Battery cell and battery

Abstract

The application relates to a battery monomer and a battery, comprising an end cover and an electrode assembly, the end cover comprising a cover plate and a plurality of groups of pole columns arranged on the cover plate, each group of pole columns comprising two pole columns with opposite polarities, and all the pole columns being arranged at intervals along the length direction of the cover plate. The electrode assembly comprises a tab end facing the cover plate, and the tab end is provided with a plurality of tabs. Each pole column has a first flow surface and a second flow surface arranged in opposite directions in the thickness direction of the cover plate, and each second flow surface is connected with a tab. In the thickness direction, the projection area of the first flow surface of each pole column is smaller than that of the second flow surface. The application optimizes the number and arrangement mode of the pole columns and the tabs, and optimizes the pole column structure, thereby improving the charging and discharging efficiency and the heat dissipation capacity of the battery monomer, improving the problem of excessively high local temperature rise, and greatly improving the reliability of the battery monomer during large-current transmission.

Description

Technical Field

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

[0002] As a new energy source, batteries are playing an increasingly important role in energy storage and power. The electrode assembly is the main structure supporting the electrochemical reactions within the battery cell. The electrode assembly primarily connects to the terminals on the battery cell end cap via its tabs, enabling communication with the external circuitry. Simultaneously, the heat generated during operation is transferred from the tabs to the terminals, and then exchanged between the terminals and an external liquid cooling structure. With the application of fast-charging batteries, the requirements for high-current transmission are becoming increasingly stringent. However, during high-current transmission, the temperature rise at the connection point between the tabs and terminals can be too rapid, potentially leading to safety hazards and reducing the reliability of the battery cell. Summary of the Invention

[0003] Based on this, a battery cell and a battery are provided, which can improve the reliability of the battery cell.

[0004] In a first aspect, this application provides a battery cell, comprising:

[0005] An end cap includes a cover plate and multiple sets of pole posts disposed on the cover plate. Each set of pole posts includes two pole posts with opposite polarities. All the pole posts are arranged at intervals along the length of the cover plate.

[0006] An electrode assembly includes an electrode tab end facing the cover plate, and the electrode tab end has a plurality of protruding electrodes;

[0007] Each of the poles has a first flow surface and a second flow surface disposed opposite to each other in the thickness direction of the cover plate, and each second flow surface is connected to a tab; along the thickness direction, the projected area of ​​the first flow surface of each pole is smaller than the projected area of ​​the second flow surface.

[0008] In some embodiments, the total length G1 of the first flow surface of all the poles in the length direction, the total length G0 of the cover plate, and the total length G2 of the second flow surface of all the poles in the length direction satisfy: 0.5G0<G1<G2<G0.

[0009] In some embodiments, along the thickness direction, the projected area S1 of the first flow surface of all the electrode posts and the projected area S2 of the outer end face of the cover plate opposite to the electrode assembly satisfy: 0.45S2≤S1<S2; and / or,

[0010] Along the thickness direction, the projected area S1' of the second flow surface of all the poles and the projected area S2 of the outer end face of the cover plate opposite to the electrode assembly satisfy: 0.5S2≤S1'<S2.

[0011] In some embodiments, the cover plate is provided with a liquid injection hole penetrating its outer end face, and each of the poles protrudes from the outer end face;

[0012] Along the length direction, a gap is formed between each pair of adjacent poles. The injection hole is arranged in part of the gap. The size of the gap with the injection hole in the length direction is m1, the diameter of the injection hole is D2, and the size of the gap without the injection hole in the length direction is m2, satisfying: 0.4m1≤D2<m1; m2≤m1.

[0013] In some embodiments, the battery cell includes an insulating support member disposed at the tab end;

[0014] The insulating support has a hollowed-out section that extends through the thickness of the cover plate, and the hollowed-out section is fitted around the electrode tab.

[0015] In some embodiments, the cutout includes a strip-shaped support groove, one end of which is closed and the other end is open, through which the insulating support allows the tab to be inserted into the support groove.

[0016] In some embodiments, the opening of the support groove is funnel-shaped, and its larger diameter end is positioned away from the closed end of the support groove relative to its smaller diameter end.

[0017] In some embodiments, a plurality of the tabs are arranged side by side at intervals along the longitudinal direction of the support groove; two insulating supports are provided, with adjacent portions of the tabs passing through the support groove of the same insulating support, and adjacent remaining portions of the tabs passing through the support groove of the other insulating support; the support grooves of the two insulating supports are spaced apart, and the openings are arranged opposite to each other.

[0018] In some embodiments, the cover plate is provided with a liquid injection hole, and the projection of the insulating support member is offset from the projection of the liquid injection hole along the thickness direction of the cover plate.

[0019] In some embodiments, the insulating support is provided with a liquid passage hole, which connects the liquid injection hole and the electrode assembly, and is offset from the hollowed-out position.

[0020] In some embodiments, the insulating support includes a first end face and a second end face disposed opposite to each other along the thickness direction of the cover plate. The first end face is configured as a planar structure that fits against the electrode assembly. A reinforcing rib is provided on the second end face, and the reinforcing rib passes through the hollowed-out position.

[0021] In some embodiments, the battery cell further includes thermally conductive adhesive located between the end cap and the tab end, and the second flow surface is located within the thermally conductive adhesive.

[0022] In some embodiments, the pole includes an adjacent mating section and a welding section, wherein the first flow surface is located at one end of the welding section away from the mating section.

[0023] In some embodiments, the cover plate includes a pole hole, the end cap includes a sealing element, the sealing element is installed in the pole hole, the sealing element has a first sealing groove that mates with the hole wall of the pole hole; the sealing element has an installation hole, the mating section passes through the installation hole, and a second sealing groove that mates with the mating section is formed on the hole wall of the installation hole.

[0024] Secondly, this application provides a battery comprising the battery cell described in any of the above embodiments.

[0025] Compared with the prior art, this application has the following beneficial effects:

[0026] The aforementioned battery cells and batteries, by optimizing the number and arrangement of terminals and tabs, and optimizing the terminal structure, improve the charging and discharging efficiency and heat dissipation capacity of the battery cells, alleviate the problem of excessive local temperature rise, and greatly improve the reliability of the battery cells during high current transmission. Attached Figure Description

[0027] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0028] Figure 1 A schematic diagram of the external shape of a battery cell in some embodiments is shown.

[0029] Figure 2 Showing Figure 1 The diagram shows an exploded view of a single battery cell.

[0030] Figure 3 Showing Figure 1 The diagram shows the internal structure of a single battery cell.

[0031] Figure 4 An exploded view of a battery cell from some embodiments is shown.

[0032] Figure 5 Showing Figure 4 Another view of the battery cell shown.

[0033] Figure 6 Cross-sectional schematic diagrams of end caps from some embodiments are shown.

[0034] Figure 7 Partial structural schematic diagrams of the cover plate in some embodiments are shown.

[0035] Figure 8 Schematic diagrams of the end caps of some embodiments are shown.

[0036] Figure 9 A partial structural schematic diagram of a battery cell from some embodiments is shown.

[0037] Figure 10 Schematic diagrams of the insulating support members of some embodiments are shown.

[0038] Figure 11 Showing Figure 14 Another view of the insulating support shown.

[0039] Figure 12 This is a schematic diagram of the structure of an insulating filler component according to some embodiments.

[0040] Figure 13 Showing Figure 12 Another view of the insulating filler shown.

[0041] Figure 14 Showing Figure 3 Enlarged view of point I in the middle.

[0042] Figure 15 An exploded view of the end caps of some embodiments is shown.

