Energy storage device and power utilization system

Abstract

The invention relates to an energy storage device and a power utilization system. The energy storage device comprises a shell, an electrode assembly, an end cover assembly and a binding piece, wherein the shell is provided with an accommodating cavity; the electrode assembly is arranged in the accommodating cavity, the electrode assembly comprises a plurality of tabs and an electrode main body which are electrically connected, and the tabs and the electrode main body are arranged along a first direction; the end cover assembly is arranged on one side of the shell and used for sealing the containing cavity. The binding piece is positioned between the end cover assembly and the electrode main body; the binding piece is provided with a penetrating hole, and the penetrating hole penetrates through the two opposite surfaces of the binding piece in the first direction. The penetrating hole extends along a second direction, the plurality of tabs penetrate through the penetrating hole, and the first direction is intersected with the second direction; the penetrating hole is provided with a first side wall and a second side wall which are oppositely arranged in the second direction, and in the second direction, the distance between the first side wall and the second side wall is larger than the size of the ends, close to the electrode body, of the tabs.

Description

Technical Field

[0001] This application relates to the field of energy storage equipment technology, specifically to an energy storage device and power system. Background Technology

[0002] A rechargeable battery, also known as a secondary battery or accumulator, is a battery that can be recharged after discharge to reactivate its active materials and continue to be used. As the capacity requirements for rechargeable batteries have increased, the length of the battery cells has become increasingly longer. The longer the cell, the more prone it is to movement within the casing, leading to poorer structural stability of the battery. Summary of the Invention

[0003] In view of this, this application provides an energy storage device and an electrical system, wherein the energy storage device can avoid bending and deformation of the electrode tabs and has stable electrical performance.

[0004] This application provides an energy storage device, comprising: a housing, an electrode assembly, an end cap assembly, and a restraining member. The housing has a receiving cavity; the electrode assembly is disposed within the receiving cavity, and the electrode assembly includes multiple electrically connected tabs and electrode bodies, the multiple tabs and the electrode bodies being arranged along a first direction; the end cap assembly is disposed on one side of the housing for sealing the receiving cavity; the restraining member is located between the end cap assembly and the electrode bodies; the restraining member has a through hole, the through hole penetrating two opposing surfaces of the restraining member along the first direction; the through hole extends along a second direction, and the multiple tabs pass through the through hole; the restraining member includes a surrounding portion and a restraining portion, the surrounding portion connecting to the outer periphery of the restraining portion, the restraining portion and the surrounding portion enclosing a receiving space facing the end cap assembly. The binding portion has the through hole, which penetrates two opposing surfaces of the binding portion along the first direction and communicates with the accommodating space. The binding member also includes a protrusion, which protrudes from the surface of the binding portion facing the accommodating space and surrounds the outer periphery of the through hole. The end face of the protrusion away from the binding portion is spaced apart from the end cap assembly. The protrusion provides an orderly bending point for the tab, so that the tab can be directionally bent within the accommodating space after passing through the through hole. The first direction intersects the second direction. The through hole has a first sidewall and a second sidewall disposed opposite each other along the second direction. Along the second direction, the distance between the first sidewall and the second sidewall is greater than the size of the ends of the plurality of tabs near the electrode body.

[0005] Furthermore, the plurality of tabs have a first end and a second end disposed opposite to each other, the first end being connected to the electrode body, and the second end being disposed away from the electrode body; the size of the plurality of tabs gradually decreases in the direction from the first end to the second end.

[0006] Furthermore, along the second direction, the distance between the first sidewall and the second sidewall is L1, and the maximum size of the plurality of tabs is L2. Then the energy storage device satisfies the relationship: 0.95≤L2 / L1≤0.99.

[0007] Furthermore, along the second direction, the minimum distance d1 between the first end and the first sidewall is in the range of 1mm≤d1≤10mm; and / or, along the second direction, the minimum distance d2 between the first end and the second sidewall is in the range of 1mm≤d2≤10mm.

[0008] Furthermore, along the third direction, the ratio γ of the width of the through hole to the total thickness of the plurality of tabs passing through the through hole is in the range of 2.1≤γ≤10, wherein the third direction intersects the first direction and the second direction respectively.

[0009] Furthermore, the restraint member includes a surrounding portion and a restraint portion. The surrounding portion connects to the outer periphery of the restraint portion, and the restraint portion and the surrounding portion enclose an accommodating space. The restraint portion has the through hole, which penetrates two opposing surfaces of the restraint portion along the first direction and communicates with the accommodating space. The end cap assembly includes a top cap, an electrode post, and an adapter. The top cap is connected to the housing, the electrode post is mounted on the top cap, and the adapter is located within the accommodating space. The adapter is electrically connected to the electrode post and the plurality of electrode tabs, respectively.

[0010] Furthermore, the restraint member also includes a protrusion, which protrudes from the surface of the restraint member facing the accommodating space and is disposed around the outer periphery of the through hole. The end face of the protrusion facing away from the restraint member is spaced apart from the top cover.

[0011] Furthermore, along the first direction, the end face of the circumferential portion facing away from the electrode body is positioned closer to the top cover than the end face of the protrusion facing away from the electrode body.

[0012] Furthermore, the number of through holes is multiple, the multiple through holes include a first group of through holes, the multiple electrode tabs include a first group of electrode tabs, the first group of electrode tabs is disposed on one side of the electrode body, and the first group of electrode tabs passes through the first group of through holes.

[0013] Furthermore, the plurality of through holes also includes a second set of through holes, the first set of through holes and the second set of through holes being arranged at intervals along the second direction; the plurality of electrode tabs also includes a second set of electrode tabs, the first set of electrode tabs and the second set of electrode tabs being disposed on the same side of the electrode body and electrically connected to the electrode body respectively, the first set of electrode tabs and the second set of electrode tabs being arranged at intervals along the second direction; the second set of electrode tabs passing through the second set of through holes.

[0014] Further, the first set of through holes includes a first through hole and a second through hole, which are spaced apart along a third direction; the first set of electrode tabs includes a first electrode tab and a second electrode tab, which are disposed on the same side of the electrode body along the third direction, the first electrode tab passes through the first through hole, and the second electrode tab passes through the second through hole, wherein the third direction intersects the first direction and the second direction respectively; the electrode post includes a first electrode post, and the adapter includes a first adapter, which includes a first connecting part, a first body part, and a second connecting part that are bent and connected in sequence, the first connecting part and the second connecting part being bent relative to the first body part toward the side away from the top cover, the first body part being electrically connected to the first electrode post, the first connecting part being electrically connected to the first electrode tab, and the second connecting part being electrically connected to the second electrode tab.

[0015] Further, the second set of through holes includes a third through hole and a fourth through hole, which are spaced apart along a third direction; the second set of electrode tabs includes a third electrode tab and a fourth electrode tab, which are disposed on the same side of the electrode body along the third direction, the third electrode tab is inserted through the third through hole, and the fourth electrode tab is inserted through the fourth through hole, wherein the third direction intersects the first direction and the second direction respectively; the electrode post includes a second electrode post, and the adapter includes a second adapter, which includes a third connecting part, a second body part, and a fourth connecting part that are bent and connected in sequence, the third connecting part and the fourth connecting part are bent relative to the second body part toward the side away from the top cover, the second body part is electrically connected to the second electrode post, the third connecting part is electrically connected to the third electrode tab, and the fourth connecting part is electrically connected to the fourth electrode tab.

[0016] Furthermore, the restraint member also includes a support portion disposed on the surface of the restraint portion opposite to the accommodating space, the support portion being used to abut against the electrode body.

[0017] Furthermore, there are multiple support portions, which are spaced apart along the second direction. The first set of through holes is located between two adjacent support portions, and the second set of through holes is located between two adjacent support portions.

[0018] Furthermore, along the second direction, if the size of the first set of electrodes is L3 and the size of the single-layer electrode in the first set of electrodes is L4, then the energy storage device satisfies the relationship: 0mm≤L3-L4≤1mm; or, along the second direction, if the size of the second set of electrodes is L5 and the size of the single-layer electrode in the second set of electrodes is L6, then the energy storage device satisfies the relationship: 0mm≤L5-L6≤1mm.

[0019] This application provides an electrical system comprising: electrical equipment and an energy storage device provided in this application, wherein the energy storage device is electrically connected to the electrical equipment and is used to supply power to the electrical equipment.

[0020] In this application, the tabs are softer than the electrode body. If directly inserted into the casing, the tabs may collapse and short-circuit upon contact with the casing. The beneficial effects of this application are: the restraining member is located between the end cap assembly and the electrode body, and the restraining member has through holes for inserting the multiple tabs and physically limiting their position. During the transportation, use, or assembly of the energy storage device, excessive bending or displacement of the tabs can be avoided, reducing malfunctions such as tab breakage and poor contact. Simultaneously, direct contact between the tabs and the casing can be prevented, thus avoiding internal short circuits in the energy storage device. Furthermore, the through hole has a first sidewall and a second sidewall arranged opposite each other along the second direction. The distance between the first sidewall and the second sidewall along the second direction is greater than the dimensions of the plurality of tabs. Therefore, on the one hand, when the plurality of tabs pass through the through hole along the first direction, the ample internal space of the through hole in the second direction prevents direct contact or friction between the opposite ends of the plurality of tabs and the first and second sidewalls along the second direction. This effectively avoids scratching the insulating layer or metal substrate on the tab surface, reducing the possibility of decreased conductivity due to mechanical damage, and ensuring stable electrical performance of the energy storage device. On the other hand, by setting the difference between the dimension of the through hole along the second direction and the dimension of the plurality of tabs along the second direction, the stringent requirements for the accuracy of the multi-layer tab arrangement during assembly can be reduced. Even if the plurality of tabs have slight positional offsets or misalignments before insertion, they can still be successfully assembled through the through hole without the need for repeated calibration and adjustment of the tabs. This design simplifies the assembly process of the tabs and the restraints, reduces the difficulty of assembling the multiple tabs with the restraints, and improves the assembly efficiency of the energy storage device. Furthermore, the restraints can fix the position of the tabs, ensuring good structural stability when the electrode assembly is placed in the receiving cavity, preventing the electrode assembly from wobbling relative to the housing, and thus providing the energy storage device with better structural stability. In addition, during the assembly of the energy storage device, the restraints can also connect with structural components within the energy storage device, such as air guide plates, to form a fixed frame structure. The air guide plates cooperate with the restraints to further fix the relative position of the electrode body and the tabs. During the process of pushing the long electrode assembly into the housing, deformation of the electrode body and the tabs can be avoided, ensuring the structural integrity and electrical connection stability of the electrode assembly, and improving the assembly performance of the energy storage device.

