Top cover assembly, battery and energy storage device

Abstract

The present application provides a top cover assembly, a battery, and an energy storage device. The assembly comprises a top cover, a first pole, a second pole, a first pressure block, and a second pressure block. The first pole and the second pole are both provided through the top cover, and the first pressure block and the second pressure block are both located on the same side of the thickness direction of the top cover. The first pressure block is sleeved on the first pole and connected to the first pole, and the second pressure block is sleeved on the second pole and connected to the second pole. The first pressure block comprises a first connecting portion and a second connecting portion connected to each other, the first connecting portion is connected to the first pole, and the material of the first connecting portion and the material of the first pole both comprise a first metal, and the material of the second connecting portion, the second pressure block, and the material of the second pole both comprise a second metal, which is different from the first metal. In the thickness direction of the top cover, the projected area of ​​the first pressure block on the top cover is larger than the projected area of ​​the second pressure block on the top cover.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a top cover assembly, a battery, and an energy storage device. Background Art

[0002] With the development of energy, batteries with recyclable properties are becoming increasingly popular. The battery includes an electrode assembly, a shell and a top cover assembly. The electrode assembly is located in the accommodation space formed by the shell and the top cover assembly. The top cover assembly includes a top cover, a pole and a pressure block. The pole is mounted on the top cover and electrically connected to the electrode assembly to serve as a channel for current to enter and exit the top cover assembly. The pressure block is electrically connected to the pole to enable the electrode of the pole to be led out. Currently, the structure of the pressure block itself and the connection between it and the pole may cause changes in the overcurrent capacity of the battery cell. Summary of the Invention

[0003] The embodiments of the present application provide a top cover assembly, a battery, and an energy storage device, which can solve the problem that the structure of the pressing block itself and the connection between the pressing block and the pole easily lead to poor overcurrent capacity of the battery cell.

[0004] In a first aspect, the present application provides a top cover assembly, the top cover assembly comprising a top cover, a first pole, a second pole, a first pressing block, and a second pressing block;

[0005] The first pole and the second pole are both provided through the top cover and spaced apart along the length direction of the top cover. The first pressing block and the second pressing block are both located on the same side of the thickness direction of the top cover. The first pressing block is sleeved on the first pole and connected to the first pole. The second pressing block is sleeved on the second pole and connected to the second pole.

[0006] The first pressing block includes a first connecting portion and a second connecting portion connected to each other, the first connecting portion is connected to the first pole, the first connecting portion and the first pole are both made of a first metal, and the second connecting portion, the second pressing block, and the second pole are both made of a second metal, which is different from the first metal;

[0007] In the thickness direction of the top cover, a projected area of ​​the first pressing block on the top cover is larger than a projected area of ​​the second pressing block on the top cover.

[0008] It is understandable that in the prior art, the first pole and the first compression block are typically connected together by welding. However, the material of the first pole and the first compression block are typically different, and the welding melting points of the first pole and the first compression block made of different materials are different. This means that although the first pole and the first compression block can form a good physical connection through welding, due to the non-interference fit between the metal and the metal, it is difficult to form a good fixed connection before welding. This can lead to incorrect fixing between the two before welding, causing welding problems and affecting the current capacity of the battery cell.

[0009] In view of this, in the embodiments of the present application, by forming the first pressing block from a composite of a first connecting portion and a second connecting portion made of different metal materials, and by making the first connecting portion and the first terminal from the same metal material, not only can the first connecting portion achieve a better connection effect when connected to the first terminal (e.g., by welding) due to being made of the same metal material, but the second connecting portion can also achieve a better connection effect in the subsequent connection process (e.g., by welding) with the tab due to being made of the same metal material, thereby improving the overall current carrying capacity of the first terminal.

[0010] In addition, since the second connection part, the second pressure block and the second pole are all made of the same metal material. Therefore, for the first pressure block, it has two different parts of the flow area, the first connection part and the second connection part, and for the second pressure block, it only has the same flow area. In addition, because in the thickness direction of the top cover, the projected area of ​​the first pressure block on the top cover is larger than the projected area of ​​the second pressure block on the top cover. This makes the flow area of ​​the second connection part of the first pressure block as roughly the same as the flow area of ​​the second pressure block as a whole as much as possible, so that the first connection part of the first pressure block and the second pressure block composed of the same metal material can tend to the same flow area, thereby ensuring that the first pole and the second pole as a whole can have roughly the same flow effect, improving the flow capacity of both, and thus improving the flow capacity of the battery cell.

[0011] In a possible embodiment, in the thickness direction of the top cover, the difference between the projected area of ​​the second connecting portion on the top cover and the projected area of ​​the second pressing block on the top cover is 0 mm. 2 -5mm 2 within the area.

[0012] In a possible implementation manner, at least part of the second connecting portion is located on both sides of the first connecting portion along the length direction of the top cover;

[0013] The dimension of the first pressing block along the length direction of the top cover is a first dimension L1, and the dimension of the second pressing block along the length direction of the top cover is a second dimension L2. The first dimension L1 is greater than the second dimension L2.

[0014] In a possible implementation, the first dimension L1, the second dimension L2, and the dimension T1 of the first connecting portion along the length direction of the top cover satisfy the relationship:

[0015] 0<(L1-L2)≤T1.

[0016] In a possible implementation manner, a dimension of the first connecting portion along the width direction of the top cover is smaller than or equal to a dimension of the second connecting portion along the width direction of the top cover.

[0017] In a possible implementation manner, at least part of the second connection portion is located on both sides of the first connection portion along the width direction of the top cover;

[0018] A dimension of the first pressing block along the width direction of the top cover is a third dimension L3, a dimension of the second pressing block along the width direction of the top cover is a fourth dimension L4, and the third dimension L3 is greater than the fourth dimension L4.

[0019] In a possible implementation manner, the third dimension L3, the fourth dimension L4, and the dimension T2 of the first connecting portion along the width direction of the top cover satisfy the relationship:

[0020] 0<(L3-L4)≤T2.

[0021] In a possible implementation manner, a dimension of the first connecting portion along the length direction of the top cover is smaller than or equal to a dimension of the second connecting portion along the length direction of the top cover.

[0022] In a possible implementation manner, the first connecting portion and the second connecting portion are connected to form an intersection line, and the intersection line is arranged parallel to the width direction of the top cover.

[0023] In a possible implementation manner, in a thickness direction of the top cover, a projection of the first connecting portion on the top cover partially overlaps with a projection of the second connecting portion on the top cover.