[0043] Figure 16 Internal cross-sectional views of seals from some embodiments are shown.

[0044] Figure 17 Showing Figure 12 Enlarged view of section II.

[0045] Figure 18 Schematic diagrams of the sealing nails in some embodiments are shown.

[0046] Figure 19 Partial structural schematic diagrams of insulating fillers from some embodiments are shown.

[0047] Figure 20 Showing Figure 2 Enlarged schematic diagram of point III in the middle.

[0048] The reference numerals in the detailed embodiments are as follows:

[0049] 100. Battery cell; Z, thickness direction; X, length direction; Y, width direction; 10. End cap; 11. Cover plate; 11a. Injection hole; a1. Submersible groove; a2. Through hole; 11b. Terminal hole; 12. Terminal; 12b. Connecting section; 12c. Welding section; GL1. First flow surface; GL2. Second flow surface; 13. Seal; 13d. Mounting hole; 13e. First sealing groove; 13i. Second sealing groove; 14. Sealing pin; 14g. Boss; 14k. Post; W. Outer end face; T. Spacing area; 20. Electrode assembly; J. Tab end; 21. Tab; 21a. Root section ; 21b, Tail section; 21c, Bending section; 30, Insulating filler; 31, Base plate; 32, Side plate; 30h, Filler space; h1, Main space; h2, Overflow space; 30i, Clearance hole; 30m, Opening; 30n, Notch; 30p, Corner position; 33, Separator strip; 33q, Overflow channel; 34, Protruding column; 34r, Injection channel; 40, Thermally conductive adhesive; 50, Insulating support; 50u, Hole; u1, Support groove; u11, Opening; d1, First end face; d2, Second end face; 51, Reinforcing rib; 50v, Liquid passage hole; 60, Outer shell; 70, Thermally conductive covering. Detailed Implementation

[0050] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0051] In the description of this application, it should be understood that, where they appear, the terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “clockwise,” “counterclockwise,” “axial,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0052] Furthermore, where applicable, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0053] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," "fixing," etc., shall be interpreted broadly. For example, they may refer to a fixed connection, a detachable connection, or an integral part; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; they may refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0054] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0055] It should be noted that, if an element is described as "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is described as "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0056] This application addresses the problems mentioned in the background art by proposing a battery cell and a battery. The battery can be a battery pack or a battery module. When the battery is a battery pack, the battery pack can include a battery management system (BMS) and multiple battery cells. Multiple battery cells can be electrically connected in series, parallel, or a combination of series and parallel connections, and communicate with the battery management system, which controls and monitors the operating status of each battery cell. Alternatively, multiple battery cells can first be assembled into a battery module, and then multiple battery modules can be electrically connected in series, parallel, or a combination of series and parallel connections, together with the battery management system, to form a battery pack.

[0057] The battery cell involved in this application embodiment includes an electrode assembly. The electrode assembly typically includes a positive electrode, a negative electrode, and a separator separating the positive and negative electrodes. Electrolyte can penetrate the interior of the electrode assembly, providing an ion migration pathway for electrochemical reactions and serving a conductive function. The electrode assembly can be in the form of a wound type, a stacked type, etc. One or more electrode assemblies can be installed within the battery cell. The positive electrode has a positive tab, the negative electrode has a negative tab, and the terminal posts on the end cap include positive and / or negative terminal posts. The positive tab is directly or indirectly electrically connected to the positive terminal post, and the negative tab is directly or indirectly electrically connected to the negative terminal post. The tabs can be full tabs or die-cut tabs.

[0058] like Figure 1 As shown, the battery cell 100 involved in the embodiments of this application typically includes a housing 60 and an end cap 10. The housing 60 and the end cap 10 together enclose a receiving space, and the electrode assembly 20 is loaded in the receiving space. In some embodiments, the housing 60 includes a receiving cavity, one end of which (e.g., Figure 2 (As shown) or with openings u11 at both ends, the end cap 10 covers the opening u11 of the receiving cavity. A terminal post 12 is typically provided on the end cap 10, with one end extending into the battery cell 100 and connected to the tab 21 of the electrode assembly 20. The housing 60 and the end cap 10 can be, but are not limited to, metals such as aluminum or steel. The housing 60 and the end cap 10 can be welded or assembled. An injection hole 11a can be formed on the end cap 10 for injecting electrolyte into the battery cell 100. An explosion-proof structure (such as an explosion-proof valve or thinning grooves) can also be provided on the end cap 10.

[0059] The battery cell 100 provided in the embodiments of this application is described in detail below.

[0060] Please combine Figure 3 , Figure 4 and Figure 5The battery cell 100 provided in this application embodiment includes an end cap 10 and an electrode assembly 20. The end cap 10 includes a cover plate 11 and multiple sets of electrode posts disposed on the cover plate 11. Each set of electrode posts includes two electrode posts 12 with opposite polarities, and all electrode posts 12 are arranged at intervals along the length direction X of the cover plate 11. The electrode assembly 20 includes a tab end J facing the cover plate 11, and the tab end J has multiple tabs 21 protruding from it. Each electrode post 12 has a first flow surface GL1 and a second flow surface GL2 disposed opposite to each other in the thickness direction Z of the cover plate 11, and each second flow surface GL2 is connected to a tab 21. Along the thickness direction Z, the projected area of ​​the first flow surface GL1 of each electrode post 12 is smaller than the projected area of ​​the second flow surface GL2.

[0061] Each electrode assembly includes a positive electrode and a negative electrode. The positive and negative electrodes can be arranged alternately along the aforementioned length direction X. Multiple tabs 21 and multiple electrodes 12 are connected one-to-one via the second flow-through surface GL2 of each electrode 12. The first flow-through surface GL1 and the second flow-through surface GL2 are located at opposite ends of the electrode 12. The cover plate 11 has an outer end face W facing away from the electrode assembly 20, and the first flow-through surface GL1 is located at the end of the electrode 12 that protrudes from the outer end face W of the cover plate 11. The first flow-through surface GL1 is used to connect to external wires, busbars, etc., for connection to an external circuit. The second flow-through surface GL2 is located at the end of the electrode 12 facing the electrode assembly 20. The second flow-through surface GL2 is connected to the tab 21; the connection method can be, but is not limited to, welding, snap-fit, etc., as long as the two are electrically connected. Optionally, both the first flow-through surface GL1 and the second flow-through surface GL2 can be planar, resulting in a simple structure. Yes, the projected shapes of the first flow surface GL1 and the second flow surface GL2 are both circular, square, etc.

[0062] In this embodiment, the electrode assembly 20 is connected to an external circuit through the cooperation of multiple sets of electrode posts 12 and multiple tabs 21. The total current-carrying area of ​​all electrode posts 12 and tabs 21 is relatively large, which can withstand large current transmission and improve the charging and discharging efficiency of the battery, making it suitable for fast-charging batteries. When transmitting the same current, the multiple sets of electrode posts reduce the current transmitted by each electrode post 12, thereby reducing the current transmitted at the connection between the electrode post 12 and the tab 21 and reducing temperature rise. At the same time, the large number of electrode posts 12 increases the heat exchange area between the electrode posts 12 and the liquid cooling structure, improving the heat dissipation capacity of the battery cell 100.

[0063] Furthermore, the increased projected area of ​​the second flow surface GL2 of the terminal post 12 increases the contact area between the tab 21 and the terminal post 12, reduces contact resistance, and decreases the internal heat generation of the battery cell 100. At the same time, the larger contact area provides more flow paths for the current, allowing the current to be evenly distributed in the connection area between the terminal post 12 and the tab 21, avoiding local overheating caused by excessive local current density. In addition, it can also increase the connection strength between the tab 21 and the terminal post 12, enabling it to withstand greater mechanical stress and avoiding problems such as loosening or breakage caused by vibration and impact.