[0021] Furthermore, the restraining member includes a surrounding portion and a restraining portion. The surrounding portion connects to the outer periphery of the restraining portion, and the restraining portion and the surrounding portion enclose a receiving space. The receiving space provides sufficient accommodating space for the relatively long electrode tab, preventing the electrode tab from being disorderly stacked inside the housing after being electrically connected to the end cap assembly. Specifically, the protrusion is disposed on the surface of the restraining portion facing the receiving space and surrounds the outer periphery of the through hole. When the electrode tab passes through the through hole, on the one hand, the protrusion forms a three-dimensional structure along a first direction, which can provide support and guidance for the electrode tab along the first direction, preventing displacement or wrinkling due to insufficient rigidity of the electrode tab itself. At the same time, it guides the electrode tab to smoothly pass through the through hole along a preset path, ensuring the stability of the electrode tab passing through the through hole. On the other hand, the protrusion provides an orderly bending point for the tab, allowing it to bend directionally within the accommodating space after passing through the through hole. This design effectively constrains the bending trajectory of the tab, preventing disordered folding, twisting, or excessive compression within the space. This prevents micro-cracks and wire breakage in the internal metal conductor due to mechanical deformation, or increased current conduction path and contact resistance due to folding. Ultimately, this ensures the assembly accuracy of the tab and subsequent welding process of the adapter, improving the conductivity and structural reliability of the welded connection. Furthermore, the end face of the protrusion facing away from the restraint portion is spaced apart from the end cap assembly to ensure sufficient space for bending after the tab extends out of the through hole. This prevents the end cap assembly from squeezing the tab, reducing the risk of damage to the metal substrate, decreased conductivity, or breakage caused by compression. This ensures the structural integrity and electrical performance stability of the tab, improving the electrical performance stability of the energy storage device. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the implementation will be briefly introduced below. Obviously, the drawings described below are some implementations of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of an energy storage system according to an embodiment of this application; Figure 2 This is a schematic diagram of the structure of an energy storage system according to another embodiment of this application; Figure 3 This is a schematic diagram of the structure of an energy storage system according to another embodiment of this application; Figure 4 This is a schematic diagram of the structure of an energy storage device according to an embodiment of this application; Figure 5This is an exploded structural diagram of an energy storage device according to an embodiment of this application; Figure 6 This is a top view of an energy storage device according to an embodiment of this application; Figure 7 for Figure 6 Schematic diagram of the cross-sectional structure along the AA direction; Figure 8 This is a partial exploded structural diagram of an energy storage device according to an embodiment of this application; Figure 9 This is a schematic diagram of the structure of an electrode assembly according to an embodiment of this application; Figure 10 for Figure 6 Another cross-sectional structural diagram along the AA direction; Figure 11 This is a schematic diagram of the structure of a restraint member according to an embodiment of this application; Figure 12 This is an exploded view of an end cap assembly according to an embodiment of this application; Figure 13 for Figure 6 Schematic diagram of the cross-sectional structure in the middle BB direction; Figure 14 This is a partial exploded structural diagram of an energy storage device according to another embodiment of this application; Figure 15 This is a schematic diagram of the structure of a restraint member according to another embodiment of this application; Figure 16 This is a schematic diagram of the structure of an electrical system according to an embodiment of this application; Figure 17 This is a circuit block diagram of an electrical system according to an embodiment of this application.

[0024] Explanation of reference numerals in the attached figures: 100 - Energy storage system; 110 - First power conversion device; 120 - First user load; 130 - Second user load; 150 - High-voltage cable; 160 - Second power conversion device; 170 - Photovoltaic-energy storage-charging station; 180 - Automobile; 200 - Energy storage device; 210 - Housing; 211 - Receptacle; 220 - Electrode assembly; 221 - Tab; 221a - First set of tabs; 221b - Second set of tabs; 221c - First tab 221d - Second electrode tab, 221e - Third electrode tab, 221f - Fourth electrode tab, 221g - First electrode tab assembly, 221h - Second electrode tab assembly, 2211 - First end, 2212 - Second end, 222 - Electrode body, 230 - End cap assembly, 230a - First end cap assembly, 230b - Second end cap assembly, 231 - Top cap, 232 - Electrode post, 232a - First electrode post, 232b - Second electrode post, 233 - Adapter, 2 33a - First adapter, 233b - Second adapter, 2331 - First connecting part, 2332 - First body part, 2333 - Second connecting part, 2334 - Third connecting part, 2335 - Second body part, 2336 - Fourth connecting part, 234 - Plastic part, 235 - Explosion-proof valve, 240 - Restraint part, 240a - First restraint part, 240b - Second restraint part, 241 - Through hole, 241a - First set of through holes, 241 b - Second group of through holes, 241c - First through hole, 241d - Second through hole, 241e - Third through hole, 241f - Fourth through hole, 2411 - First side wall, 2412 - Second side wall, 242 - Surrounding part, 243 - Binding part, 244 - Accommodating space, 245 - Protrusion, 246 - Support part, 247 - Vent hole, 250 - Air guide plate, 260 - Insulating film, 300 - Electrical system, 310 - Electrical equipment. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0026] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0027] In this document, references to "embodiment" or "implementation" mean that a particular feature, structure, or characteristic described in connection with an embodiment or implementation may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0028] A rechargeable battery, also known as a secondary battery or accumulator, is a battery that can be recharged after discharge to reactivate its active materials and continue to be used. As the capacity requirements for rechargeable batteries have increased, the length of the battery cells has become increasingly longer. The longer the cell, the more prone it is to movement within the casing, leading to poorer structural stability of the battery.

[0029] For example, as the length of blade battery cells continues to increase, terminals need to be installed on the end caps at both ends of the blade battery, forming a double-sided tab structure. Due to assembly process limitations, one side tab needs to be welded to the end cap assembly before being inserted into the casing, while the other side tab needs to be welded to the end cap assembly after the cell is inserted into the casing. Therefore, the tab on the other side needs to have a longer allowance. However, tabs that are too long are prone to bending, damage, and scratching during assembly. Therefore, a restraining structure is needed to limit and constrain the long tabs, while preventing bending, scratching, and damage during assembly, thereby improving the structural stability of the long cell assembled in the casing.

[0030] Understandably, as the length of the battery cell increases, if the terminals are only located at one end, the current must flow through the cell and converge at the same end. This results in a longer internal current path, leading to a significant increase in ohmic internal resistance and severe heat generation during high-rate charging and discharging, ultimately causing the blade battery to experience high temperature and poor safety performance. By placing terminals at both ends of the blade battery and designing the cell with a dual-sided tab structure, the current inside the cell can be diverted from the middle to both ends, shortening the internal current path and significantly reducing internal resistance, thereby improving the safety performance of the blade battery.

[0031] Because the energy we need is highly time- and space-dependent, in order to utilize energy rationally and improve energy efficiency, it is necessary 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 for future applications. Currently, the main way to generate green electricity is to develop green energy sources such as photovoltaics and wind power to replace fossil fuels. Currently, the generation of green electricity generally relies on solar, wind, and hydropower. However, wind and solar power are generally characterized by strong intermittency and large fluctuations, which can cause grid instability, insufficient power during peak demand periods, and excessive power during off-peak periods. Unstable voltage can also damage the power grid. Therefore, insufficient electricity demand or insufficient grid capacity may lead to the problem of "wind and solar curtailment." Solving these problems requires energy storage. This involves converting electrical energy into other forms of energy through physical or chemical means and storing it. When needed, this energy can be converted back into electrical energy and released. Simply put, energy storage is like a large "power bank," storing electrical energy when solar and wind power are abundant and releasing the stored electricity when needed.

[0032] Taking electrochemical energy storage as an example, this solution provides an energy storage device 200, which is applied to the energy storage system 100. The energy storage device 200 is equipped with a set of chemical batteries, which mainly use the chemical elements in the batteries as energy storage medium. The charging and discharging process is accompanied by the chemical reaction or change of the energy storage medium. Simply put, the electrical energy generated by wind and solar energy is stored in the chemical batteries. When the use of external electrical energy reaches its peak, the stored electrical energy is released for use, or transferred to places with a shortage of electricity for use.

[0033] Current energy storage applications are quite widespread, including generation-side energy storage, grid-side energy storage, and consumption-side energy storage. The corresponding energy storage devices include: (1) Large-scale energy storage power stations (including multiple prefabricated energy storage modules) applied to wind power and photovoltaic power stations can help renewable energy power generation meet grid connection requirements and improve the utilization rate of renewable energy. As a high-quality active / reactive power regulation power source on the power supply side, the energy storage power station can realize the load matching of power in time and space, enhance the renewable energy absorption capacity, reduce instantaneous power changes, reduce the impact on the power grid, improve the problem of new energy power generation absorption, and is of great significance in power grid system backup, alleviating peak load power supply pressure and peak regulation and frequency regulation.

[0034] (2) The energy storage prefabricated cabin applied on the grid side mainly functions as peak regulation, frequency regulation and grid congestion relief. In terms of peak regulation, it can realize peak 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 electricity load period, thereby achieving a balance between power production and consumption.

[0035] (3) Small energy storage cabinets applied to the electricity consumption side mainly function as self-consumption of electricity, peak-valley price arbitrage, capacity cost management, and improvement of power supply reliability. Depending on the application scenario, electricity consumption side energy storage can be divided into industrial and commercial energy storage cabinets, household energy storage devices 200, 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 electricity market implementing peak-valley pricing, by charging the energy storage system 100 when the electricity price is low and discharging the energy storage system 100 when the electricity price is high, peak-valley price arbitrage can be achieved, reducing electricity costs. In addition, industrial enterprises subject to two-part tariffs can use the energy storage system 100 to store energy during the low electricity consumption period and discharge it during the peak load period, thereby reducing peak power and the maximum demand declared, and achieving the goal of reducing capacity electricity costs. Household photovoltaics with energy storage can improve the level of self-consumption of electricity. Due to high electricity prices and poor power supply stability, the demand for household photovoltaic installations is driven. Given that photovoltaic power generation occurs during the day, while user load is generally higher at night, configuring energy storage can better utilize photovoltaic power, improve self-consumption levels, and reduce electricity costs. Furthermore, energy storage is needed in areas such as communication base stations and data centers for backup power.

[0036] In some embodiments, see Figure 1 , Figure 1 This is a schematic diagram of the structure of an energy storage system 100 according to an embodiment of this application. Figure 1 The embodiments are illustrated using a home energy storage scenario in user-side energy storage as an example. The energy storage device 200 in this application is not limited to an energy storage box in a home energy storage scenario.

[0037] This application provides an energy storage system 100, which includes a first power conversion device 110 (photovoltaic panel), a first user load 120 (household lighting fixtures), a second user load 130 (e.g., household appliances such as air conditioners), and the energy storage device 200 of this application. The energy storage device 200 is a small energy storage box that can be wall-mounted on an outdoor wall. However, the energy storage device 200 is not limited to wall mounting and can also be placed in a user's residence in other ways. Specifically, the photovoltaic panel can convert solar energy into electrical energy during periods of low electricity prices, and the energy storage device 200 is used to store this electrical energy and supply it to lighting fixtures and household appliances during periods of high electricity prices, or to provide power during power outages / power failures.

[0038] Optionally, the first power conversion device 110 may include, but is not limited to, a photovoltaic panel, and the first power conversion device 110 can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy and mechanical energy into electrical energy.

[0039] In some embodiments, see Figure 2 , Figure 2 This is a schematic diagram of the structure of an energy storage system 100 according to another embodiment of this application, and this application Figure 2 The embodiments are illustrated using a shared energy storage scenario on the power generation / distribution side as an example. The energy storage device 200 in this application is not limited to a prefabricated energy storage module in a power generation / distribution energy storage scenario.