[0024] In a possible implementation manner, the second connecting portion is provided with a mounting groove, the opening of the mounting groove faces the surface of the first pressing block away from the top cover, and the first connecting portion is embedded in the mounting groove.

[0025] In a possible embodiment, the second connecting portion includes a first sub-portion and a second sub-portion, the first sub-portion is provided with the mounting groove, and the second sub-portion is connected to the first sub-portion on both sides along the length direction of the first pressing block;

[0026] The first connecting portion includes a third sub-portion and a fourth sub-portion, the third sub-portion is located in the mounting groove, the third sub-portion is abutted against the second sub-portion on both sides along the length direction of the first pressing block, the fourth sub-portion is connected to the third sub-portion on both sides along the width direction of the first pressing block, and the fourth sub-portion is connected to the second sub-portion in the thickness direction of the first pressing block.

[0027] In a second aspect, the present application also provides a battery, which includes an electrode assembly, a shell and a top cover assembly as described above, wherein the top cover assembly is connected to the shell and is arranged together with the shell to form a receiving space, and the electrode assembly is located in the receiving space.

[0028] In a third aspect, the present application provides an energy storage device, which includes the battery as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of an energy storage system provided in an embodiment of the present application;

[0030] Figure 2 This is a schematic structural diagram of a battery provided in an embodiment of the present application;

[0031] Figure 3 This is a structural schematic diagram of a top cover assembly provided in an embodiment of the present application;

[0032] Figure 4 yes Figure 3 A schematic diagram of the exploded structure of the top cover assembly shown;

[0033] Figure 5 yes Figure 3 A schematic structural diagram of the top cover of the top cover assembly shown;

[0034] Figure 6 It is along Figure 3 A schematic cross-sectional view of a portion of the top cover assembly obtained by cutting along the cutting line AA shown;

[0035] Figure 7 yes Figure 3 A schematic structural diagram of the first pressing block of the top cover assembly shown;

[0036] Figure 8 It is along Figure 7 The cross-sectional structure diagram of the first compact obtained by cutting along the cutting line BB is shown;

[0037] Figure 9 It is along Figure 7 The cross-sectional structure diagram of the first compact obtained by cutting along the cutting line CC shown;

[0038] Figure 10 yes Figure 9 An enlarged schematic diagram of region Q is shown;

[0039] Figure 11 yes Figure 3 A schematic structural diagram of the top cover assembly from another angle shown;

[0040] Figure 12 This is another structural schematic diagram of the top cover assembly provided in an embodiment of the present application.

[0041] Reference numerals:

[0042] Energy storage system 400, high-voltage cable 410, first power conversion device 420, second power conversion device 430, energy storage device 300, battery 200, top cover assembly 100, housing 210, electrode assembly 220, top cover 10, first upper plastic 21, second upper plastic 22, lower plastic 30, first pole 41, second pole 42, first sealing ring 51, second sealing ring 52, first pressure block 61, second pressure block 62, explosion-proof valve assembly 70, first surface 101, second surface 102, first hole 11, second hole 12, first accommodating groove 13, second accommodating groove 14, explosion-proof valve 71, explosion-proof valve protection plate 72, first perforation 31, second perforation 32, first through hole 211, first groove 212, second through hole 221, second groove 222, first connecting portion 611, second connecting portion 612, mounting groove 613, third sub-portion 6111, fourth sub-portion 6112, first connecting hole 6113, first sub-portion 6121, second sub-portion 6122, second connecting hole 6123, third connecting hole 621. DETAILED DESCRIPTION

[0043] For ease of understanding, the terms involved in the embodiments of the present application are first explained.

[0044] And / or: It is just a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0045] Multiple: refers to two or more than two.

[0046] Connection: should be understood in a broad sense. For example, A and B are connected, which can be either directly connected or indirectly connected through an intermediary.

[0047] The specific implementation of the present application will be clearly described below with reference to the accompanying drawings.

[0048] Embodiments of the present application provide a top cover assembly, a battery, and an energy storage device.

[0049] Since the energy people need is highly time- and space-dependent, in order to rationally utilize energy and improve energy utilization, it is necessary to use a medium or device to store one form of energy in the same form or convert it into another form of energy, and then release it in a specific form based on future application needs. Currently, the main way to generate green electricity is to develop green energy such as photovoltaics and wind power to replace fossil energy.

[0050] Currently, the generation of green electricity generally relies on photovoltaics, wind power, and hydropower. However, wind and solar energy are generally intermittent and highly volatile, which can cause grid instability, insufficient electricity during peak hours, and excessive electricity during off-peak hours. Unstable voltage can also damage electricity. Therefore, insufficient electricity demand or insufficient grid capacity may lead to the problem of "wind and solar power curtailment". To solve these problems, we must rely on energy storage. This means converting electrical energy into other forms of energy through physical or chemical means and storing them. When needed, this energy is converted into electrical energy and released. Simply put, energy storage is like a large "power bank", storing electricity when photovoltaic and wind energy are sufficient and releasing the stored electricity when needed.

[0051] Taking electrochemical energy storage as an example, this solution provides an energy storage device for use in energy storage systems. The energy storage device is equipped with a group of chemical batteries, which mainly use the chemical elements in the batteries as energy storage media. The charging and discharging process is accompanied by chemical reactions or changes in the energy storage medium. Simply put, the electricity generated by wind and solar energy is stored in the chemical battery. When the use of external electricity reaches its peak, the stored electricity is released for use, or transferred to places where electricity is scarce for use.

[0052] Currently, energy storage (i.e., energy storage) has a wide range of application scenarios, including power generation side energy storage, grid side energy storage, and power consumption side energy storage. The corresponding types of energy storage devices include:

[0053] (1) Large-scale energy storage power stations applied to wind power and photovoltaic power stations can help renewable energy generation meet grid connection requirements and improve the utilization rate of renewable energy. As a high-quality active / reactive power supply on the power supply side, energy storage power stations can achieve load matching of electricity in time and space, enhance the capacity to absorb renewable energy, reduce instantaneous power changes, reduce the impact on the power grid, improve the absorption of new energy generation, and are of great significance in grid system backup, alleviating peak load power supply pressure, and peak and frequency regulation.