[0064] Meanwhile, the projected area of ​​the first flow surface GL1 of the pole post 12 is designed to be smaller than the projected area of ​​the second flow surface GL2, so that the pole post 12 can reserve more space on the side of the cover plate 11 away from the electrode assembly 20, which is conducive to the spatial layout of the pole post 12 and the external conductive busbar, improves the reliability of the connection between the pole post 12 and the conductive busbar, and also ensures the electrical clearance between adjacent pole posts 12.

[0065] Moreover, since each electrode post 12 is arranged at intervals along the length X of the cover, correspondingly, multiple tabs 21 are arranged at intervals along the length of the cover. The arrangement of the tabs 21 and electrode posts 12 is relatively dispersed, forming multiple paths to transfer the heat of the electrode assembly 20 outward, which can make the temperature rise of the electrode assembly 20 uniform and improve the temperature uniformity of the battery cell 100.

[0066] In summary, the battery cell 100 provided in this application embodiment improves the charging and discharging efficiency and heat dissipation capacity of the battery cell 100 by optimizing the number and arrangement of the terminals 12 and the tabs 21, and by optimizing the structure of the terminals 12. This improves the problem of excessive local temperature rise and greatly enhances the reliability of the battery cell 100 during high current transmission.

[0067] It is worth mentioning that in this embodiment, multiple positive terminals and multiple negative terminals are arranged on the end cover 10, which can effectively utilize the space of the battery cell 100 in the projected area of ​​the cover plate 11, improve the current distribution, reduce local overheating, increase the current carrying capacity, increase the diversity of the connection between the terminal 12 and the external conductive bus, and can use the same liquid cooling structure to cool the battery cell 100, which helps the thermal management of the battery cell 100 and improves the safety of the battery cell 100.

[0068] In some embodiments, such as Figure 4 and Figure 5 As shown, the cover plate 11 has a square structure, and the battery cell 100 has a square structure. The square structure of the battery cell 100 can improve the utilization rate of the internal space of the battery.

[0069] Understandably, the number N of pole posts 12 is greater than or equal to 4 and is an even number. Specifically, in the embodiment, as... Figure 4 and Figure 5 As shown, the number of terminals 12 is configured as 4, including two positive terminals and two negative terminals, with the positive and negative terminals arranged alternately. Thus, under the same conditions of S1 and S1', the assembly efficiency of the battery cell 100 is higher than that of setting more terminals 12.

[0070] In some embodiments, the total length G1 of the first flow surface GL1 of all pole posts 12 in the aforementioned length direction X, the total length G0 of the cover plate 11, and the total length G2 of the second flow surface GL2 of all pole posts 12 in the aforementioned length direction X satisfy: 0.5G0<G1<G2<G0.

[0071] Specifically, to simplify the design, the first flow surface GL1 and the second flow surface GL2 have the same dimensions in the width direction Y of the cover plate 11, but their dimensions in the length direction X of the cover plate 11 are different, resulting in unequal areas. Further to simplify the design, the first flow surface GL1 of each pole post 12 has the same dimensions in all directions, and the second flow surface GL2 of each pole post 12 has the same dimensions in all directions.

[0072] When 0.5G0 < G1 < G2 < G0, and the width dimensions of the first flow surface GL1 and the second flow surface GL2 are the same, the area of ​​the first flow surface GL1 can be smaller than the area of ​​the second flow surface GL2. This increases the electrical clearance between the electrical connectors outside the cover plate 11 (between poles 12 and between conductive bars), reduces the risk of short circuits, and also facilitates the design of the poles 12 and external connections, improves structural compactness, and thus improves overall performance and reliability.

[0073] In some embodiments, combined with Figure 3 and Figure 4 It is understood that, along the thickness direction Z, the projected area S1 of the first flow surface GL1 of all pole posts 12 and the projected area S2 of the outer end face W of the cover plate 11 away from the electrode assembly 20 satisfy: 0.45S2≤S1<S2.

[0074] Area S1 can be understood as the sum of the projected areas of the first flow surfaces GL1 of all pole posts 12 in the thickness direction Z of the cover plate 11. Area S2 can be understood as the sum of the projected areas of the outer end face W in the thickness direction Z of the cover plate 11.

[0075] Typically, each of the pole posts 12 has the same shape and size, and the same area of ​​its first flow surface GL1.

[0076] In practical applications, the terminal 12 is connected to wires, busbars, etc., via the first flow-through surface GL1 to connect to the external circuit. With the same outer end face W size of the cover plate 11, the larger the value of S1 / S2, the larger the area S1 of the first flow-through surface GL1 of all terminals 12, the larger the contact area between the terminal 12 and the wires, busbars, etc., the smaller the contact resistance, the stronger the current-carrying capacity of the terminal 12, and the higher the current transmission efficiency. Simultaneously, a larger area of ​​the first flow-through surface GL1 increases the heat dissipation between the terminal 12 and the outside, improving the heat dissipation capacity of the battery cell 100.

[0077] In this embodiment, the ratio of S1 / S2 is taken in the range of [0.45, 1), which makes the area S1 of the first flow surface GL1 of all the pole posts 12 larger, which can effectively improve the flow capacity and heat dissipation capacity of the pole posts 12, thereby improving the performance of the battery cell 100.

[0078] Specifically, S1 / S2 can be selected as a value of 0.45, 0.5, 0.6, 0.7, 0.8, 0.9, 0.95, or any value between adjacent selections. Furthermore, to ensure the strength of the cover plate 11 and the electrical clearance between the poles 12, S1 / S2 ≤ 0.7.

[0079] In some embodiments, combined with Figure 3 and Figure 5 It is understood that, along the thickness direction Z, the projected area S1' of the second flow surface GL2 of all pole posts 12 and the projected area S2 of the outer end face W of the cover plate 11 away from the electrode assembly 20 satisfy: 0.5S2≤S1'<S2.

[0080] The area S1' can be understood as the sum of the projected areas of the second flow surface GL2 of all pole posts 12 in the thickness direction Z of the cover plate 11.

[0081] A larger S1' / S2 value results in a larger area S1' of the second flow surface GL2 of all terminals 12. Under the same current, this not only reduces the internal resistance of the battery cell 100 but also disperses the current distribution, reduces current density, minimizes polarization caused by excessive local current density, and improves charging and discharging efficiency. Furthermore, it facilitates the conduction of internal heat from the battery cell 100 to the external environment through the terminals 12, lowering the operating temperature and preventing performance degradation or safety hazards (such as thermal runaway) caused by overheating. Simultaneously, it improves the connection strength between the terminals 12 and the tabs 21, enhancing the reliability of the battery cell.

[0082] In this embodiment, the ratio of S1' / S2 is within the range of [0.5, 1). The area S1' of the second flow surface GL2 of all the pole posts 12 is relatively large, which can effectively reduce the current density, improve the charging and discharging efficiency, improve the heat dissipation and heat conduction capacity inside the battery cell 100, and thus improve the performance of the battery cell 100.

[0083] Specifically, S1' / S2 can be selected as a value of 0.5, 0.6, 0.7, 0.8, 0.9, 0.95, or any value between adjacent selections. Furthermore, to ensure the strength of the cover plate 11 and the electrical clearance between the poles 12, S1' / S2 ≤ 0.8.

