battery cells

Abstract

This application discloses a battery cell, relating to the field of battery technology. The battery cell includes a housing, a cover assembly, multiple sets of electrode core units, and a first separator. The housing has an opening; the cover assembly is disposed at the opening; the multiple sets of electrode core units are stacked and installed within the housing, each electrode core unit including at least one electrode core disposed along the stacking direction; the first separator is disposed between at least partially adjacent sets of electrode core units; in the stacking direction of the multiple sets of electrode core units, the projection surface of the first separator covers the projection surface of the electrode core unit; the first separator is an elastic insulating separator. This application can be used to simultaneously meet the requirements for accommodating expansion and the requirements for electrode core constraint.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell. Background Technology

[0002] Currently, battery cells expand due to gas production during cycling, so a gap is reserved between the battery cell casing and the electrode core to accommodate the expansion.

[0003] The group margin is determined by the ratio of the total thickness of the electrode core to the thickness of the cell. However, as the size of the cell gradually increases, it is difficult to find a group margin that can simultaneously satisfy the requirements of accommodating expansion and constraining the electrode core. If the group margin is too small, it means that the gap between the electrode core and the inner wall of the casing is too large. The electrode core lacks sufficient constraint within the casing and is prone to poor contact at the electrode interface due to shaking, which affects the charging and discharging efficiency. If the group margin is too large, it means that the gap between the electrode core and the inner wall of the casing is too small. The casing cannot accommodate the expansion of the electrode core, and the electrode core will be squeezed and damaged, ultimately leading to a sharp drop in performance. Utility Model Content

[0004] The main objective of this application is to propose a battery cell that addresses the technical problem of simultaneously satisfying the requirements for accommodating expansion and the requirements for core constraint.

[0005] On the one hand, a battery cell is provided, comprising: A housing having an opening; A cover assembly is disposed at the opening; Multiple sets of electrode core units are stacked and installed inside the housing; each electrode core unit includes at least one electrode core arranged along the stacking direction. The first partition is disposed between at least two partially adjacent sets of pole core units; in the stacking direction of the multiple sets of pole core units, the projection surface of the first partition covers the projection surface of the pole core unit; the first partition is an elastic insulating partition.

[0006] In one embodiment, each group of the core units includes a plurality of stacked cores.

[0007] In one embodiment, multiple sets of the electrode core units are arranged along the width direction of the housing; The number of the first partition plates = the number of the pole core units - 1.

[0008] In one embodiment, the thickness of the first partition is 1.5 mm to 5 mm; the width of the shell is 200 mm to 350 mm; and the thickness of the pole core is 15 mm to 100 mm.

[0009] In one embodiment, the thickness of each set of the core units is 20 mm to 40 mm.

[0010] In one embodiment, the height of the first partition is not less than the height of the electrode core, and the length of the first partition is not less than the length of the electrode core.

[0011] In one embodiment, the first partition is made of any one of fluororubber board, EPDM rubber board, or polypropylene foam board.

[0012] In one embodiment, multiple sets of the electrode core units are arranged along the width direction of the housing, and the cell further includes a second partition. The second partition is provided between at least one inner sidewall of the housing in the width direction and the electrode core unit; the second partition is an elastic insulating partition.

[0013] In one embodiment, there are two second partitions, which are disposed opposite to each other on both sides of the plurality of pole core units along the width direction of the housing; The battery cell includes a separator, which includes a first separator and a second separator. The number of separators is equal to the number of electrode core units plus 1.

[0014] In one embodiment, the cover plate assembly includes a cover plate body and a first pole post and a second pole post disposed on the cover plate body; each of the pole cores has a first pole tab and a second pole tab; The battery cell further includes a first current collector structure and a second current collector structure. The first current collector structure is used to connect the first tab and the first terminal of the battery core. The second current collector structure is used to connect the second tab and the second terminal of the battery core.

[0015] In one embodiment, the battery cell further includes a first insulating structure; The first insulating structure is provided between the first current collecting structure and the electrode core; Alternatively, the first insulating structure may be provided between the second current collecting structure and the electrode core; Alternatively, the first insulating structure may be provided between the first current collecting structure and the electrode core, and between the second current collecting structure and the electrode core.

[0016] The above-described one or more technical solutions in the embodiments of this application have at least one of the following technical effects: The first partition is an elastic insulating partition. Due to its elasticity, the first partition is compressed after multiple sets of core units are assembled into the housing. This allows the expansion space or gap reserved inside the housing to be filled, so that the cores of multiple sets of core units will not shake or be damaged due to excessive gaps during manufacturing and transportation. By separating two adjacent sets of core units with the first partition, the shaking of the cores in the housing is reduced, the interface contact stability between the core plates is maintained, and the constraint requirements of the cores are met. This effectively solves the problem that it is impossible to simultaneously meet the expansion requirements and core constraint requirements of large-size or high-capacity cells. The electrode core unit includes at least one electrode core arranged along the stacking direction; during the cell cycling process, the first partition restricts the expansion displacement of each electrode core unit through physical support and is used to separate adjacent electrode core units. Due to its elasticity, the first partition buffers the expansion force generated by the expansion of the electrode core of the electrode core unit, thereby reducing the accumulation of expansion force in the stacking direction of the electrode core units and allowing the expansion force of the electrode core unit to be uniformly transmitted to the housing, reducing the risk of housing failure and improving the cycle performance of the cell. The first partition is also used to fix the position of the pole core unit. In the stacking direction of multiple pole core units, the projection surface of the first partition covers the projection surface of the pole core unit. Due to its insulation, the first partition is used to protect the edge of the pole core unit and avoid direct contact between the edges of adjacent pole core units, thereby reducing the risk of short circuit between pole core units. When each core unit comprises one core, a first partition between two adjacent cores allows each core to be independently confined within the housing, further improving the interfacial contact stability between the core's electrodes and reducing the impact of core expansion on cell failure. When each core unit comprises multiple cores stacked together, reducing the number of first partitions decreases their occupation of the housing's internal space, thereby increasing the overall core volume ratio, improving energy density, meeting the requirements for high-capacity cell manufacturing, simplifying the stacking process, and improving production efficiency. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of one embodiment of the battery cell of this application; Figure 2 for Figure 1 A cross-sectional view of an embodiment in the AA direction; Figure 3 for Figure 1 A cross-sectional view of another embodiment in the AA direction; Figure 4 for Figure 1 A cross-sectional view of another embodiment in the AA direction; Figure 5 This is an exploded view of another embodiment of the battery cell of this application; Figure 6 This is a schematic diagram of the structure of one embodiment of the first cover plate assembly of this application; Figure 7 This is an exploded view of yet another embodiment of the battery cell of this application.

[0019] Explanation of icon numbers: 100. Shell; 101. Opening; 110. First plate; 120. Second plate; 200, Cover plate assembly; 210, First cover plate assembly; 211, First cover plate body; 220, Second cover plate assembly; 231, First pole post; 232, Second pole post; 240, Pressure relief structure; 250, Injection hole; 310, Core unit; 311, Core; 3111, Positive tab; 3112, Negative tab; 320, Separator; 321, First separator; 322, Second separator; 410. First collector structure; 420. Second collector structure; 500, First insulating structure; 510, Through hole; 600. Second insulation structure.

[0020] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] 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 a part of the embodiments of this application, and not all of the 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.