[0054] (2) Energy storage containers used on the grid side are mainly used for peak load regulation, frequency regulation, and relief of grid congestion. They can realize peak load shaving and valley filling of electricity load, that is, charging the energy storage battery when the electricity load is low and releasing the stored electricity during the peak load period, thereby achieving a balance between electricity production and consumption;

[0055] (3) Small energy storage cabinets used on the power consumption side, whose main functions are self-generation and self-use of electricity, peak-valley price arbitrage, capacity cost management and improving power supply reliability. According to different application scenarios, energy storage on the power consumption side can be divided into industrial and commercial energy storage cabinets, household energy storage devices, energy storage charging piles, etc., which are generally used in conjunction with distributed photovoltaics. Industrial and commercial users can use energy storage for peak-valley price arbitrage and capacity cost management. In the power market that implements peak-valley electricity prices, by charging the energy storage system when the electricity price is low and discharging the energy storage system when the electricity price is high, peak-valley electricity price arbitrage is achieved and electricity costs are reduced. In addition, industrial enterprises that are subject to two-part electricity prices can use energy storage systems to store energy during low electricity consumption and discharge it during peak load, thereby reducing peak power and the maximum demand reported, and achieving the purpose of reducing capacity electricity charges. Household photovoltaic storage can improve the level of self-generation and self-use of electricity. Due to high electricity prices and poor power supply stability, the demand for household photovoltaic installation is driven. Considering that photovoltaic power generation occurs during the day, while user loads are generally higher at night, deploying energy storage can better utilize photovoltaic power, increasing self-generation and self-consumption while reducing electricity costs. Furthermore, energy storage is required for backup power in areas such as communication base stations and data centers.

[0056] In some embodiments, see Figure 1 , Figure 1 Schematic diagram of the structure of the energy storage system 400 provided in the embodiment of the present application. Figure 1 In the embodiment of the present application, the shared energy storage scenario on the power generation / distribution side is used as an example for description. The energy storage device 300 of the present application is not limited to the energy storage scenario on the power generation / distribution side.

[0057] An embodiment of the present application provides an energy storage system 400 . The energy storage system 400 includes a high-voltage cable 410 , a first power conversion device 420 , a second power conversion device 430 , and an energy storage device 300 .

[0058] In some embodiments of the power generation side scenario, the second power conversion device 430 can be a wind power conversion device. Since the power generated by wind power conversion is volatile, random, and intermittent, the unstable power output by the wind power conversion device can be first stored in the energy storage device 300 by connecting to the grid. The energy storage device 300 is connected to the high-voltage cable and outputs smooth power to the power distribution network for use, thereby achieving peak load regulation and frequency regulation, and stable operation of the power grid. Alternatively, the wind power conversion device is always connected to the high-voltage cable. Under normal power generation conditions, the power output by the wind power conversion device is supplied to the power distribution network for use through the high-voltage cable. When the current power load is low and the wind power conversion device generates excess power, the excess power is first stored in the energy storage device 300, thereby reducing the wind and solar power abandonment rates and improving the problem of new energy power generation and consumption. When the power load is high, the power grid issues a command to transmit the electricity stored in the energy storage device 300 in conjunction with the high-voltage cable 410 in a grid-connected mode to the power consumption side, providing peak-shaving, frequency regulation, standby and other services for the power grid operation, giving full play to the peak-shaving role of the power grid, promoting peak-shaving and valley-filling of the power grid, and alleviating the power supply pressure of the power grid.

[0059] In some embodiments on the distribution network side, the first power conversion device 420 may be a photovoltaic power conversion device. The energy storage device 300 is connected to the high-voltage cable 410 and installed between the downstream portion of the high-voltage cable 410 and the user load. The power output by the photovoltaic power conversion device is stored in the energy storage device 300, providing a timely response and backup power source in the event of a power grid / distribution network failure. Alternatively, this device can alleviate congestion in the high-voltage cable 410 transmission line and provide power supply support during planned grid expansion to mitigate the economic pressures associated with grid / distribution capacity expansion.

[0060] Optionally, the first power conversion device 420 may include but is not limited to a wind power conversion device, and the second power conversion device 430 may include but is not limited to a photovoltaic power conversion device. The first power conversion device 420 and the second power conversion device 430 can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy and mechanical energy into electrical energy.

[0061] Optionally, the energy storage device 300 may include but is not limited to energy storage application scenarios such as energy storage power stations, hydropower / thermal / wind power generation systems, solar power generation systems, mobile power systems, smart home systems or temporary power supply systems, and is also used in data centers, military equipment, aerospace, charging piles, electric vehicles and other fields.

[0062] Optionally, the energy storage device 300 may include, but is not limited to, a single cell 200, or a battery integrated system such as a battery module, battery pack, battery cluster, mobile power supply, energy storage cabinet / container, etc. comprised of single cells 200. The actual application form of the energy storage device 300 provided in the embodiments of this application may include, but is not limited to, the products listed above, and may also include other application forms. This embodiment of this application does not impose strict restrictions on the application form of the energy storage device 300. This embodiment of this application only uses the energy storage device 300 as a multi-core battery 200 as an example for description.

[0063] Optionally, when the energy storage device 300 is a single battery 200, the energy storage device 300 may be, but is not limited to, at least one of a cylindrical battery, a square battery, a prismatic battery, or batteries of other shapes.

[0064] Optionally, the battery 200 may be a secondary battery. A secondary battery is a battery cell that can be recharged to activate the active material after discharge and continue to be used. The battery cell may be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, or the like, and the embodiments of this application do not specifically limit this.

[0065] See also Figure 2 , Figure 2 It is a structural diagram of a battery 200 provided in an embodiment of the present application.

[0066] The battery 200 may include a top cap assembly 100, a housing 210, and an electrode assembly 220. The top cap assembly 100 is connected to the housing 210 and forms a housing space with the housing 210. The electrode assembly 220 is located within the housing space. For example, the top cap assembly 100 may be welded to the housing 210. The housing 210 may be made of a metal material, such as an aluminum alloy. The battery 200 may be a cylindrical battery or a prismatic battery.

[0067] The electrode assembly 220 may include at least two electrode cores (not shown). The at least two electrode cores are arranged in sequence along the thickness direction of the battery 200. The provision of multiple electrode cores can increase the capacity of the battery 200, thereby allowing the battery 200 to be used for a long time, thereby increasing the applicable scenarios of the battery 200. Each electrode core may include a winding core, a first electrode tab, and a second electrode tab. The first electrode tab and the second electrode tab are both connected to the winding core. The polarity of the first electrode tab and the second electrode tab are opposite, one is a positive electrode tab and the other is a negative electrode tab.

[0068] It should be noted that Figure 2The purpose is only to schematically describe the connection relationship between the top cover assembly 100, the housing 210 and the electrode assembly 220, and it does not specifically limit the connection position, specific structure and quantity of each component. The structure shown in the embodiment of the present application does not constitute a specific limitation on the battery 200. In other embodiments of the present application, the battery 200 may include Figure 2 More or fewer components may be shown, or some components may be combined or separated, or the components may be arranged differently. Figure 2 The components shown can be implemented in hardware, software, or a combination of software and hardware.

