Electrode assembly, battery cell monomer and battery pack
By using a split-type electrode design and staggered connections, the problem of the electrode tab length limitation in stacked batteries is solved, thereby increasing battery capacity and facilitating welding.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SUNGROW POWER SUPPLY CO LTD
- Filing Date
- 2025-04-09
- Publication Date
- 2026-05-01
AI Technical Summary
When increasing the number of internal stacked cells in a stacked battery, the length of the tabs is limited, which leads to an upper limit on the design of the stack thickness, making it difficult to further increase the battery capacity.
The first and second electrodes adopt a split design, including multiple sub-electrodes separated by a diaphragm. After folding, the electrodes are folded to one side to reduce the number and thickness of the tabs and increase the cell capacity.
Without increasing the length of the tabs, the thickness of the electrode sheet is doubled, the cell capacity is significantly improved, the thickness of the tabs is halved, the number of tabs is reduced, welding is easier to achieve, and the battery capacity is increased.
Smart Images
Figure CN224190981U_ABST
Abstract
Description
Electrode components, individual cells, and battery packs Technical Field
[0001] This application relates to the field of battery technology, and in particular to an electrode assembly, a single battery cell, and a battery pack. Background Technology
[0002] Stacked batteries are a type of battery structure manufactured using a stacking process. Their core feature is the alternating stacking of positive electrode sheets, negative electrode sheets, and separators to form a multi-layered electrode structure. Compared to traditional wound batteries, stacked batteries offer more uniform current distribution, higher energy density, and better mechanical stability, making them particularly suitable for high-rate charge / discharge and high-capacity applications. The stacking process effectively reduces internal polarization, improving cycle life and safety. Furthermore, stacked batteries offer greater structural flexibility, allowing for customized electrode sizes and the number of layers to meet diverse market demands.
[0003] Generally speaking, to improve the energy storage capacity of stacked batteries, the number of internal stacks is increased. As the number of internal stacks increases, the overall thickness also increases. This means that the tabs need to be designed to be very long during the stacking process in order to achieve the desired welding effect. Summary of the Invention
[0004] Several embodiments in this application propose an electrode assembly, a single cell, and a battery pack, aiming to provide an electrode assembly that can shorten the tab length and double the design limit standard for the thickness dimension of the stacked cells.
[0005] An embodiment of this application provides an electrode assembly including a first electrode, a second electrode, and a diaphragm disposed between the first electrode and the second electrode; the polarity of the second electrode is opposite to that of the first electrode; the first electrode includes at least two first sub-electrodes stacked together, and two adjacent first sub-electrodes are connected by a first connector.
[0006] In one embodiment, the second electrode includes at least two second sub-electrodes, and two adjacent second sub-electrodes are connected by a second connector.
[0007] In one embodiment, each pair of adjacent first sub-electrodes is connected by at least two first connectors; and / or
[0008] Each pair of adjacent second sub-electrodes is connected by at least two second connectors.
[0009] In one embodiment, the first electrode includes two first sub-electrodes connected in series, the two first sub-electrodes being connected in series and stacked, and the second electrode includes two second sub-electrodes connected in series, with each first sub-electrode having a second sub-electrode opposite to it.
[0010] In one embodiment, the first electrode has a first tab, and the second electrode has a second tab, the first tab and the second tab being offset in a plane parallel to the first sub-electrode and the second sub-electrode.
[0011] In one embodiment, the diaphragm includes a plurality of straight segments disposed along the stacking direction of the first sub-electrode and the second sub-electrode, and a transition segment connecting two adjacent straight segments, wherein the straight segments are at least partially disposed between the first sub-electrode and the second sub-electrode.
[0012] An embodiment of this application also proposes a single battery cell, including a cover plate, a terminal post, and at least two electrode assemblies as described above; the terminal post includes a first terminal post and a second terminal post, at least two first tabs of the first electrode are connected to the first terminal post, and at least two second tabs of the second electrode are connected to the second terminal post.
[0013] In one embodiment, the first pole and the second pole are disposed through the cover plate.