[0040] This application provides an energy storage system 100, which includes: a high-voltage cable 150, a first power conversion device 110, a second power conversion device 160, and an energy storage device 200 provided in this application. In some embodiments of the power generation scenario, the second power conversion device 160 can be a wind power conversion device. Since the electricity generated by wind power conversion is volatile, random, and intermittent, the unstable electricity output by the wind power conversion device can be stored in the energy storage device 200 through grid connection. The energy storage device 200 is connected to the high-voltage cable and outputs smooth electricity to the power consumption side of the distribution network, realizing peak shaving and frequency regulation, and stable grid operation; or, wind power... The conversion device is always connected to the high-voltage cable. Under normal power generation conditions, the power output of the wind power conversion device is supplied to the power consumption side of the distribution network 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 200 to reduce the curtailment rate of wind and solar power and improve the problem of new energy power generation consumption. When the power load is high, the power grid issues an instruction to transmit the power stored in the energy storage device 200 together with the high-voltage cable 150 in grid-connected mode to supply power to the power consumption side. This provides the power grid with various services such as peak shaving, frequency regulation, and backup, giving full play to the peak shaving role of the power grid, promoting peak shaving and valley filling, and alleviating the power supply pressure of the power grid.

[0041] In some embodiments on the distribution network side, the first power conversion device 110 can be a photovoltaic panel, and the energy storage device 200 is connected to the high-voltage cable 150 and installed downstream of the high-voltage cable 150 between the user load and the photovoltaic power conversion device. The electrical energy output by the photovoltaic power conversion device is stored in the energy storage device 200, which can respond in a timely manner to act as a backup power source when the power grid / distribution network fails; or, it can provide power supply support to alleviate line congestion when the high-voltage cable 150 transmission line is blocked, and to delay the economic pressure caused by the expansion of the power grid / distribution capacity when the power grid is planned to be expanded.

[0042] Optionally, the first power conversion device 110 may include, but is not limited to, a wind power conversion device, and the second power conversion device 160 may include, but is not limited to, a photovoltaic panel. The first power conversion device 110 and the second power conversion device 160 can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy, and mechanical energy into electrical energy.

[0043] In some embodiments, see Figure 3 , Figure 3 This is a schematic diagram of the structure of an energy storage system 100 according to another embodiment of this application, and this application Figure 3 The embodiments are illustrated using an industrial and commercial energy storage scenario as an example. The energy storage device 200 in this application is not limited to an energy storage cabinet in an industrial and commercial energy storage scenario.

[0044] This application provides an energy storage system 100, which includes: an energy storage device 200, a high-voltage cable 150, a factory equipped with a first power conversion device 110, a photovoltaic-energy storage-charging station 170 equipped with a second power conversion device 160, and a vehicle 180. In some embodiments of industrial and commercial scenarios, the first power conversion device 110 can be a photovoltaic panel, which converts solar energy into electrical energy and stores it in the energy storage device 200 in the factory. In the event of a power grid failure, the energy storage device 200 provides power to ensure the safe and stable operation of the factory without interruption. Alternatively, when the factory's power load is high, the power grid issues an instruction to transmit the electricity stored in the energy storage device 200 in conjunction with the high-voltage cable 150 in a grid-connected mode to supply the factory with electricity, providing various services such as peak shaving / frequency regulation and backup for the power grid operation. In addition, the second power conversion device 160 can also be a photovoltaic panel, which converts solar energy into electrical energy and stores it in the energy storage device 200 of the photovoltaic-energy storage-charging station 170, directly charging the vehicle 180 through the photovoltaic-energy storage-charging station 170, which is fast and convenient.

[0045] Optionally, the first power conversion device 110 and the second power conversion device 160 may include, but are not limited to, photovoltaic panels. The first power conversion device 110 can convert at least one of solar energy, light energy, wind energy, thermal energy, tidal energy, biomass energy, and mechanical energy into electrical energy.

[0046] Optionally, the energy storage device 200 may include, but is not limited to, energy storage applications 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 may also be applied in multiple fields such as data centers, military equipment, aerospace, charging piles, and electric vehicles.

[0047] Optionally, the energy storage device 200 may include, but is not limited to, single-cell batteries, or battery modules, battery packs, battery clusters, power banks, energy storage cabinets / prefabricated energy storage compartments, and other battery integrated systems composed of single-cell batteries. The actual application form of the energy storage device 200 provided in this application embodiment may be, but is not limited to, the listed products, and may also be other application forms. This application embodiment does not strictly limit the application form of the energy storage device 200. This application embodiment only uses a multi-cell battery of the energy storage device 200 as an example for illustration.

[0048] Optionally, the individual battery cells constituting the energy storage device 200 can be, but are not limited to, at least one of cylindrical, prismatic, prismatic, or other shaped batteries.

[0049] Optionally, the energy storage device 200 may include, but is not limited to, energy storage applications 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 may also be applied in multiple fields such as data centers, military equipment, aerospace, charging piles, and electric vehicles.

[0050] Optionally, the energy storage device 200 may include battery modules, battery packs, battery clusters, mobile power supplies, energy storage cabinets / prefabricated energy storage compartments, and other battery integrated systems composed of individual batteries. The actual application form of the energy storage device 200 provided in this application embodiment may be, but is not limited to, the listed products, and may also be other application forms. This application embodiment does not strictly limit the application form of the energy storage device 200.

[0051] Alternatively, the single cell is not limited to at least one of cylindrical, square, prismatic, or other shaped cells.

[0052] Optionally, the single cell can be a rechargeable battery, which refers to a single cell that can be recharged after discharge to activate the active materials and continue to be used. The single cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this application does not specifically limit it.

[0053] Please see Figures 4 to 7 This application provides an energy storage device 200, which includes: a housing 210, an electrode assembly 220, an end cap assembly 230, and a restraining member 240. The housing 210 has a receiving cavity 211; the electrode assembly 220 is disposed within the receiving cavity 211, and the electrode assembly 220 includes a plurality of electrically connected tabs 221 and an electrode body 222, the plurality of tabs 221 and the electrode body 222 being connected along a first direction (e.g., ...). Figure 2 Arranged in the X direction (as shown); the end cap assembly 230 is disposed on one side of the housing 210 for sealing the accommodating cavity 211; the restraining member 240 is located between the end cap assembly 230 and the electrode body 222; the restraining member 240 has a through hole 241, the through hole 241 penetrating two opposing surfaces of the restraining member 240 along the first direction; the through hole 241 is arranged along the second direction (as shown in the X direction). Figure 2Extending in the Y direction, the plurality of tabs 221 are inserted through the through hole 241. The restraining member 240 includes a surrounding portion 242 and a restraining portion 243. The surrounding portion 242 connects to the outer periphery of the restraining portion 243. The restraining portion 243 and the surrounding portion 242 enclose a receiving space 244 facing the end cap assembly 230. The restraining portion 243 has the through hole 241, which penetrates two opposing surfaces of the restraining portion 243 along the first direction and communicates with the receiving space 244. The restraining member 240 also includes a protrusion 245, which protrudes from the surface of the restraining portion 243 facing the receiving space 244 and surrounds it. The protrusion 245 is disposed around the outer periphery of the through hole 241, and the end face of the protrusion 245 facing away from the binding part 243 is spaced apart from the end cap assembly 230; the protrusion 245 provides the electrode tab 221 with an orderly bending point, so that the electrode tab 221 can be directionally bent within the receiving space 244 after passing through the through hole 241; wherein, the first direction intersects the second direction; the through hole 241 has a first sidewall 2411 and a second sidewall 2412 disposed opposite to each other along the second direction, and the distance between the first sidewall 2411 and the second sidewall 2412 along the second direction is greater than the size of the ends of the plurality of electrode tabs 221 near the electrode body 222.

[0054] Optionally, in some embodiments, the plurality of tabs 221 are spaced apart from the first sidewall 2411 along the second direction; in other embodiments, the plurality of tabs 221 are spaced apart from the second sidewall 2412 along the second direction; in still other embodiments, the opposite ends of the plurality of tabs 221 are spaced apart from the first sidewall 2411 and the second sidewall 2412 respectively along the second direction.

[0055] Understandably, the distance between the first sidewall 2411 and the second sidewall 2412 along the second direction can be the size of the through hole 241 along the second direction.

[0056] Optionally, in some embodiments, the first direction is perpendicular to the second direction.

[0057] Understandably, the ends of the plurality of tabs 221 near the electrode body 222 are the first ends 2211.

[0058] Understandably, the end cap assembly 230 includes a top cap 231, which is connected to the housing 210, and the protrusion 245 is spaced apart from the end face of the restraint portion 243 from the top cap 231.

[0059] Understandably, the protrusion 245 is a ring structure.

[0060] Understandably, the protrusion 245 is located within the accommodating space 244.

[0061] Understandably, in the embodiments of this application, "orderly bending" means that the tab 221 does not bend randomly or irregularly, but deforms according to a preset trajectory, fixed angle and fixed bending position under the action of the fixed bending point provided by the protrusion 245, and the bending shape is regular, the position is uniform and there is no random offset.

[0062] Understandably, in the embodiments of this application, "directional bending" refers to the controlled bending of the tab 221 along a predetermined direction. Specifically, the tab 221 is S-shaped, that is, after the tab 221 passes through the through hole 241, it bends in one direction first, and then bends in the opposite direction along the intersecting other direction, forming a continuous, smooth, and symmetrical S-shaped curve shape, with the protrusion 245 as the bending fulcrum.

[0063] In this embodiment, the tab 221 is softer than the electrode body 222. If it is directly inserted into the shell, the tab 221 may collapse and short-circuit upon contact with the shell 210. The restraint member 240 is located between the end cap assembly 230 and the electrode body 222, and the restraint member 240 has a through hole 241. The through hole 241 is used to insert the plurality of tabs 221 and to physically limit the plurality of tabs 221. During the transportation, use, or assembly of the energy storage device 200, the tabs 221 can be prevented from excessive bending or displacement, reducing failures such as breakage and poor contact of the tabs 221. At the same time, it can prevent the tabs 221 from directly contacting the shell 210 and causing a short circuit inside the energy storage device 200. Furthermore, the through hole 241 has a first sidewall 2411 and a second sidewall 2412 disposed opposite to each other along the second direction. Along the second direction, the distance between the first sidewall 2411 and the second sidewall 2412 is greater than the size of the plurality of tabs 221. Therefore, on the one hand, when the plurality of tabs 221 pass through the through hole 241 along the first direction, the sufficient internal space of the through hole 241 in the second direction prevents direct contact or friction between the opposite ends of the plurality of tabs 221 and the first sidewall 2411 and the second sidewall 2412 along the second direction. This effectively avoids scratching the insulating layer or metal substrate on the surface of the tabs 221, reducing the possibility of decreased conductivity due to mechanical damage, and ensuring stable electrical performance of the energy storage device 200. On the other hand, by setting the difference between the size of the through hole 241 along the second direction and the size of the ends of the plurality of tabs 221 near the electrode body 222 along the second direction, the stringent requirements for the arrangement accuracy of the multi-layer tabs 221 during assembly can be reduced. Even if the multiple tabs 221 have slight positional misalignment or misalignment before insertion, they can still be smoothly assembled through the insertion holes 241 without the need for repeated calibration and adjustment of the tabs 221. This design simplifies the assembly process of the tabs 221 and the restraint member 240, reduces the difficulty of assembling the multiple tabs 221 and the restraint member 240, and improves the assembly efficiency of the energy storage device 200. Furthermore, the restraint member 240 can fix the position of the tabs 221, so that the electrode assembly 220 has good structural stability when it is placed in the receiving cavity 211, avoiding the electrode assembly 220 from shaking relative to the housing 210, and the energy storage device 200 has good structural stability. Furthermore, during the assembly of the energy storage device 200, the restraint member 240 can also be connected to structural components such as the air guide plate 250 within the energy storage device 200 to form a fixed frame structure. The air guide plate 250 cooperates with the restraint member 240 to further fix the relative position of the electrode body 222 and the electrode tab 221.During the process of pushing the relatively long electrode assembly 220 into the housing 210, deformation of the electrode body 222 and the tab 221 can be avoided, ensuring the structural integrity and electrical connection stability of the electrode assembly 220 and improving the assembly performance of the energy storage device 200.

