Energy storage device and energy storage system

Abstract

The application provides an energy storage device and an energy storage system. The energy storage device comprises a battery module, a first liquid cooling plate and a second liquid cooling plate. The first liquid cooling plate is in thermal conduction connection with a first side wall of the battery module along the height direction of the battery module. The second liquid cooling plate is vertically arranged on the first liquid cooling plate, and the second liquid cooling plate is in contact with a second side wall of the battery module. The first liquid cooling plate and the second liquid cooling plate are both provided with circulating flow channels. The circulating flow channel of the first liquid cooling plate and the circulating flow channel of the second liquid cooling plate are in communication. The first side wall is perpendicular to the second side wall. The first liquid cooling plate has a plurality of liquid cooling zones. The corresponding circulating flow channels of the plurality of liquid cooling zones are arranged in parallel. The flow channel length of at least one circulating flow channel corresponding to at least one liquid cooling zone is smaller than the flow channel length of other circulating flow channels corresponding to other liquid cooling zones. Temperature neutralization can be performed, and the overall temperature uniformity is improved.

Description

Technical Field

[0001] This invention generally relates to the field of energy storage technology, and more specifically, to an energy storage device and an energy storage system. Background Technology

[0002] Existing energy storage devices consist of a battery box and multiple battery modules connected in series within the battery box to enhance the power supply capacity. During charging and discharging, the battery modules inevitably generate heat, which accumulates inside the battery box. To prevent overheating, a liquid cooling plate with flow channels is typically installed at the bottom of the battery box to exchange heat with the internal components through fluid flow. However, with the increasing power density of battery modules, the existing single liquid cooling method is insufficient to meet the heat dissipation requirements of high power density batteries. Summary of the Invention

[0003] This invention provides an energy storage device and energy storage system, which improves the heat dissipation effect of the energy storage device.

[0004] According to a first aspect of the present invention, an energy storage device is provided, comprising a battery module, a first liquid cooling plate, and a second liquid cooling plate. The first liquid cooling plate is thermally connected to a first sidewall of the battery module along the height direction of the battery module. The second liquid cooling plate is erected on the first liquid cooling plate and contacts a second sidewall of the battery module. Both the first and second liquid cooling plates are provided with circulation channels, and the circulation channels of the first and second liquid cooling plates are connected. The first sidewall is perpendicular to the second sidewall. The first liquid cooling plate has multiple liquid cooling zones, and the circulation channels corresponding to the multiple liquid cooling zones are arranged in parallel. The channel length of at least one circulation channel corresponding to at least one of the multiple liquid cooling zones is less than the channel length of the other circulation channels corresponding to the other liquid cooling zones.

[0005] The energy storage device provided in this embodiment of the invention uses a first liquid cooling plate to support a battery module. When a cooling medium flows through the first liquid cooling channel of the first liquid cooling plate, heat exchange occurs between the cooling medium in the circulating channel of the first liquid cooling plate and the heat generated at the bottom of the battery module. Since heat exchange at the bottom alone would result in a large temperature difference between the top and bottom of the battery module along the first direction, the battery module is positioned on one side of the second liquid cooling plate of the liquid cooling assembly. When a cooling medium flows through the second liquid cooling channel of the second liquid cooling plate, heat exchange occurs between the cooling medium in the circulating channel of the second liquid cooling plate and the heat generated at the side of the battery module. This effectively alleviates the temperature difference between the top and bottom of the battery module. Furthermore, the bottom and side of the battery module are in contact with the first and second liquid cooling plates respectively, achieving simultaneous cooling of the bottom and side of the battery module. The battery module has two cooling surfaces, which can reduce the temperature difference between the individual battery modules.

[0006] Since the initial temperature of the cooling medium is lowest in the inlet channel, the circulation channel of the first liquid cooling plate in one of the liquid cooling zones has a relatively short channel length. The cooling medium can directly enter the circulation channel of the second liquid cooling plate through the circulation channel of the first liquid cooling plate with a shorter channel length. At this time, the temperature of the cooling medium is slightly higher than the initial temperature, but much lower than the cooling medium flowing through the circulation channels of the first liquid cooling plate with a longer channel length. That is, the cooling medium entering the circulation channel of the second liquid cooling plate comes from two parts: the cooling medium with a shorter channel length and a lower temperature and the cooling medium with a longer channel length and a higher temperature. The two parts can neutralize the temperature, reduce the temperature difference of the cooling medium in the inlet channel and the circulation channel of the second liquid cooling plate, and improve the overall temperature uniformity.

[0007] In some embodiments, the projected areas of the plurality of liquid cooling zones on the first liquid cooling plate are not the same along the height direction of the battery module.

[0008] In this way, the multiple liquid cooling zones have an asymmetrical structure, and the cooling media with lower and higher temperature rises are neutralized before entering the circulation channel of the second liquid cooling plate to achieve a temperature balance.

[0009] In some embodiments, the circulation channels of the first liquid cooling plate and the circulation channels of the second liquid cooling plate are connected by a connecting channel, and the channel length of the circulation channels of the plurality of liquid cooling zones gradually decreases along the direction close to the connecting channel; and / or, the circulation channels of the first liquid cooling plate and the circulation channels of the second liquid cooling plate are connected by a connecting channel, and the cross-sectional area of ​​the circulation channels of the plurality of liquid cooling zones gradually decreases along the direction close to the connecting channel.

[0010] With this setup, the circulating channels closer to the connecting channels are shorter, resulting in a shorter flow path for the cooling medium and less heat exchange with the battery module. Consequently, the temperature of the cooling medium flowing into the connecting channels is lower. Since the flow rate of the circulating channels is related to their cross-sectional area and length, with a fixed cross-sectional area, the pressure difference within the circulating channels changes significantly as the channel length increases, leading to a reduction in the channel's length. Therefore, for circulating channels with longer lengths, their cross-sectional area is increased to balance the flow rate, ensuring that the flow rates of the corresponding circulating channels in different liquid cooling zones are approximately the same, further improving overall temperature uniformity.

[0011] In some embodiments, the first liquid cooling plate is provided with a liquid inlet channel, and the second liquid cooling plate is provided with a liquid outlet channel. The liquid inlet channel, the circulation channel of the first liquid cooling plate, the circulation channel of the second liquid cooling plate, and the liquid outlet channel are connected. The liquid inlet channel and the liquid outlet channel are located on the same side of the first liquid cooling plate along the length direction of the first liquid cooling plate; and / or, the liquid inlet channel and the liquid outlet channel are located on the same side of the first liquid cooling plate along the width direction of the first liquid cooling plate.

