the circuit elements inside the shell being able to dissipate heat, the shell itself can also be cooled, further meeting the heat dissipation requirements of the balancing module.

[0070] In some embodiments, the balancing module 50 is in contact with the cold plate 20, and the side of the shell 501 of the balancing module 50 facing the cold plate is in contact with the cold plate 20, so that the cold plate 20 dissipates heat to the shell 501 and the cold plate 20 dissipates heat to the circuit element 503 through the radiator 502. For example, the circuit board 504 can be fixed to the shell 501 by bolts, and on the one hand, heat exchange is performed between the cold plate 20 and the shell 501, and heat exchange is performed between the shell 501 and the circuit board 504, and on the other hand, heat exchange is performed between the cold plate 20 and the radiator 502, and heat exchange is performed between the radiator 502 and the circuit element 503, thereby achieving dual heat dissipation of the balancing module 50, and further improving the heat dissipation efficiency of the balancing module, but the embodiments of the present application are not limited thereto.

[0071] In some embodiments, the housing 501 of the balancing module 50 contacts the cold plate 20 on one side thereof facing the cold plate, the first part of the heat sink 502 includes a first heat sink 5023 and a second heat sink 5024, the first heat sink 5023 is perpendicular to the second heat sink 5024, the first side is the side of the first heat sink 5023 facing the plurality of battery cells, the second side is the side of the second heat sink 5024 facing the cold plate, the first side of the first heat sink 5023 and the side of the second heat sink 5024 facing the plurality of battery cells are on the same vertical plane, and the vertical distance from the side of the first heat sink 5023 away from the balancing module 50 to the first side is shorter than the vertical distance from the side of the second heat sink 5024 away from the balancing module 50 to the first side. In the embodiment of the present application, by setting the heat sink to be L-shaped and the housing of the balancing module in contact with the cold plate, the cooling area of ​​the heat sink and the balancing module is further increased, thereby improving the cooling efficiency of the balancing module.

[0072] Figure 3 2 is a schematic diagram of a cold plate suitable for an embodiment of the present application. The cold plate 20 includes a bottom plate 203 and a top plate 204. The top plate 204 is bonded to the bottom plate 203 in the height direction of the cold plate. The top plate is a plane. The battery module and the radiator 502 are both arranged on the top plate. A groove is formed on the side where the bottom plate and the top plate are bonded. The bottom plate and the top plate together form a first cooling medium flow channel 201.

[0073] In some embodiments, the cold plate 20 includes a shell with a cavity formed inside the shell. A support structure is arranged in the cavity. The support structure is connected to two inner walls along the height direction of the cold plate. A cavity for cooling medium to flow is formed inside the support structure, but the embodiments of the present application are not limited to this.

[0074] In some embodiments, Figure 3 As shown, the cold plate 20 also includes side beams 202, which surround the structure formed by connecting the bottom plate 203 and the top plate 204. The cold plate 20 also includes a cross beam 207, which is arranged on a side of the bottom plate 203 away from the top plate 204, and both ends of the cross beam 207 are respectively connected to the side beams 202.

[0075] For example, the length direction of the cross beam 207 is parallel to the width direction of the cold plate 20, and the two ends of the cross beam 207 along the width direction of the cold plate 20 are respectively connected to the side beams 202, and multiple cross beams 207 can be arranged along the length direction of the cold plate 20; or, the length direction of the cross beam 207 is parallel to the length direction of the cold plate 20, and the two ends of the cross beam 207 along the length direction of the cold plate 20 are respectively connected to the side beams 202, and multiple cross beams 207 can be arranged along the width direction of the cold plate 20. In the embodiment of the present application, a cross beam is arranged at the bottom of the cold plate to strengthen the structural performance of the cold plate and improve the stability of the cold plate.

[0076] In some embodiments, a metal connecting sheet is disposed on a surface of the bottom plate 203 away from the top plate 204 , and the cross beam 207 and the bottom plate 203 are connected via the metal connecting sheet, but the embodiments of the present application are not limited thereto.

[0077] Figure 4 is a top view of a cold plate suitable for use in an embodiment of the present application.

[0078] In some embodiments, in combination Figure 4 As shown, when the cooling medium is a coolant, the cold plate 20 further includes a liquid inlet 205 and a liquid outlet 206. The liquid inlet 205 and the liquid outlet 206 can be arranged on one of the surfaces of the cold plate 20 along the length direction, or the liquid inlet 205 and the liquid outlet 206 are respectively arranged on two surfaces of the cold plate 20 that are opposite to each other along the length direction, and the liquid inlet 205 and the liquid outlet 206 are both connected to the first cooling medium flow channel 201.