[0084] In some embodiments, combined with Figure 6 and Figure 7 It is understood that the cover plate 11 is provided with a liquid injection hole 11a penetrating its outer end face W, and each pole post 12 protrudes from its outer end face W. Along the aforementioned length direction X, a gap region T is formed between each pair of adjacent pole posts 12. The liquid injection hole 11a is arranged in part of the gap region T. The size of the gap region T with the liquid injection hole 11a in the aforementioned length direction X is m1, and the diameter of the liquid injection hole 11a is D2. The size of the gap region T without the liquid injection hole 11a in the aforementioned length direction X is m2, satisfying: 0.4m1≤D2<m1; m2≤m1.

[0085] The interval T refers to the area on the cover plate 11 located between two adjacent poles 12 in its length direction X. The injection hole 11a is used for filling with electrolyte. The injection hole 11a is arranged within a portion of the interval T, penetrating the interval T. The number of injection holes 11a is typically one, arranged within one interval T. The diameter D2 of the injection hole 11a refers to the maximum projected size of the injection hole 11a along the thickness direction Z of the cover plate 11. When the injection hole 11a includes the aforementioned settling groove a1 and the aforementioned through hole a2, its maximum projected size is the inner diameter of the settling groove a1.

[0086] In this embodiment, m2 ≤ m1, meaning the length of the interval T without injection holes 11a is less than the length of the interval T with injection holes 11a, which facilitates the placement of the injection holes 11a. Simultaneously, 0.4m1 ≤ D2 < m1, ensuring the injection hole 11a occupies a suitable area in its respective interval T, thus having a minimal impact on the strength of the interval T.

[0087] Specifically, in the embodiments, refer to Figure 8 Understand that the dimension of the first flow surface GL1 of each pole post 12 in the length direction X of the cover plate 11 is b, and the dimension of the first flow surface GL1 of each pole post 12 in the width direction Y of the cover plate 11 is a. In the plane containing the outer end face W, the interval between the first flow surfaces GL1 of adjacent pole posts 12 is m, the distance between the first flow surfaces GL1 of the first and last pole posts 12 in the length direction X and the edge of the outer end face W is p, and the distance between the first flow surfaces GL1 of all pole posts 12 in the width direction Y and the edge of the outer end face W is n, satisfying:

[0088] S2=(a+2n)*[N*b+2p+(N-1)*m], where m≥2mm, n≥4mm, p≥4mm.

[0089] The terminals 12 are arranged at equal intervals along the length X of the cover plate 11. m, n, and p determine the arrangement of the terminals 12 on the cover plate 11. The smaller these three values ​​are, the larger the area occupied by the first flow-through surface GL1 of the terminal 12 on the outer end face W of the cover plate 11, given that the size of the cover plate 11 remains constant. As mentioned above, a larger first flow-through surface GL1 area results in a larger contact area between the terminal 12 and the wires, conductors, etc., leading to lower contact resistance, stronger current-carrying capacity, and higher current transmission efficiency. Simultaneously, a larger first flow-through surface GL1 area increases heat dissipation between the terminal 12 and the external environment, improving the heat dissipation capacity of the battery cell 100. However, the dimensions of m, n, and p cannot be infinitely small; smaller dimensions indicate lower strength of the cover plate 11. Furthermore, excessively small dimensions of m, n, and p are detrimental to the electrical clearance between the terminals 12 and the connection design with the external conductors.

[0090] When m, n, and p each need to satisfy the above relationships, the strength of the cover plate 11, the performance of the battery cell 100, and the connection design with the external conductive busbar can be balanced. Furthermore, m ≤ 5mm, n ≤ 10mm, and p ≤ 10mm can also balance the strength of the cover plate 11 and the performance of the battery cell 100.

[0091] In practical applications, a square-shaped cover plate 11 can be designed based on the above dimensions. Specifically, (a+2n) can be considered as the width of the cover plate 11, and [N*b+2p+(N-1)*m] can be considered as the length of the cover plate 11, thereby determining the area S2 of the outer end face W of the cover plate 11. At this point, after determining the dimensions of the pole post 12 and the spacing distances n, p, and m, the dimensions of the cover plate 11 can be determined based on these data, without needing to consider the occupancy of other structures on the cover plate 11, thus simplifying the design of the cover plate 11.

[0092] For specific implementation examples, see Figure 8 It is understood that the projection of the terminal post 12 along the thickness direction Z of the cover plate 11 is rectangular. Normally, the cover plate 11 is square. Designing the terminal post 12 as a square structure not only makes the end cap 10 more aesthetically pleasing but also simplifies its structure. With the same m, n, and p, the terminal post 12 has a larger configuration area, resulting in a more significant improvement in the performance of the battery cell 100.

[0093] Of course, in other embodiments, the pole post 12 may also be cylindrical or other prismatic structures.

[0094] In some embodiments, refer to Figure 9It is understood that there are multiple tabs 21, which are arranged at intervals along the length direction X of the cover plate 11. Each pole post 12 is welded to a corresponding tab 21, and the polarities of adjacent tabs 21 are opposite. In the length direction X of the cover plate 11, the length L1 of the negative polarity tab 21 and the length L2 of the positive polarity tab 21 satisfy: L1≤L2.

[0095] The tab 21 with negative polarity is called the negative tab, and the tab 21 with positive polarity is called the positive tab. The negative tab is usually made of copper, and the positive tab is usually made of aluminum. When L1 = L2, it means that the length L2 of the positive tab and the length L1 of the negative tab are the same. When the width of the positive and negative tabs is the same, the size and structure of each tab 21 are the same, which simplifies the fabrication of the electrode assembly 20. Since the conductivity of aluminum is weaker than that of copper, when L1 < L2, when the width of the positive and negative tabs is the same, the current carrying capacity of the positive and negative tabs can be balanced, avoiding excessive heat generation by the positive tab.

[0096] In other embodiments, the length L1 of the negative electrode tab 21 and the length L2 of the positive electrode tab 21 satisfy: 0.25L2≤L1≤0.9L2. In this case, L1 / L2 takes a value between 0.25 and 0.9, which, when the widths of the positive and negative electrodes are the same, allows for a better match in current-carrying capacity between the two electrodes. Specifically, L1 / L2 can be selected from values ​​of 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.85, 0.9, and any values ​​between adjacent selections.

[0097] Typically, the dimensions of each tab 21 in the width direction Y of the cover plate 11 (i.e., the width of the tab 21) are equal to each other, simplifying the preparation of the battery cell 100.

[0098] In some embodiments, refer to Figure 3 The battery cell 100 includes an insulating support member 50, which is located at the tab end J. The insulating support member 50 is provided with a hollowed-out position 50u that extends through the thickness direction Z of the cover plate 11, and the hollowed-out position 50u is fitted around the tab 21.

[0099] Specifically, the hollowed-out part 50u can be a hole structure or a groove structure, as long as it can be fitted around the tab 21.

[0100] The insulating support 50 provides insulation and strengthens the isolation cover 11 and the electrode assembly 20. The insulating support 50 is supported at the tab end J. The tabs 21 on the tab end J are sequentially connected to the electrode post 12 via perforated sections 50u (e.g., by welding). The tabs 21 are typically thin sheets, and the perforated sections 50u are fitted around the tabs 21, providing some support and enhancing their structural stability.

[0101] Specifically, in the embodiments, refer to Figure 10 and Figure 11 Understandably, the cutout 50u includes a support groove u1 arranged in a strip shape. One end of the support groove u1 is closed in its longitudinal direction, and the other end is constructed as an opening u11. The insulating support 50 allows the tab 21 to be inserted into the support groove u1 through the opening u11, so as to limit the tab 21 in multiple directions.