[0022] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0024] Currently, battery cells expand due to gas generation during cycling, so a gap is reserved between the cell casing and the electrode core to accommodate this expansion. Therefore, as battery capacity increases, cell size also increases to allow for expansion space.

[0025] The group margin is determined by the ratio of the total electrode thickness to the cell thickness. Thickness group margin = total electrode thickness ÷ cell thickness (cell width).

[0026] Taking the battery cell in related technologies as an example, the cell thickness is determined by the cell width, which ranges from 12mm to 80mm. The number of electrodes inside the cell ranges from 1 to 4, with a gap between the electrodes and the casing to allow for electrode expansion. Generally, the electrode thickness ÷ cell width is designed to be 0.9 to 0.95 (thickness margin). However, to increase battery capacity, the cell size needs to be increased accordingly. As the cell size gradually increases, such as when the cell width is greater than 200mm, it is difficult to find a thickness margin that can simultaneously meet the requirements for accommodating expansion and constraining the electrodes. If the thickness margin is too small, it means that the gap between the electrode and the inner wall of the casing is too large, and the electrode lacks sufficient constraint within the casing. This can easily lead to poor contact at the electrode interface due to shaking, affecting charging and discharging efficiency. If the thickness margin is too large, it means that the gap between the electrode and the inner wall of the casing is too small, and the casing cannot accommodate the electrode expansion. The electrode will be squeezed and damaged, ultimately causing a performance drop.

[0027] like Figure 1 , Figure 2 As shown, in order to simultaneously meet the expansion requirements and core constraint requirements of large-size or high-capacity battery cells, this application proposes a high-capacity battery cell. The battery cell includes a housing 100, a cover plate assembly 200, multiple sets of core units 310 and a first partition 321. The housing 100 has an opening 101; the cover plate assembly 200 is disposed at the opening 101.

[0028] Multiple sets of core units 310 are stacked and installed within the housing 100. Each core unit 310 includes at least one core 311 disposed along the stacking direction. A first partition 321 is disposed between at least partially adjacent sets of core units 310. In the stacking direction of the multiple sets of core units 310, the projection surface of the first partition 321 covers the projection surface of the core unit 310; the first partition 321 is an elastic insulating partition.

[0029] The electrode core 311 comprises a positive electrode sheet, a separator, and a negative electrode sheet stacked together. The stacking direction of the positive electrode sheet, separator, and negative electrode sheet is the same as the stacking direction of the multiple electrode cores 311. During the use of the battery cell, lithium ions flow between the positive and negative electrodes (the process of insertion and extraction from the electrode sheets: during charging, lithium ions are extracted from the positive electrode and inserted into the negative electrode; during discharging, lithium ions are extracted from the negative electrode and inserted into the positive electrode). The electrode sheets expand due to the insertion of lithium ions, generating expansion force. As the battery cell is used for a longer period of time, the electrode core 311 expands due to the insertion of lithium ions, and the thickness of the electrode core 311 continuously increases, which in turn generates expansion force.

[0030] Multiple sets of electrode core units 310 are installed inside the housing 100, and expansion space is reserved inside the housing 100 to meet the expansion requirements. At least some of the adjacent sets of electrode core units 310 are provided with a first partition 321. The first partition 321 is an elastic insulating partition. The elastic first partition 321 can absorb the expansion force generated by the expansion of the electrode core 311, so as to avoid excessive expansion force and affect the cycle performance of the cell. At the same time, in the initial stage of cycling, the first partition 321 can fill the tiny gaps on the surface of the electrode core 311 when it is not expanded by its own elasticity or compression, so that the electrode core 311 and the first partition 321 fit tightly, which to a certain extent avoids the problems of poor contact and uneven stress caused by gaps.

[0031] like Figure 2As shown, large-capacity battery cells, due to their large size and low rigidity, are prone to wobbling during charging, discharging, or transportation due to excessive gaps, leading to electrode misalignment and affecting ion conduction efficiency. In the embodiments of this application, the first separator 321 is an elastic insulating separator. Due to its elasticity, the first separator 321 is compressed after multiple sets of electrode core units 310 are assembled into the housing 100, which fills the expansion space or gap reserved inside the housing 100. This prevents the electrode cores 311 of the multiple sets of electrode core units 310 from wobbling and being damaged due to excessive gaps during manufacturing and transportation. By separating two adjacent sets of electrode core units 310 with the first separator 321, the electrode cores 311 can also avoid wobbling within the housing 100 to a certain extent, maintaining the interface contact stability between the electrodes (positive electrode, separator, and negative electrode) of the electrode cores 311, meeting the constraint requirements of the electrode cores 311, and effectively solving the problem of not being able to simultaneously meet the expansion requirements of large-size or large-capacity battery cells and the constraint requirements of the electrode cores 311. During cell cycling, the first separator 321 provides physical support, restricting the expansion displacement of each electrode core unit 310 and separating adjacent electrode core units 310. Due to its elasticity, the first separator 321 buffers the expansion force generated by the expansion of the electrode core 311 of the electrode core unit 310, thus preventing the expanding electrode core unit 310 from directly and without buffering the expansion force to the adjacent electrode core unit 310. This reduces the accumulation of expansion force in the stacking direction of the electrode core units 310 and allows the expansion force of the electrode core unit 310 to be evenly transmitted to the housing 100, reducing the risk of housing 100 failure. The expansion force generated by the electrode core 311 during cell cycling is absorbed by the first separator 321 built into the cell, which can also prevent the electrode from being subjected to excessive force and causing abnormal electrolyte absorption, thereby improving the cell's cycling performance. The first partition 321 also serves to fix the position of the electrode core unit 310. In the stacking direction of multiple sets of electrode core units 310, the projection surface of the first partition 321 covers the projection surface of the electrode core unit 310. Due to its insulation properties, the first partition 321 is used to protect the edges of the electrode core unit 310, thereby avoiding direct contact between the edges of adjacent electrode core units 310 to a certain extent, thus reducing the risk of short circuits between electrode core units 310. In addition, the heat conduction through the first partition 321 can also improve the heat dissipation effect of the battery cell.

[0032] like Figure 2 , Figure 3As shown in the embodiments of this application, the positive electrode of the core has a positive tab 3111, and the negative electrode has a negative tab 3112. Because the number of layers welded to the tabs is limited by the power of the welding equipment, there are multiple cores 311. Each core 311 includes multiple positive electrode sheets, multiple negative electrode sheets, and multiple separators stacked in a sequence of one negative electrode sheet, one separator, one positive electrode sheet, one separator, and one negative electrode sheet. Each group of core units 310 includes at least one core 311; that is, each group of core units 310 may include one, two, three, or more cores 311. The number of cores 311 in each group of core units 310 may be equal or unequal. When the number of electrode cores 311 in multiple sets of electrode core units 310 is equal, the size, expansion, and heat of each electrode core unit 310 are similar, which can make the first separator 321 and the shell 100 subject to uniform force and facilitate the control of the uniformity of the internal structure of the cell, reducing manufacturing complexity and manufacturing cost. When the number of electrode cores 311 in multiple sets of electrode core units 310 is not equal, it can be adapted to electrode core units 310 with different numbers of electrode cores 311, meeting the manufacturing requirements of cells of different sizes and different total battery capacities.

[0033] like Figure 2 , Figure 3 As shown, each set of pole core units 310 includes at least one pole core 311 disposed along the stacking direction.