[0064] Furthermore, the restraint member 240 includes a surrounding portion 242 and a restraint portion 243. The surrounding portion 242 connects to the outer periphery of the restraint portion 243. The restraint portion 243 and the surrounding portion 242 enclose a receiving space 244. The receiving space 244 provides sufficient accommodating space for the long electrode tab 221, which can prevent the electrode tab 221 from being stacked disorderly in the housing 210 after being electrically connected to the end cap assembly 230. Specifically, the protrusion 245 is disposed on the surface of the binding part 243 facing the accommodating space 244 and surrounds the outer periphery of the through hole 241. When the tab 221 passes through the through hole 241, on the one hand, the protrusion 245 forms a three-dimensional structure along the first direction, which can provide support and guidance for the tab 221 along the first direction, avoiding displacement or wrinkling due to insufficient rigidity of the tab 221 itself. At the same time, it guides the tab 221 to pass smoothly through the through hole 241 along a preset path, ensuring the stability of the tab 221 passing through the through hole 241. On the other hand, the protrusion 245 provides the electrode tab 221 with an orderly bending point, so that the electrode tab 221 can be directionally bent within the accommodating space 244 after passing through the through hole 241. This design can effectively constrain the bending trajectory of the electrode tab 221, avoid disorderly folding, twisting or excessive compression of the electrode tab 221 in the space, and thus prevent the metal conductor inside the electrode tab 221 from generating microcracks or broken wires due to mechanical deformation, or the current conduction path from becoming longer and the contact resistance from increasing due to folding. Ultimately, it ensures the assembly accuracy of the electrode tab 221 and the adapter 233 in subsequent welding processes, and improves the conductivity and structural reliability of the welded connection. Furthermore, the protrusion 245 is spaced apart from the end face of the restraint portion 243 and the end cap assembly 230 to ensure that the tab 221 has sufficient space to bend after extending out of the through hole 241, thereby preventing the end cap assembly 230 from squeezing the tab 221. This reduces the risk of damage to the metal substrate, decreased conductivity, or breakage of the tab 221 caused by squeezing, ensuring the structural integrity and electrical performance stability of the tab 221, and improving the stability of the electrical performance of the energy storage device 200.

[0065] Understandably, without the protrusion 245, when the longer tabs 221 pass through the through-hole 241 and enter the receiving space 244, they are prone to irregular and disorderly stacking due to the lack of limiting and bending guidance. The bending position, bending direction, and bending shape of the tabs 221 are uncontrollable, easily resulting in wrinkles, twisting, mutual scraping, local bending, or even deformation and damage. At the same time, disorderly wrinkles and stacking of the tabs 221 will lead to a reduction in the effective current-carrying area and an increase in contact resistance, thereby increasing the overall resistance of the tabs 221 and affecting the current-carrying capacity, reducing the electrical performance and reliability of the energy storage device 200.

[0066] Please see also Figure 8 Optionally, the energy storage device 200 further includes an air guide plate 250, which extends along the first direction. There are two air guide plates 250, which are disposed on opposite sides of the electrode body 222 along the second direction, so as to limit and support the structure of the electrode body 222 along the first direction while guiding air.

[0067] Optionally, the energy storage device 200 further includes an insulating film 260, which is disposed on the surface of the electrode body 222 to insulate the electrode body 222 from the housing 210. Two insulating films 260 are provided, each disposed on the electrode body 222 along a third direction (e.g., ...). Figure 5 The three directions are located on opposite sides of the Z-direction, wherein the third direction intersects the first direction and the second direction respectively.

[0068] Understandably, the electrode body 222 has a first side (not shown), a second side (not shown), a third side (not shown), and a fourth side (not shown) that are bent and connected in sequence. Along the second direction, the first side and the third side are arranged opposite to each other; along the third direction, the second side and the fourth side are arranged opposite to each other.

[0069] Optionally, in some embodiments, the third direction is perpendicular to the first direction and the second direction, respectively.

[0070] Understandably, one of the two air guide plates 250 is disposed corresponding to the first side, and the other of the two air guide plates 250 is disposed corresponding to the third side. One of the two insulating films 260 is disposed corresponding to the second side, and the other of the two insulating films 260 is disposed corresponding to the fourth side. The air guide plates 250 and the insulating films 260 cooperate with each other to achieve insulation between the electrode body 222 and the housing 210, thereby preventing the energy storage device 200 from experiencing an internal short circuit.

[0071] Understandably, during the assembly of the energy storage device 200 provided in this application, the tab 221 passes through the restraint member 240, and the first and third sides of the electrode body 222 are provided with the air guide plate 250. The two air guide plates 250 are respectively connected to the two opposite ends of the restraint member 240 along the second direction to form a fixed frame structure. Further, the air guide plate 250 and the restraint member 240 provide heat fusion points for the insulating film 260, so that the insulating film 260 is heat-fused to the air guide plate 250 and the restraint member 240. Further still, the connected air guide plate 250, restraint member 240, and insulating film 260 are pushed into the housing 210.

[0072] During this process, the relative positions of the air guide plate 250, the restraint member 240, and the insulating film 260 are stable, so that when the electrode tab 221 passes through the restraint member 240, the positions of the electrode tab 221 and the electrode body 222 can be fixed, preventing the electrode tab 221 from bending. Simultaneously, when the connected air guide plate 250, restraint member 240, and insulating film 260 are pushed into the housing 210, even if the electrode body 222 has a large dimension along the first direction and requires a large pushing force during assembly, the cooperation of the air guide plate 250, restraint member 240, and insulating film 260 can improve the balance of the electrode assembly 220 when it enters the housing, preventing deformation of the electrode body 222 and the electrode tab 221, and improving the electrical connection stability of the energy storage device 200. Furthermore, during the process of inserting the electrode assembly 220 into the housing, it can also prevent the opening of the housing 210 from scratching the electrode assembly 220, thereby ensuring the structural integrity and electrical connection stability of the electrode assembly 220.

[0073] Please see also Figure 9 In some embodiments, the plurality of tabs 221 have a first end 2211 and a second end 2212 disposed opposite to each other, the first end 2211 being connected to the electrode body 222, and the second end 2212 being disposed away from the electrode body 222; the size of the plurality of tabs 221 gradually decreases from the first end 2211 to the second end 2212.

[0074] Understandably, the plurality of tabs 221 have a trapezoidal structure.

[0075] Understandably, the dimension of the second end 2212 along the second direction is smaller than the dimension of the first end 2211 along the second direction.

[0076] In this embodiment, the first end 2211 of the plurality of tabs 221 is connected to the electrode body 222, and the second end 2212 is disposed away from the electrode body 222. When the plurality of tabs 221 are assembled with the restraint member 240, and the plurality of tabs 221 pass through the through hole 241 of the restraint member 240, the second end 2212 serves as a free end, and the second end 2212 enters the through hole 241 before the first end 2211. In this embodiment, the size of the plurality of tabs 221 gradually decreases from the first end 2211 to the second end 2212. On one hand, the tabs 221 form a "tip-guided" structure, allowing the second end 2212 to quickly pass through and enter the through hole 241 during installation. This avoids the tabs 221 getting stuck in the through hole 241 due to their uniform overall size, thus improving the assembly efficiency of the plurality of tabs 221 and the restraint member 240. On the other hand, the gradually decreasing size of the plurality of tabs 221 provides more assembly space for the second end 2212 when passing through the through hole 241, significantly reducing the probability of scratches during initial installation and further protecting the structural integrity of the tab surface, thereby ensuring the electrical connection stability of the energy storage device 200.

[0077] Please see also Figure 10 In some embodiments, along the second direction, the distance between the first sidewall 2411 and the second sidewall 2412 is L1, and the maximum size of the plurality of tabs 221 is L2. Then the energy storage device 200 satisfies the relationship: 0.95≤L2 / L1≤0.99.

[0078] Understandably, the maximum dimension of the plurality of tabs 221 along the second direction is the same as the maximum dimension of the first end 2211 along the second direction.

[0079] Specifically, the value of L2 / L1 can be, but is not limited to, 0.95, 0.952, 0.953, 0.954, 0.955, 0.956, 0.958, 0.96, 0.962, 0.964, 0.965, 0.966, 0.968, 0.97, 0.972, 0.975, 0.978, 0.979, 0.98, 0.982, 0.985, 0.988, and 0.99.

[0080] In this embodiment, when the energy storage device 200 satisfies the relationship 0.95≤L2 / L1≤0.99, the distance between the first sidewall 2411 and the second sidewall 2412, and the maximum size of the plurality of tabs 221 are all within a reasonable range. On the one hand, during the assembly process of the tabs 221 and the restraint member 240, the space allowance of the through hole 241 along the second direction is within a suitable range, so that the plurality of tabs 221 can quickly pass through the through hole 241, while greatly reducing the probability of the opposite ends of the tabs 221 rubbing against the first sidewall 2411 and the second sidewall 2412 along the second direction, avoiding damage to the tabs 221, and ensuring the electrical performance of the tabs 221. On the other hand, when the tab 221 passes through the through hole 241, the restraint member 240 can effectively restrain the position of the tab 221, preventing the tab 221 from bending disorderly and inserting backwards into the electrode body 222, thereby avoiding short circuit connection inside the energy storage device 200 and further improving the safety performance of the energy storage device 200. When the value of L2 / L1 is too large, the distance between the first sidewall 2411 and the second sidewall 2412 is too small, or the maximum size of the plurality of tabs 221 is too large. On the one hand, when the plurality of tabs 221 pass through the through hole 241, the space margin of the through hole 241 in the second direction is too small. The plurality of tabs 221 are very likely to come into contact with the first sidewall 2411 and / or the second sidewall 2412 and rub against each other, which may damage the tab 221 and cause a decrease in the electrical performance of the tab 221. On the other hand, it increases the difficulty for the tab 221 to pass through the through hole 241, thereby reducing the assembly efficiency of the tab 221 and the restraint member 240. When the value of L2 / L1 is too small, the distance between the first sidewall 2411 and the second sidewall 2412 is too large, or the maximum size of the plurality of tabs 221 is too small. During the assembly process of the energy storage device 200, although the tab 221 can quickly pass through the through hole 241 and the assembly efficiency is high, the through hole 241 occupies too much of the size of the restraint member 240 along the second direction, which may reduce the structural strength of the restraint member 240, reduce the restraining effect of the restraint member 240 on the tab 221, and make it difficult to ensure the electrical connection stability of the energy storage device 200.

[0081] Please see also Figure 10 and Figure 11 In some embodiments, along the second direction, the minimum distance d1 between the first end 2211 and the first sidewall 2411 is in the range of 1mm≤d1≤10mm.

[0082] Understandably, the minimum distance between the first end 2211 and the first sidewall 2411 along the second direction is the minimum distance between the side of the first end 2211 closest to the first sidewall 2411 and the first sidewall 2411.