[0014] One embodiment of this application also proposes a battery pack comprising at least one battery cell as described above.
[0015] In several embodiments provided in this application, the first electrode and the second electrode are designed as separate units. Specifically, the first electrode includes at least two first sub-electrodes, and the second electrode has at least two corresponding second sub-electrodes. The advantage of this separate design is that the stacked electrode can be folded to one side, thus doubling the electrode thickness and significantly increasing the overall capacity of the battery cell without increasing the thickness of the tabs. Specifically, the first electrode includes at least two first sub-electrodes connected and stacked sequentially, with each first sub-electrode having a first tab. Correspondingly, the second electrode has at least two second sub-electrodes connected and stacked sequentially, with each second sub-electrode stacked on top of a first sub-electrode. Each first sub-electrode and second sub-electrode is separated by a diaphragm. In this technical solution, the stacked electrode is folded to one side, reducing the number of tabs used for current inflow / outflow and resulting in a relatively thinner electrode that is easier to fold and weld. This allows for an increase in battery cell capacity without increasing the number of tabs or their length. Moreover, by reducing the thickness of the tabs by half, the maximum design thickness of the stacked cores can be doubled, thereby increasing the battery capacity. Attached Figure Description
[0016] To more clearly illustrate the technical solutions in the embodiments or prior art of this application, the drawings used in the description of the embodiments or 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.
[0017] Figure 1 is an exploded structural diagram of the first embodiment of the electrode assembly provided in this application;
[0018] Figure 2 is a schematic diagram of the electrode assembly provided in the first embodiment;
[0019] Figure 3 is an exploded structural diagram of the second embodiment of the electrode assembly provided in this application;
[0020] Figure 4 is a schematic diagram of the electrode assembly provided in the second embodiment;
[0021] Figure 5 is a structural schematic diagram of the third embodiment of the electrode assembly provided in this application;
[0022] Figure 6 is a schematic diagram of the stacked electrode assembly in the third embodiment;
[0023] Figure 7 is a schematic diagram of the connection between electrode assemblies;
[0024] Figure 8 is a cross-sectional schematic diagram of the electrode assembly provided in the first embodiment in a folded state;
[0025] Figure 9 is a structural schematic diagram of an embodiment of a battery cell provided in this application;
[0026] Figure 10 is a structural schematic diagram of an embodiment of the battery pack provided in this application.
[0027] Explanation of icon numbers:
[0028] 100. Electrode assembly; 1. First electrode; 11. First sub-electrode; 12. First tab; 13. First connector; 2. Second electrode; 21. Second sub-electrode; 22. Second tab; 23. Second connector; 3. Diaphragm;
[0029] 200. Single cell; 211. First terminal; 212. Second terminal; 220. Housing; 230. Cover plate;
[0030] 1000, battery pack; 1100, upper casing; 1200, lower casing. Detailed Implementation
[0031] The technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of several embodiments. 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.
[0032] It should be noted that if directional indications (such as up, down, left, right, front, back, etc.) are involved in multiple embodiments of this application, the directional indications 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 indications will also change accordingly.
[0033] Furthermore, if multiple 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 implies three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of 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.
[0034] Generally speaking, to improve the energy storage capacity of stacked batteries, the number of internal stacks is increased. As the number of internal stacks increases, the overall thickness also increases. This means that the tabs need to be designed to be very long during the stacking process in order to achieve the desired welding effect.
[0035] To address the aforementioned problems, this application proposes an electrode assembly 100 to solve the technical issues mentioned above.
[0036] Please refer to Figures 1 to 10. In one embodiment of this application, the electrode assembly 100 includes a first electrode 1, a second electrode 2, and a diaphragm 3. The first electrode 1 includes at least two first sub-electrodes 11 that are connected and stacked in sequence. One first sub-electrode 11 is provided with a first electrode tab 12. The second electrode 2 includes at least two second sub-electrodes 21 that are connected and stacked in sequence. Each second sub-electrode 21 is stacked on a first sub-electrode 11. One of the second sub-electrodes 21 is provided with a second electrode tab 22 that is disposed on the same side as the first electrode tab 12. The diaphragm 3 is disposed on both sides of each first sub-electrode 11.