[0034] like Figure 2 As shown, in one embodiment, each set of pole core units 310 includes a pole core 311.

[0035] When the number of pole cores 311 in each group of pole core units 310 is one, each pole core 311 can be precisely constrained by the first partition 321 located between two adjacent pole cores 311, so that each pole core 311 is independently confined within the housing 100, which is used to further improve the interface contact stability between the pole pieces of the pole core 311 and reduce the impact of the expansion of each pole core 311 on cell failure.

[0036] like Figure 3 As shown, in another embodiment, each set of pole core units 310 includes a plurality of pole cores 311 stacked together.

[0037] When there are multiple pole cores 311 in each pole core unit 310, the number of first partitions 321 can be reduced. By reducing the number of first partitions 321, the first partitions 321 occupy less space inside the housing 100, thereby increasing the total volume ratio of pole cores 311, increasing energy density, meeting the requirements for manufacturing large-capacity cells, and simplifying the stacking process and improving production efficiency.

[0038] Depending on the specific circumstances, all pole core units 310 may be configured to include one pole core 311; or, all pole core units 310 may be configured to include multiple stacked pole cores 311; or, some pole core units 310 may include one pole core 311, and some pole core units 310 may include multiple stacked pole cores 311; no specific limitations are imposed here.

[0039] like Figure 2 , Figure 3 As shown, each set of pole core units 310 includes at least one pole core 311, and the number of pole cores 311 in multiple sets of pole core units 310 may be equal or unequal.

[0040] For example, a first partition 321 may be provided between each connected electrode core 311, that is, each group of electrode core units 310 includes one electrode core 311, and a first partition 321 is provided between one electrode core 311 and an adjacent electrode core 311; alternatively, each group of electrode cores 311 may include two, three, or more electrode cores 311, and a first partition 321 is provided between every two, three, or more electrode cores 311, that is, a first partition 321 is provided between every multiple electrode cores 311 and an adjacent multiple electrode cores 311. As the battery cell is used for an extended period, the thickness of the electrode cores 311 will also increase, thus generating an expansion force along the stacking direction of the multiple groups of electrode core units 310. The first partition 321 is used to separate adjacent electrode cores 311 and to buffer the expansion force generated by the expansion of the electrode cores 311, which can, to a certain extent, prevent the electrode cores 311 from being squeezed and damaged, thus affecting the battery cell life. During battery cycling, the repeated expansion and contraction of the cells may cause relative displacement of the electrode cores 311 in the stacking direction. At least some adjacent electrode cores 311 are provided with a first partition 321, which can be used to fix the position of the electrode cores 311 and reduce the possible stacking misalignment problem. The first partition 321 is an elastic insulating partition made of elastic insulating material, which is used to prevent the electrode cores 311 from directly contacting each other due to external forces such as vibration and compression, thereby reducing the risk of short circuit.

[0041] The multiple electrode cores 311 disposed within the housing 100 share a common electrolyte, resulting in inconsistent pressure differences between them and leading to lithium plating. Since connecting them in series would exacerbate the risk of lithium plating, a structure is adopted in which multiple electrode cores 311 are connected in parallel. When multiple electrode cores 311 are connected in parallel, the first separator 321 balances the temperature of the electrode cores 311 through thermal conduction, reducing the inconsistency in internal resistance caused by temperature differences and thus optimizing the uniformity of current distribution; it also enhances heat dissipation and slows down the rate of thermal runaway propagation.

[0042] like Figure 2As shown, each group of pole core units 310 may include one pole core 311, and a first partition 321 may be provided between one pole core 311 and an adjacent pole core 311; or each group of pole core units 310 may include multiple pole cores 311, and other partitions may be provided between two adjacent pole cores 311 in each group of pole core units 310.

[0043] like Figure 2 , Figure 3 , Figure 4 As shown, for example, multiple electrode core units 310 and the first separator 321 disposed between adjacent electrode core units 310 can be configured as a single molded part to improve the overall structural strength and reduce stress concentration problems that may occur during cell charging and discharging to a certain extent. In this way, modular design of multiple electrode cores 311 and the first separator 321 can be realized, simplifying the overall structure. By reducing the assembly gap between the electrode cores 311 and the first separator 321, the overall volume can be reduced, thereby accommodating more electrode cores 311 in the same housing 100 space and improving energy density. Alternatively, multiple electrode core units 310 and the first separator 321 disposed between any adjacent electrode core units 310 can also be set independently to suit the assembly of different numbers of electrode cores 311, meet different battery capacity requirements, and facilitate cell assembly and maintenance.

[0044] Examples of embodiments in which a first partition 321 is provided between any three or four other adjacent pole cores 311 can be referred to accordingly without further details.

[0045] like Figure 5 As shown, the embodiments of this application apply to prismatic battery cells. The length of the battery cell represents the longer side dimension of the bottom surface of the housing 100, and the width of the battery cell represents the shorter side dimension of the bottom surface of the housing 100. The length direction L of the housing 100 is perpendicular to the width direction W. The height of the battery cell represents the side dimension perpendicular to the bottom surface of the housing 100, and the height direction H of the housing 100 is perpendicular to the bottom surface of the housing 100. The length, width, and height of the housing 100 correspond to the length, width, and height of the battery cell, respectively. The width of the battery cell represents the thickness, and the thickness of the electrode core 311 is determined by the dimension of the electrode core 311 in the width direction W of the housing 100. Multiple electrode cores 311 are stacked along the width direction W, and the width of the housing 100 determines the number of electrode cores 311.

[0046] Multiple electrode cores 311 are arranged in an orderly manner along the width direction W of the housing 100, so that the stack thickness matches the width of the housing 100. In addition, the deformation of the electrode cores 311 is constrained by the sidewalls of the housing 100 to reduce the risk of misalignment. As the battery cell is used for a longer period of time, the thickness of the electrode cores 311 will continue to increase, which will generate an expansion force along the width direction W of the housing 100. The separator 320 is used to separate adjacent electrode cores 311 and to buffer the expansion force generated by the expansion of the electrode cores 311.

[0047] like Figure 5 As shown, in one embodiment, the length of the housing 100 is 400mm to 700mm, the width of the housing 100 is 200mm to 350mm, and the height of the housing 100 is 200mm to 350mm. The length, width, and height of the housing 100 are larger than those of other battery cells in the related art, allowing for the installation of electrode cores 311 with larger battery capacity, increasing the number of electrode cores 311 stacked, and effectively improving the total battery capacity.

[0048] In some embodiments, the length of the housing 100 can be any length range such as 400mm-550mm, 550mm-700mm, 450mm-700mm, 400mm-700mm, etc., or any length range such as 700mm-850mm; or, it can be any length suitable for actual use such as 400mm, 450mm, 500mm, 550mm, 600mm, 650mm, 700mm; it is not limited here. The width of the housing 100 can be any width range such as 200mm-350mm, 200mm-300mm, 200mm-400mm, 250mm-300mm, 300mm-350mm, 250mm-400mm; or, it can be any width suitable for actual use such as 200mm, 300mm, 350mm, 400mm; it is not limited here. The height of the housing 100 can be any range of 200mm-250mm, 250mm-300mm, 300mm-350mm, 200mm-300mm, 200mm-350mm, etc.; or, it can be any practical height such as 200mm, 250mm, 300mm, 350mm, etc.; it is not limited here.