[0012] Since the initial position of the cooling medium is at the inlet channel, its initial temperature is relatively low, while the final position of the cooling medium is at the outlet channel, its temperature is relatively high after heat exchange with the battery module. By setting the inlet and outlet channels approximately on the same side, the cooling medium in the entire cooling circuit enters and exits on the same side. The higher-temperature cooling medium and the lower-temperature cooling medium play a neutralizing role to a certain extent, effectively reducing the temperature difference of the cooling medium and thus improving the temperature uniformity of the entire liquid cooling component.

[0013] In some embodiments, the cross-sections of the circulation channels corresponding to the plurality of liquid cooling zones are different at the end near the liquid inlet channel.

[0014] By using this method, the flow rate can be automatically adjusted according to the pressure difference of the circulation channels corresponding to different liquid cooling zones, which can effectively reduce excessive local temperature rise and thus reduce the temperature difference.

[0015] In some embodiments, each of the liquid cooling zones includes a circulation channel comprising multiple cooling units arranged in series; wherein the liquid inlet channel is connected to the cooling unit adjacent to the liquid inlet channel via a main path, and the main path and the liquid inlet channel extend in different directions.

[0016] The series-connected cooling units increase the overall length of the circulation channel, allowing it to cover as much of the battery module's area as possible. The cooling medium flowing out of the inlet channel does not directly enter the main path but is bent to be divided into multiple channels, thus entering the corresponding liquid cooling area through the main body.

[0017] In some embodiments, the cooling unit includes a plurality of cooling branches arranged in parallel; the cooling branches extend along the length direction of the first liquid cooling plate; or, the cooling branches extend along the width direction of the first liquid cooling plate.

[0018] Multiple parallel cooling branches divide the main circuit into a large number of smaller branches, which can increase the contact area between the cooling medium and the cold plate wall of the first liquid cooling plate and enhance the heat exchange effect.

[0019] In some embodiments, the circulation channel of the first liquid cooling plate is connected to the circulation channel of the second liquid cooling plate through a connecting channel; two adjacent cooling units are connected through a main cooling path, and a flow-deflecting element is also provided in the cooling unit and / or the main cooling path; wherein the flow-deflecting element is provided on the side of the first liquid cooling plate near the connecting channel.

[0020] The flow-deflecting element increases the turbulence of the cooling medium, ensuring that the cooling media of different temperatures flowing from each cooling branch are mixed evenly before flowing to the next cooling unit or the next cooling branch. Since the cooling medium flowing out of the connecting channel needs to flow upward along the height of the battery module to the circulation channel of the second liquid cooling plate, placing the flow-deflecting element near the connecting channel increases the turbulence resistance of the cooling medium, thereby increasing the flow velocity of the cooling medium and allowing it to quickly rush upward along the height of the battery module into the circulation channel of the second liquid cooling plate.

[0021] In some embodiments, the energy storage device further includes a support member, one end of which is connected to the first liquid cooling plate and the other end of which is connected to the second liquid cooling plate along the height direction of the battery module; wherein the first liquid cooling plate, the second liquid cooling plate and the support member are integrally formed.

[0022] The support structure effectively raises the height of the second liquid cooling plate, allowing it to cool the upper side of the battery module and effectively alleviate the temperature difference between the top and bottom of the module. Compared to separate bottom and side cooling systems, this integrated approach combines the advantages of both, eliminating the need for additional connecting pipes and sealing joints. This maximizes the use of internal space while reducing production costs.

[0023] In some embodiments, the energy storage device further includes a support member and a connecting pipe. One end of the support member along the height direction of the battery module is connected to the first liquid cooling plate. The other end of the support member along the height direction of the battery module and one of the second liquid cooling plates are provided with a positioning post, and the other is provided with a positioning hole. The positioning post passes through the positioning hole. The connecting pipe is located between the first liquid cooling plate and the second liquid cooling plate. The connecting pipe is detachably connected to the first liquid cooling plate and the second liquid cooling plate respectively. A connecting channel is provided in the connecting pipe. The circulation channel of the first liquid cooling plate is connected to the circulation channel of the second liquid cooling plate through the connecting channel.

[0024] The first and second liquid cooling plates feature a detachable design, facilitating replacement and maintenance should one plate be damaged. The positioning posts and holes work together to allow the second liquid cooling plate to mate with the first liquid cooling plate via the support, ensuring accurate positioning between the two plates. Furthermore, structural adhesive can be used to secure the positioning posts and holes, enhancing the fixing effect.

[0025] In some embodiments, the energy storage device further includes a partition disposed within the circulation channel of the second liquid cooling plate. The partition is disposed along the extending direction of the circulation channel of the second liquid cooling plate and divides the circulation channel of the second liquid cooling plate into two sub-channels. The two sub-channels are respectively thermally connected to the second sidewall of the two battery modules.

[0026] The two battery modules located on both sides of the second liquid cooling plate can be cooled simultaneously through two sub-channels. The second liquid cooling plate adopts a double-sided cooling method to increase the heat exchange area, so that each battery module can be cooled from one side alone, resulting in good heat dissipation.

[0027] According to a second aspect of the present invention, embodiments of the present invention also provide an energy storage system, including an electrical device and the above-described energy storage device, wherein the energy storage device supplies power to the electrical device.

[0028] The cooling medium flowing through the circulation channels of the first liquid cooling plate and the second liquid cooling plate effectively reduces the temperature inside the tank, keeping the energy storage device at a lower temperature. This ensures the charging and discharging performance of the energy storage device while reducing safety hazards and improving the overall reliability of the energy storage device. Attached Figure Description

[0029] To better understand the present invention, reference may be made to the embodiments shown in the following drawings. Components in the drawings are not necessarily to scale, and related elements may be omitted to emphasize and clearly illustrate the technical features of the invention. Furthermore, related elements or components may have different arrangements as known in the art. Additionally, in the drawings, the same reference numerals denote the same or similar components in various figures. The above and other features and advantages of the present invention will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0030] in:

[0031] Figure 1 The diagram shown is a structural schematic of the energy storage system provided in Embodiment 1 of the present invention;

[0032] Figure 2 The diagram shown is a structural schematic of the energy storage device provided in Embodiment 1 of the present invention;

[0033] Figure 3 The diagram shown is a partial exploded structural diagram of the energy storage device provided in Embodiment 1 of the present invention;

[0034] Figure 4 The diagram shown is a structural schematic of the first liquid-cooled plate in the energy storage device provided in Embodiment 1 of the present invention. Figure 1 ;

[0035] Figure 5 The diagram shown is a structural schematic of the first liquid-cooled plate in the energy storage device provided in Embodiment 1 of the present invention. Figure 2 ;

[0036] Figure 6 The diagram shown is a structural schematic of the first side plate in the energy storage device provided in Embodiment 1 of the present invention;

[0037] Figure 7 The diagram shown is a structural schematic of the second side plate in the energy storage device provided in Embodiment 1 of the present invention;

[0038] Figure 8 The diagram shown is a partial exploded view of the liquid cooling component in the energy storage device provided in Embodiment 2 of the present invention;

[0039] Figure 9 The diagram shown is a cross-sectional schematic of the second liquid cooling plate in the energy storage device provided in Embodiment 3 of the present invention.