[0037] It is understood that the electrode assembly 100 proposed in this application is applicable to stacked batteries, which are batteries manufactured using a stacking process. Their structure mainly consists of a first electrode 1, a second electrode 2, a separator 3, and an electrolyte. In stacked batteries, the first electrode 1 and the second electrode 2 are typically made of metal foil, such as aluminum foil and copper foil, as current collectors, while the active material is coated onto these foils. The separator 3 is made of materials such as polyolefins, which have good chemical stability and mechanical strength, preventing short circuits. During manufacturing, the first electrode 1, separator 3, and second electrode 2 are stacked sequentially. Specifically, please refer to Figure 8. The separator 3 isolates the positive and negative electrodes, preventing short circuits, while allowing lithium ions to pass through to complete the electrochemical reaction. During the stacking process, the separator 3 can be folded in a Z-shape, alternately stacking the positive and second electrode 2 to form a stable electrode assembly 100. This configuration not only ensures the ion conduction path within the battery but also enhances battery safety through the microporous structure of the separator 3, such as limiting current and preventing thermal runaway in cases of overheating or overcharging. The separator 3, the first electrode 1, the separator 3, and the second electrode 2, stacked sequentially, constitute the smallest energy storage unit (hereinafter referred to as a cell unit). An array of two or more cell units forms the electrode assembly 100 described above. Subsequently, the stacked electrode assembly 100 is placed into the casing 220 of the cell 200, and electrolyte is injected. After sealing, formation, and other processes, a stacked battery is finally manufactured. The electrode assembly 100 described above provides a larger electrode surface area, which helps to improve the battery's energy density and charge / discharge efficiency.
[0038] Based on the above introduction to stacked batteries, it is evident that the number of electrodes in a stacked battery is limited by the length of its tabs. Due to the limited tab length, the thickness of the stacked core also has a corresponding design upper limit. In several embodiments provided in this application, the first electrode 1 and the second electrode 2 are designed as separate units. Specifically, the first electrode 1 includes at least two first sub-electrodes 11, and the second electrode 2 has at least two corresponding second sub-electrodes 21. The advantage of this separate design is that the stacked electrodes can be folded to one side, thereby doubling the electrode thickness and significantly increasing the overall capacity of the single cell 200 without increasing the tab thickness. Specifically, the first electrode 1 includes at least two first sub-electrodes 11 connected and stacked sequentially, with each first sub-electrode 11 having a first tab 12. Correspondingly, the second electrode 2 has at least two second sub-electrodes 21 connected and stacked sequentially. Each second sub-electrode 21 is stacked on top of a first sub-electrode 11, and each first sub-electrode 11 and second sub-electrode 21 are separated by a separator 3. In the technical solution of this application, the electrode sheets of the stacked core are folded to one side, reducing the number of tabs used for current lead-out / lead-in and making the core relatively thinner. This facilitates easy folding and welding, allowing for an increase in cell capacity without increasing the number of tabs or their length. Moreover, by halving the thickness of the tabs, the maximum design thickness of the stacked core can be doubled, thereby increasing the battery capacity.
[0039] To facilitate the folding of the two first sub-electrodes 11 on the first electrode 1 and the two second sub-electrodes 21 on the second electrode 2, the crease between the two first sub-electrodes 11, i.e., the wrinkled area, is configured as a first connector 13. Correspondingly, the crease between the two second sub-electrodes 21 is configured as a second connector 23. Specifically, please refer to Figure 1. Taking the first electrode 1 as an example, the width of the first connector 13 is much smaller than the width of the two first sub-electrodes 11, thus enabling easier folding. The narrower first connector 13 can effectively reduce stress concentration, making the stress distribution more uniform along the width direction, thereby reducing the problem of excessive local stress. At the same time, the first connector 13 is more adaptable to a smaller bending radius, which can give full play to the flexibility of the material, ensuring a smooth folding process and preventing uneven internal stress distribution due to width limitations. In addition, it avoids damage to the first sub-electrodes 11 after folding. The connection through the first connector 13 can ensure the flatness of the two after folding and avoid the risk of internal short circuit. Similarly, the second connector 23 is also a mirror image of the first connector 13 mentioned above. The overall position is staggered, but the two have the same structure and achieve the same effect, which will not be elaborated here.