[0049] In the embodiments of this application, the total battery capacity of the battery cell is 3200Ah to 7500Ah, and the battery capacity of the electrode core 311 is 200Ah to 850Ah. By using electrode cores 311 with a battery capacity of 200Ah to 850Ah, and by increasing the battery capacity and energy density of a single electrode core 311, a large-capacity battery cell can be directly assembled from large-capacity electrode cores 311. This effectively reduces the use of connecting components such as electrical connection components and strength connection components, thereby simplifying the internal structure of the battery cell. In related technologies, small-capacity battery cells need to be connected in series and parallel to form modules to solve the voltage and battery capacity matching problem, and then combined layer by layer to form a larger system. However, the improved structure of this application, with a total battery capacity of 3200Ah to 7500Ah, basically meets the requirements of energy storage systems. The cells can be used directly as energy storage systems, or two, three, four, or other multiple cells can be connected in parallel or series to form energy storage systems, effectively reducing intermediate levels such as modules, energy storage packs, and clusters. In this way, not only is the total battery capacity effectively increased, but by eliminating the intermediate casing 100 and the space for spacing, system space can also be saved and energy density can be increased. By reducing the electrical connection components and strength connection components required for multi-level parallel and series connections, the contact resistance caused by the connection can be reduced, effectively reducing energy loss, effectively reducing material costs, improving assembly and replacement efficiency, and further reducing labor costs.

[0050] By increasing the capacity and energy density of the 311 core battery, 311 cores with capacities ranging from 200Ah to 850Ah can be directly assembled into cells, resulting in a total cell capacity of 3200Ah to 7500Ah. These cells can be used directly as energy storage systems, or a small number of cells can be connected in series and parallel to form an energy storage system. Alternatively, multiple cells can be used to form modules or battery packs to meet the requirements of energy storage systems with larger capacities. This effectively reduces the cost of cells and energy storage systems, enabling the energy storage system to operate stably and continuously, meeting the high-power and long-term power generation needs of energy storage systems, and solving the technical problem of limited total cell capacity in traditional cells. Simultaneously, it reduces the use of connecting components, making the overall structure of the energy storage system more compact, effectively improving volumetric energy density, and increasing space utilization.

[0051] like Figure 5As shown, in one embodiment, the cover plate assembly of the battery cell includes a cover plate body and a first terminal 231 and a second terminal 232 disposed on the cover plate body, wherein one of the first terminal 231 and the second terminal 232 is a positive terminal and the other is a negative terminal. The terminals (first terminal 231 and second terminal 232) of the battery cell extend from the side end of the battery cell. Compared to the structure where the terminals of the battery cell extend from the top, extending the terminals (first terminal and second terminal) from the side end of the battery cell is not merely a spatial rotation of 90°. By extending the terminals through the side end, no additional top connector is required, effectively reducing the space occupied by the battery cell at the top. Furthermore, the heat generated by the terminals can be directly dissipated through the side end, effectively improving heat dissipation efficiency.

[0052] like Figure 5 As shown, exemplarily, the width of the battery cell (width of the housing 100) is 200mm to 400mm, and the electrode core 311 has tabs (positive tab 3111, negative tab 3112). The tabs can be welded using various welding processes such as ultrasonic welding, laser welding, and resistance welding. In some embodiments of this application, the lower limit of the number of welding layers is 15mm, and the maximum number of layers is 135. When the number of layers exceeds 135, incomplete welding is likely to occur. Therefore, the upper limit of the number of welding layers is 135mm. Taking the aluminum foil thickness as an example to determine the welding thickness, the welding aluminum foil thickness is generally 0.013mm. Thus, the total welding process thickness can be further determined as: welding layer thickness × aluminum foil thickness, and the total welding process thickness is 0.195mm to 1.755mm.

[0053] Because the smallest unit of the electrode core 311 consists of one positive electrode sheet, one separator sheet, and one negative electrode sheet, with the positive electrode sheet having a positive tab 3111 and the negative electrode sheet having a negative tab 3112, the lower limit of the electrode core 311 thickness is not limited by the welding process and can be determined by the external dimensions of the battery cell (length, width, height, etc.); the upper limit of the electrode core 311 thickness is limited by the tab welding process. The reason for this limitation is that the thicker the electrode core 311, the more layers of lamination (positive electrode sheet, negative electrode sheet, separator) are required. The more layers there are, the higher the defect rate of a single electrode core 311 and the higher the manufacturing cost. For example, when the thickness of the positive electrode sheet is 0.15mm, the thickness of the separator is 0.012mm, and the thickness of the negative electrode sheet is 0.17mm, the maximum thickness of multiple electrode cores 311 = maximum number of welding layers × (thickness of positive electrode sheet + thickness of separator + thickness of negative electrode sheet) = 135 × (0.15mm + 0.012mm + 0.17mm) = 44.82mm. Rounding to the nearest integer, the maximum thickness of multiple electrode cores 311 is 45mm.

[0054] Based on this, the number of electrode cores 311 is calculated. The lower limit of the number of electrode cores 311 = lower limit of cell width ÷ upper limit of electrode core thickness 311 = 200mm ÷ 45mm ≈ 4.4444. Rounding to the nearest integer, the lower limit of the number of electrode cores 311 is 5. Since the lower limit of electrode core thickness 311 can theoretically be very small, the actual number of electrode cores 311 can be very large. However, more electrode cores 311 mean more electrode tab welding processes are required, resulting in higher manufacturing costs. To reduce manufacturing costs and improve efficiency, the thickness of electrode cores 311 can be set to be no less than 16mm, and the number of electrode cores 311 can not exceed 25 (determined based on the upper limit of cell width and the lower limit of electrode core thickness 311, the number of electrode cores 311 ≤ 400mm ÷ 16mm = 25). Therefore, in the embodiments of this application, the number of electrode cores 311 can be determined to be 5 to 25, such as 5, 6, 10, 13, 16, 20, 25, or other multiples.

[0055] When the battery capacity of multiple 311 pole pieces is equal, the battery capacity of a single 311 pole piece = the total battery capacity of the cells ÷ the number of 311 pole pieces. Therefore, the ratio of the battery capacity of a single 311 pole piece to the total battery capacity of the cells = 1 ÷ the number of 311 pole pieces. Thus, the ratio of the battery capacity of a single 311 pole piece to the total battery capacity of the cells can be obtained as: (1 ÷ upper limit of the number of 311 pole pieces) ~ (1 ÷ lower limit of the number of 311 pole pieces) = 1 ÷ 25 ~ 1 ÷ 5 = 4% ~ 20%.

[0056] The total battery capacity of the cells ranges from 3200Ah to 7500Ah. The total battery capacity of the cells can be any range, such as 3200Ah to 5500Ah, 5500Ah to 7500Ah, 3500Ah to 6500Ah, 6000Ah to 7500Ah, 4500Ah to 6500Ah, or 3200Ah to 7500Ah; or it can be 3200Ah, 3500Ah, 4000Ah, 4500Ah, 5000Ah, 5500Ah, 6000Ah, 6500Ah, 7000Ah, or 7500Ah; no specific limitation is imposed here.