[0083] Specifically, the minimum distance d1 between the first end 2211 and the first sidewall 2411 can be, but is not limited to, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm and 10mm.

[0084] In this embodiment, along the second direction, when the minimum distance d1 between the first end 2211 and the first sidewall 2411 satisfies the range 1mm≤d1≤10mm, the minimum distance between the first end 2211 and the first sidewall 2411 is within a reasonable range. During the handling, use, or assembly of the energy storage device 200, along the second direction, the side of the tab 221 closest to the first sidewall 2411 has a certain distance from the first sidewall 2411, which can prevent the tab 221 from contacting or rubbing against the first sidewall 2411, ensuring the integrity of the tab 221 and improving the electrical connection stability of the energy storage device 200. When the value of d1 is too large, given a fixed dimension of the tab 221 along the second direction, the minimum distance between the first end 2211 and the first sidewall 2411 is too large. Correspondingly, the dimension of the through hole 241 along the second direction is too large. The through hole 241 occupies too much space in the restraint member 240 along the second direction, which may reduce the structural strength of the restraint member 240 and may interfere with other components on the restraint member 240. Specifically, the restraint member 240 is also provided with a vent hole 247 corresponding to the explosion-proof valve 235 of the end cap assembly 230. If the dimension of the through hole 241 along the second direction is too large, it may encroach on the space on the restraint member 240 used for setting the vent hole 247, thereby affecting the ventilation performance of the restraint member 240 and ultimately affecting the exhaust performance and safety performance of the energy storage device 200. When the value of d1 is too small, during the handling, use or assembly of the energy storage device 200, the side of the electrode 221 closest to the first sidewall 2411 along the second direction is very likely to come into contact with or rub against the first sidewall 2411, thereby damaging the electrode 221 and shortening its service life.

[0085] Understandably, the end cap assembly 230 includes an explosion-proof valve 235, which is installed on the top cover 231. When the air pressure in the accommodating cavity 211 reaches a threshold, the explosion-proof valve 235 bursts open to release pressure and open the valve.

[0086] In some embodiments, along the second direction, the minimum distance d2 between the first end 2211 and the second sidewall 2412 ranges from 1mm ≤ d2 ≤ 10mm.

[0087] Understandably, the minimum distance between the first end 2211 and the second sidewall 2412 along the second direction is the minimum distance between the side of the first end 2211 closest to the second sidewall 2412 and the second sidewall 2412.

[0088] Specifically, the minimum distance d2 between the first end 2211 and the second sidewall 2412 can be, but is not limited to, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm and 10mm.

[0089] In this embodiment, along the second direction, when the minimum distance d2 between the first end 2211 and the second sidewall 2412 satisfies the range 1mm≤d2≤10mm, the minimum distance between the first end 2211 and the second sidewall 2412 is within a reasonable range. During the handling, use, or assembly of the energy storage device 200, along the second direction, the side of the tab 221 closest to the second sidewall 2412 has a certain distance from the second sidewall 2412, which can prevent the tab 221 from contacting or rubbing against the second sidewall 2412, ensuring the integrity of the tab 221 and improving the electrical connection stability of the energy storage device 200. When the value of d2 is too large, given a fixed dimension of the tab 221 along the second direction, the minimum distance between the first end 2211 and the second sidewall 2412 is too large. Consequently, the dimension of the through hole 241 along the second direction is too large, and the through hole 241 occupies too much space in the restraint member 240 along the second direction. This may reduce the structural strength of the restraint member 240 and may also interfere with other components on the restraint member 240, reducing its performance. When the value of d2 is too small, during the handling, use, or assembly of the energy storage device 200, the side of the tab 221 closest to the second sidewall 2412 along the second direction is prone to contacting or rubbing against the second sidewall 2412, thereby damaging the tab 221 and shortening its service life.

[0090] In some embodiments, along a third direction, the ratio γ of the width of the through hole 241 to the total thickness of the plurality of tabs 221 passing through the through hole 241 is in the range of 2.1≤γ≤10, wherein the third direction intersects the first direction and the second direction respectively.

[0091] The value of γ can be, but is not limited to, 2.1, 2.2, 2.5, 2.8, 3, 3.5, 3.8, 4, 4.2, 4.5, 4.8, 5, 5.2, 5.5, 6, 6.2, 6.5, 6.8, 7, 7.2, 7.5, 7.8, 8, 8.2, 8.5, 8.8, 9, 9.5, 9.8 and 10.

[0092] Understandably, the total thickness of the plurality of tabs 221 passing through the through hole 241 is the thickness of the plurality of tabs 221 after being stacked and welded together.

[0093] In this embodiment, when the ratio γ of the width of the through hole 241 along the third direction to the total thickness of the plurality of tabs 221 passing through the through hole 241 satisfies the range 2.1≤γ≤10, both the width of the through hole 241 along the third direction and the total thickness of the plurality of tabs 221 passing through the through hole 241 are within a reasonable range. On the one hand, during the process of multiple layers of tabs 221 passing through the through hole 241, the through hole 241 has a certain amount of space to avoid damage to the plurality of tabs 221 during assembly, thereby enabling the restraining member 240 to have better assembly performance. On the other hand, when the plurality of tabs 221 are disposed in the through hole 241, the restraining member 240 can provide support for the plurality of tabs 221 to prevent the plurality of tabs 221 from swaying in the third direction, which facilitates the improvement of the electrical connection stability of the positive tab. When the value of γ is too large, with a fixed total thickness of the multiple tabs 221 passing through the through hole 241, the width of the through hole 241 along the third direction is too large. This results in a large movement space for the multiple tabs 221 within the through hole 241, causing them to sway in the third direction after being inserted, thus weakening the restraining effect of the restraining member 240 on the positive tab. When the value of γ is too small, with a fixed total thickness of the multiple tabs 221 passing through the through hole 241, the width of the through hole 241 along the third direction is too small. During the assembly process of the multiple tabs 221 with the through hole 241, the multiple tabs 221 are difficult to pass through the through hole 241, and the tabs 221 are easily damaged during assembly, reducing the assembly efficiency of the tabs 221 and the restraining member 240.

[0094] In some embodiments, the tab 221 is a positive tab, and the material of the positive tab is selected from aluminum foil.

[0095] In some embodiments, the tab 221 is a negative tab, and the material of the negative tab is selected from copper foil.

[0096] Understandably, the positive electrode tab and the negative electrode tab are selected from different materials so that the thickness of the positive electrode tab and the thickness of the negative electrode tab are different. When the width of the through hole 241 along the third direction is constant, the number of layers of the positive electrode tab and the number of layers of the negative electrode tab through the corresponding through hole 241 are different. In other words, when the number of layers of the positive electrode tab and the number of layers of the negative electrode tab through the through hole 241 are constant, the width of the corresponding through hole 241 along the third direction is different.

[0097] Please see also Figures 11 to 13 In some embodiments, the restraint member 240 includes a surrounding portion 242 and a restraint portion 243. The surrounding portion 242 is connected to the outer periphery of the restraint portion 243. The restraint portion 243 and the surrounding portion 242 enclose an accommodating space 244. The restraint portion 243 has a through hole 241 that penetrates two opposing surfaces of the restraint portion 243 along the first direction. The through hole 241 communicates with the accommodating space 244. The end cap assembly 230 includes a top cap 231, a pole post 232, and an adapter 233. The top cap 231 is connected to the housing 210. The pole post 232 is mounted on the top cap 231. The adapter 233 is located within the accommodating space 244. The adapter 233 is electrically connected to the pole post 232 and the plurality of tabs 221, respectively.

[0098] Understandably, the pole post 232 is mounted on the top cover 231 and is insulated from the top cover 231.

[0099] Understandably, the top cover 231, the restraint member 240, and the electrode body 222 are arranged sequentially along the first direction.

[0100] In this embodiment, the restraint member 240 includes a surrounding portion 242 and a restraint portion 243. The surrounding portion 242 connects to the outer periphery of the restraint portion 243. The restraint portion 243 and the surrounding portion 242 enclose a receiving space 244. The receiving space 244 provides bending space for the electrode tab 221 and can also accommodate the adapter 233 to facilitate the electrical connection between the adapter 233 and the electrode tab 221. At the same time, it protects the adapter 233 and the electrode tab 221 so that the electrical connection stability of the adapter 233 and the electrode tab 221 can be avoided due to impact during transportation or use of the energy storage device 200. Furthermore, the binding portion 243 has the through hole 241, which penetrates two opposing surfaces of the binding portion 243 along a first direction. When the end of the tab 221 facing away from the electrode body 222 passes through the through hole 241, the binding portion 243 can bind and constrain the tab 221, preventing it from becoming scattered or misaligned. Simultaneously, the second end 2212 of the tab 221 extends out of the through hole 241 and bends within the accommodating space 244, improving the regularity of the tab 221 and ensuring good electrical connection stability between the tab 221 and the adapter 233.

[0101] Optionally, the end cap assembly 230 further includes a plastic part 234, which is disposed on the side of the top cover 231 facing the accommodating space 244. In other words, the plastic part 234 is disposed between the top cover 231 and the restraining portion 243.

[0102] Understandably, the electrode post 232 is sequentially inserted through the plastic part 234 and the top cover 231, and the adapter 233 is disposed on the side of the plastic part 234 away from the top cover 231 and is electrically connected to the electrode post 232.

[0103] In some embodiments, the restraint member 240 further includes a protrusion 245, which protrudes from the surface of the restraint member 243 facing the accommodating space 244 and is disposed around the outer periphery of the through hole 241. The end face of the protrusion 245 facing away from the restraint member 243 is spaced apart from the top cover 231.

[0104] In this embodiment, the protrusion 245 is disposed on the surface of the binding portion 243 facing the accommodating space 244 and surrounds the outer periphery of the through hole 241. When the tab 221 passes through the through hole 241, on the one hand, the protrusion 245 forms a three-dimensional structure along the first direction, which can provide support and guidance for the tab 221 along the first direction, avoiding displacement or wrinkling due to insufficient rigidity of the tab 221 itself. At the same time, it guides the tab 221 to pass smoothly through the through hole 241 along a preset path, ensuring the stability of the tab 221 passing through the through hole 241. On the other hand, the protrusion 245 provides the electrode tab 221 with an orderly bending point, so that the electrode tab 221 can be directionally bent within the accommodating space 244 after passing through the through hole 241. This design can effectively constrain the bending trajectory of the electrode tab 221, avoid disorderly folding, twisting or excessive compression of the electrode tab 221 in the space, and thus prevent the metal conductor inside the electrode tab 221 from generating microcracks or broken wires due to mechanical deformation, or the current conduction path from becoming longer and the contact resistance from increasing due to folding. Ultimately, it ensures the assembly accuracy of the electrode tab 221 and the adapter 233 in subsequent welding processes, and improves the conductivity and structural reliability of the welded connection. Furthermore, the protrusion 245 is spaced apart from the end face of the binding part 243 and the top cover 231 to ensure that the tab 221 has sufficient space to bend after extending out of the through hole 241 and to make electrical connection with the adapter 233. This avoids the top cover 231 or the plastic part 234 from squeezing the tab 221, thereby reducing the risk of damage to the metal substrate, decreased conductivity, and breakage of the tab 221 caused by squeezing. This ensures the structural integrity and electrical performance stability of the tab 221 and improves the stability of the electrical performance of the energy storage device 200.