[0040] It should be noted that the first connector 13 and the second connector 23 can be made of aluminum or electroplated alloy materials, such as nickel-plated copper. This application does not impose any restrictions on this. In one embodiment of this application, the first connector 13 and the second connector 23 are made of aluminum and nickel-plated copper, respectively. Both of these materials have good conductivity, corrosion resistance, and low density, which helps to reduce battery weight and increase energy density. In addition, these two metal materials have good ductility, which can adapt to the large deformation and bending requirements of the connectors, effectively reducing stress concentration in the connectors during folding, reducing the risk of connector breakage, and thus improving battery reliability and service life.
[0041] In one embodiment of this application, each first sub-electrode 11 of the first electrode 1 is stacked with a second sub-electrode 21 of the second electrode 2, with a diaphragm 3 between them. In a direction perpendicular to the first electrode 1 and the second electrode 2, a first connector 13 for connecting the first sub-electrode 11 and a second connector 23 for connecting the second sub-electrode 21 are arranged in a staggered configuration. Specifically, please refer to Figure 2. Since the charge polarities flowing on the first connector 13 and the second connector 23 are opposite, if the first connector 13 and the second connector 23 are directly stacked, they may come into contact due to vibration, thermal expansion, or mechanical stress, leading to a short circuit between the internal electrodes. Such a short circuit can cause local overheating or even thermal runaway. Therefore, a staggered configuration is used to avoid the possibility of contact between the two. In addition, the staggered design can also optimize the force balance of the first connector 13 and the second connector 23, ensuring that when the first electrode 1 and the second electrode 2 are stacked and folded, the first connector 13 and the second connector 23 are located near the two sides of the stacked core structure, thereby ensuring uniform force at each point and improving the stability of the folded structure.
[0042] It should be noted that each first electrode 1 may include two first sub-electrodes 11 connected by a first connector 13. For details, please refer to Figures 1 to 4. Alternatively, it may be composed of two or more first sub-electrodes 11, with each pair of adjacent first sub-electrodes 11 electrically connected by a first connector 13. For details, please refer to Figures 5 to 6. This application does not limit this and can make adaptive adjustments according to the actual capacity requirements of the battery cell 200. For example, when the length of the battery cell 200 is designed to be large, the area of a single electrode sheet, i.e., the energy storage capacity, can be reduced, and multiple electrode sheets can be connected in series through multiple connectors to ensure a large single-cell energy storage capacity. For another example, when the external dimensions of the battery cell 200 are designed to be small, in addition to using double electrode sheets connected in series, a multi-electrode sheet arrangement can also be used. Finally, the multiple battery cell units after stacking are folded in a Z-shape or wound in sequence to reduce the length of the battery cell unit, thereby making it easier to assemble into the housing 220. By adopting the above settings, it is possible to further increase the capacity of the electrode sheet while reducing the overall thickness of the tab, thereby allowing the thickness of the stacked sheet to break through the constraint of the tab length, and thus increasing the capacity of the 200-cell battery cell.
[0043] It should be noted that several adjacent first sub-electrodes 11 in each first electrode 1 of this application can be connected by one first connector 13 or by multiple first connectors 13. This application does not limit this. In the first embodiment of this application, specifically referring to Figures 1 and 2, each pair of adjacent first sub-electrodes 11 is connected by one first connector 13. In the second embodiment of this application, specifically referring to Figures 3 and 4, each pair of adjacent first sub-electrodes 11 is connected by two first connectors. The number of connectors between adjacent electrodes can be adjusted as needed. For example, when the number of cell units is small, the bending moment borne by the first connector 13 is small, so the number of connectors can be reduced, thereby reducing material costs and achieving battery weight reduction. For another example, when the number of stacked cells is large, the bending moment borne by the first connector 13 is large. By increasing the number of connectors, sufficient connection strength between adjacent electrodes can be ensured, preventing the entire first electrode 1 from being affected if a single first connector 13 breaks, thus achieving redundant design. Similarly, the second connector 23 is also a mirror image of the first connector 13, and the overall position is staggered. That is, the number of the second connector 23 can be set to one or more. Since the second connector 23 and the first connector 13 have the same structure, the effect is also the same, so it will not be described in detail here.