[0069] Please refer to Figure 3 and Figure 4 , Figure 3 is a structural diagram of a top cover assembly 100 provided in an embodiment of the present application. Figure 4 yes Figure 3 The exploded structural diagram of the top cover assembly 100 is shown.

[0070] In an embodiment of the present application, the top cover assembly 100 may include a top cover 10, a first upper plastic 21, a second upper plastic 22, a lower plastic 30, a first pole 41, a second pole 42, a first sealing ring 51, a second sealing ring 52, a first pressure block 61, a second pressure block 62 and an explosion-proof valve assembly 70.

[0071] The first upper plastic part 21, the second upper plastic part 22, and the lower plastic part 30 are all mounted on the top cover 10. The first and second upper plastic parts 21 and 22 are located on the same side of the top cover 10, and are also located on opposite sides of the top cover 10 in the longitudinal direction (the X direction in the figure). The lower plastic part 30 is located on the other side of the top cover 10 away from the first and second upper plastic parts 21 and 22. The lower plastic part 30 and the first upper plastic part 21, as well as the lower plastic part 30 and the second upper plastic part 22, are each protruded from two opposing surfaces of the top cover 10 in the thickness direction.

[0072] The first electrode 41 is mounted on the top cover 10, the first upper plastic 21, and the lower plastic 30, and is insulated from the top cover 10 by the first upper plastic 21, the lower plastic 30, and the first sealing ring 51. The second electrode 42 is mounted on the top cover 10, the second upper plastic 22, and the lower plastic 30, and is insulated from the top cover 10 by the second upper plastic 22, the second sealing ring 52, and the lower plastic 30. The first electrode 41 and the second electrode 42 can also be used as electrode leads of the battery 200 to achieve electrical connection between the battery 200 and external devices. The first electrode 41 can be one of the positive electrode and the negative electrode, and the second electrode 42 can be the other of the positive electrode and the negative electrode. The structure of the electrode will be described below using the first electrode 41 as a negative electrode and the second electrode 42 as a positive electrode as an example, but it should be understood that this is not a limitation.

[0073] The first sealing ring 51 is mounted on the outside of the first electrode 41 and is located between the lower plastic 30 and the first electrode 41, as well as between the top cover 10 and the first electrode 41. The first sealing ring 51 can be used to seal the gap between the top cover 10 and the first electrode 41, preventing electrolyte from invading this gap and reducing the insulation between the top cover 10 and the first electrode 41 and the safety of the electrode assembly 220. The second sealing ring 52 is mounted on the outside of the second electrode 42 and is located between the lower plastic 30 and the second electrode 42, as well as between the top cover 10 and the second electrode 42. The second sealing ring 52 can be used to seal the gap between the top cover 10 and the second electrode 42, preventing electrolyte from invading this gap and reducing the insulation between the top cover 10 and the second electrode 42 and the safety of the battery cell.

[0074] The first pressing block 61 is mounted on the first upper plastic 21 and sleeved around the outside of the first pole 41 and electrically connected to the first pole 41. The second pressing block 62 is mounted on the second upper plastic 22 and sleeved around the outside of the second pole 42 and electrically connected to the second pole 42.

[0075] The explosion-proof valve assembly 70 is mounted on the top cover 10 and is used to protect the battery 200 from pressure relief.

[0076] The following will describe in detail the structure of each component in the top cover assembly 100 and the assembly relationship between the components with reference to the accompanying drawings.

[0077] See also Figure 5 , Figure 5 yes Figure 3 The structure diagram of the top cover 10 of the top cover assembly 100 is shown.

[0078] The top cover 10 may include a first surface 101 and a second surface 102. The second surface 102 and the first surface 101 are disposed opposite to each other in the thickness direction (Z direction in the figure) of the top cover 10. The first surface 101 may face away from the electrode assembly 220, and the second surface 102 may face toward the electrode assembly 220.

[0079] The top cover 10 may be provided with a first hole 11 and a second hole 12. The first hole 11 and the second hole 12 may be spaced apart in the length direction of the top cover 10. The first hole 11 and the second hole 12 may both penetrate the top cover 10 along the thickness direction of the top cover 10. That is, the first hole 11 and the second hole 12 may both penetrate the first surface 101 and the second surface 102.

[0080] The top cover 10 may be provided with a first receiving groove 13 and a second receiving groove 14. The first receiving groove 13 and the second receiving groove 14 may be spaced apart in the longitudinal direction of the top cover 10. The opening of the first receiving groove 13 and the opening of the second receiving groove 14 may both be located on the first surface 101. The first receiving groove 13 may be recessed from the first surface 101 toward the interior of the top cover 10 and communicate with the first hole 11. The length of the first receiving groove 13 along the longitudinal direction of the top cover 10 may be greater than the length of the first hole 11 along the longitudinal direction of the top cover 10. The length of the first receiving groove 13 along the width direction of the top cover 10 may be greater than the length of the first hole 11 along the width direction of the top cover 10. The second receiving groove 14 may be recessed from the first surface 101 toward the interior of the top cover 10 and communicate with the second hole 12. The length of the second receiving groove 14 along the longitudinal direction of the top cover 10 may be greater than the length of the second hole 12 along the longitudinal direction of the top cover 10. The length of the second receiving groove 14 along the width direction of the top cover 10 may be greater than the length of the second hole 12 along the width direction of the top cover 10.

[0081] The first receiving groove 13 and the second receiving groove 14 can both be blind grooves. The area of ​​the area enclosed by the first receiving groove 13 on the top cover 10 is larger than the area of ​​the area enclosed by the second receiving groove 14 on the top cover 10. For example, Figure 5 As shown, the dimension of the first receiving groove 13 along the length direction of the top cover 10 may be greater than the dimension of the second receiving groove 14 along the length direction of the top cover 10, and the dimension of the first receiving groove 13 along the width direction of the top cover 10 may be equal to the dimension of the second receiving groove 14 along the width direction of the top cover 10. Alternatively, the dimension of the first receiving groove 13 along the length direction of the top cover 10 may be equal to the dimension of the second receiving groove 14 along the length direction of the top cover 10, and the dimension of the first receiving groove 13 along the width direction of the top cover 10 may be greater than the dimension of the second receiving groove 14 along the width direction of the top cover 10.