[0079] In some embodiments, Figure 4 As shown, the first cooling medium channel 201 is distributed in the shape of a U-shaped letter "U". The first cooling medium channel 201 includes a first channel 2011 and a second channel 2012, the first channel 2011 and the second channel 2012 are connected, the first channel 2011 is used to flow in the coolant, and the second channel 2012 is used to flow out the coolant after the cooling effect is exerted. Among them, the first channel 2011 is connected to the liquid inlet 205, and the second channel 2012 is connected to the liquid outlet 206. The first channel 2011 is bent in the shape of a U-shaped letter "U" and distributed inside the cold plate 20, and the second channel 2012 is distributed side by side inside the cold plate 20 along the bending direction of the first channel 2011. The distribution range of the first cooling medium channel in the cold plate can be increased, the temperature consistency of the cold plate can be improved, and the temperature difference between the battery cells can be reduced, thereby helping to improve the temperature uniformity of the battery pack. The distribution method of the first cooling medium channel inside the cold plate is not limited to this embodiment of the present application.

[0080] In some embodiments, the radiator 502 includes a second cooling medium flow channel for the circulation of cooling medium, and the second cooling medium flow channel is connected to the first cooling medium flow channel 201. For example, there is a cavity inside the radiator 502, and a plurality of support structures are arranged in the cavity, each support structure is perpendicular to the inner wall of the radiator, and is connected to the inner wall to form a second cooling medium flow channel for the circulation of cooling medium, one end of the second cooling medium flow channel is connected to the first flow channel 2011, and the other end of the second cooling medium flow channel is connected to the second flow channel 2012, so that the coolant enters the first flow channel 2011 from the liquid inlet 205, flows to the second cooling medium flow channel, and then flows to the second flow channel, and then is discharged from the liquid outlet. By arranging the second cooling medium flow channel inside the radiator, the flow range of the cooling medium is larger, the heat dissipation range of the radiator to the balancing module is increased, and the cooling efficiency of the balancing module is further improved.

[0081] In some embodiments, the cooling medium in the first cooling medium flow channel 201 is a phase change material, and the phase change material is encapsulated in the first cooling medium flow channel 201. Optionally, the phase change material can be a liquid-to-gas, solid-to-liquid phase change material, or a solid-to-gas phase change material. It should be noted that the phase change material reaches the phase change temperature point and undergoes enthalpy change, which is related to the selected phase change material. Exemplarily, the phase change material can be a low-temperature metal phase change material such as a bismuth alloy or other alloy metal. The low-temperature metal phase change material can be a liquid metal. The low-temperature metal phase change material has better thermal conductivity and lower electrical impedance among phase change materials, which can effectively promote heat transfer and reduce the temperature of the equalization module 50, but the embodiments of the present application are not limited to this.

[0082] The embodiment of the present application also provides an energy storage system, including a controller, a liquid cooling unit and one or more of the aforementioned liquid cooling battery packs, the battery management unit of the liquid cooling battery pack is used to collect the temperature information of the multiple battery cells, the controller and the liquid cooling unit are located outside the liquid cooling battery pack, the controller is used to control the liquid cooling unit to start the circulation of the cooling medium of the cold plate according to the temperature information of the multiple battery cells, and the balancing module performs heat exchange with the cold plate through the radiator, so as to achieve the purpose of heat dissipation of the balancing module. In some embodiments, the controller can be a battery control unit BCU.

[0083] The embodiment of the present application also provides an electric vehicle, which includes the battery pack described above, and a vehicle load, and the battery pack can be used to power the vehicle load. The electric vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the vehicle load can include in-vehicle air conditioning equipment, lights, speakers, and other equipment, which are not limited in the present application.

[0084] It should be noted that the electric vehicle described above is only an example of an application scenario of the battery pack described in this application. The battery pack provided in this application can also be applied to other electrical equipment, such as ship equipment, aerospace equipment, etc.

[0085] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0086] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0087] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0088] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. Specifically, the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0089] The term "plurality" used in the present application refers to two or more (including two).

[0090] In the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0091] It should be noted that in the embodiments of the present application, the terms "upper", "lower", "vertical", "horizontal", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0092] The limitations such as symmetry (e.g., axisymmetry, or center symmetry, etc.) and sameness (e.g., same length, same width, etc.) mentioned in the embodiments of the present application are all for the current technological level, rather than being absolutely strict definitions in a mathematical sense. There may be a deviation of a predetermined threshold or a predetermined angle between the two.