[0102] When the cover plate 11 is a square plate, the longitudinal direction of the support groove u1 corresponds to the length direction X of the cover plate 11.

[0103] In actual operation, the opening u11 of the support groove u1 is oriented towards the tab 21, and the insulating support 50 is moved along the longitudinal direction of the support groove u1 at the tab end J. During this process, the tab 21 is continuously inserted into the support groove u1 from the opening u11 until it is fully inserted (e.g., it is fully inserted when it abuts against the closed end), thereby limiting the tab 21 in the length direction X. Typically, the width of the support groove u1 (the dimension of the support groove u1 in the direction perpendicular to its longitudinal direction) is slightly larger than or equal to the width of the tab 21, which facilitates the insertion of the tab 21 while the insulating support can effectively support the tab 21.

[0104] Thus, the assembly process of the insulating support 50 and the tab 21 is simpler and easier to implement.

[0105] In some embodiments, continue to refer to Figure 10 and Figure 11 The opening u11 of the support groove u1 is funnel-shaped, and its large diameter end is positioned away from the closed end of the support groove u1 relative to its small diameter end.

[0106] The opening u11 of the support groove u1 decreases in the width direction from its larger diameter end to its smaller diameter end.

[0107] When inserting the tab 21, the tab 21 first passes through the large-diameter end of the opening u11, and then through the small-diameter end of the opening u11 before being inserted into the support groove u1. The opening u11 is designed in a trumpet shape to make it easier for the tab 21 to be inserted into the support groove u1.

[0108] In some embodiments, combined with Figure 2 , Figure 3 and Figure 9It is understood that multiple tabs 21 are arranged side-by-side at intervals along the longitudinal direction of the support groove u1. Two insulating supports 50 are provided, with adjacent portions of the tabs 21 passing through the support groove u1 of the same insulating support 50, and the remaining portions of the adjacent tabs 21 passing through the support groove u1 of the other insulating support 50. The support grooves u1 of the two insulating supports 50 are spaced apart, and their openings u11 are arranged opposite each other.

[0109] Obviously, "adjacent" here refers to being adjacent in the longitudinal direction of the support groove u1. In one embodiment, each electrode assembly 20 has a plurality of electrodes 21 at its electrode end J, which are arranged side by side at intervals in the longitudinal direction X of the cover plate 11. Specifically, the plurality of electrodes 21 may include one or more positive electrodes and one or more negative electrodes. Along the longitudinal direction X of the cover plate 11 (corresponding to the longitudinal direction of the support groove u1), all the electrodes 21 on each electrode assembly 20 are divided into two groups. One group of electrodes 21 is inserted into the support groove u1 of one of the insulating supports 50, and the other group of electrodes 21 is inserted into the support groove u1 of the other insulating support 50. The support groove u1 of the two insulating supports 50 are configured with their openings u11 facing each other. When the two can move relative to each other along the longitudinal direction of the support groove u1, each group of electrodes 21 is inserted into the corresponding support groove u1.

[0110] At this point, at least one tab 21 is inserted into each support slot u1 of each insulating support 50. This reduces the number of insulating supports 50 required, thus lowering costs. Furthermore, it improves the installation efficiency of the insulating supports 50, thereby increasing the assembly efficiency of the battery cell 100.

[0111] It is worth noting that the same pole post 12 can be connected to the tab 21 on one electrode assembly 20, or it can be connected to the tab 21 on different electrode assemblies 20 at the same time.

[0112] In one embodiment, combined with Figure 2 and Figure 9 To improve the performance of the battery cell 100, at least two electrode assemblies 20 are configured inside the battery cell 100. Each of the at least two electrode assemblies 20 has a tab 21 connected to the same terminal post 12, and these tabs 21 are spaced apart along the width of the support groove u1. Alternatively, the insulating support member 50 may have multiple support grooves u1, which extend longitudinally in the same direction and are arranged side-by-side in a direction perpendicular to the longitudinal direction. Each support groove u1 corresponds to a tab 21, allowing the same insulating support member 50 to support multiple tabs 21 connected to the same terminal post 12, thereby improving the assembly efficiency of the battery cell 100 and reducing costs.

[0113] Of course, only one support groove u1 can be configured on the insulating support member 50, with each tab 21 correspondingly inserted into the support groove u1 of the insulating support member 50, or multiple tabs 21 connected to the same pole post 12 correspondingly inserted into the support groove u1 of the insulating support member 50 at the same time.

[0114] In one specific embodiment, combined with Figure 2 and Figure 9 It is understood that two electrode assemblies 20 and two insulating support members 50 are each configured. Each electrode assembly 20 has multiple tabs 21 on its tab end J at the same end. All tabs 21 on each electrode assembly 20 are spaced apart along the length X of the cover plate 11, and all tabs 21 of the two electrode assemblies 20 are arranged correspondingly along the width Y of the cover plate 11. Two corresponding tabs 21 on the two electrode assemblies 20 are connected to the same pole post 12 and are respectively inserted into two different support slots u1 on the same insulating support member 50. The openings u11 of the support slots u1 on the two insulating support members 50 are arranged opposite each other. As recorded above, the support slot u1 of one insulating support member 50 is inserted into the adjacent portion of the tabs 21 along the length X of the cover plate 11, while the support slot u1 of the other insulating support member 50 is inserted into the other adjacent portion of the tabs 21.

[0115] In some embodiments, combined with Figure 3 It is understood that the cover plate 11 is provided with a liquid injection hole 11a, and the projection of the insulating support 50 is offset from the projection of the liquid injection hole 11a along the thickness direction Z of the cover plate 11.

[0116] Specifically, in one example (such as...) Figure 3 As shown, two insulating supports 50 are configured, spaced apart along the length X of the cover plate 11, with the space between them corresponding to the injection hole 11a. In other examples, clearance holes may also be provided in the insulating supports 50, arranged opposite to the injection hole 11a.

[0117] When the above-mentioned protrusion 34 is provided on the insulating filler 30, the projection of the protrusion 34 includes the projection of the injection hole 11a, and the projection of the protrusion 34 is set to be offset from the projection of the insulating support 50.

[0118] At this time, the insulating support 50 will not obstruct the flow of electrolyte to the tab end J, which is conducive to the smooth wetting of the electrode assembly 20 by the electrolyte.

[0119] In some embodiments, refer to Figure 9 , Figure 11 and Figure 12 An insulated support member 50 is provided with a liquid passage hole 50v, which connects the liquid injection hole 11a and the electrode assembly 20, and is offset from the hollowed-out position 50u.

[0120] Specifically, the liquid passage hole 50v is disposed through the insulating support member 50 along the thickness direction Z of the cover plate 11, and is offset from the hollow position 50u. The electrode tab 21 in the hollow position 50u will not interfere with the liquid passage hole 50v, thus affecting its liquid passage. Multiple liquid passage holes 50v are usually provided on the insulating support member 50 to increase the liquid passage capacity. The multiple liquid passage holes 50v are distributed on the insulating support member 50 to allow the electrolyte to flow to multiple positions of the electrode assembly 20.

[0121] Since the insulating support 50 is supported at the tab end J, it will hinder the flow of electrolyte to the electrode assembly 20 to a certain extent. At this time, providing a liquid passage hole 50v on the insulating support 50 can increase the path of electrolyte flow to the tab end J, so that the electrolyte can be more evenly wetted into the interior of the electrode assembly 20, thereby improving the circulation capacity of the electrode assembly 20.