[0057] The battery capacity range of a single cell can be determined by the total battery capacity of the cells and the number of electrode cores 311. When the battery capacity of multiple electrode cores 311 is equal, the battery capacity of a single electrode core 311 = the total battery capacity of the cells ÷ the number of electrode cores 311. The maximum battery capacity of a single electrode core 311 = the maximum battery capacity of the cell ÷ the minimum number of electrode cores 311 = 7500Ah ÷ 5 = 1500Ah; the minimum battery capacity of a single electrode core 311 = the minimum battery capacity of the cell ÷ the maximum number of electrode cores 311 = 3200Ah ÷ 25 = 128Ah. Therefore, in the embodiments of this application, the battery capacity of the electrode core 311 can be determined to be 128Ah to 1500Ah. In order to reduce manufacturing costs and improve energy density, electrode cores 311 with battery capacities of 200Ah to 850Ah are mainly selected. The battery capacity of the selected electrode core 311 can be any range such as 200Ah to 550Ah, 550Ah to 850Ah, 350Ah to 650Ah, 300Ah to 700Ah, 600Ah to 850Ah, 200Ah to 850Ah, etc.; or, it can be 200Ah, 300Ah, 400Ah, 450Ah, 500Ah, 550Ah, 600Ah, 650Ah, 700Ah, 750Ah, 800Ah, 850Ah, etc.; it is not limited here.

[0058] The first partition 321 is a separating structure used to buffer expansion and constrain the electrode core 311. Its thickness needs to be determined in combination with the gap between the housing 100 and the electrode core 311 and the elastic compression of the material. Due to its elasticity, the first partition 321 will be compressed after the electrode core 311 is assembled into the housing 100 to fill the expansion space or gap reserved inside the housing 100, so that the electrode core 311 will not be damaged due to excessive gap during manufacturing and transportation. The first partition 321 also needs to absorb the expansion space and expansion force of the electrode core 311 through compression during the cell cycle to meet the requirement of buffering expansion force, and can still provide continuous support for the electrode core unit 310 after compression to improve the cycle performance of the cell. Therefore, the thickness of the first partition 321 cannot be too thin, otherwise it will lose rigidity after compression and will not be able to effectively constrain the core unit 310 and limit the displacement of the core 311; the thickness of the first partition 321 cannot be too thick either, otherwise it will occupy too much space before compression and reduce the energy density of the cell. In addition, the thickness of the first partition 321 needs to be set according to the material of the first partition 321 and the factor of the elastic compression of the material.

[0059] like Figure 3 , Figure 4 As shown, for example, the thickness of the first partition 321 is 1.5mm to 5mm, which is used to meet the requirements of buffering expansion force and reduce the space occupied.

[0060] For example, the thickness of the first partition 321 can be any thickness range such as 1.5mm~3mm, 1.5mm~3.25mm, 1.5mm~3.5mm, 1.5mm~4mm, 1.5mm~5mm, 3mm~5mm, 3.25mm~5mm, 3.5mm~5mm, 4mm~5mm; or, it can be any thickness suitable for actual use such as 1.5mm, 2mm, 3mm, 3.25mm, 3.5mm, 4mm, 5mm; it is not limited here.

[0061] Based on the aforementioned embodiments, the width of the casing 100 can be set according to the actual total battery capacity requirements. The width of the casing 100 is 200mm to 350mm. By increasing the width and other dimensions of the casing 100, it is suitable for installing electrode cores 311 with larger battery capacity and increasing the number of electrode cores 311 stacked, thereby effectively increasing the total battery capacity. The thickness of the electrode core 311 is related to the battery capacity of the electrode core 311. The greater the thickness of the electrode core 311, the more active material there is, and the higher the battery capacity of the electrode core 311. However, the upper limit of the electrode core 311 thickness is limited by the tab welding process. The reason for the limitation is that a thicker electrode core 311 requires more layers of lamination (positive electrode sheet, negative electrode sheet, separator). The more layers there are, the higher the defect rate of manufacturing a single electrode core 311 and the higher the manufacturing cost. Therefore, the thickness of the electrode core 311 is 15mm to 100mm.

[0062] For example, the thickness of the electrode core 311 can be any thickness range such as 15mm~50mm, 15mm~57.5mm, 15mm~60mm, 15mm~20mm, 15mm~30mm, 15mm~40mm, 15mm~100mm, 40mm~100mm, etc.; or, it can be any thickness suitable for actual use such as 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, etc.; it is not limited here. Based on the foregoing embodiments, the thickness of the electrode core 311 can be determined to be 15mm~45mm according to the actual welding process, and further, 45mm is taken as the upper limit of the thickness of the electrode core 311.

[0063] like Figure 3 As shown, in one embodiment, the thickness of each set of core units 310 is 20mm to 40mm.

[0064] The thickness of each core unit 310 can be any range of 20mm-25mm, 20mm-30mm, 20mm-35mm, 20mm-40mm, 25mm-40mm, 30mm-40mm, 35mm-40mm, etc.; or, it can be any thickness suitable for actual use, such as 20mm, 21mm, 22mm, 23mm, 24mm, 25mm, 26mm, 27mm, 28mm, 29mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, etc.; no limitation is imposed here.

[0065] To further optimize battery performance stability and improve manufacturing feasibility and safety, the thickness of each set of electrode core units 310 is determined to be 20mm to 40mm. Each set of electrode core units 310 may include one electrode core 311, or two, three, or more electrode cores 311. The first separator 321 is disposed between two adjacent electrode core units 310. If the electrode core 311 is too thick, the buffering effect of the first separator 321 on expansion force and the constraint effect on adjacent electrode core units 310 will be limited. If the electrode core unit 310 is too thin and the number of first separators 321 used increases, it will affect the energy density of the cell.

[0066] like Figure 2 , Figure 3 As shown, in one embodiment, multiple sets of electrode core units 310 are arranged along the width direction W of the housing 100. When each electrode core unit 310 includes multiple electrode cores 311, the stacking direction of the multiple electrode cores 311 of each electrode core unit 310 is consistent with the stacking direction of the multiple sets of electrode core units 310, and they are all stacked along the width direction W of the housing 100. The multiple electrode cores 311 are stacked in an orderly manner along the width direction W of the housing 100, so that the total thickness of the electrode cores 311 and the partitions 320 disposed between adjacent electrode core units 310 is adapted to the width of the housing 100, thereby improving the utilization rate of the internal space of the housing 100. In this way, the risk of expansion and misalignment of the electrode cores 311 during charge and discharge cycles can be reduced by constraining the stacking direction by the sidewalls of the housing 100; at the same time, the total volume ratio of the electrode cores 311 in the housing 100 is increased, effectively improving the energy density of the battery cell, thereby adapting to the design requirements of large-size, large-capacity battery cells.

[0067] like Figure 2 As shown, the number of first partitions = the number of pole core units - 1.

[0068] The number of first partitions is determined by the number of electrode core units installed in the housing. Taking each group of electrode core units 310 as an example, which includes one electrode core 311, a first partition 321 is provided between two adjacent groups of electrode core units 310. When the thickness of each electrode core is equal and the number of electrode cores is uncertain, the number of first partitions 321 can be determined by the formula "Number of first partitions = (Housing width ÷ Electrode core thickness) - 1" (rounding the result). Taking a housing width of 300mm (ignoring the thickness of the two plates along the width direction of the housing) and an electrode core thickness of 30mm as an example, the number of first partitions = (300 ÷ 30) - 1 = 9, and the number of first partitions is 9. This formula can, to a certain extent, ensure that the number of first partitions 321 meets the buffering requirements of the cyclic expansion of the electrode core 311, while avoiding excessive space occupation and energy density sacrifice due to the excessive number of first partitions 321. In this way, it can also be adapted to design schemes that prioritize increasing cell capacity.