[0040] The reference numerals in the attached figures are explained as follows:

[0041] 100. Energy storage devices; 200. Power conversion devices; 300. Electrical equipment;

[0042] 10. Housing; 20. Battery module; 30. Liquid cooling assembly;

[0043] 301. Circulating flow channel; 3011. Sub-flow channel; 302. Connecting flow channel; 303. Inlet flow channel; 304. Outlet flow channel;

[0044] 31. First liquid cooling plate; 311. Liquid cooling zone; 3111. First liquid cooling zone; 3112. Second liquid cooling zone; 312. Cooling unit; 3121. First cooling unit; 3122. Second cooling unit; 3123. Third cooling unit; 3124. Fourth cooling unit; 3125. Fifth cooling unit; 3120. Cooling branch; 313. Main path; 3131. First main path; 3132. Second main path; 314. Baffle; 315. Main cooling path; 316. Positioning post;

[0045] 32. Second liquid cooling plate; 321. First side plate; 322. Second side plate; 323. Connecting plate; 33. Support component; 331. Positioning hole; 34. Connecting pipe; 35. Partition plate. Detailed Implementation

[0046] The technical solutions of the exemplary embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The exemplary embodiments described herein are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Therefore, it should be understood that various modifications and changes can be made to the exemplary embodiments without departing from the scope of protection of the present invention.

[0047] In the description of this invention, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more; and the term "and / or" includes any and all combinations of one or more of the associated listed items. In particular, references to "the / described" object or "an" object are also intended to indicate one of a possible plurality of such objects.

[0048] Unless otherwise specified or stated, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, an integral connection, an electrical connection, or a signal connection; "connection" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0049] Furthermore, in the description of this invention, it should be understood that the directional terms such as "upper," "lower," "inner," and "outer" described in the exemplary embodiments of this invention are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the exemplary embodiments of this invention. It should also be understood that, in the context of an element or feature being connected to another element (one or more) "upper," "lower," "inner," or "outer," it can be directly connected to the other element (one or more) "upper," "lower," "inner," or "outer," or indirectly connected to the other element (one or more) "upper," "lower," "inner," or "outer" through an intermediate element.

[0050] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that the invention will be thorough and complete, and the concept of the exemplary embodiments will be fully conveyed to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.

[0051] Because the energy we need is highly time- and space-dependent, in order to utilize energy rationally and improve its efficiency, we need a medium or device to store one form of energy in the same way or by converting it into another, and then release it in a specific energy form based on future application needs. As is well known, the current main approach is to replace fossil fuels with green energy to achieve the goal of generating green electricity.

[0052] Currently, green energy mainly includes solar energy, wind energy, and hydropower. However, solar and wind energy generally suffer from strong intermittency and large fluctuations, which can cause voltage instability in the green power grid (insufficient electricity during peak demand and excessive electricity during off-peak demand). Unstable voltage can damage the power grid, and therefore may lead to the problem of "curtailment of wind and solar power" due to insufficient electricity demand or insufficient grid capacity.

[0053] To solve the problem of insufficient electricity demand or insufficient grid capacity, it is necessary to rely on energy storage devices 100. That is, the energy storage device 100 converts electrical energy into other forms of energy through physical or chemical means and stores it. When needed, the energy stored in the energy storage device 100 is converted into electrical energy and released. Simply put, the energy storage device 100 is like a large "power bank". When there is sufficient solar and wind energy, it stores electrical energy and releases the stored electrical energy when needed.

[0054] Current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, renewable energy grid-connected energy storage, and user-side energy storage. The corresponding types of energy storage devices 100 include:

[0055] (1) Large energy storage containers used in grid-side energy storage scenarios can serve as high-quality active and reactive power regulation power sources in the grid, enabling load matching of electrical energy in time and space, enhancing the absorption capacity of renewable energy, and playing a significant role in grid system backup, alleviating peak load power supply pressure, and peak regulation and frequency regulation.

[0056] (2) Small and medium-sized energy storage cabinets used in commercial and industrial energy storage scenarios (banks, shopping malls, etc.) and small household energy storage boxes used in residential energy storage scenarios primarily operate under the "peak shaving and valley filling" mode. Because there are significant price differences in electricity consumption during peak and off-peak periods, users with energy storage devices typically charge the cabinets / boxes during off-peak hours to reduce costs; during peak hours, the electricity stored in the devices is released for use, thus saving on electricity bills. Furthermore, in remote areas and regions prone to natural disasters such as earthquakes and hurricanes, the presence of household energy storage devices effectively provides backup power for users and the power grid, eliminating the inconvenience caused by frequent power outages due to disasters or other reasons.

[0057] This explanation will take the residential energy storage scenario in user-side energy storage as an example. Figure 1 A residential energy storage system is illustrated, comprising an energy storage device 100, a power conversion device 200 (such as a photovoltaic panel), and electrical appliances 300 (such as streetlights, household appliances, etc.). The energy storage device 100 is a small energy storage box that can be wall-mounted to an outdoor wall. Specifically, the power conversion device 200 can convert solar energy into electrical energy during periods of low electricity prices and store it in the energy storage device 100, then supply it to the electrical appliances 300 during periods of high electricity prices, or during power outages / power interruptions.

[0058] In conjunction with the aforementioned energy storage methods using physical or electrochemical means, taking electrochemical energy storage as an example, the energy storage device 100 includes at least one chemical battery. The chemical elements within the battery serve as the energy storage medium, and the charging and discharging process is achieved through the chemical reactions or changes in the storage medium. Simply put, it stores electrical energy generated from solar or wind power in at least one set of chemical batteries through the chemical reactions or changes in the storage medium. When external power consumption reaches its peak, the stored energy in at least one set of chemical batteries is released for use or transferred to areas with power shortages through the chemical reactions or changes in the storage medium.

[0059] The electrical equipment 300 can also be an energy storage device, a vehicle, an energy storage container, etc., and the energy storage device 100 supplies power to the electrical equipment 300. Thus, in combination with the above, this application ensures the stability of the operation of the electrical equipment 300 while the energy storage device 100 has stable charging and discharging performance.