[0122] In some embodiments, combined with Figure 10 and Figure 11 The insulating support member 50 includes a first end face d1 and a second end face d2 arranged opposite to each other along the thickness direction Z of the cover plate 11. The first end face d1 is constructed as a planar structure that fits against the electrode assembly 20. A reinforcing rib 51 is provided on the second end face d2, and the reinforcing rib 51 passes through the hollowed-out position 50u.

[0123] The first end face d1 is flat, and its contact area with the tab end J is large. The pressure exerted by the insulating support 50 on the electrode assembly 20 is more uniform, avoiding local compression of the electrode assembly 20 and causing safety problems.

[0124] Multiple reinforcing ribs 51 can be configured on the second end face d2 of the insulating support member 50. Each reinforcing rib 51 is arranged in a strip shape, and the multiple reinforcing ribs 51 can be interwoven to form a mesh structure. The arrangement of the reinforcing ribs 51 not only enhances the overall strength of the insulating support member 50, but also the hollowed-out position 50u passes through the reinforcing ribs 51, which can improve the support strength of the insulating support member 50 for the tabs 21 that pass through the hollowed-out position 50u.

[0125] It is worth mentioning that a liquid passage hole 50v is provided on the insulating support 50. Since the liquid passage hole 50v passes through the second end face d2, even if a reinforcing rib 51 is provided on the second end face d2, the electrolyte can be prevented from accumulating on the second end face d2, ensuring that the electrolyte flows out smoothly.

[0126] In some embodiments, refer to Figure 2 It is understood that the battery cell 100 also includes thermally conductive adhesive 40, which is located between the end cap 10 and the tab end J, and the second flow surface GL2 is located within the thermally conductive adhesive 40.

[0127] In this embodiment, the thermally conductive adhesive 40 can be thermally connected to the cover plate 11 of the end cap 10. In other examples, the thermally conductive adhesive 40 thermally connects both the cover plate 11 and the tab end J. The second flow surface GL2 is located within the thermally conductive adhesive 40, indicating that the connected tab 21 is also located within the thermally conductive adhesive 40. In this case, the thermally conductive adhesive 40 can cover the connection between the terminal post 12 and the tab 21, transferring heat from both to the outside through the thermally conductive adhesive 40 and the end cap 10, thus improving the heat dissipation capacity of the battery cell 100. Moreover, by covering the connection between the tab 21 and the terminal post 12, the thermally conductive adhesive 40 can improve the connection reliability of both, ensuring an effective connection to effectively transfer heat from inside the battery cell 100, further guaranteeing the heat dissipation capacity of the battery cell 100, while also ensuring the temperature uniformity inside the battery cell 100, thereby improving the reliability of the battery cell 100.

[0128] Furthermore, the thermally conductive adhesive 40 can insulatingly cover the side of the electrode post 12 facing the tab 21, thereby ensuring the electrical clearance between the electrode posts 12 inside adjacent battery cells 100, thus maximizing the projected area of ​​the second flow surface GL2, making the second flow surface GL2 larger than the first flow area GL1. The thermally conductive adhesive 40 is insulating and can insulatingly cover the entire side of the electrode post 12 facing the tab 21 (including the welding area between the electrode post 12 and the tab 21), that is, cover the second flow surface GL2 of the electrode post 12, thereby achieving electrical isolation between adjacent electrode posts 12.

[0129] Specifically, in the embodiments, refer to Figure 2 and Figure 3 The battery cell 100 includes an insulating filler 30, which is disposed between the end cap 10 and the tab end J. The insulating filler 30 is thermally connected to the cover plate 11. The insulating filler 30 has a filling space 30h and a clearance hole 30i communicating with the filling space 30h. The end of the insulating filler 30 facing the tab end J has an opening 30m. The tab 21 extends into the filling space 30h through the opening 30m. The terminal post 12 passes through the clearance hole 30i and is connected to the tab 21 within the filling space 30h. Thermally conductive adhesive 40 fills the filling space 30h through the opening 30m and covers the tab 21 and the terminal post 12.

[0130] The insulating filler 30 is insulating and is arranged between the tab end J and the cover plate 11, insulating and isolating the tab end J from the cover plate 11, reducing the risk of leakage from the cover plate 11. The insulating filler 30 forms a filling space 30h, and its end facing the tab end J is provided with an opening 30m, which is an open hole / orifice structure that connects the filling space 30h with the tab end J.

[0131] One end of the pole post 12 passes through the clearance hole 30i and extends into the glue-filling space 30h, and the pole lug 21 passes through the opening 30m and extends into the glue-filling space 30h. The two are connected within the glue-filling space 30h, and the connection point between the two is located within the glue-filling space 30h. The insulating glue-filling component 30 and the cover plate 11 can be connected by assembly, bonding, etc., to fix the position of the insulating glue-filling component 30.

[0132] In one embodiment, reference is made to Figure 12 and Figure 13 The insulating filler 30 can be formed by a base plate 31 and a side plate 32. The side plate 32 is arranged in a ring around the edge of the base plate 31, and the two together form a filling space 30h. The end of the side plate 32 facing away from the base plate 31 is completely open to form the aforementioned opening 30m. The base plate 31 is arranged close to the cover plate 11, and the clearance hole 30i is located on the base plate 31. In this case, the structure of the insulating filler 30 is simple, which can reduce manufacturing costs. Alternatively, the shape of the base plate 31 can usually match the shape of the cover plate 11. For example, if the cover plate 11 is a square plate, then the base plate 31 can also be a square plate.

[0133] In other embodiments, the insulating filler 30 may further include a sealing plate (not shown), which is disposed at the end of the side plate 32 opposite to the bottom plate 31. An opening on the sealing plate facing the tab end J serves as the aforementioned opening 30m. In this case, one or more openings may be provided on the sealing plate, each opening extending into the filler space 30h through one or more tabs 21.

[0134] Specifically, the number of insulating filler parts 30 can be one or more. If multiple insulating filler parts 30 are configured, different tabs 21 and different posts 12 can extend into the filling space of each insulating filler part 30, that is, one insulating filler part 30 is configured for each set of tabs 21 and posts 12. This can be achieved, for example... Figure 3 As shown, only one insulating filler 30 is configured, and all the tabs 21 and all the posts 12 are located within the filling space 30h of the insulating filler 30, which simplifies the structure of the battery cell 100.

[0135] During the fabrication of the battery cell 100, after the insulating filler 30 is fixed (its opening 30m is opposite to the cover plate 11), the tab 21 and the terminal post 12 are fixed together (e.g., by welding or snapping) within the filler space 30h. Then, flowing thermally conductive adhesive 40 is injected into the filler space 30h through the opening 30m, and allowed to solidify. It should be noted that the thermally conductive adhesive 40 can completely fill the filler space 30h and make thermally conductive contact with the tab end J of the electrode assembly 20. Alternatively, the thermally conductive adhesive 40 can only fill a portion of the filler space 30h, as long as it effectively covers the tab 21 and the terminal post 12.

[0136] In this embodiment, an insulating filler 30 is provided between the cover plate 11 of the end cap 10 and the tab end J of the electrode assembly 20. Both the electrode post 12 and the tab 21 extend into the filling space 30h within the insulating filler 30. During the preparation of the battery cell 100, the thermally conductive adhesive 40 is injected into the filling space 30h through the opening 30m of the insulating filler 30, ensuring that the thermally conductive adhesive 40 effectively covers the electrode post 12 and the tab 21, enhancing the connection reliability between the two, and also increasing the heat transfer area and improving the heat transfer efficiency of the two to a certain extent. Moreover, by limiting the amount of thermally conductive adhesive 40 using the filling space 30h, the consumption of thermally conductive adhesive 40 can be reduced, thus reducing costs. The thermally conductive adhesive 40 can fill the entire filling space 30h, thereby covering the entire area of ​​the electrode post 12 facing the electrode assembly 20, achieving electrical isolation between adjacent electrode posts 12.