[0082] Please refer to Figure 4 and Figure 5 The explosion-proof valve assembly 70 may include an explosion-proof valve 71 and an explosion-proof valve protection sheet 72. The explosion-proof valve 71 and the explosion-proof valve protection sheet 72 may both be mounted on the top cover 10 and arranged sequentially in the thickness direction of the top cover 10. The explosion-proof valve protection sheet 72 may also cover the explosion-proof valve 71.

[0083] The lower plastic member 30 is mounted on one side of the second surface 102 of the top cover 10. The lower plastic member 30 may be provided with a first through-hole 31 and a second through-hole 32. The first through-hole 31 and the second through-hole 32 may be spaced apart along the length of the lower plastic member 30 (the X direction in the figure). Both the first through-hole 31 and the second through-hole 32 may extend through the top cover 10 along the thickness of the lower plastic member 30. The first through-hole 31 may be coaxially disposed with and connected to the first hole 11 of the top cover 10. The second through-hole 32 may be coaxially disposed with and connected to the second hole 12 of the top cover 10.

[0084] Please continue reading Figure 4 and Figure 5 The first upper plastic 21 can be installed in the first receiving groove 13 of the top cover 10. The shape of the first upper plastic 21 can be adapted to the shape of the first receiving groove 13 of the top cover 10, so as to better achieve the relative fixation of the first upper plastic 21 and the top cover 10.

[0085] The first upper plastic portion 21 may be provided with a first through-hole 211. The first through-hole 211 may extend through the first upper plastic portion 21 along its thickness (Z-direction in the figure). The first through-hole 211 may be coaxially arranged with and communicate with the first hole 11 of the top cover 10. The first upper plastic portion 21 may be provided with a first groove 212. The first groove 212 may be formed recessed from the surface of the first upper plastic portion 21 facing away from the top cover 10 toward the interior of the first upper plastic portion 21. The first groove 212 may communicate with the first through-hole 211.

[0086] The second upper plastic 22 can be installed in the second receiving groove 14 of the top cover 10. The shape of the second upper plastic 22 can be adapted to the shape of the second receiving groove 14 of the top cover 10, so as to better achieve relative fixation between the second upper plastic 22 and the top cover 10.

[0087] The second upper plastic portion 22 may be provided with a second through-hole 221. The second through-hole 221 may extend through the second upper plastic portion 22 along its thickness direction (Z direction in the figure). The second through-hole 221 may be coaxially arranged with and communicate with the second hole 12 of the top cover 10. The second upper plastic portion 22 may be provided with a second groove 222. The second groove 222 may be formed from the surface of the second upper plastic portion 22 facing away from the top cover 10 and recessed into the interior of the second upper plastic portion 22. The second groove 222 may communicate with the second through-hole 221.

[0088] Please refer to Figure 6 and Figure 7 , Figure 6 It is along Figure 3 The cross-sectional view of a portion of the structure of the top cover assembly 100 obtained by cutting along the cutting line AA is shown. Figure 7 yes Figure 3 FIG. 1 is a schematic structural diagram of the first pressing block 61 of the top cover assembly 100 .

[0089] The first pressing block 61 can be located on one side of the first surface 101 of the top cover 10 and mounted in the first receiving groove 13 of the first upper plastic 21. The first pressing block 61 can be sleeved over the first terminal 41 and connected to the first terminal 41. The first pressing block 61 and the first terminal 41 can be connected by riveting to form an integrated structure. Furthermore, after the first pressing block 61 and the first terminal 41 are riveted together, the first pressing block 61 and the first terminal 41 can be welded together.

[0090] It is understood that by riveting the first clamp 61 to the first terminal 41, when external tension is generated on the surface of the first terminal 41 during use of the top cover assembly 100, the riveted location can bear and prevent the tension, reducing the risk of tension at the welding location of the first terminal 41. Riveting the first clamp 61 to the first terminal 41 before welding can improve current carrying capacity and efficiency, avoid the problem of a certain assembly gap caused by the riveting of the first clamp 61 and the first terminal 41, and play a role in preventing movement and improving sealing.

[0091] The first pressing block 61 may include a first connecting portion 611 and a second connecting portion 612 connected to each other. The first connecting portion 611 may be connected to the first pole 41, and the material of the first connecting portion 611 and the material of the first pole 41 may both include the first metal. The second connecting portion 612 may be used to connect to the bar, so that the first pole 41 can achieve electrode lead-out through the first pressing block 61. The material of the second connecting portion 612 and the material of the bar may both include the second metal. The second metal may be different from the first metal. The welding melting point of the second metal may be different from the welding melting point of the first metal. The color of the first metal may be different from the color of the second metal. For example, the material of the first metal may be copper, and the material of the second metal may be aluminum. The melting point of the first metal may be 1083°C, and the melting point of the second metal may be 660°C.

[0092] It is understandable that since the first pressure block 61 needs to be connected between the first pole 41 and the bar, it plays the role of electrically connecting the first pole 41 and the bar, and the first pole 41 and the bar are usually made of different materials. In this way, by making the first connecting portion 611 and the first pole 41 connected together be made of the same metal material, the connection effect between the first connecting portion 611 and the first pole 41 can be improved, thereby improving the connection quality between the first pressure block 61 and the first pole 41, and ensuring the overcurrent performance between the first pressure block 61 and the first pole 41. By making the second connecting portion 612 and the bar be made of the same metal material, the connection effect between the second connecting portion 612 and the bar can be improved, thereby improving the connection quality between the first pressure block 61 and the bar, and improving the overcurrent effect of the current path of "first pole 41-first pressure block 61-bar", with better reliability.

[0093] Please refer to Figure 7 and Figure 8 , Figure 8 It is along Figure 7 The cross-sectional structure diagram of the first pressing block 61 obtained by cutting along the cutting line BB is shown.

[0094] The first connecting portion 611 can be embedded in the second connecting portion 612. Specifically, the second connecting portion 612 can be provided with a mounting groove 613. The opening of the mounting groove 613 can be oriented toward the surface of the first pressing block 61 facing away from the top cover 10. The mounting groove 613 can be formed by being recessed from the surface of the first pressing block 61 facing away from the top cover 10 toward the interior of the first pressing block 61. The first connecting portion 611 can be embedded in the mounting groove 613.

[0095] It can be understood that since the material of the first connecting part 611 is different from the material of the second connecting part 612, by providing an installation groove 613 in the second connecting part 612, the first connecting part 611 can be conveniently embedded in the second connecting part 612, so that the first pressing block 61 can conveniently realize the composite connection of two different materials.