[0060] This application provides an energy storage device 100, which can be a battery module 20, battery pack, battery box, battery system, etc., composed of individual batteries. The individual batteries can be lithium-ion secondary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, and magnesium-ion batteries, etc., and the individual batteries can be cylindrical, flat, cuboid, etc., and this application does not limit the shape of the individual batteries.

[0061] like Figure 2 As shown, the energy storage device 100 includes a housing 10 (the bottom plate of the housing 10), a liquid cooling component 30, and a battery module 20, which are fixedly installed inside the housing 10.

[0062] like Figure 3As shown, the liquid cooling assembly 30 includes a first liquid cooling plate 31 and a second liquid cooling plate 32. The first liquid cooling plate 31 is thermally connected to the first side arm of the battery module 20 along the height direction of the battery module 20 (the height direction can be identified by H). The second liquid cooling plate 32 is erected on the first liquid cooling plate 31 and contacts the second side wall of the battery module 20. Both the first liquid cooling plate 31 and the second liquid cooling plate 32 are provided with circulation channels 301. The circulation channels 301 of the first liquid cooling plate 31 and the second liquid cooling plate 32 are connected. A cooling medium circulates within the circulation channels 301. The cooling medium can be cooling water, coolant, or other media with cooling function.

[0063] The first sidewall is perpendicular to the second sidewall. Specifically, the first sidewall of the battery module 20 along its height direction can refer to the bottom wall, top wall, or both the top and bottom walls of the battery module 20. Since the second liquid cooling plate 32 is erected on the first liquid cooling plate 31, the second sidewall of the battery module 20 can specifically refer to the circumferential sidewall of the battery module 20, specifically the sidewall of the battery module 20 along the length direction (which can be identified by L) and / or the length direction (which can be identified by W) of the first liquid cooling plate 31.

[0064] The battery module 20 is disposed on the first liquid cooling plate 31 of the liquid cooling assembly 30. The first liquid cooling plate 31 is used to support the battery module 20. When a cooling medium flows through the first liquid cooling channel of the first liquid cooling plate 31, heat exchange can be performed between the cooling medium in the circulation channel 301 of the first liquid cooling plate 31 and the heat generated at the bottom of the battery module 20. Since bottom heat exchange alone would result in a large temperature difference between the top and bottom of the battery module 20 along the first direction, the battery module 20 is positioned on one side of the second liquid cooling plate 32 of the liquid cooling assembly 30. When cooling medium flows through the second liquid cooling channel of the second liquid cooling plate 32, heat exchange can be performed between the cooling medium in the circulation channel 301 of the second liquid cooling plate 32 and the heat generated on the side of the battery module 20. This can effectively alleviate the temperature difference between the bottom and top of the battery module. Furthermore, the bottom and side of the battery module 20 are respectively in contact with the first liquid cooling plate 31 and the second liquid cooling plate 32, achieving simultaneous cooling of the bottom and side of the battery module 20. The battery module 20 has two cooling surfaces, which can reduce the temperature difference between the individual battery modules 20.

[0065] For the energy storage device 100 with the liquid cooling component 30, the cooling medium flowing in the circulation channel 301 of the first liquid cooling plate 31 and the circulation channel 301 of the second liquid cooling plate 32 effectively reduces the temperature inside the housing 10, so that the energy storage device 100 is at a lower temperature, thereby ensuring the charging and discharging performance of the energy storage device 100 while reducing safety hazards, which is conducive to improving the reliability of the entire energy storage device 100.

[0066] like Figure 4As shown, the first liquid cooling plate 31 has multiple liquid cooling zones 311, and the circulation channels 301 of the first liquid cooling plate 31 corresponding to the multiple liquid cooling zones 311 are arranged in parallel.

[0067] Multiple liquid cooling zones 311 correspond to multiple branches, dividing the cooling medium flowing from the liquid inlet channel 303 into multiple branches, thus serving as a liquid cooling medium distribution system. Each of the multiple liquid cooling zones 311 corresponds to a local area of ​​the battery module 20, allowing for independent heat exchange in these local areas. Because the circulation channels 301 of the first liquid cooling plate 31 corresponding to the multiple liquid cooling zones 311 are arranged in parallel, the heat exchange in each local area of ​​the battery module 20 is independent and does not interfere with each other.

[0068] If the circulation channels 301 of the first liquid cooling plate 31 corresponding to each liquid cooling zone 311 have the same length, then the temperature of the cooling medium entering the circulation channel 301 of the second liquid cooling plate 32 through the circulation channels 301 of the first liquid cooling plate 311 corresponding to each liquid cooling zone 311 is approximately the same, and the temperature difference between the cooling medium and the initial temperature when the cooling medium is located in the liquid inlet channel 303 is relatively large, resulting in poor temperature uniformity of the cooling medium.

[0069] Therefore, in this embodiment, the flow length of at least one circulating flow channel 301 corresponding to at least one of the multiple liquid cooling zones 311 is less than the flow length of other circulating flow channels 301 corresponding to other liquid cooling zones 311.

[0070] Since the initial temperature of the cooling medium is lowest in the inlet channel 303, the cooling medium can directly enter the circulation channel 301 of the second liquid cooling plate 32 through the circulation channel 301 of the first liquid cooling plate 31 with a shorter channel length. At this time, the temperature of the cooling medium is slightly higher than the initial temperature, but much lower than the cooling medium flowing through the circulation channel 301 of the first liquid cooling plate 31 with a longer channel length. That is, the cooling medium entering the circulation channel 301 of the second liquid cooling plate 32 comes from two parts: the cooling medium with a shorter channel length and a lower temperature and the cooling medium with a longer channel length and a higher temperature. The two parts can neutralize the temperature, reduce the temperature difference between the cooling medium in the inlet channel 303 and the circulation channel 301 of the second liquid cooling plate 32, and improve the overall temperature uniformity of the liquid cooling assembly 30.

[0071] In one embodiment, the projected areas of multiple liquid cooling zones 311 on the first liquid cooling plate 31 along the height direction of the battery module 20 are not the same.

[0072] The liquid cooling zone 311 with a smaller projected area corresponds to a smaller area of ​​the battery module 20, resulting in less heat exchange with the battery module 20 and a lower temperature rise of the cooling medium after heat exchange. Conversely, the liquid cooling zone 311 with a larger projected area corresponds to a larger area of ​​the battery module 20, resulting in more thorough heat exchange with the battery module 20 and a higher temperature rise of the cooling medium after heat exchange. In this way, the multiple liquid cooling zones 311 have an asymmetrical structure, and the cooling media with lower and higher temperature rises are neutralized before entering the circulation channel 301 of the second liquid cooling plate 32, achieving a temperature balance.