[0044] It is understood that a first tab 12 is provided on one side of the first electrode 1, and a second tab 22 is provided on one side of the second electrode 2. The tabs are used for the introduction and output of current in the battery cell unit, connected to an external terminal, and then electrically connected to an external circuit through the terminal. It should be noted that, taking the first tab 12 as an example, the first tab 12 can be set on the side of one of the first sub-electrodes 11 of the first electrode 1 facing away from the first connector 13 connected to it, that is, at the position shown in Figure 1, or it can be set on the side adjacent to that position. This application does not limit this. When the first tab 12 needs to be set on the side adjacent to the first connector 13, it is necessary to ensure that the first sub-electrode 11 set there is an end electrode, so as to ensure that the current can be smoothly input and output after multiple first sub-electrodes 11 are connected in series. In one embodiment of this application, the first tab 12 is disposed on one end electrode and located on the opposite side of the first sub-electrode 11 and the first connector 13. In the layout of the battery cell 200, one side of the first tab 12 is disposed near the top cover of the battery, the first connector 13 is disposed near the bottom cover of the battery, and the first sub-electrode 11 is vertically disposed. This layout makes the utilization rate of the cavity inside the housing 220 higher, and the structural layout more compact and reasonable. Similarly, the second tab 22 disposed on the second electrode 2 has the same external structure as the first tab 12, but its position is offset along the direction perpendicular to the electrode. The offset setting can reduce the welding difficulty and improve the convenience of welding quality control. By distributing the first tab 12 and the second tab 22 separately, the number of layers during welding can be reduced, avoiding problems such as poor welding or failure to weld due to too many tab layers. The offset setting can enhance the safety of the battery by reducing the overlap and contact between the tabs, thereby reducing the risk of short circuit.
[0045] When multiple first tabs 12 or multiple second tabs 22 are stacked together, they need to be brought together and ultrasonically welded for lead-out. The specific operation steps are as follows: First, the multiple first tabs 12 are neatly brought together and stacked, ensuring that the tabs are tightly fitted and without obvious misalignment. Next, using an ultrasonic welding device, the welding head is aligned with the overlapping area of the tabs. The high-frequency vibration of the ultrasonic waves causes local high temperatures to be generated on the contact surface of the tab materials, thereby achieving melting and bonding of the materials. During the welding process, welding parameters, such as welding time, amplitude, and pressure, need to be precisely controlled to ensure welding quality. This welding method can not only quickly and efficiently complete the connection of the tabs, but also provide good welding strength and conductivity. After being brought together, the tabs need to be welded to their corresponding battery terminals. The first tab 12 is welded to the first terminal 211, and the second tab 22 is welded to the second terminal 212. This welding method can refer to the above-mentioned welding operation procedure between tabs, which will not be repeated here.
[0046] The internal tabs of a battery are key components connecting the electrodes to the external circuitry, requiring good conductivity and ductility. It should be noted that various metallic materials such as aluminum, nickel, and nickel-copper alloys can be used; this application does not impose any limitations on this. In one embodiment of this application, the first tab 12 and the second tab 22 are the positive and negative tabs, respectively. The first tab 12 is made of aluminum, and the second tab 22 is made of copper with a nickel plating treatment. Aluminum has excellent conductivity, effectively reducing the battery's internal resistance. Simultaneously, aluminum has a low density, helping to reduce the overall weight of the battery, thereby increasing its energy density. The second tab 22 uses copper plated with nickel. Copper itself has extremely high conductivity and good mechanical properties, meeting the requirements of high-current charging and discharging, while the nickel plating further enhances the material's corrosion resistance and weldability. This material combination not only ensures the stability and reliability of the battery during use but also effectively extends its lifespan.