[0069] In some other embodiments, such as Figure 3 As shown, when the number of pole cores 311 in each group of pole core units 310 is equal, and each group of pole cores 311 includes two, three, or other multiple pole cores 311, when the thickness of each pole core unit is determined, a first partition 321 is provided between two adjacent groups of pole core units 310. The number of first partitions 321 can be determined by the formula "Number of first partitions = (Shell width ÷ Pole core unit thickness) - 1" (the calculation result is rounded up). In addition, when the number of pole cores 311 in at least some pole core units 310 is not equal, the number of first partitions 321 can be determined by the formula "Number of first partitions = (Shell width ÷ Average thickness of pole core units) - 1" (the calculation result is rounded up); the specific number of first partitions 321 can be determined according to actual conditions, and is not limited here.

[0070] like Figure 2 , Figure 3 As shown, in the stacking direction of the multiple sets of pole core units 310, the projection surface of the first partition 321 covers the projection surface of the pole core unit 310. In one embodiment, the height of the first partition 321 is not less than the height of the pole core 311, and the length of the first partition 321 is not less than the length of the pole core 311.

[0071] During charge-discharge cycles, the electrode core 311 expands not only in the width direction (W) of the housing 100, but also laterally in the length direction (L) and height direction (H). The partition 320 is larger than the electrode core 311 in both the height direction (H) and length direction (L), and its excess portion covers the electrode core 311, providing comprehensive protection for its edges through insulation. This avoids direct contact between the edges of adjacent electrode core units 310 to some extent, reducing the risk of short circuits between them. Furthermore, the excess portion absorbs the lateral expansion force of the electrode core 311, reducing direct compression between the electrode core 311 and the housing 100, especially between the electrode core 311 and the metal housing 100, thus reducing the risk of short circuits caused by contact between the electrode core 311 and the housing 100. It also helps to mitigate deformation of the housing 100 caused by concentrated stress, further reducing the risk of damage to the electrode core 311 due to compression.

[0072] For example, the material of the first partition 321 is required to be resistant to electrolyte and also elastic.

[0073] In one embodiment, the first partition 321 is made of any one or a combination of multiple of the following: a fluororubber sheet made of fluororubber (FKM), an ethylene propylene diene monomer (EPDM) sheet made of ethylene propylene diene monomer (EPDM), and a polypropylene foam sheet made of polypropylene foam (PP).

[0074] The first partition 321 may also be made of other electrolyte-resistant and elastic materials; or the first partition 321 may include multiple elastic layers stacked along its thickness direction, each elastic layer being made of electrolyte-resistant and elastic materials, and the materials of the multiple elastic layers may be the same or different; the specific configuration can be based on actual conditions and is not limited here.

[0075] like Figure 4 As shown, in one embodiment, multiple sets of core units 310 are arranged along the width direction W of the housing 100. The cell also includes a second partition 322. The second partition 322 is provided between at least one inner sidewall of the housing 100 in the width direction W and the core unit 310. The second partition 322 is an elastic insulating partition.

[0076] Multiple electrode cores 311 of the battery cell are stacked along the width W of the housing 100. The expansion force has a cumulative effect in the stacking direction of the electrode cores 311 (along the width W of the housing 100). In the later stages of cycling, the expansion force may exceed the tolerance limit of the housing 100, causing the housing 100 to bulge and crack. A second partition 322 is provided between the electrode cores 311 and the inner wall of the housing 100 to reduce the direct compression of the housing 100 by the expansion of the electrode cores 311, protecting the structure of the housing 100. The second partition 322 can be made of an elastic insulating material. It can also, to some extent, prevent direct contact between the electrode cores 311 and the metal housing 100, which could cause the housing 100 to become electrified or experience an internal short circuit, leading to safety issues. The second partition 322 can also conduct heat from the multiple electrode cores 311 to the housing 100, improving heat dissipation.

[0077] In one embodiment, the second partition 322 is made of any one or a combination of multiple of the following: a fluororubber sheet made of fluororubber (FKM), an ethylene propylene diene monomer (EPDM) rubber sheet, and a polypropylene foam sheet made of polypropylene foam (PP). The second partition 322 may also be made of other electrolyte-resistant and elastic materials; or the second partition 322 may include multiple elastic layers stacked along its thickness direction, each elastic layer being made of an electrolyte-resistant and elastic material, and the materials of the multiple elastic layers may be the same or different; the specific configuration can be determined according to actual conditions and is not limited here. The specific structure of the second partition 322 can be referred to the relevant embodiments of the first partition 321 in the above embodiments, and will not be repeated here.

[0078] like Figure 2 , Figure 3 , Figure 4 As shown, for example, the housing 100 includes two first plates 110 and two second plates 120. The two first plates 110 are disposed opposite each other along the height direction H, and the two second plates 120 are disposed opposite each other between the two first plates 110 along the width direction W.

[0079] As an example, a second partition 322 is provided between the multiple sets of core units 310 and the inner sidewall of the housing 100.

[0080] The second partition 322 can be used to buffer the expansion force on one side, which can avoid direct compression between the electrode core 311 and the inner wall of the housing 100 to a certain extent, thereby reducing the risk of deformation of the housing 100 or damage to the electrode core 311.

[0081] like Figure 4 As shown, as another example, there are two second partitions 322, which are arranged opposite each other on both sides of the multiple sets of pole core units 310 along the width direction W of the housing 100.

[0082] When the electrode core 311 expands to both sides along the width direction W of the housing 100 during the charge and discharge cycle, a second partition 322 is arranged on each side of the multiple sets of electrode core units 310 along the width direction W of the housing 100. The second partitions 322 on both sides can symmetrically absorb the expansion force, realize uniform constraint on the multiple sets of electrode core units 310, and thus reduce the risk of overall offset, short circuit and deformation of the housing 100.

[0083] like Figure 4 As shown, in some embodiments, the battery cell includes a separator, which includes a first separator 321 and a second separator 322 as described in the previous embodiments. The number of separators is equal to the number of electrode core units plus 1.

[0084] Taking each group of core units 310 as an example, which includes one core 311 and has an equal core thickness, a first partition 321 is provided between two adjacent groups of core units 310. Two second partitions 322 are arranged opposite each other on both sides of the multiple groups of core units 310 along the width direction W of the shell 100. The partitions 320 include first partitions 321 and second partitions 322. When two second partitions are clearly provided, the number of partitions is the number of first partitions + 2. The total number of partitions 320 can be determined by the formula "number of first partitions = (shell width ÷ core thickness) + 1" (the calculation result is rounded down). Taking a shell width of 300mm and a core thickness of 30mm as an example, the number of partitions = (300 ÷ 30) + 1 = 11. The sum of the number of first partitions and second partitions is 11. This formula can, to a certain extent, ensure that the number of partitions 320 meets the buffering requirements of the cyclic expansion of the core 311.

[0085] like Figure 5 As shown, in one embodiment, the cover plate assembly 200 includes a cover plate body and a first terminal post 231 and a second terminal post 232 disposed on the cover plate body; each electrode core 311 has a first electrode tab and a second electrode tab. The battery cell also includes a first current collector structure 410 and a second current collector structure 420, the first current collector structure 410 being used to connect the first electrode tab of the electrode core 311 to the first terminal post 231; the second current collector structure 420 being used to connect the second electrode tab of the electrode core 311 to the second terminal post 232.