[0073] For example, the plurality of liquid cooling zones 311 include a first liquid cooling zone 3111 and a second liquid cooling zone 3112, wherein the flow channel length of the circulation channel 301 corresponding to the second liquid cooling zone 3112 is less than the flow channel length of the circulation channel 301 corresponding to the first liquid cooling zone 3111. The first liquid cooling zone 3111 and the second liquid cooling zone 3112 have an asymmetrical structure, that is, the first liquid cooling zone 3111 can be referred to as the large circulation, and the second liquid cooling zone 3112 can be referred to as the small circulation.

[0074] Meanwhile, the projected area of ​​the second liquid cooling zone 3112 relative to the first liquid cooling plate 31 is smaller than the projected area of ​​the first liquid cooling zone 3111 relative to the first liquid cooling plate 31. For example, the ratio of the projected area of ​​the second liquid cooling zone 3112 relative to the first liquid cooling plate 31 to the projected area of ​​the first liquid cooling zone 3111 relative to the first liquid cooling plate 31 can be selected as 1:2.

[0075] It is understandable that the first liquid cooling zone 3111 and the second liquid cooling zone 3112 can be arranged side by side on the first liquid cooling plate 31, or the second liquid cooling zone 3112 can be located inside the first liquid cooling zone 3111, that is, the first liquid cooling zone 3111 is partially wrapped around the second liquid cooling zone 3112.

[0076] In one embodiment, the circulation channel 301 of the first liquid cooling plate 31 is connected to the circulation channel 301 of the second liquid cooling plate 32 through the connecting channel 302, and the projected area of ​​the plurality of liquid cooling zones 311 relative to the first liquid cooling plate 31 gradually decreases along the direction close to the connecting channel 302.

[0077] That is, the liquid cooling zone 311, which is relatively close to the connecting channel 302, has a smaller projected area than the first liquid cooling plate 31. After the cooling medium exchanges heat with the bottom of the battery module 20, the temperature rise is relatively low. The cooling medium can be quickly and timely replenished into the connecting channel 302 to improve the temperature uniformity of the cooling medium.

[0078] Specifically, along the direction close to the connecting flow channel 302, the flow channel length of the circulation channels 301 of the multiple liquid cooling zones 311 gradually decreases. With this arrangement, the circulation channels 301 that are closer to the connecting flow channel 302 have shorter flow channels, shorter flow paths for the cooling medium, and less heat exchange with the battery module 20, resulting in a lower temperature of the cooling medium when it flows to the connecting flow channel 302.

[0079] Specifically, along the direction close to the connecting flow channel 302, the cross-sectional area of ​​the circulation channels 301 of the multiple liquid cooling zones 311 gradually decreases.

[0080] Since the flow rate of the circulation channel 301 is related to the channel cross-section and the channel length, when the channel cross-section is fixed, the pressure difference in the circulation channel 301 changes significantly as the channel length increases, resulting in a reduction in the flow of the circulation channel 301. Therefore, the cross-section of the circulation channel 301 with a relatively large channel length is increased to balance the flow rate, so that the flow rate of the circulation channel 301 corresponding to different liquid cooling zones 311 is approximately the same, further improving the overall temperature uniformity.

[0081] In one embodiment, the cross-sections of the circulation channels 301 corresponding to two adjacent liquid cooling zones 311 near the liquid inlet channel 303 are different. By using this method, the flow rate is automatically matched according to the pressure difference of the circulation channels 301 corresponding to different liquid cooling zones 311, which can effectively reduce excessive local temperature rise and thus reduce the temperature difference.

[0082] In one embodiment, such as Figures 3-4 As shown, the first liquid cooling plate 31 is provided with a liquid inlet channel 303, and the second liquid cooling plate 32 is provided with a liquid outlet channel 304. The liquid inlet channel 303, the circulation channel 301 of the first liquid cooling plate 31, the circulation channel 301 of the second liquid cooling plate 32, and the liquid outlet channel 304 are connected. The cooling medium is injected from the liquid inlet channel 303, and after flowing through the circulation channel 301 of the first liquid cooling plate 31 and the circulation channel 301 of the second liquid cooling plate 32, it is discharged from the liquid outlet channel 304 to complete the heat exchange process of the cooling medium.

[0083] For example, the liquid inlet channel 303 is disposed on the first liquid cooling plate 31, and the liquid outlet channel 304 is disposed on the second liquid cooling plate 32. The liquid inlet channel 303, the circulation channel 301 of the first liquid cooling plate 31, the circulation channel 301 of the second liquid cooling plate 32, and the liquid outlet channel 304 are connected in sequence. The cooling medium introduced from the liquid inlet channel 303 first enters the circulation channel 301 of the first liquid cooling plate 31, so that the cooling medium in the circulation channel 301 of the first liquid cooling plate 31 heats the bottom of the battery module 20. The cooling medium flowing out from the circulation channel 301 of the first liquid cooling plate 31 is discharged from the liquid outlet channel 304 through the circulation channel 301 of the second liquid cooling plate 32, so that the cooling medium in the circulation channel 301 of the second liquid cooling plate 32 heats the side of the battery module 20.

[0084] Of course, the positions of the liquid inlet channel 303 and the liquid outlet channel 304 can also be interchanged. That is, the liquid inlet channel 303 can be disposed on the second liquid cooling plate 32 and the liquid outlet channel 304 can be disposed on the first liquid cooling plate 31. Alternatively, the liquid inlet channel 303 and the liquid outlet channel 304 can be disposed on the first liquid cooling plate 31 at the same time, or the liquid inlet channel 303 and the liquid outlet channel 304 can be disposed on the second liquid cooling plate 32 at the same time. The embodiments of this application do not limit this and can be adjusted according to actual production needs.

[0085] Specifically, the inlet channel 303 and the outlet channel 304 are located on the same side of the first liquid cooling plate 31 along its length; and / or, the inlet channel 303 and the outlet channel 304 are located on the same side of the first liquid cooling plate 31 along its width. In other words, the projection of the inlet channel 303 relative to the first liquid cooling plate 31 and the projection of the outlet channel 304 relative to the first liquid cooling plate 31 at least partially overlap.

[0086] Since the cooling medium is initially located at the inlet channel 303, its initial temperature is relatively low. However, at the outlet channel 304, the cooling medium is at its end, resulting in a higher temperature after heat exchange with the battery module 20. By positioning the inlet channel 303 and the outlet channel 304 approximately on the same side, the cooling medium in the entire cooling circuit enters and exits on the same side. This allows the higher-temperature cooling medium and the lower-temperature cooling medium to neutralize each other to a certain extent, effectively reducing the temperature difference of the cooling medium and thus improving the temperature uniformity of the entire liquid cooling component 30.