[0096] The structure of the first pressing block 61 will be described in detail below through two specific implementations.

[0097] In one possible implementation, Figure 7 and Figure 8 As shown, the mounting groove 613 can be a blind groove. That is, the depth of the mounting groove 613 can be less than the thickness of the first pressing block 61. In the thickness direction of the top cover 10, the projection of the first connecting portion 611 on the top cover 10 partially overlaps with the projection of the second connecting portion 612 on the top cover 10.

[0098] It can be understood that by making the orthographic projection of the first connecting part 611 on the top cover 10 partially overlap with the orthographic projection of the second connecting part 612 on the top cover 10, it can be ensured that the first connecting part 611 and the second connecting part 612 have a certain overlapping area in the thickness direction of the top cover 10, which is beneficial to improving the connection strength of the first connecting part 611 and the second connecting part 612, and ensuring the connection reliability and assembly stability of each structure in the first pressure block 61.

[0099] Please refer to Figure 8 、 Figure 9 and Figure 10 , Figure 9 It is along Figure 7 The cross-sectional structure diagram of the first pressing block 61 obtained by cutting along the cutting line CC is shown in FIG. Figure 10 yes Figure 9 An enlarged schematic diagram of region Q is shown.

[0100] In this embodiment, the first connecting portion 611 may include a third sub-portion 6111 and a fourth sub-portion 6112. The fourth sub-portion 6112 is connected to the third sub-portion 6111 on both sides along the width direction (Y direction in the figure) of the first pressing block 61. The second connecting portion 612 may include a first sub-portion 6121 and a second sub-portion 6122. The first sub-portion 6121 may be provided with the mounting groove 613 described above. The second sub-portion 6122 is connected to the first sub-portion 6121 on both sides along the length direction (X direction in the figure) of the first pressing block 61. The third sub-portion 6111 may be located within the mounting groove 613 of the first sub-portion 6121. The third sub-portion 6111 abuts against the second sub-portion 6122 on both sides along the length direction of the first pressing block 61. The fourth sub-portion 6112 is connected to one of the second sub-portions 6122 in the thickness direction of the first pressing block 61.

[0101] It can be understood that by ensuring that the first connection part 611 and the second connection part 612 have a certain overlapping area in the thickness direction of the first pressure block 61, the connection strength between the first connection part 611 and the second connection part 612 can be better guaranteed, and the connection reliability and assembly stability of each structure in the first pressure block 61 can be guaranteed.

[0102] In this embodiment, the first connection portion 611 may be provided with a first connection hole 6113. The first connection hole 6113 may penetrate the first connection portion 611 along the thickness direction of the first pressing block 61 and allow the first pole 41 to pass through.

[0103] The second connection portion 612 may be provided with a second connection hole 6123. The second connection hole 6123 may extend through the second connection portion 612 along the thickness direction of the first pressing block 61. The second connection hole 6123 may be coaxially arranged with and communicate with the first connection hole 6113. In other words, the second connection hole 6123 and the first connection hole 6113 may together form a hole structure in the first pressing block 61 through which the first terminal 41 can pass.

[0104] In this implementation, please refer to Figure 11 , Figure 11 yes Figure 3 The schematic structural diagram of the top cover assembly 100 from another angle is shown. The dimension D1 of the first connecting portion 611 along the width direction of the top cover 10 can be the same as the dimension D2 of the second connecting portion 612 along the width direction of the top cover 10. Alternatively, the dimension D1 of the first connecting portion 611 along the width direction of the top cover 10 can be different from the dimension D2 of the second connecting portion 612 along the width direction of the top cover 10.

[0105] For example, the dimension D1 of the first connection portion 611 along the width direction of the top cover 10 can be less than or equal to the dimension D2 of the second connection portion 612 along the width direction of the top cover 10. In this way, it can not only play a positioning role when the first terminal 41 is welded to the first pressing block 61, but also play a positioning role when the first pressing block 61 is welded to the tab, thereby achieving a dual positioning effect.

[0106] In another possible embodiment, the details common to the previous embodiment are omitted. Unlike the previous embodiment, the mounting groove 613 may be a through groove. That is, the depth of the mounting groove 613 may be equal to the thickness of the first pressing block 61. In the thickness direction of the top cover 10, the projection of the first connecting portion 611 on the top cover 10 is adjacent to the projection of the second connecting portion 612 on the top cover 10.

[0107] In this embodiment, the first connection portion 611 is provided with a first connection hole 6113. The second connection portion 612 is not provided with a second connection hole 6123. That is, the first connection hole 6113 alone constitutes a hole structure in the first pressing block 61 through which the first pole 41 can pass.

[0108] Please refer to Figure 3 and Figure 5 In an embodiment of the present application, the second pressing block 62 can be located on one side of the first surface 101 of the top cover 10 and installed in the second receiving groove 14 of the second upper plastic 22. The second pressing block 62 can be sleeved on the second pole 42 and connected to the second pole 42. The material of the second pressing block 62 can be the same as the material of the second pole 42. The second pressing block 62 and the second pole 42 can be connected by riveting to form an integrated structure. Furthermore, after the second pressing block 62 and the second pole 42 are riveted together, the second pressing block 62 and the second pole 42 can be welded.

[0109] The second pressing block 62 may be provided with a third connection hole 621. The third connection hole 621 may penetrate the second pressing block 62 along the thickness direction of the second pressing block 62 and allow the second pole 42 to pass through.

[0110] In the embodiment of the present application, in the thickness direction of the top cover 10 , the projected area of ​​the first pressing block 61 on the top cover 10 is larger than the projected area of ​​the second pressing block 62 on the top cover 10 .

[0111] It is understandable that in the prior art, the first pole and the first compression block are typically connected together by welding. However, the material of the first pole and the first compression block are typically different, and the welding melting points of the first pole and the first compression block made of different materials are different. This means that although the first pole and the first compression block can form a good physical connection through welding, due to the non-interference fit between the metal and the metal, it is difficult to form a good fixed connection before welding. This can lead to incorrect fixing between the two before welding, causing welding problems and affecting the current capacity of the battery cell.

[0112] In view of this, in the embodiment of the present application, the first pressing block 61 is formed by combining a first connecting portion 611 and a second connecting portion 612 made of different metal materials, and the first connecting portion 611 and the first pole 41 are made of the same metal material. This not only enables the first connecting portion 611 to achieve a better connection with the first pole 41 (e.g., by welding) due to being made of the same metal material, but also enables the second connecting portion 612 to achieve a better connection with the tab (e.g., by welding) in the subsequent process, due to being made of the same metal material, thereby improving the overall current carrying capacity of the first pole 41.