[0086] For example, the housing 100 has an opening 101, and the cover plate assembly 200 is disposed at the opening 101 of the housing 100. The cover plate assembly 200 can be connected and fixed to the housing 100 by means of laser welding, bonding, etc. By sealing the opening 101 of the housing 100 with the cover plate assembly 200, a sealed receiving space can be formed, in which multiple electrode cores 311 are installed. The cover plate assembly 200 integrates a first electrode post 231 and a second electrode post 232, wherein one of the first electrode post 231 and the second electrode post 232 is a positive electrode post and the other is a negative electrode post. The first electrode post 231 and the second electrode post 232 are used to conduct current. The first electrode post 231 and the second electrode post 232 are both disposed on the cover plate body of the cover plate assembly 200. Through the single-sided electrode post centralized layout design, the connection path between the electrode post and the electrode tab can be shortened, the internal resistance can be reduced, and space can be effectively saved to achieve a compact design.

[0087] Taking the first tab as the positive tab 3111 and the second tab as the negative tab 3112, the first post 231 as the positive post and the second post 232 as the negative post as an example, and taking the first current collector structure 410 for connecting the positive tab 3111 and the positive post of each core 311, and the second current collector structure 420 for connecting the negative tab 3112 and the negative post of each core 311, the first current collector structure 410 and the second current collector structure 420 are set separately, which can avoid the risk of short circuit caused by direct connection of the positive tab 3111 and the negative tab 3112 to a certain extent.

[0088] The first current collector structure 410 and the second current collector structure 420 serve as conductive connectors, functioning to collect and conduct current. The first current collector structure 410 electrically connects the first tabs of the multiple electrode cores 311 to the first terminal post 231 located on the cover plate body, and the second current collector structure 420 electrically connects the second tabs of the multiple electrode cores 311 to the second terminal post 232 located on the cover plate body, forming a current conduction path and realizing current transfer between the cover plate assembly 200 and the electrode cores 311. They also optimize the current path, improve the energy density of the battery cell, and increase the charging and discharging efficiency. The first current collector structure 410 and the second current collector structure 420 can also be used to fix the position of the tabs, which can prevent the tabs from loosening due to vibration to a certain extent, thereby improving the stability and reliability of the structure.

[0089] In some other embodiments, the housing 100 has a bidirectional conduction structure, with two cover plate assemblies, namely a first cover plate assembly 210 and a second cover plate assembly 220, and two openings 101, namely a first opening 101 and a second opening 101. Taking the cover plate assembly 200 with a first pole post 231 and a second pole post 232 provided in the aforementioned embodiment as the first cover plate assembly 210, the first cover plate assembly 210 includes a first cover plate body 211 and a first pole post 231 and a second pole post 232 disposed on the first cover plate body 211. The first cover plate assembly 210 is disposed at the first opening 101, and the second cover plate assembly 220 is disposed at the second opening 101. The first cover plate assembly 210 and the second cover plate assembly 220 can be connected and fixed to the housing 100 by laser welding, bonding, or other methods. By sealing the openings 101 of the housing 100 with the first cover plate assembly 210 and the second cover plate assembly 220 respectively, a sealed receiving space can be formed, in which multiple pole cores 311 are installed. The first opening 101 and the second opening 101 can be located at different positions on the housing 100. In some embodiments, the first opening 101 and the second opening 101 are arranged opposite each other along the length direction L of the housing 100, which allows the electrode to be designed on the side of the cell and improves the space utilization of the energy storage system.

[0090] At least one of the first cover plate assembly 210 and the second cover plate assembly 220 may be equipped with a pressure relief structure 240. The pressure relief structure 240 may be, but is not limited to, a pressure relief valve or an explosion-proof valve. When the gas pressure inside the battery cell exceeds a threshold due to thermal runaway or other reasons, the pressure relief structure 240 automatically opens to release gas, thereby reducing the potential risk of explosion. If pressure relief structures 240 are respectively provided in the first cover plate assembly 210 and the second cover plate assembly 220, the pressure relief effect can be further optimized, reducing the risk of explosion inside the battery cell due to thermal runaway or other reasons.

[0091] Taking the second cover plate assembly 220 with a pressure relief structure 240 as an example, the second cover plate assembly 220 includes a second cover plate body and a pressure relief structure 240 disposed on the second cover plate body. The pressure relief structure 240 disposed on the second cover plate body is separate from the first electrode post 231 and the second electrode post 232, which can realize directional pressure relief and reduce the risk of short circuit caused by electrolyte contact with the electrode post during pressure relief, thereby improving safety.

[0092] like Figure 6 As shown, in one embodiment, at least one of the first cover plate assembly 210 and the second cover plate assembly 220 is provided with an injection hole 250.

[0093] After the battery cell assembly is completed, electrolyte is injected into the housing 100 through the injection hole 250, so that the electrode core 311 is fully wetted and an ion conduction channel is formed, allowing the electrochemical reaction of the battery cell to proceed normally.

[0094] The injection port 250 can be located on the cover plate body with the pressure relief structure 240 for integrated design; the injection port 250 can also be located on the cover plate body without the pressure relief structure 240 to reduce the risk of internal gas pressure driving electrolyte to spray out from the injection port 250 during pressure relief, thus improving safety. The number of injection ports 250 can be one or more. Having multiple injection ports 250 effectively increases injection efficiency and makes electrolyte distribution more uniform. Multiple electrode cores 311 are stacked along the width direction W of the housing 100, and multiple injection ports 250 can be arranged sequentially along the height direction H of the housing 100, or sequentially along the width direction W of the housing 100. The specific arrangement can be determined based on actual conditions and is not limited here.

[0095] When an injection hole 250 is provided in one of the first cover plate body 211 and the second cover plate body, a compact design can be achieved; when both the first cover plate body 211 and the second cover plate body are provided with injection holes 250, the uniformity of electrolyte distribution and the reliability of injection can be improved.

[0096] like Figure 5 As shown, in one embodiment, the battery cell further includes a first insulating structure 500. The first insulating structure 500 is disposed between the first current collector 410 and the electrode core; or, the first insulating structure 500 is disposed between the second current collector 420 and the electrode core; or, the first insulating structure 500 is disposed between both the first current collector 410 and the electrode core, and between the second current collector 420 and the electrode core.

[0097] It is understandable that the first insulating structure 500 may be disposed between the first current collector structure 410 and the pole core 311; or the first insulating structure 500 may be disposed between the second current collector structure 420 and the pole core 311; or the first insulating structure 500 may be disposed simultaneously between the first current collector structure 410, the second current collector structure 420 and the pole core 311.

[0098] The first insulating structure 500 provides insulation, achieving electrical isolation and preventing direct contact between the positive tab 3111 and negative tab 3112 of the electrode core 311 through the current collector structure. This reduces the risk of short circuits and leakage, improving the reliability and safety of the battery cell. The first insulating structure 500, positioned between the current collector structure and the electrode core 311, also helps to fix the current collector structure, ensuring a stable connection and further enhancing structural stability and reliability. Furthermore, the first insulating structure 500 can be used for tab shaping, constraining the shape and limiting the position of the tabs, thus addressing potential connection problems caused by tab misalignment.