[0093] Specifically, in various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0094] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A liquid-cooled battery pack, characterized in that: Including cold plate, multiple cells, balancing module and heat sink, The cold plate includes a first cooling medium flow channel for cooling medium to flow through. The plurality of battery cells are arranged on the cold plate, The balancing module includes a DC / DC converter, and the balancing module is used to control the charging or discharging of the multiple battery cells. The heat sink contacts the balancing module to perform heat exchange with the balancing module. The heat sink contacts the cold plate to perform heat exchange with the cold plate.

2. The liquid-cooled battery pack according to claim 1, characterized in that: The liquid-cooled battery pack further includes a cover body, wherein the cover body and the cold plate form a first receiving cavity, and the plurality of battery cells and the balancing module are received in the first receiving cavity. The heat sink comprises a first portion located in the first receiving cavity, A first surface of the first portion contacts the balancing module, and a second surface of the first portion contacts the cold plate.

3. The liquid-cooled battery pack according to claim 2, characterized in that: The heat sink further includes heat dissipation teeth arranged on a third surface of the first part, and the third surface is a surface of the first part away from the balancing module in a direction perpendicular to the first surface.

4. The liquid-cooled battery pack according to claim 2, characterized in that: The first part includes a first heat dissipation plate and a second heat dissipation plate, the first heat dissipation plate is perpendicular to the second heat dissipation plate, the second heat dissipation plate is arranged parallel to the cold plate, the first surface is the surface of the first heat dissipation plate facing the multiple battery cells, and the second surface is the surface of the second heat dissipation plate facing the cold plate.

5. The liquid-cooled battery pack according to claim 4, characterized in that: The balancing module includes a shell, the shell is in contact with a fourth surface, and the fourth surface is a surface of the second heat dissipation plate away from the cold plate.

6. The liquid-cooled battery pack according to claim 2, characterized in that: The balancing module includes a shell, the shell and the first surface of the first part form a second receiving cavity, the balancing module also includes a circuit board received in the second receiving cavity, the circuit board is fixed to the inner wall of the shell, The DC / DC converter includes a plurality of circuit elements, and the plurality of circuit elements are arranged on a surface of the circuit board away from the housing. The first surface of the first portion includes a plurality of bosses protruding toward the plurality of circuit elements. The plurality of bosses are received in the second receiving cavity and contact the plurality of circuit elements.

7. The liquid-cooled battery pack according to claim 1, characterized in that: The balancing module comprises a shell, and a surface of the shell facing the cold plate is in contact with the cold plate, so that the cold plate and the balancing module can perform heat exchange.

8. The liquid-cooled battery pack according to claim 1, characterized in that: The radiator includes a second cooling medium flow channel for the cooling medium to flow therethrough, and the second cooling medium flow channel is communicated with the first cooling medium flow channel.

9. The liquid-cooled battery pack according to claim 1, characterized in that: The cold plate includes a bottom plate and a top plate, the bottom plate and the top plate are bonded together, the multiple battery cells and the heat sink are arranged on the top plate, a groove is formed on a surface of the bottom plate bonded to the top plate, and the groove and the top plate together form the first cooling medium flow channel.

10. The liquid-cooled battery pack according to claim 9, characterized in that: The cold plate further includes side beams and cross beams, the side beams surround the structure formed by connecting the bottom plate and the top plate, the cross beams are arranged on a side of the bottom plate away from the top plate, and both ends of the cross beams are respectively connected to the side beams.

11. The liquid-cooled battery pack according to any one of claims 1 to 10, characterized in that: The first cooling medium flow channel includes a first flow channel and a second flow channel, the first flow channel and the second flow channel are connected, the first flow channel is bent in a U-shape and distributed inside the cold plate, and the second flow channel is distributed side by side inside the cold plate along the bending direction of the first flow channel, the first flow channel is used for the cooling medium to flow into the first cooling medium flow channel, and the second flow channel is used for the cooling medium to flow out of the first cooling medium flow channel.

12. The liquid-cooled battery pack according to claim 11, characterized in that: The cooling medium is a cooling liquid, and the cold plate further includes a liquid inlet and a liquid outlet, the liquid inlet is connected to an end of the first flow channel away from the second flow channel, and the liquid outlet is connected to an end of the second flow channel away from the first flow channel.

13. The liquid-cooled battery pack according to any one of claims 1 to 10, characterized in that: The cooling medium is a phase change material.

14. An energy storage system, characterized in that: A liquid-cooled battery pack comprising a controller, a liquid cooling unit and any one of claims 1 to 13, wherein the liquid-cooled battery pack further comprises a battery management unit; The battery management unit is located in the liquid-cooled battery pack and is used to collect temperature information of the multiple battery cells; The controller and the liquid cooling unit are located outside the liquid-cooled battery pack. The controller is used to control the liquid cooling unit to start the circulation of the cooling medium in the cold plate according to the temperature information to dissipate heat from the liquid-cooled battery pack.

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