[0113] In addition, since the second connection portion 612, the second pressure block 62, and the second pole 42 are all made of the same metal material, the first pressure block 61 has two different flow areas, namely the first connection portion 611 and the second connection portion 612, while the second pressure block 62 has only one flow area. Furthermore, in the thickness direction of the top cover 10, the projected area of ​​the first pressure block 61 on the top cover 10 is larger than the projected area of ​​the second pressure block 62 on the top cover 10. This ensures that the flow area of ​​the second connection portion 612 in the first pressure block 61 is roughly equivalent to the flow area of ​​the second pressure block 62 as a whole, so that the first connection portion 611 and the second pressure block 62 of the first pressure block 61, which are made of the same metal material, can approach the same flow area, thereby ensuring that the first pole 41 and the second pole 42 as a whole have roughly equivalent flow effects, improving the flow capacity of both, and thus improving the flow capacity of the battery cell.

[0114] Furthermore, in the thickness direction of the top cover 10, the difference between the projected area of ​​the second connection portion 612 on the top cover 10 and the projected area of ​​the second pressing block 62 on the top cover 10 can be 0 mm. 2 -5mm 2 Within the area range (including the endpoint value 0mm 2 and 5mm 2 ).

[0115] It is understood that because different metal materials have different melting points, the best welding effect is achieved when components made of the same metal are welded together. By making the projected area of ​​the second connecting portion 612 on the top cover 10 along the thickness direction of the top cover 10 approximately equal to the projected area of ​​the second pressing block 62 on the top cover 10 along the thickness direction of the top cover 10 (for example, the projected areas of the two can be the same or the difference between the projected areas can be small), the second connecting portion 612 and the second pressing block 62, made of the same metal material, can have equivalent flow areas. This, in turn, ensures that the first and second poles 41, 42 have the same flow effect, thereby ensuring the overall flow performance of the top cover assembly 100.

[0116] The structural possibilities of the first pressing block 61 and the second pressing block 62 will be described below through two different embodiments.

[0117] In one possible implementation, Figure 11 As shown, the placement direction of the first pressing block 61 and the placement direction of the second pressing block 62 can be the same, and both are placed along the length direction of the top cover 10 (X direction in the figure).

[0118] Specifically, in the first pressing block 61, at least part of the second connecting portion 612 is located on both sides of the first connecting portion 611 along the length of the top cover 10. The dimension of the first pressing block 61 along the length of the top cover 10 is a first dimension L1, and the dimension of the second pressing block 62 along the length of the top cover 10 is a second dimension L2. The first dimension L1 is greater than the second dimension L2.

[0119] It is understandable that, since the first metal and the second metal have different melting points, welding the first metal to the first metal and the second metal to the second metal is the most preferred solution. The battery 200 is assembled into groups by connecting the bars, and the material of the bars is the second metal. Therefore, in order to ensure the same flow effect on the first pole 41 and the second pole 42, it is necessary to ensure that the area connected to the bars has the same flow area, so the area of ​​the second connection portion 612 of the first pressure block 61 must be equal to the area of ​​the second pressure block 62. Because the first connection portion 611 of the first pressure block 61 itself occupies a certain area, the first dimension L1 of the first pressure block 61 is larger than the second dimension L2 of the second pressure block 62.

[0120] In addition, because the first dimension L1 of the first pressing block 61 is generally larger than the second dimension L2 of the second pressing block 62, foolproof identification of the tab can be achieved during welding with the first and second poles 41 and 42. Furthermore, during the welding process of the first pole 41 itself, the first connecting portion 611 of the first pressing block 61 can provide positive positioning for the tab welding, ensuring that the intersection line of the first connecting portion 611 and the second connecting portion 612 is parallel to the width direction of the top cover 10 during the tab welding, preventing the tab from being skewed or other structural problems from occurring during welding, and providing good alignment performance.

[0121] In this embodiment, the first dimension L1, the second dimension L2, and the dimension T1 of the first connecting portion 611 along the length direction of the top cover 10 may satisfy the relationship:

[0122] 0<(L1-L2)≤T1.

[0123] It is understandable that because the first pressing block 61 has two distinct regions, the first connecting portion 611 and the second connecting portion 612, the first pressing block 61 must be welded to the tab away from the region where the first connecting portion 611 is located. By ensuring that the length difference between the first pressing block 61 and the second pressing block 62 satisfies the aforementioned relationship, sufficient welding area is ensured for the first pressing block 61 when welding to the tab, and the first electrode 41 can have better current flow performance and reliability during welding.

[0124] In this embodiment, the first connecting portion 611 and the second connecting portion 612 can be connected to form an intersection line F1. The intersection line F1 is arranged parallel to the width direction of the top cover (the Y direction in the figure). This arrangement can better ensure that the first pressing block 61 will not be skewed or misaligned during assembly, which helps to ensure the positioning accuracy of the first pressing block 61.

[0125] In another possible implementation manner, the same contents as the previous implementation manner will not be repeated, and the differences will be explained below.

[0126] See also Figure 12 , Figure 12 This is another structural schematic diagram of the top cover assembly 100 provided in an embodiment of the present application.

[0127] In this embodiment, the first pressing block 61 and the second pressing block 62 can be arranged in the same orientation and are both arranged along the width direction (Y direction in the figure) of the top cover 10. Specifically, in the first pressing block 61, at least a portion of the second connecting portion 612 is located on both sides of the first connecting portion 611 along the width direction of the top cover 10. The dimension of the first pressing block 61 along the width direction of the top cover 10 is a third dimension L3, and the dimension of the second pressing block 62 along the width direction of the top cover 10 is a fourth dimension L4, where the third dimension L3 is greater than the fourth dimension L4.

[0128] It is understandable that, due to the different melting points of the first metal and the second metal, welding the first metal to the first metal and the second metal to the second metal is the most preferred solution. The battery 200 is assembled into groups by connecting the bars, which are made of the second metal. Therefore, in order to ensure the same flow rate effect on the first pole 41 and the second pole 42, it is necessary to ensure that the area connected to the bars has the same flow rate area. Therefore, the area of ​​the second connection portion 612 of the first pressure block 61 must be equal to the area of ​​the second pressure block 62. Because the first connection portion 611 of the first pressure block 61 itself occupies a certain area, the third dimension L3 of the first pressure block 61 is larger than the fourth dimension L4 of the second pressure block 62.