[0087] For example, the inlet channel 303 is located on the right side of the first liquid cooling plate 31 along its width direction, and the connecting channel 302 is located on the left side of the first liquid cooling plate 31 along its width direction. This allows the cooling medium to enter from the right side of the first liquid cooling plate 31, pass through the circulation channel 301 of the first liquid cooling plate 31, and then enter the circulation channel 301 of the second liquid cooling plate 32 from the left side of the first liquid cooling plate 31, finally flowing out from the right side of the second liquid cooling plate 32. Since the temperature of the cooling medium in the circulation channel 301 of the first liquid cooling plate 31 is lower on the right side and higher on the left side, while the temperatures of the cooling medium on the left and right sides of the circulation channel 301 of the second liquid cooling plate 32 are exactly opposite, this neutralization effect effectively reduces the temperature difference of the cooling medium.

[0088] In one embodiment, such as Figure 5 As shown, each liquid cooling zone 311 has a circulation channel 301 that includes multiple cooling units 312 arranged in series, increasing the overall length of the circulation channel 301 so that the circulation channel 301 covers as much of the area corresponding to the battery module 20 as possible.

[0089] For example, the first liquid cooling zone 3111 has a first cooling unit 3121, a second cooling unit 3122, and a third cooling unit 3123 connected in series. The liquid inlet channel 303 is connected to the first cooling unit 3121, and the third cooling unit 3123 is connected to the circulation channel 301 of the second liquid cooling plate 32. The second cooling unit 3122 is located between the first cooling unit 3121 and the third cooling unit 3123. The three cooling units 312 arranged in series can increase the coverage area of ​​the battery module 20, thereby improving the heat exchange effect of the battery module 20.

[0090] For example, the second liquid cooling zone 3112 includes a fourth cooling unit 3124 and a fifth cooling unit 3125 connected in series. The fourth cooling unit 3124 is connected to the liquid inlet channel 303, and the fifth cooling unit 3125 is connected to the circulation channel 301 of the second liquid cooling plate 32. The second liquid cooling zone 3112 has only two cooling units 312 connected in series, resulting in less heat exchange with the battery module 20, a smaller temperature rise of the cooling medium, and timely replenishment to the connecting channel 302, thus improving the overall temperature uniformity.

[0091] In one embodiment, the liquid inlet channel 303 is connected to the cooling unit 312 located near the liquid inlet channel 303 via the main channel 313, and the main channel 313 and the liquid inlet channel 303 extend in different directions. In this way, the cooling medium flowing out of the liquid inlet channel 303 does not flow directly into the main channel 313, but has a certain bend, so that it can be divided into multiple channels, thereby entering the corresponding liquid cooling zone 311 through the main body.

[0092] For example, the liquid inlet channel 303 is connected to the first cooling unit 3121 via the first main channel 3131, and the liquid inlet channel 303 is connected to the fourth cooling unit 3124 via the second main channel 3132. The first main channel 3131 and the liquid inlet channel 303 have different extension directions, and the second main channel 3132 and the liquid inlet channel 303 have different extension directions. For example, the liquid inlet channel 303 extends along the length direction of the first liquid cooling plate 31, and the first main channel 3131 and the second main channel 3132 extend along the width direction of the first liquid cooling plate 31. The cooling medium flowing out of the liquid inlet channel 303 is divided into two parts, left and right, along the width direction of the first liquid cooling plate 31, thereby correspondingly entering the large circulation and small circulation.

[0093] In one embodiment, the cooling unit 312 includes a plurality of cooling branches 3120 arranged in parallel. The plurality of cooling branches 3120 arranged in parallel divide the main path 313 into a large number of smaller branches, which can increase the contact area between the cooling medium and the cold plate wall of the first liquid cooling plate 31 and enhance the heat exchange effect.

[0094] In one embodiment, two adjacent cooling units 312 are connected by a main cooling path 315. That is, multiple parallel cooling branches 3120 converge at intervals to form the main cooling path 315. The main cooling path 315 allows the cooling media in the multiple cooling branches 3120 to mix before being distributed to the multiple cooling branches 3120 of the next cooling unit 312, ensuring the uniformity of the cooling media temperature. Simultaneously, it ensures that the cooling media can be remixed at intervals via the main cooling path 315, preventing excessively high temperatures in any one cooling branch 3120 that could lead to a large temperature difference.

[0095] In one embodiment, the cooling branch 3120 extends along the length direction (represented by L) of the first liquid cooling plate 31; or, the cooling branch 3120 extends along the width direction (represented by W) of the first liquid cooling plate 31.

[0096] For example, after the cooling medium in the liquid inlet channel 303 is introduced along the L direction, it is divided into a first main channel 3131 and a second main channel 3132 flowing along the W direction. The cooling medium in the first main channel 3131 flows to the first cooling unit 3121. The cooling medium in the cooling branch channel 3120 of the first cooling unit 3121 flows along the W direction and then flows to the second cooling unit 3122. The cooling branch channel 3120 of the second cooling unit 3122 flows along the L direction and then flows to the third cooling unit 3123. The cooling branch channel 3120 of the third cooling unit 3123 flows along the L direction and finally enters the circulation channel 301 of the second liquid cooling plate 32 through the connecting channel 302. The cooling medium in the second main channel 3132 flows to the fourth cooling unit 3124. The cooling medium flows in the W direction in the cooling branch 3120 of the fourth cooling unit 3124, and then flows to the fifth cooling unit 3125. The cooling medium flows in the L direction in the cooling branch 3120 of the fifth cooling unit 3125, and preferably enters the circulation channel 301 of the second liquid cooling plate 32 through the connecting channel 302.

[0097] In one embodiment, a flow-dispersing element 314 is further provided within the cooling unit 312 and / or the main cooling path 315. The flow-dispersing element 314 can increase the turbulence of the cooling medium, ensuring that the cooling media of different temperatures flowing out of each cooling branch 3120 are mixed evenly before flowing into the next cooling unit 312 or the next cooling branch 3120. The number of flow-dispersing elements 314 can be cylindrical, and multiple flow-dispersing elements 314 can be selected. The area around multiple flow-dispersing elements 314 forms a pressure equalization cavity, further improving the turbulence and temperature uniformity effect.

[0098] Among them, a flow-disrupting element 314 is provided on the side of the first liquid cooling plate 31 near the connecting flow channel 302.

[0099] Since the cooling medium flowing out from the connecting channel 302 needs to flow upward along the height direction of the battery module 20 to the circulation channel 301 of the second liquid cooling plate 32, the flow deflector 314 is set near the connecting channel 302. The flow deflector 314 can increase the disturbance resistance of the cooling medium, thereby increasing the flow rate of the cooling medium, so that the cooling medium can quickly rush upward along the height direction of the battery module 20 to the circulation channel 301 of the second liquid cooling plate 32.