[0047] This application also proposes a battery cell 200, which includes a housing 220, an electrode assembly, and an electrode assembly 100 as described above. The housing 220 forms a receiving cavity in which the electrode assembly 100 is received. The electrode assembly includes a first terminal 211 and a second terminal 212, both of which penetrate the housing 220. The electrode assembly 100 is electrically connected to the first terminal 211 and the second terminal 212 via a first tab 12 and a second tab 22, respectively. Specifically, please refer to Figures 7 and 9. The battery cell 200 may include one or more electrode assemblies 100. In the embodiments provided in this application, the battery cell 200 includes two electrode assemblies 100, which are arranged side by side and both are electrically connected to the electrode assembly. The specific structure of the electrode assembly 100 is as described in the above embodiments. Since the battery cell 200 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.
[0048] This application also proposes a battery pack 1000, comprising an upper shell 1100, a lower shell 1200, and individual battery cells 200 disposed within a cavity formed by the upper shell 1100 and the lower shell 1200. It is understood that the battery pack is obtained by electrically connecting and arranging multiple individual battery cells 200 according to a certain pattern. The multiple individual battery cells 200 are installed inside the battery pack casing in a parallel or array arrangement and are electrically connected via a busbar. The busbar is installed and fixed to the outside of the terminals using connection methods such as screwing, snap-fitting, welding, or interference fit. This battery pack 1000 can be used as a power source for electrical devices or as an energy storage unit for electrical devices. Electrical devices can include mobile devices (e.g., mobile phones, laptops), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, range-extended vehicles, electric bicycles, electric scooters, electric golf carts, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc., but are not limited to these.
[0049] 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. An electrode assembly, characterized in that, It includes a first electrode (1), a second electrode (2), and a diaphragm (3) disposed between the first electrode (1) and the second electrode (2); the polarity of the second electrode (2) is opposite to that of the first electrode (1); the first electrode (1) includes at least two first sub-electrodes (11) stacked together, and two adjacent first sub-electrodes (11) are connected by a first connector (13).
2. The electrode assembly as described in claim 1, characterized in that, The second electrode (2) includes at least two second sub-electrodes (21), and two adjacent second sub-electrodes (21) are connected by a second connector (23).
3. The electrode assembly as described in claim 2, characterized in that, Each pair of adjacent first sub-electrodes (11) is connected by at least two first connectors (13); and / or each pair of adjacent second sub-electrodes (21) is connected by at least two second connectors (23).
4. The electrode assembly as described in any one of claims 1 to 3, characterized in that, The first electrode (1) includes two first sub-electrodes (11) connected in series. The two first sub-electrodes (11) are connected in series and stacked. The second electrode (2) includes two second sub-electrodes (21) connected in series. Each first sub-electrode (11) is provided with a second sub-electrode (21) opposite to it.
5. The electrode assembly as described in claim 4, characterized in that, The first electrode (1) has a first tab (12), and the second electrode (2) has a second tab (22). The first tab (12) and the second tab (22) are offset in a plane parallel to the first sub-electrode (11) and the second sub-electrode (21).
6. The electrode assembly as claimed in claim 4, characterized in that, The diaphragm (3) includes a plurality of straight segments arranged along the stacking direction of the first sub-electrode (11) and the second sub-electrode (21) and a transition segment connecting two adjacent straight segments, wherein the straight segments are at least partially disposed between the first sub-electrode (11) and the second sub-electrode (21).
7. A single battery cell, characterized in that, It includes a cover plate (230), a pole post, and at least two electrode assemblies as described in any one of claims 1 to 6; the pole post includes a first pole post (211) and a second pole post (212), at least two first tabs (12) of the first pole pieces (1) are connected to the first pole post (211), and at least two second tabs (22) of the second pole pieces (2) are connected to the second pole post (212).
8. The single cell as described in claim 7, characterized in that, The first pole post (211) and the second pole post (212) are disposed through the cover plate (230).
9. A battery pack, characterized in that, It includes at least one battery cell as described in any one of claims 7 to 8.