[0137] Specifically, in the embodiments of this application, both the insulating filler 30 and the insulating support 50 can be made of polymer materials with good insulating properties, such as nylon (Polyamide, abbreviated as PA), polycarbonate (Polycarbonate, abbreviated as PC), polybutylene terephthalate (Polybutylene terephthalate, abbreviated as PBT), and acelonitrile butadiene styrene (abbreviated as ABS). Fillers that enhance thermal conductivity and insulation (such as Al2O3, AlN, BN, MgO, ZnO, NiO, Si3N4, etc.) can also be added to these polymer materials.

[0138] In some embodiments, combined with Figure 3 It is understood that the projection of the opening 30m along the thickness direction Z of the cover plate 11 includes the projection of the tab end J along the thickness direction Z. At this time, the open area of ​​the opening 30m is relatively large. When the tab 21 and the pole post 12 are welded, it facilitates the welding operation of the pole post 12 and the tab 21 within the glue-filling space 30h, and also makes the glue-filling process visible, ensuring that the thermally conductive adhesive 40 effectively covers the pole post 12 and the tab 21. Specifically, the projection of the opening 30m can extend beyond the projection range of the tab end J. Specifically, the opening 30m can be formed by the end of the side plate 32 facing away from the bottom plate 31.

[0139] In some embodiments, refer to Figure 3 and Figure 14 Understand that the pole post 12 includes an adjacent mating section 12b and a welding section 12c, a first flow surface GL1 located at the end of the welding section 12c away from the mating section 12b, and a second flow surface GL2 located in the welding section 12c.

[0140] The mating section 12b is mated to the clearance hole 30i either by itself or through the seal 13. The welding section 12c extends into the glue-filling space 30h and is connected to the electrode tab 21.

[0141] In one example (not shown), the mating section 12b mates with the clearance hole 30i, for example, one of them has a mating groove, and the other has a mating protrusion that engages within the mating groove. Figure 5 In the example shown, the mating section 12b of the pole 12 mates with the clearance hole 30i via the seal 13.

[0142] In one specific embodiment, combined with Figure 14 , Figure 15 and Figure 16 Understandably, the cover plate 11 includes a pole post hole 11b, a sealing member 13 is installed in the pole post hole 11b, the sealing member 13 is provided with a first sealing groove 13e that mates with the hole wall of the pole post hole 11b, the sealing member 13 has an installation hole 13d, a mating section 12b passes through the installation hole 13d, and a second sealing groove 13i is formed on the hole wall of the installation hole 13d that mates with the mating section 12b.

[0143] The sealing element 13 can be made of soft materials such as silicone or rubber. The sealing element 13 is ring-shaped, such as a circle or a square. The inner wall of the sealing element 13 forms a mounting hole 13d, which is continuous in the thickness direction Z of the cover plate 11. The sealing element 13 passes through the pole post hole 11b and is sealed and engaged with the concave-convex structure on the hole wall of the pole post hole 11b through the first sealing groove 13e. The mating section 12b of the pole post 12 passes through the mounting hole 13d of the sealing element 13, and the concave-convex structure on its outer wall is sealed and engaged with the second sealing groove 13i.

[0144] At this time, the pole post 12 and the pole post hole 11b of the cover plate 11 are sealed and connected by the concave-convex seal 13. The sealing path is relatively long, which can effectively ensure the sealing performance at the connection between the pole post 12 and the cover plate 11, and also play an insulating role.

[0145] Specifically, such as Figure 14 As shown, the inner wall of the clearance hole 30i of the insulating filler 30 can be fitted together with the hole wall of the pole hole 11b in the first sealing groove 13e.

[0146] In some embodiments, along the thickness direction Z of the cover plate 11, the projection of the welding section 12c exceeds the projection of the mating section 12b and the projection of the clearance hole 30i. The inner wall of the clearance hole 30i is configured to be deformable.

[0147] The projected shapes of the welding section 12c, the mating section 12b, and the clearance hole 30i are basically matched. For example, when all three projected shapes are circular, the outer diameter of the welding section 12c is larger than the outer diameter of the mating section 12b, and the inner diameter of the clearance hole 30i is smaller than the outer diameter of the welding section 12c. As another example, when all three projected shapes are square, the dimensions of the welding section 12c are larger than the dimensions of the mating section 12b and the clearance hole 30i in both the length direction (X) and width direction (Y) of the square projection.

[0148] The deformable inner wall of the clearance hole 30i means that the clearance hole 30i can change shape under the action of external force to allow the welding section 12c to pass through the clearance hole 30i. In order to achieve the internal deformability of the clearance hole 30i, the insulating filler 30 can be made of a soft structure, such as silicone or rubber.

[0149] When assembling the battery cell 100, the insulating filler 30 is installed on the inside of the end cover 10. During this process, as the insulating filler 30 gradually approaches the inside of the cover plate 11, the clearance hole 30i first gets into the welding section 12c (during this process, the clearance hole 30i deforms under the action of the welding section 12c). After the welding section 12c passes through the clearance hole 30i, the clearance hole 30i reaches the position of mating with the mating section 12b (the clearance hole 30i returns to its initial state).

[0150] At this time, the insulating filler 30 part where the clearance hole 30i is located cannot be removed from the welding section 12c of the pole post 12 in the thickness direction Z of the cover plate 11, thereby improving the installation position stability of the insulating filler 30.

[0151] Specifically, in the embodiments, refer to Figure 12 and Figure 13 The inner wall of the clearance hole 30i is recessed to form multiple notches 30n, which are spaced apart circumferentially along the clearance hole 30i. Each notch 30n penetrates the wall of the insulating filler 30 along the aforementioned thickness direction Z, so that the inner wall of the clearance hole 30i can be bent and deformed.

[0152] During the assembly of the battery cell 100, as the insulating filler 30 gradually approaches the inner side of the cover plate 11, the clearance hole 30i is inserted into the welding section 12c. Due to the compression of the welding section 12c, the inner wall portion of the clearance hole 30i located on both sides of the notch 30n bends towards the filling space 30h, thereby increasing the size of the hole structure formed by the clearance hole 30i, thus allowing the welding section 12c to pass through the clearance hole 30i. After the welding section 12c passes through the clearance hole 30i, the compression effect of the welding section 12c causes the bent portion of the insulating filler 30 to deform in the opposite direction until it returns to its initial state and successfully mates with the mating section 12b.

[0153] At this time, by setting multiple notches 30n in the circumferential direction of the clearance hole 30i, the inner wall of the clearance hole 30i can be deformed through the notches 30n, so as to allow the welding section 12c to pass through. Whether the material of the insulating filler 30 is a flexible material is not required, which makes the selection range of materials for the insulating filler 30 wider and can improve the overall strength of the insulating filler 30.

[0154] In one embodiment, such as Figure 12 and Figure 13 As shown, the clearance hole 30i is a square hole, and the notch 30n is arranged at the corner position 30p of the clearance hole 30i. At this time, by arranging the notch 30n at the corner position 30p of the clearance hole 30i, the inner wall of the clearance hole 30i is more likely to bend and deform. At the same time, when it returns to its original state after bending and deformation, it can avoid the notch 30n not being able to deform or the notch 30n being torn and deformed and unable to recover, which would affect the sealing effect.