[0129] In addition, because the third dimension L3 of the first pressing block 61 is generally larger than the fourth dimension L4 of the second pressing block 62, foolproof identification of the tab can be achieved during welding with the first and second poles 41 and 42. Furthermore, during the welding process of the first pole 41 itself, the first connecting portion 611 of the first pressing block 61 can provide positive positioning for the tab welding, ensuring that the intersection line of the first connecting portion 611 and the second connecting portion 612 is parallel to the length direction of the top cover 10 during the tab welding, preventing the tab from being skewed or other structural problems from occurring during welding, and providing good alignment performance.

[0130] In this embodiment, the third dimension L3, the fourth dimension L4, and the dimension T2 of the first connecting portion 611 along the width direction of the top cover 10 satisfy the relationship:

[0131] 0<(L3-L4)≤T2.

[0132] It is understandable that because the first pressing block 61 has two distinct regions, the first connecting portion 611 and the second connecting portion 612, the first pressing block 61 must be welded to the tab away from the region where the first connecting portion 611 is located. By ensuring that the length difference between the first pressing block 61 and the second pressing block 62 satisfies the aforementioned relationship, sufficient welding area is ensured for the first pressing block 61 when welding to the tab, and the first electrode 41 can have better current flow performance and reliability during welding.

[0133] In this embodiment, the dimension D3 of the first connecting portion 611 along the length direction of the top cover 10 may be the same as the dimension D4 of the second connecting portion 612 along the length direction of the top cover 10. Alternatively, the dimension D3 of the first connecting portion 611 along the length direction of the top cover 10 may be different from the dimension D4 of the second connecting portion 612 along the length direction of the top cover 10.

[0134] For example, the dimension D3 of the first connecting portion 611 along the length of the top cover 10 can be less than or equal to the dimension D4 of the second connecting portion 612 along the length of the top cover 10. This allows for positioning not only when the first terminal 41 is welded to the first pressing block 61, but also when the first pressing block 61 is welded to the tab, thereby achieving dual positioning.

[0135] In this embodiment, the first connecting portion 611 and the second connecting portion 612 can be connected to form an intersection line F2. The intersection line F2 is arranged parallel to the length direction of the top cover (the X direction in the figure). This arrangement can better prevent the first pressing block 61 from tilting or misalignment during assembly, thereby ensuring the accurate positioning of the first pressing block 61.

[0136] Please refer to Figure 4 and Figure 6 The first terminal 41 can be disposed through the lower plastic 30, the top cover 10, the first upper plastic 21, and the first pressing block 61. Specifically, a portion of the first terminal 41 can be located in the first through-hole 31 of the lower plastic 30, the first hole 11 of the top cover 10, the first through-hole 211 of the first upper plastic 21, and the first connection hole 6113 and the second connection hole 6123 of the first pressing block 61. The remaining portion of the first terminal 41 can be disposed protruding from the surface of the lower plastic 30 facing away from the top cover 10.

[0137] The second pole 42 can be inserted through the lower plastic 30, the top cover 10, the second upper plastic 22, and the second pressing block 62. Specifically, a portion of the second pole 42 can be located in the second through-hole 32 of the lower plastic 30, the second hole 12 of the top cover 10, the second through-hole 221 of the second upper plastic 22, and the third connection hole 621 of the second pressing block 62. The remaining portion of the second pole 42 can protrude from the surface of the lower plastic 30 facing away from the top cover 10.

[0138] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, according to the idea of ​​the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A top cover assembly, characterized in that: The top cover assembly includes a top cover, a first pole, a second pole, a first pressing block and a second pressing block; The first pole and the second pole are both provided through the top cover and spaced apart along the length direction of the top cover. The first pressing block and the second pressing block are both located on the same side of the thickness direction of the top cover. The first pressing block is sleeved on the first pole and connected to the first pole. The second pressing block is sleeved on the second pole and connected to the second pole. The first pressing block includes a first connecting portion and a second connecting portion connected to each other, at least part of the second connecting portion is located on both sides of the first connecting portion along the length direction of the top cover, the first connecting portion is connected to the first pole, the material of the first connecting portion and the material of the first pole both include a first metal, and the material of the second connecting portion, the second pressing block, and the material of the second pole all include a second metal, and the second metal is different from the first metal; In the thickness direction of the top cover, the projected area of ​​the first pressing block on the top cover is larger than the projected area of ​​the second pressing block on the top cover; The dimension of the first pressing block along the length direction of the top cover is a first dimension L1, and the dimension of the second pressing block along the length direction of the top cover is a second dimension L2. The first dimension L1 is greater than the second dimension L2.

2. The top cover assembly according to claim 1, wherein: In the thickness direction of the top cover, the difference between the projected area of ​​the second connecting portion on the top cover and the projected area of ​​the second pressing block on the top cover is within 0 mm. 2 -5mm 2 within the area.

3. The top cover assembly according to claim 1, wherein: A dimension of the first connecting portion along a width direction of the top cover is smaller than or equal to a dimension of the second connecting portion along the width direction of the top cover.

4. The top cover assembly according to any one of claims 1 to 3, wherein: The first connecting portion and the second connecting portion are connected to form an intersection line, and the intersection line is arranged parallel to the width direction of the top cover.

5. The top cover assembly according to any one of claims 1 to 3, characterized in that: In the thickness direction of the top cover, a projection of the first connecting portion on the top cover partially overlaps with a projection of the second connecting portion on the top cover.

6. The top cover assembly according to claim 5, wherein: The second connecting portion is provided with a mounting groove, the opening of the mounting groove faces the surface of the first pressing block away from the top cover, and the first connecting portion is embedded in the mounting groove.

7. The top cover assembly according to claim 6, wherein: The second connecting portion includes a first sub-portion and a second sub-portion, the first sub-portion is provided with the mounting groove, and the second sub-portion is connected to the first sub-portion on both sides along the length direction of the first pressing block; The first connecting portion includes a third sub-portion and a fourth sub-portion, the third sub-portion is located in the mounting groove, the third sub-portion is abutted against the second sub-portion on both sides along the length direction of the first pressing block, the fourth sub-portion is connected to the third sub-portion on both sides along the width direction of the first pressing block, and the fourth sub-portion is connected to the second sub-portion in the thickness direction of the first pressing block.

8. A battery, characterized in that: The battery includes an electrode assembly, a shell and a top cover assembly according to any one of claims 1 to 7, wherein the top cover assembly is connected to the shell and is formed together with the shell to form a receiving space, and the electrode assembly is located in the receiving space.

9. An energy storage device, characterized in that: The energy storage device comprises the battery as claimed in claim 8.

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