[0105] In some embodiments, along the first direction, the end face of the circumferential portion 242 facing away from the electrode body 222 is positioned closer to the top cover 231 than the end face of the protrusion 245 facing away from the electrode body 222.

[0106] In this embodiment, along the first direction, the end face of the surrounding portion 242 facing away from the electrode body 222 is closer to the top cover 231 than the end face of the protrusion 245 facing away from the electrode body 222. When the restraint member 240 is disposed on the energy storage device 200, the end of the protrusion 245 facing away from the electrode body 222 is spaced apart from the top cover 231, so that the tab 221 extending out of the through hole 241 has enough space to bend, while avoiding interference between the top cover 231 and the tab 221, thus ensuring the structural stability inside the energy storage device 200.

[0107] Optionally, in some embodiments, the end face of the surrounding portion 242 opposite to the electrode body 222 abuts against the top cover 231. In other embodiments, the end face of the surrounding portion 242 opposite to the electrode body 222 abuts against the plastic part 234.

[0108] Please see also Figure 14 In some embodiments, the number of through holes 241 is multiple and includes a first group of through holes 241a; the multiple tabs 221 include a first group of tabs 221a, the first group of tabs 221a is disposed on one side of the electrode body 222; the first group of tabs 221a passes through the first group of through holes 241a.

[0109] In this embodiment, the first set of through holes 241a are provided corresponding to the first set of tabs 221a and are used to pass through the first set of tabs 221a to bind the first set of tabs 221a, thereby improving the regularity of the first set of tabs 221a within the accommodating cavity 211 and preventing the first set of tabs 221a from being scattered or misaligned and overlapping with each other. This reduces the probability of short circuits occurring inside the energy storage device 200 and improves the safety performance of the energy storage device 200. The energy storage device 200 of this embodiment is particularly suitable for battery scenarios where the electrode body 222 is large. When the size of the electrode body 222 along the first direction is large, its power output demand increases accordingly, requiring the configuration of more and larger tabs 221 to achieve efficient power transfer. By setting the through holes 241 in groups and binding the multiple groups of tabs 221 respectively, it is possible to adapt to the arrangement requirements of multiple tabs 221 and large-size tabs 221. While ensuring the regularity and safety of the tabs 221, it meets the power transmission efficiency requirements of the large-size electrode body 222, thus expanding the applicability of the energy storage device 200.

[0110] Optionally, in some embodiments, the first set of tabs 221a is a positive tab; or, the first set of tabs 221a is a negative tab.

[0111] Please see also Figure 14In some embodiments, the number of through holes 241 is multiple and includes a first group of through holes 241a and a second group of through holes 241b, the first group of through holes 241a and the second group of through holes 241b being arranged at intervals along the second direction; the multiple tabs 221 include a first group of tabs 221a and a second group of tabs 221b, the first group of tabs 221a and the second group of tabs 221b being disposed on the same side of the electrode body 222 and electrically connected to the electrode body 222 respectively, the first group of tabs 221a and the second group of tabs 221b being arranged at intervals along the second direction; the first group of tabs 221a is inserted through the first group of through holes 241a, and the second group of tabs 221b is inserted through the second group of through holes 241b.

[0112] Understandably, the first group of through holes 241a and the second group of through holes 241b both refer to through holes 241. The terms "first group" and "second group" are used only to distinguish through holes 241 in different positions.

[0113] Understandably, both the first group of tabs 221a and the second group of tabs 221b refer to tabs 221. The terms "first group" and "second group" are used only to distinguish tabs 221 in different positions.

[0114] In this embodiment, the first set of through holes 241a and the second set of through holes 241b are arranged at intervals along the second direction, and the first set of tabs 221a and the second set of tabs 221b are arranged at intervals along the second direction. The first set of through holes 241a is provided corresponding to the first set of tabs 221a and is used to pass through the first set of tabs 221a to restrain the first set of tabs 221a; the second set of through holes 241b is provided corresponding to the second set of tabs 221b and is used to pass through the second set of tabs 221b to restrain the second set of tabs 221b. This improves the regularity of the first set of tabs 221a and the second set of tabs 221b in the accommodating cavity 211, and avoids the first set of tabs 221a and the second set of tabs 221b from being scattered or misaligned and overlapping with each other, thereby reducing the probability of short circuit connection inside the energy storage device 200 and improving the safety performance of the energy storage device 200. The energy storage device 200 of this embodiment is particularly suitable for battery scenarios where the electrode body 222 is large. When the size of the electrode body 222 along the first direction is large, its power output demand increases accordingly, requiring the configuration of more and larger tabs 221 to achieve efficient power transfer. By grouping the through holes 241 and binding multiple groups of tabs 221, the arrangement requirements of multiple tabs 221 and large-size tabs 221 can be accommodated. Under the premise of ensuring the regularity and safety of the tabs 221, the power transmission efficiency requirements of the large-size electrode body 222 are met, thus expanding the applicability of the energy storage device 200.

[0115] Optionally, in some embodiments, the polarity of the first set of tabs 221a is the same as that of the second set of tabs 221b. Specifically, both the first set of tabs 221a and the second set of tabs 221b are positive tabs; or, both the first set of tabs 221a and the second set of tabs 221b are negative tabs.

[0116] Optionally, in some other embodiments, the polarity of the first set of tabs 221a is different from that of the second set of tabs 221b. Specifically, the first set of tabs 221a are all positive tabs, and the second set of tabs 221b are all negative tabs.

[0117] In some embodiments, along the second direction, the size of the first set of tabs 221a is L3 (not shown in the figure), and the size of the single-layer tab 221 in the first set of tabs 221a is L4 (not shown in the figure). Then the energy storage device 200 satisfies the relationship: 0mm≤L3-L4≤1mm.

[0118] Specifically, the values ​​of L3-L4 can be, but are not limited to, 0mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, and 1mm.

[0119] In this embodiment, the dimension of a single layer of electrode 221 in the first group of electrode tabs 221a in the second direction is L4. When multiple layers of electrode tabs 221 are stacked and welded together to form the first group of electrode tabs 221a, it is difficult for the multiple layers of electrode tabs 221 to be completely aligned, resulting in an overall size that is too large. In other words, the multiple layers of electrode tabs 221 in the first group of electrode tabs 221a may be misaligned during the stacking process. The value of L3-L4 is the amount of misalignment of the multiple layers of electrode tabs 221 in the first group of electrode tabs 221a. Controlling the values ​​of L3-L4 to satisfy the range 0mm≤L3-L4≤1mm ensures that when the first set of tabs 221a are inserted through the first set of insertion holes 241a, each tab 221 in the first set of tabs 221a has a gap with the first sidewall 2411 and / or the second sidewall 2412. This avoids interference with the first sidewall 2411 and / or the second sidewall 2412, prevents the first set of tabs 221a from rubbing against the restraint member 240 and damaging the first set of tabs 221a, and ensures the structural integrity and electrical connection stability of the first set of tabs 221a.

[0120] In some embodiments, along the second direction, the size of the second set of tabs 221b is L5 (not shown in the figure), and the size of the single-layer tab 221 in the second set of tabs 221b is L6 (not shown in the figure). Then the energy storage device 200 satisfies the relationship: 0mm≤L5-L6≤1mm.

[0121] Specifically, the values ​​of L5-L6 can be, but are not limited to, 0mm, 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, and 1mm.

[0122] In this embodiment, the dimension of a single layer of electrode 221 in the second group of electrode tabs 221b in the second direction is L6. When multiple layers of electrode tabs 221 are stacked and welded together to form the second group of electrode tabs 221b, it is difficult for the multiple layers of electrode tabs 221 to be completely aligned, resulting in the overall size of the multiple layers of electrode tabs 221 being too large. In other words, there may be misalignment between electrode tabs 221 during the stacking process. The value of L5-L6 is the amount of misalignment of the multiple layers of electrode tabs 221 in the second group of electrode tabs 221b. Controlling the values ​​of L5-L6 to satisfy the range 0mm≤L5-L6≤1mm ensures that when the second set of tabs 221b passes through the second set of through holes 241b, each tab 221 in the second set of tabs 221b has a gap with the first sidewall 2411 and / or the second sidewall 2412. This avoids interference with the first sidewall 2411 and / or the second sidewall 2412, prevents the second set of tabs 221b from rubbing against the restraint member 240 and damaging the second set of tabs 221b, and ensures the structural integrity and electrical connection stability of the second set of tabs 221b.

[0123] In some embodiments, the first set of through holes 241a includes a first through hole 241c and a second through hole 241d, the first through hole 241c and the second through hole 241d being spaced apart along the third direction; the first set of electrode tabs 221a includes a first electrode tab 221c and a second electrode tab 221d, the first electrode tab 221c and the second electrode tab 221d being disposed on the same side of the electrode body 222 along the third direction, the first electrode tab 221c passing through the first through hole 241c, and the second electrode tab 221d passing through the second through hole 241d; the electrode post 232 includes The first pole post 232a, the adapter 233 includes a first adapter 233a, the first adapter 233a includes a first connecting portion 2331, a first body portion 2332 and a second connecting portion 2333 connected in sequence by bending. The first connecting portion 2331 and the second connecting portion 2333 are respectively bent relative to the first body portion 2332 toward the side away from the top cover 231. The first body portion 2332 is electrically connected to the first pole post 232a, the first connecting portion 2331 is electrically connected to the first tab 221c, and the second connecting portion 2333 is electrically connected to the second tab 221d.

[0124] Understandably, the first through hole 241c and the second through hole 241d both refer to through hole 241. The terms "first" and "second" are used only to distinguish through holes 241 in different positions.

[0125] Understandably, both the first tab 221c and the second tab 221d refer to tab 221. The terms "first" and "second" are used only to distinguish tabs 221 in different positions.

[0126] Understandably, the first electrode 221c and the second electrode 221d both belong to the first group of electrodes 221a, and the polarity of the first electrode 221c is the same as that of the second electrode 221d. Specifically, in some embodiments, the first electrode 221c and the second electrode 221d are both positive electrodes; in other embodiments, the first electrode 221c and the second electrode 221d are both negative electrodes.

[0127] Understandably, the first adapter 233a is configured in a "U" shape.

[0128] Optionally, in the first set of tabs 221a, there are multiple first tabs 221c, and multiple first tabs 221c are stacked; there are multiple second tabs 221d, and multiple second tabs 221d are stacked.

[0129] Understandably, when both the first tab 221c and the second tab 221d are positive tabs, the first terminal 232a is a positive terminal; when both the first tab 221c and the second tab 221d are negative tabs, the first terminal 232a is a negative terminal.

[0130] In this embodiment, the first adapter 233a includes a first connecting portion 2331, a first body portion 2332, and a second connecting portion 2333 that are bent and connected together. The first body portion 2332 is disposed on the side of the plastic part 234 away from the top cover 231. When the first pole post 232a is sequentially inserted through the plastic part 234 and the top cover 231, the first body portion 2332 achieves an electrical connection with the first pole post 232a. Compared to the scheme where the first adapter 233a is a flat plate structure, the first connecting portion 2331 and the second connecting portion 2333 are bent relative to the first body portion 2332 toward the side away from the top cover 231, so that the adapter 233 is arranged in a "U-shaped" structure. The first connecting portion 2331 and the second connecting portion 2333 are arranged closer to the tab 221 than the first body portion 2332, so that the tab 221 does not need to be too long to achieve electrical connection with the first adapter 233a when the overcurrent condition is met, thereby avoiding the tab 221 being too long and inserted backward into the electrode body 222, and improving the stability of the electrical connection between the electrode assembly 220 and the end cover assembly 230. Furthermore, the first set of tabs 221a includes a first tab 221c and a second tab 221d, which are arranged along the third direction. The first connecting part 2331 is disposed corresponding to the first tab 221c and electrically connected to the first tab 221c. The second connecting part 2333 is disposed corresponding to the second tab 221d and electrically connected to the second tab 221d. The first connecting part 2331 and the second connecting part 2333 serve as the welding points between the first adapter 233a and the first set of tabs 221a, which can ensure the stability of the weld width when the first set of tabs 221a is welded to the first adapter 233a, thereby ensuring the welding strength between the first adapter 233a and the first set of tabs 221a.