[0100] In one embodiment, such as Figure 3 and Figure 6As shown, the energy storage device 100 also includes a support member 33. One end of the support member 33 along the height direction of the battery module 20 is connected to the first liquid cooling plate 31, and the other end is connected to the second liquid cooling plate 32. A connecting flow channel 302 is provided inside the support member 33. By using the support member 33, the height of the second liquid cooling plate 32 is effectively raised. The second liquid cooling plate 32 can cool the upper side of the battery module 20, which can effectively alleviate the temperature difference between the top and bottom of the battery module 20.

[0101] The first liquid cooling plate 31, the second liquid cooling plate 32, and the support member 33 are integrally formed structures.

[0102] Compared to separate bottom and side cooling systems, this system combines the advantages of both bottom and side cooling, eliminating the need for additional connecting pipes 34 and sealing joints. This fully utilizes the internal space of the enclosure 10 while also reducing production costs.

[0103] In one embodiment, such as Figure 3 , Figures 6-7 As shown, the second liquid cooling plate 32 is approximately U-shaped. The second liquid cooling plate 32 includes a first side plate 321, a second side plate 322, and a connecting plate 323. The first side plate 321 and the second side plate 322 are respectively disposed on both sides of the first liquid cooling plate 31 along the W direction. The connecting plate 323 is disposed between the first side plate 321 and the second side plate 322, increasing stability relative to the tail connection structure of the first side plate 321 and the second side plate 322, making the second liquid cooling plate 32 less prone to deformation. The first side plate 321 and the second side plate 322 extend along the L direction to cool the side of the battery module 20 along the W direction, and the middle plate extends along the W direction to cool the side of the battery module 20 along the L direction.

[0104] The circulation channels 301 of the first side plate 321 and the second side plate 322 are similar to those of the first liquid cooling plate 31, and may also have multiple cooling units 312 arranged in series. Adjacent cooling units 312 are connected by a main cooling path 315. Each cooling unit 312 includes multiple cooling branches 3120 arranged in parallel. The number and arrangement of cooling units 312 and cooling branches 3120 can be adjusted according to actual production needs, and therefore will not be described in detail.

[0105] The first side plate 321 is disposed on the side of the first liquid cooling plate 31 along the W direction and away from the liquid inlet channel 303, and the liquid outlet channel 304 is disposed on the second side plate 322. The connecting channel 302 is disposed between the bottom of the first side plate 321 and the first liquid cooling plate 31. The cooling medium flowing out from the connecting channel 302 first enters the circulation channel 301 of the first side plate 321, then enters the circulation channel 301 of the second side plate 322 through the circulation channel 301 of the connecting plate 323, and finally exits from the liquid outlet channel 304.

[0106] Example 2

[0107] This embodiment is similar to Embodiment 1, except that the connection between the first liquid cooling plate 31 and the second liquid cooling plate 32 is different. Other structures can be referred to Embodiment 1.

[0108] like Figure 8 As shown, the energy storage device 100 also includes a support member 33. One end of the support member 33 along the height direction of the battery module 20 is connected to the first liquid cooling plate 31. The other end of the support member 33 along the height direction of the battery module 20 and the second liquid cooling plate 32 are provided with a positioning post 316 and a positioning hole 331, respectively. The positioning post 316 passes through the positioning hole 331.

[0109] The first liquid cooling plate 31 and the second liquid cooling plate 32 are designed to be detachable, facilitating replacement and maintenance should one of the liquid cooling plates be damaged. The positioning post 316 and the positioning hole 331 work together to facilitate the second liquid cooling plate 32's connection with the first liquid cooling plate 31 via the support member 33, ensuring accurate positioning between the two plates. Furthermore, structural adhesive can be used to fix the positioning post 316 and the positioning hole 331, improving the fixation effect.

[0110] The number of positioning posts 316 and positioning holes 331 is multiple, and multiple positioning posts 316 and multiple positioning holes 331 are arranged correspondingly. The multiple positioning posts 316 are arranged along the circumference of the second liquid cooling plate 32.

[0111] A receiving space is formed between the first liquid cooling plate 31 and the second liquid cooling plate 32. During installation, the battery module 20 is first placed on the first liquid cooling plate 31 and corresponds to the position of the receiving space. Then, the second liquid cooling plate 32 with the support member 33 is placed on the first liquid cooling plate 31, and the positioning post 316 and the positioning hole 331 are inserted to facilitate overall assembly.

[0112] In one embodiment, such as Figure 8 As shown, the energy storage device 100 also includes a connecting pipe 34, which is located between the first liquid cooling plate 31 and the second liquid cooling plate 32. The connecting pipe 34 is detachably connected to the first liquid cooling plate 31 and the second liquid cooling plate 32 respectively. A connecting channel 302 is provided in the connecting pipe 34, and the circulation channel 301 of the first liquid cooling plate 31 is connected to the circulation channel 301 of the second liquid cooling plate 32 through the connecting channel 302.

[0113] Specifically, the connecting pipe 34 can be a flexible hose. The lower end of the connecting pipe 34 can be installed on the connector of the first liquid cooling plate 31 via a clamp. The upper end of the connecting pipe 34 is connected to a female connector. The circulation channel 301 of the second liquid cooling plate 32 is provided with a male connector corresponding to the female connector. The male and female connectors are detachably connected by a snap-fit ​​structure. Using the connecting channel 302 of the connecting pipe 34, the cooling medium enters the circulation channel 301 of the second liquid cooling plate 32 from the circulation channel 301 of the first liquid cooling plate 31 through the connecting channel 302.

[0114] Example 3

[0115] This embodiment is similar to Embodiment 1, except that the only difference is the internal structure of the second liquid cooling plate 32.

[0116] like Figure 9 As shown, the liquid cooling assembly 30 provided in this embodiment also includes a partition 35. The partition 35 is disposed in the circulation channel 301 of the second liquid cooling plate 32. The partition 35 is disposed along the extension direction of the circulation channel 301 of the second liquid cooling plate 32. The partition 35 divides the circulation channel 301 of the second liquid cooling plate 32 into two sub-channels 3011 to facilitate the flow of coolant. The two sub-channels 3011 are respectively connected to the second sidewall of the two battery modules 20 for thermal conduction.

[0117] The second liquid cooling plate 32 adopts a double-sided cooling method, which allows the two battery modules 20 located on both sides of the second liquid cooling plate 32 along the W direction to be cooled simultaneously through two sub-flow channels 3011, increasing the heat exchange area and enabling each battery module 20 to be cooled independently from one side, resulting in good heat dissipation.