[0099] The first insulating structure 500 can be disposed between the first current collector 410 and the electrode core 311; or, it can be disposed between the second current collector 420 and the electrode core 311; in addition, insulating materials such as insulating adhesive can be coated between the current collector without the first insulating structure 500 and the electrode core 311 to achieve electrical isolation.

[0100] like Figure 5 As shown, when the first insulation structure 500 is disposed between the first current collector structure 410, the second current collector structure 420 and the pole core 311, the first insulation structure 500 can isolate the positive and negative current collector structures respectively, optimize electrical safety, make the pole core 311 subjected to uniform force on both sides, further improve the stability of the structure, and optimize the consistency of the assembly structure.

[0101] It should be noted that when the first insulating structure 500 is disposed between the first current collector structure 410, the second current collector structure 420, and the electrode core 311: Two first insulating structures 500 can be used, one disposed between the first current collector structure 410 and the first tab of the electrode core 311, and the other disposed between the second current collector structure 420 and the second tab of the electrode core 311. This further optimizes the electrical isolation effect, facilitates replacement and maintenance, and reduces maintenance costs. Alternatively, only one first insulating structure 500 can be used, suitable for a single-sided electrode design, to isolate the first current collector structure 410 and the second current collector structure 420. Reducing the number of first insulating structures 500 makes the structure more compact, simplifies assembly processes, reduces costs, and also helps to uniformly distribute the electric field between the positive and negative electrodes, aiding in heat dissipation.

[0102] For example, the number of first insulating structures 500 can be one or more. When there is only one first insulating structure 500, it is disposed between the current collector structure (first current collector structure 410 and / or second current collector structure 420) and the pole core 311, which simplifies the structure, reduces the number of parts, and reduces assembly difficulty. When there are multiple first insulating structures 500, some of the multiple pole cores 311 are connected to the current collector structure (first current collector structure 410 and / or second current collector structure 420) through the first insulating structure 500, and other parts of the multiple pole cores 311 are connected to other current collector structures (first current collector structure 410 and / or second current collector structure 420) through other first insulating structures 500; this is used to group the multiple pole cores 311, with each group of pole cores 311 connected to the current collector structure through an independent first insulating structure 500, which helps to distribute stress and is also suitable for assembling different numbers of pole cores 311, reducing maintenance costs.

[0103] like Figure 5As shown, in one embodiment, the first insulating structure 500 is provided with multiple through holes 510, through which the positive tabs 3111 and negative tabs 3112 of the multiple electrode cores 311 pass. The through holes 510 can be, but are not limited to, holes or slits. The through holes 510 on the first insulating structure 500, allowing the tabs to pass through, effectively prevent direct contact between the current collector structure (first current collector structure 410 and / or second current collector structure 420) and the electrode core 311, reducing potential short-circuit problems. The size of the through holes 510 is adapted to the tabs, defining the position of the tabs so that they can be accurately connected to the current collector structure, reducing assembly errors and improving production assembly efficiency. The through holes 510 can also, to some extent, reduce the possibility of loosening of the tabs, improving the stability and reliability of the connection.

[0104] like Figure 7 As shown, in some other optional embodiments, the battery cell further includes a second insulation structure 600. The second insulation structure 600 is disposed on the side of the cover assembly 200 near the first current collector 410; or, the second insulation structure 600 is disposed on the side of the cover assembly 200 near the second current collector 420; or, the second insulation structure 600 is disposed on both the side of the cover assembly 200 near the first current collector 410 and the side of the cover assembly 200 near the second current collector 420.

[0105] Understandably, the second insulating structure 600 can be disposed on the current collecting structures (first current collecting structure 410, second current collecting structure 420) and integrated with them; it can be disposed on the cover plate assembly 200 and integrated with it; or it can be disposed independently relative to the current collecting structures and the cover plate assembly 200, and disposed between the cover plate assembly 200 and the second current collecting structure 420 in the form of an insulating bracket, insulating sheet, insulating board, insulating component, etc. Taking the second insulating structure disposed on the cover plate assembly 200 as an example, the second insulating structure can be disposed on the side of the cover plate assembly 200 closer to the first current collecting structure 410; it can be disposed on the side of the cover plate assembly 200 closer to the second current collecting structure 420; or it can be disposed on the side of the cover plate assembly 200 closer to both the first current collecting structure 410 and the second current collecting structure 420.

[0106] The second insulation structure 600 has multiple holes through which the positive electrode tab 3111 and the negative electrode tab 3112 pass. The second insulation structure 600 can prevent the current collector structure and the cover plate assembly 200 from directly contacting each other, thereby reducing the risk of short circuit and reducing the problems of heating and electrolyte decomposition and gas generation that may be caused by short circuit, thus extending the service life of the battery cell.

[0107] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A battery cell, characterized in that, include: A housing having an opening; A cover assembly is disposed at the opening; Multiple sets of electrode core units are stacked and installed inside the housing; each electrode core unit includes at least one electrode core arranged along the stacking direction. The first partition is disposed between at least two partially adjacent sets of pole core units; in the stacking direction of the multiple sets of pole core units, the projection surface of the first partition covers the projection surface of the pole core unit; the first partition is an elastic insulating partition.

2. The battery cell as described in claim 1, characterized in that, Multiple sets of the aforementioned core units are arranged along the width direction of the housing; The number of the first partition plates = the number of the pole core units - 1.

3. The battery cell as described in claim 1, characterized in that, The thickness of the first partition is 1.5mm to 5mm; the width of the shell is 200mm to 350mm; and the thickness of the pole core is 15mm to 100mm.

4. The battery cell as described in claim 1, characterized in that, The thickness of each set of core units is 20mm to 40mm.

5. The battery cell as described in claim 1, characterized in that, The height of the first partition is not less than the height of the electrode core, and the length of the first partition is not less than the length of the electrode core.

6. The battery cell as described in claim 1, characterized in that, The first partition is made of any one of fluororubber board, EPDM rubber board, or polypropylene foam board.

7. The battery cell according to any one of claims 1 to 6, characterized in that, Multiple sets of the electrode core units are arranged along the width direction of the housing. The cell also includes a second partition. The second partition is provided between at least one inner sidewall of the housing in the width direction and the electrode core unit. The second partition is an elastic insulating partition.

8. The battery cell as described in claim 7, characterized in that, There are two second partitions, which are arranged opposite to each other on both sides of the plurality of pole core units along the width direction of the housing; The battery cell includes a separator, which includes a first separator and a second separator. The number of separators is equal to the number of electrode core units plus 1.

9. The battery cell according to any one of claims 1 to 6, characterized in that, The cover plate assembly includes a cover plate body and a first pole post and a second pole post disposed on the cover plate body; each pole core has a first pole tab and a second pole tab; The battery cell further includes a first current collector structure and a second current collector structure. The first current collector structure is used to connect the first tab and the first terminal of the battery core. The second current collector structure is used to connect the second tab and the second terminal of the battery core.

10. The battery cell as described in claim 9, characterized in that, The battery cell also includes a first insulation structure; The first insulating structure is provided between the first current collecting structure and the electrode core; Alternatively, the first insulating structure may be provided between the second current collecting structure and the electrode core; Alternatively, the first insulating structure may be provided between the first current collecting structure and the electrode core, and between the second current collecting structure and the electrode core.

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