[0131] Understandably, "weld width" refers to the width of the molten metal covering the surface of the base material in the cross-section of the weld bead, that is, the width of the electrode 221 on the surface of the adapter 233 after the electrode 221 is welded to the adapter 233.

[0132] In one specific embodiment, along the third direction, the first tab 221c and the second tab 221d are respectively located on opposite sides of the first connecting portion 2331 and the second connecting portion 2333. That is, the first connecting portion 2331 is located on the side of the first tab 221c facing the second tab 221d, and the second connecting portion 2333 is located on the side of the second tab 221d facing the first tab 221c. This allows the adapter 233 and the tab 221 to be welded from the side during the welding process, reducing the difficulty of welding the adapter 233 and the tab 221. At the same time, it avoids pulling the tab 221 from the first direction, so as to prevent the tab 221 from being torn off and affecting the electrical performance of the energy storage device 200.

[0133] In some embodiments, the second set of through holes 241b includes a third through hole 241e and a fourth through hole 241f, the third through hole 241e and the fourth through hole 241f being spaced apart along the third direction; the second set of electrode tabs 221b includes a third electrode tab 221e and a fourth electrode tab 221f, the third electrode tab 221e and the fourth electrode tab 221f being disposed on the same side of the electrode body 222 along the third direction, the third electrode tab 221e passing through the third through hole 241e, and the fourth electrode tab 221f passing through the fourth through hole 241f; the electrode post 232 includes The second pole post 232b, the adapter 233 includes a second adapter 233b, the second adapter 233b includes a third connecting portion 2334, a second body portion 2335 and a fourth connecting portion 2336 that are bent and connected in sequence. The third connecting portion 2334 and the fourth connecting portion 2336 are respectively bent relative to the second body portion 2335 toward the side away from the top cover 231. The second body portion 2335 is electrically connected to the second pole post 232b, the third connecting portion 2334 is electrically connected to the third tab 221e, and the fourth connecting portion 2336 is electrically connected to the fourth tab 221f.

[0134] Understandably, the third through hole 241e and the fourth through hole 241f both refer to through hole 241. The terms "third" and "fourth" are used only to distinguish through holes 241 in different positions.

[0135] Understandably, the third tab 221e and the fourth tab 221f both refer to tab 221, and the terms "third" and "fourth" are only used to distinguish tabs 221 in different positions.

[0136] Understandably, both the third electrode 221e and the fourth electrode 221f belong to the second group of electrodes 221b, and the polarity of the third electrode 221e is the same as that of the fourth electrode 221f. Specifically, in some embodiments, both the third electrode 221e and the fourth electrode 221f are positive electrodes; in other embodiments, both the third electrode 221e and the fourth electrode 221f are negative electrodes.

[0137] Understandably, the second adapter 233b is configured in a "U" shape.

[0138] Optionally, in the second set of tabs 221b, there are multiple third tabs 221e, and the multiple third tabs 221e are stacked; there are multiple fourth tabs 221f, and the multiple fourth tabs 221f are stacked.

[0139] Understandably, when both the third tab 221e and the fourth tab 221f are positive tabs, the second pole piece 232b is a positive pole piece; when both the third tab 221e and the fourth tab 221f are negative tabs, the second pole piece 232b is a negative pole piece.

[0140] In this embodiment, the second adapter 233b includes a third connecting portion 2334, a second body portion 2335, and a fourth connecting portion 2336 that are bent and connected together. The second body portion 2335 is disposed on the side of the plastic part 234 away from the top cover 231. When the second pole post 232b is sequentially inserted through the plastic part 234 and the top cover 231, the second body portion 2335 achieves electrical connection with the second pole post 232b. Compared to the design where the second adapter 233b is a flat plate structure, the third connecting portion 2334 and the fourth connecting portion 2336 are bent relative to the second body portion 2335 towards the side away from the top cover 231, so that the adapter 233 is arranged in a "U-shaped" structure. The third connecting portion 2334 and the fourth connecting portion 2336 are located closer to the tab 221 than the second body portion 2335, so that the tab 221 does not need to be too long to achieve electrical connection with the second adapter 233b when the overcurrent condition is met. This avoids the tab 221 being too long and inserted backward into the electrode body 222, thereby improving the stability of the electrical connection between the electrode assembly 220 and the end cover assembly 230. Furthermore, the second set of tabs 221b includes a third tab 221e and a fourth tab 221f, which are arranged along the third direction. The third connecting part 2334 is disposed corresponding to the third tab 221e and electrically connected to the third tab 221e. The fourth connecting part 2336 is disposed corresponding to the fourth tab 221f and electrically connected to the fourth tab 221f. The third connecting part 2334 and the fourth connecting part 2336 serve as the welding points between the second adapter 233b and the second set of tabs 221b, which can ensure the stability of the weld width when the second set of tabs 221b and the second adapter 233b are welded, thereby ensuring the welding strength between the second adapter 233b and the second set of tabs 221b.

[0141] Understandably, "weld width" refers to the width of the molten metal covering the surface of the base material in the cross-section of the weld bead, that is, the width of the electrode 221 on the surface of the adapter 233 after the electrode 221 is welded to the adapter 233.

[0142] In one specific embodiment, along the third direction, the third tab 221e and the fourth tab 221f are respectively located on opposite sides of the third connecting portion 2334 and the fourth connecting portion 2336. That is, the third connecting portion 2334 is located on the side of the third tab 221e facing the fourth tab 221f, and the fourth connecting portion 2336 is located on the side of the fourth tab 221f facing the third tab 221e. This allows the adapter 233 and the tab 221 to be welded from the side during the welding process, reducing the difficulty of welding the adapter 233 and the tab 221. At the same time, it avoids pulling the tab 221 from the first direction, so as to prevent the tab 221 from being torn off and affecting the electrical performance of the energy storage device 200.

[0143] Understandably, when each of the energy storage devices 200 includes the first pole post 232a and the second pole post 232b, the first pole post 232a and the second pole post 232b are arranged at intervals along the second direction.

[0144] Understandably, when all the energy storage devices 200 include the first adapter 233a and the second adapter 233b, the first adapter 233a and the second adapter 233b are arranged at intervals along the second direction.

[0145] Please see also Figure 15 In some embodiments, the restraint member 240 further includes a support portion 246 disposed on the surface of the restraint member 243 opposite to the accommodating space 244, and the support portion 246 is used to abut against the electrode body 222.

[0146] In this embodiment, the support portion 246 is disposed on the surface of the restraint portion 243 opposite to the accommodating space 244 to form a rigid limit on the electrode assembly 220 in the first direction. The support portion 246 can prevent the electrode body 222 from shifting within the accommodating cavity 211 due to transportation vibration, charging and discharging expansion, etc., thereby ensuring the stability of the relative positions of the restraint member 240, the electrode body 222 and the tab 221, and thus ensuring the stability of the electrical connection between the tab 221 and the pole post 232, and improving the stability of the electrical performance of the energy storage device 200.

[0147] In some embodiments, there are multiple support portions 246, which are spaced apart along the second direction. The first set of through holes 241a is located between two adjacent support portions 246, and the second set of through holes 241b is located between two adjacent support portions 246.

[0148] In this embodiment, multiple support portions 246 are arranged at intervals along the second direction, so that the holding force of the restraining member 240 on the electrode body 222 can be distributed to multiple areas of the electrode body 222, avoiding local stress concentration and deformation of the electrode body 222 due to single-point support, especially ensuring the structural integrity of the connection area of ​​the tab 221 and reducing stress damage at the root of the tab 221. In addition, the first set of through holes 241a is located between two adjacent support portions 246, and the second set of through holes 241b is located between two adjacent support portions 246, which helps to improve the structural strength of the restraining member 240 along the second direction, avoids the restraining member 240 from warping or deforming due to stress during assembly, transportation or use, ensures the positional accuracy of the through holes 241, and thus prevents the tab 221 from shifting after being inserted into the through holes 241 and scraping against the tab 221, thereby improving the performance of the restraining member 240.

[0149] Optionally, in some embodiments, the support portion 246 has a plurality of vent holes 247, which penetrate two opposing surfaces of the support portion 246 along its thickness direction. By providing a plurality of vent holes 247, gas inside the accommodating cavity 211 can flow through the vent holes 247 from the side of the restraint member 240 facing the electrode body 222 to the side of the restraint member 240 away from the electrode body 222, so as to approach the explosion-proof valve 235 provided on the top cover 231, thereby improving the venting performance of the energy storage device 200.

[0150] Please see also Figures 4 to 15 Optionally, the number of end cap assemblies 230 is two sets, namely a first end cap assembly 230a and a second end cap assembly 230b. The first end cap assembly 230a and the second end cap assembly 230b are respectively connected to the opposite sides of the housing 210 along the first direction to close the accommodating cavity 211. The electrode tabs 221 include a first electrode tab group 221g and a second electrode tab group 221h. The first electrode tab group 221g and the second electrode tab group 221h are respectively located at opposite ends of the electrode body 222 along the first direction and are respectively electrically connected to the electrode body 222. The number of restraint members 240 is one. The restraint member 240 is disposed between the electrode body 222 and the first end cap assembly 230a. The first electrode tab group 221g passes through the through hole 241.

[0151] Understandably, both the first end cap assembly 230a and the second end cap assembly 230b refer to "end cap assembly 230". The terms "first" and "second" are used only to distinguish end cap assemblies 230 in different positions.

[0152] Understandably, both the first electrode group 221g and the second electrode group 221h refer to "electrode 221". Here, "first electrode group 221g" and "second electrode group 221h" are only used to distinguish electrode 221 in different positions.

[0153] Understandably, the first electrode group 221g includes the first electrode group 221a and the second electrode group 221b; the second electrode group 221h includes the first electrode group 221a and the second electrode group 221b.

[0154] Understandably, along the first direction, the first end cap assembly 230a, the first electrode tab 221c, the electrode body 222, the second electrode tab 221d, and the second end cap assembly 230b are arranged sequentially.