[0118] It should be noted that the number of baffles 35 and sub-channels 3011 can be adjusted according to the pressure difference and heat exchange conditions.

[0119] It should be noted that the liquid cooling assembly shown in the accompanying drawings and described in this specification is merely one example of the application of the principles of the invention. Those skilled in the art will clearly understand that the principles of the invention are not limited to any details or components of the apparatus shown in the drawings or described in the specification.

[0120] It should be understood that the application of this invention is not limited to the detailed structure and arrangement of the components presented in this specification. The invention can have other embodiments and can be implemented and performed in various ways. The foregoing variations and modifications fall within the scope of this invention. It should be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more individual features mentioned or apparent in the text and / or drawings. All these different combinations constitute multiple alternative aspects of the invention. The embodiments described in this specification illustrate the best known mode for carrying out the invention and will enable those skilled in the art to utilize the invention.

[0121] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and exemplary embodiments are to be considered as exemplary only, and the true scope and spirit of the invention are indicated by the appended claims.

[0122] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of protection of the present invention is limited only by the appended claims.

Claims

1. An energy storage device, characterized in that, include: Battery module (20); The first liquid cooling plate (31) is thermally connected to the first sidewall of the battery module (20) along the height direction of the battery module (20); The second liquid cooling plate (32) is erected on the first liquid cooling plate (31). The second liquid cooling plate is in contact with the second side wall of the battery module (20). Both the first liquid cooling plate (31) and the second liquid cooling plate (32) are provided with circulation channels (301). The circulation channels (301) of the first liquid cooling plate (31) and the circulation channels (301) of the second liquid cooling plate (32) are connected. Wherein, the first sidewall is perpendicular to the second sidewall, the first liquid cooling plate (31) has a plurality of liquid cooling zones (311), the circulation channels (301) corresponding to the plurality of liquid cooling zones (311) are arranged in parallel, and the flow length of at least one circulation channel (301) corresponding to at least one of the plurality of liquid cooling zones (311) is less than the flow length of the other circulation channels (301) corresponding to the other liquid cooling zones (311); The first liquid cooling plate (31) is provided with a liquid inlet channel (303), and the second liquid cooling plate (32) is provided with a liquid outlet channel (304). The liquid inlet channel (303), the circulation channel (301) of the first liquid cooling plate (31), the circulation channel (301) of the second liquid cooling plate (32) and the liquid outlet channel (304) are connected.

2. The energy storage device according to claim 1, characterized in that, The projected areas of the multiple liquid cooling zones (311) on the first liquid cooling plate are not the same along the height direction of the battery module (20).

3. The energy storage device according to claim 2, characterized in that, The circulation channel (301) of the first liquid cooling plate (31) and the circulation channel (301) of the second liquid cooling plate (32) are connected by a connecting channel (302). Along the direction close to the connecting channel (302), the channel length of the circulation channel (301) of the plurality of liquid cooling zones (311) gradually decreases. And / or, the circulation channel (301) of the first liquid cooling plate (31) and the circulation channel (301) of the second liquid cooling plate (32) are connected by a connecting channel (302), and the cross-sectional area of ​​the circulation channel (301) of the plurality of liquid cooling zones (311) gradually decreases along the direction close to the connecting channel (302).

4. The energy storage device according to claim 1, characterized in that, The inlet channel (303) and the outlet channel (304) are located on the same side of the first liquid cooling plate (31) along the length direction of the first liquid cooling plate (31); and / or, the inlet channel (303) and the outlet channel (304) are located on the same side of the first liquid cooling plate (31) along the width direction of the first liquid cooling plate (31).

5. The energy storage device according to claim 4, characterized in that, The cross-sections of the circulation channels (301) corresponding to the multiple liquid cooling zones (311) are different at the end near the liquid inlet channel (303).

6. The energy storage device according to claim 4, characterized in that, Each of the liquid cooling zones (311) and the corresponding circulation channels (301) include multiple cooling units (312) arranged in series. The liquid inlet channel (303) is connected to the cooling unit (312) near the liquid inlet channel (303) via the main road (313), and the main road (313) and the liquid inlet channel (303) extend in different directions.

7. The energy storage device according to claim 6, characterized in that, The cooling unit (312) includes multiple cooling branches (3120) arranged in parallel; The cooling branch (3120) extends along the length of the first liquid cooling plate (31); or, the cooling branch (3120) extends along the width of the first liquid cooling plate (31).

8. The energy storage device according to claim 6, characterized in that, The circulation channel (301) of the first liquid cooling plate (31) is connected to the circulation channel (301) of the second liquid cooling plate (32) through the connecting channel (302); Two adjacent cooling units (312) are connected by a cooling main road (315), and a baffle (314) is also provided in the cooling unit (312) and / or the cooling main road (315). The first liquid cooling plate (31) is provided with the flow-disrupting element (314) on the side near the connecting channel (302).

9. The energy storage device according to claim 1, characterized in that, The energy storage device also includes: Support member (33), one end of which is connected to the first liquid cooling plate (31) along the height direction of the battery module (20), and the other end is connected to the second liquid cooling plate (32). The first liquid cooling plate (31), the second liquid cooling plate (32), and the support member (33) are integrally formed structures.

10. The energy storage device according to claim 1, characterized in that, The energy storage device also includes: A support member (33) is connected to the first liquid cooling plate (31) at one end along the height direction of the battery module (20). The other end of the support member (33) along the height direction of the battery module (20) and the second liquid cooling plate (32) are provided with a positioning post (316) and a positioning hole (331), respectively. The positioning post (316) passes through the positioning hole (331). A connecting pipe (34) is located between the first liquid cooling plate (31) and the second liquid cooling plate (32). The connecting pipe (34) is detachably connected to the first liquid cooling plate (31) and the second liquid cooling plate (32) respectively. A connecting channel (302) is provided in the connecting pipe (34). The circulation channel (301) of the first liquid cooling plate (31) is connected to the circulation channel (301) of the second liquid cooling plate (32) through the connecting channel (302).

11. The energy storage device according to any one of claims 1-10, characterized in that, The energy storage device further includes a partition (35), which is disposed in the circulation channel (301) of the second liquid cooling plate (32). The partition (35) is disposed along the extension direction of the circulation channel (301) of the second liquid cooling plate (32). The partition (35) divides the circulation channel (301) of the second liquid cooling plate (32) into two sub-channels (3011). The two sub-channels (3011) are respectively thermally connected to the second sidewall of the two battery modules (20).

12. An energy storage system, characterized in that, It includes an electrical appliance (300) and an energy storage device according to any one of claims 1-11, wherein the energy storage device supplies power to the electrical appliance (300).

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