[0155] In this embodiment, the first end cap assembly 230a and the second end cap assembly 230b respectively enclose the opposite sides of the accommodating cavity 211 along the first direction, and the first electrode group 221g is electrically connected to the electrode post 232 of the first end cap assembly 230a, and the second electrode group 221h is electrically connected to the electrode post 232 of the second end cap assembly 230b, thereby realizing the electrical connection between the electrode assembly 220 and the two sets of end cap assemblies 230. Furthermore, in a specific embodiment, both the first end cap assembly 230a and the second end cap assembly 230b include a positive electrode post and a negative electrode post. This arrangement greatly shortens the current transmission path in the electrode assembly 220, effectively improving the energy efficiency of the energy storage device 200. Compared to a solution with only one set of end cap assemblies 230, the solution provided in this application halves the current path inside the energy storage device 200, greatly improving the current transmission efficiency and avoiding uneven heating of the electrode body 222, thereby extending the service life of the energy storage device 200. Furthermore, in the energy storage device 200, there is only one binding member 240. Understandably, the positive and negative tabs have different lengths, and the binding member 240 can be used to bind the longer positive tab. Compared to using two binding members 240 to bind the first tab group 221g and the second tab group 221h respectively, providing only one binding member 240 at one end of the electrode body 222 allows for a better reduction in the volume of the energy storage device 200 and an increase in its volumetric energy density.

[0156] In some embodiments, the number of restraint members 240 is two, and the restraint members 240 include a first restraint member 240a and a second restraint member 240b. The first restraint member 240a is disposed between the electrode body 222 and the first end cap assembly 230a, and the first tab 221c passes through the through hole 241 of the first restraint member 240a. The second restraint member 240b is disposed between the electrode body 222 and the second end cap assembly 230b, and the second tab 221d passes through the through hole 241 of the second restraint member 240b.

[0157] Understandably, the first restraint 240a and the second restraint 240b both refer to restraint 240, and the terms "first" and "second" are only used to distinguish restraints 240 in different positions.

[0158] Understandably, along the first direction, the first end cap assembly 230a, the first restraint member 240a, the electrode body 222, the second restraint member 240b, and the second end cap assembly 230b are arranged sequentially.

[0159] In this embodiment, there are two restraining members 240, namely a first restraining member 240a and a second restraining member 240b. The first restraining member 240a is disposed between the electrode body 222 and the first end cap assembly 230a and is used to restrain the first tab assembly 221g. The second restraining member 240b is disposed between the electrode body 222 and the second end cap assembly 230b and is used to restrain the second tab assembly 221h. This can improve the regularity and structural stability of the tabs 221 within the receiving cavity 211. Furthermore, when the first restraining member 240a and the second restraining member 240b are both disposed, the first tab assembly 221g and the second tab assembly 221h are of the same length, which is beneficial to improving the consistency of the electrode assembly 220. Meanwhile, when the positions of the first restraint member 240a and the first end cap assembly 230a are fixed, and the positions of the second restraint member 240b and the second end cap assembly 230b are fixed, the relative positions of the electrode assembly 220 and the housing 210 can be restricted, preventing the electrode assembly 220 from shifting during the use or transportation of the energy storage device 200, thereby improving the structural stability and electrical connection stability of the energy storage device 200.

[0160] Please see Figure 16 and Figure 17 This application provides an electrical system 300, which includes an electrical device 310 and an energy storage device 200 provided in this application. The energy storage device 200 is electrically connected to the electrical device 310 and is used to supply power to the electrical device 310.

[0161] Understandably, the energy storage device 200 is electrically connected to the electrical equipment 310.

[0162] In this embodiment, the power system 300 includes the energy storage device 200 provided in this application. In the energy storage device 200, the restraining member 240 can effectively restrain the electrode tab 221 to prevent the electrode tab 221 from being excessively bent or shifted. Simultaneously, it can prevent the electrode tab 221 from rubbing against the first sidewall 2411 and the second sidewall 2412 of the through hole 241. The electrode tab 221 has a long service life, thus ensuring the energy storage device 200 has good safety and reliability. When the energy storage device 200 is applied to the power system 300, it can provide stable power to the electrical equipment 310, which is beneficial to improving the user experience.

[0163] Optionally, the power system 300 in this application embodiment can be, but is not limited to, portable electronic devices such as mobile phones, tablets, laptops, desktop computers, smart bracelets, smartwatches, e-readers, and game consoles. It can also be a vehicle such as a car, truck, sedan, van, freight train, high-speed train, or electric vehicle. Furthermore, it can be various household appliances. Figure 16 The power system 300 in this embodiment is an energy storage battery cabinet.

[0164] It is understood that the power system 300 described in this embodiment is merely one form of the power system 300 used by the energy storage device 200, and should not be construed as a limitation on the power system 300 provided in this application, nor should it be construed as a limitation on the power system 300 provided in various embodiments of this application.

[0165] In this application, the terms "embodiment" and "implementation" mean that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of these phrases in various locations throughout the specification does not necessarily refer to the same embodiment, nor are they independent or alternative embodiments mutually exclusive with other embodiments. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described in this application can be combined with other embodiments. Furthermore, it should be understood that the features, structures, or characteristics described in the various embodiments of this application can be arbitrarily combined to form another embodiment that does not depart from the spirit and scope of the technical solution of this application, provided there is no contradiction between them.

[0166] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not intended to limit it. Although this application has been described in detail with reference to the above preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application should not depart from the spirit and scope of the technical solutions of this application.

Claims

1. An energy storage device, characterized in that, The energy storage device includes: A housing having a receiving cavity; An electrode assembly is disposed within the accommodating cavity. The electrode assembly includes a plurality of electrically connected tabs and an electrode body, and the plurality of tabs and the electrode body are arranged along a first direction. An end cap assembly, disposed on one side of the housing, for closing the receiving cavity; and A restraining member is located between the end cap assembly and the electrode body. The restraining member has a through-hole that penetrates two opposing surfaces of the restraining member along a first direction. The through-hole extends along a second direction, and a plurality of electrode tabs pass through the through-hole. The restraining member includes a surrounding portion and a restraining portion. The surrounding portion connects to the outer periphery of the restraining portion, and the restraining portion and the surrounding portion enclose a receiving space facing the end cap assembly. The restraining portion has the through-hole that penetrates two opposing surfaces of the restraining portion along the first direction and communicates with the receiving space. The restraining member also includes a protrusion that protrudes from the surface of the restraining portion facing the receiving space and surrounds the outer periphery of the through-hole. The end face of the protrusion facing away from the restraining portion is spaced apart from the end cap assembly. The protrusion provides orderly bending points for the electrode tabs, allowing the electrode tabs to bend directionally within the receiving space after passing through the through-hole. The first direction intersects the second direction. The through hole has a first sidewall and a second sidewall disposed opposite to each other along the second direction. Along the second direction, the distance between the first sidewall and the second sidewall is greater than the size of the ends of the plurality of tabs near the electrode body.

2. The energy storage device according to claim 1, characterized in that, The plurality of tabs have a first end and a second end arranged opposite to each other. The first end is connected to the electrode body, and the second end is arranged away from the electrode body. The size of the plurality of tabs gradually decreases from the first end to the second end.

3. The energy storage device according to claim 2, characterized in that, Along the second direction, the distance between the first sidewall and the second sidewall is L1, and the maximum size of the plurality of tabs is L2. Then the energy storage device satisfies the relationship: 0.95≤L2 / L1≤0.

99.

4. The energy storage device according to claim 2, characterized in that, Along the second direction, the minimum distance d1 between the first end and the first sidewall is in the range of 1mm≤d1≤10mm; and / or, along the second direction, the minimum distance d2 between the first end and the second sidewall is in the range of 1mm≤d2≤10mm.

5. The energy storage device according to claim 1, characterized in that, Along the third direction, the ratio γ of the width of the through hole to the total thickness of the plurality of tabs passing through the through hole is in the range of 2.1≤γ≤10, wherein the third direction intersects the first direction and the second direction respectively.

6. The energy storage device according to any one of claims 1 to 5, characterized in that, The end cap assembly includes a top cover, a pole post, and an adapter. The top cover is connected to the housing, the pole post is installed on the top cover, and the adapter is located within the accommodating space. The adapter is electrically connected to the pole post and the plurality of tabs respectively.

7. The energy storage device according to claim 6, characterized in that, Along the first direction, the end face of the circumferential portion facing away from the electrode body is positioned closer to the top cover than the end face of the protrusion facing away from the electrode body.

8. The energy storage device according to claim 6, characterized in that, The number of through holes is multiple, the multiple through holes include a first group of through holes, the multiple electrode tabs include a first group of electrode tabs, the first group of electrode tabs is disposed on one side of the electrode body, and the first group of electrode tabs passes through the first group of through holes.

9. The energy storage device according to claim 8, characterized in that, The plurality of through holes further includes a second set of through holes, the first set of through holes and the second set of through holes being arranged at intervals along the second direction; the plurality of electrode tabs further includes a second set of electrode tabs, the first set of electrode tabs and the second set of electrode tabs being disposed on the same side of the electrode body and electrically connected to the electrode body respectively, the first set of electrode tabs and the second set of electrode tabs being arranged at intervals along the second direction; the second set of electrode tabs passing through the second set of through holes.

10. The energy storage device according to claim 8, characterized in that, The first set of through holes includes a first through hole and a second through hole, which are spaced apart along a third direction; the first set of electrode tabs includes a first electrode tab and a second electrode tab, which are disposed on the same side of the electrode body along the third direction, with the first electrode tab passing through the first through hole and the second electrode tab passing through the second through hole, wherein the third direction intersects the first direction and the second direction respectively; The electrode post includes a first electrode post, and the adapter includes a first adapter. The first adapter includes a first connecting portion, a first body portion, and a second connecting portion that are bent and connected in sequence. The first connecting portion and the second connecting portion are bent relative to the first body portion toward the side away from the top cover. The first body portion is electrically connected to the first electrode post, the first connecting portion is electrically connected to the first electrode tab, and the second connecting portion is electrically connected to the second electrode tab.

11. The energy storage device according to claim 9, characterized in that, The second set of through holes includes a third through hole and a fourth through hole, which are spaced apart along a third direction; the second set of electrode tabs includes a third electrode tab and a fourth electrode tab, which are disposed on the same side of the electrode body along the third direction, with the third electrode tab passing through the third through hole and the fourth electrode tab passing through the fourth through hole, wherein the third direction intersects the first direction and the second direction respectively; The electrode post includes a second electrode post, and the adapter includes a second adapter. The second adapter includes a third connecting portion, a second body portion, and a fourth connecting portion that are bent and connected in sequence. The third connecting portion and the fourth connecting portion are bent relative to the second body portion toward the side away from the top cover. The second body portion is electrically connected to the second electrode post, the third connecting portion is electrically connected to the third electrode lug, and the fourth connecting portion is electrically connected to the fourth electrode lug.

12. The energy storage device according to claim 9, characterized in that, The restraint member further includes a support portion disposed on the surface of the restraint portion opposite to the accommodating space, and the support portion is used to abut against the electrode body.

13. The energy storage device according to claim 12, characterized in that, The number of support parts is multiple, and the multiple support parts are spaced apart along the second direction. The first set of through holes is located between two adjacent support parts, and the second set of through holes is located between two adjacent support parts.

14. The energy storage device according to claim 9, characterized in that, Along the second direction, if the size of the first set of electrodes is L3, and the size of a single-layer electrode in the first set of electrodes is L4, then the energy storage device satisfies the relationship: 0mm≤L3-L4≤1mm; or, Along the second direction, the size of the second set of electrodes is L5, and the size of the single-layer electrode in the second set of electrodes is L6. Then the energy storage device satisfies the relationship: 0mm≤L5-L6≤1mm.

15. An electrical system, characterized in that, The power system includes: Electrical equipment; and The energy storage device according to any one of claims 1 to 14, wherein the energy storage device is electrically connected to the electrical equipment for supplying power to the electrical equipment.

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