[0155] In some embodiments, combined with Figure 12 and Figure 17 It is understood that the insulating filler 30 includes a separator 33. The separator 33 is located in the filler space 30h and divides the filler space 30h into a main space h1 and an overflow space h2. The clearance hole 30i is connected to the main space h1, and the electrode tab 21 extends into the main space h1. The separator 33 forms an overflow channel 33q that connects the overflow space h2 and the main space h1. At least the main space h1 is filled with thermally conductive adhesive 40.

[0156] Understandably, the pole post 12 extends into the main space h1 after passing through the clearance hole 30i, and connects with the pole lug 21 located in the main space h1. When the insulating filler 30 is formed by the base plate 31 and the side plate 32 mentioned above, the partition strip 33 is provided on the base plate 31. Specifically, the partition strip 33 can form an overflow space h2 within the filler space 30h by itself, and the partition strip 33 can also form an overflow space h2 at intervals with the side plate 32.

[0157] The overflow channel 33q is used to store excess thermally conductive adhesive 40 in the overflow space h2 when the required amount of thermally conductive adhesive 40 is poured into the main space h1, so as to prevent the thermally conductive adhesive 40 from overflowing into the filling space 30h.

[0158] In one embodiment, the overflow channel 33q includes an overflow hole formed in the partition strip 33 itself. The overflow hole is arranged at a height in the thickness direction Z of the cover plate 11 that is not less than the required thickness of the thermally conductive adhesive 40 in the main space h1. In another embodiment, the partition strip 33 is positioned below the end face where the opening 30m is located (i.e., the partition strip 33 is below the end of the side plate 32 facing away from the bottom plate 31), so that an overflow channel 33q is formed between the partition strip 33 and the end face where the opening 30m is located. The height of the partition strip 33 determines the thickness of the thermally conductive adhesive 40. This method simplifies the structure of the partition strip 33.

[0159] During the glue-filling process, thermally conductive adhesive 40 is injected into the main space h1 through the open end 30m until it effectively covers the tab 21 and the post 12. If the injection of thermally conductive adhesive 40 in the main space h1 reaches the required amount but is not stopped in time, excess adhesive 40 can flow to the overflow space h2 through the overflow channel 33q. This not only prevents the thermally conductive adhesive 40 from overflowing the filling space 30h, but also facilitates judgment of whether the glue filling is complete, effectively controlling the amount of thermally conductive adhesive 40 used.

[0160] In one specific embodiment, such as Figure 17 As shown, the separator 33 and the side wall (formed by the side plate 32) of the glue filling space 30h are spaced apart to form an overflow groove, which serves as the overflow space h2. At this time, the overflow space h2 is located in the edge area of ​​the glue filling space 30h, which facilitates the layout of the tab 21 and the pole 12.

[0161] In some embodiments, refer to Figure 12 and Figure 13 The insulating filler 30 includes a protrusion 34. A liquid injection hole 11a is provided on the cover plate 11. The protrusion 34 is located in the filling space 30h and extends towards the tab end J, passing through the opening 30m, and is spaced apart from the tab end J. A liquid injection channel 34r is formed within the protrusion 34, communicating with the liquid injection hole 11a. Along the thickness direction Z of the cover plate 11, the projection of the outlet end of the liquid injection hole 11a is located within the projection range of the inlet end of the liquid injection channel 34r.

[0162] Specifically, the base plate 31 is fitted to the cover plate 11. A protruding post 34 is provided on the base plate 31 corresponding to the position of the injection hole 11a and protruding towards the tab end J. The injection channel 34r inside the protruding post 34 is arranged opposite to the injection hole 11a. The electrolyte injected through the injection hole 11a first flows through the injection channel 34r and then wets the tab end J of the electrode assembly 20.

[0163] Because the projection of the outlet end of the injection hole 11a is located within the projection range of the inlet end of the injection channel 34r (i.e., the inner diameter of the inlet end of the injection channel 34r is larger than the inner diameter of the outlet end of the injection hole 11a), the electrolyte smoothly enters the injection channel 34r after being discharged from the injection hole 11a, without flowing out of the injection channel 34r. Because the protrusion 34 extends 30m beyond the opening, the thermally conductive adhesive 40 will not block the injection channel 34r during the potting process. Because the protrusion 34 is spaced from the tab end J, the electrolyte, after flowing out of the injection channel 34r, can flow towards all parts of the tab end J, allowing the electrolyte to more uniformly wet the electrode assembly 20.

[0164] Thus, the protrusion 34 allows the electrolyte to be smoothly injected into the battery cell 100 and facilitates the uniform distribution of the electrolyte within the electrode assembly 20.

[0165] In some embodiments, refer to Figure 3 The end cap 10 also includes a sealing pin 14 disposed at the injection hole 11a. The sealing pin 14 is disposed at the injection hole 11a to prevent the free electrolyte inside the battery cell 100 from leaking from the injection hole 11a.

[0166] Specifically, in the embodiments, combined with Figure 7 and Figure 18 It is understood that the injection hole 11a includes an adjacent and connected sinker a1 and a through hole a2, and the sealing nail 14 includes a connected boss portion 14g and a pillar portion 14k. The boss portion 14g is supported on the bottom wall of the sinker a1 and is spaced apart from the side wall of the sinker a1. The pillar portion 14k is fitted into the through hole a2. The inner diameter D1 of the through hole a2, the inner diameter D2 of the sinker a1, the outer diameter D3 of the boss portion 14g, and the outer diameter D4 of the pillar portion 14k satisfy: D4 < D1 < D3, 0.7D2 < D3 < D2.

[0167] D4 < D1 < D3. On the one hand, this makes it easier to insert the column 14k into the through hole a2. On the other hand, during the process of inserting the sealing nail 14, when the boss 14g is limited by the bottom of the groove a1, it indicates that the sealing nail 14 is installed in place, making the installation of the sealing nail 14 more reliable.

[0168] 0.7D2<D3<D2 indicates that there is a certain gap between the boss part 14g and the side wall of the sinker a1, which can be used for welding the gap between the sealing nail 14 and the injection hole 11a to improve the sealing effect.

[0169] In some embodiments, combined with Figure 19 and Figure 7 It is understood that the orifice diameter D5 of the injection channel 34r satisfies: D5 > D1. In this way, the electrolyte can flow smoothly from the injection hole 11a into the injection channel 34r without leakage.

[0170] It is worth noting that in one embodiment, such as Figure 20 As shown, the electrode tab 21 includes a root segment 21a and a tail segment 21b that are intersected, and a curved segment 21c that is zigzagly connected between the root segment 21a and the tail segment 21b. The tail segment 21b is located in the glue-filling space 30h and is welded to the electrode post 12. The root segment 21a has a hollowed-out position 50u. The thermally conductive adhesive 40 at least covers the tail segment 21b.

[0171] Specifically, the thermally conductive adhesive 40 can also cover the bent section 21c. In practical applications, before bending, the electrode assembly 20 is positioned horizontally, with its tab end J offset from the cover plate 11 in the horizontal plane. Since the tab 21 is also horizontal, it is easier to weld to the electrode post 12 within the adhesive-filled space 30h. After the tail section 21b of the tab 21 is welded to the electrode post 12, the tab 21 is bent until its tab end J is positioned opposite the cover plate 11. Specifically, the root section 21a of the tab 21 has a perforated position 50u.

[0172] In some embodiments, refer to Figure 1 and Figure 2 The battery cell 100 also includes a housing 60, which includes a receiving cavity with an opening u11. A cover plate 11 covers the opening u11 of the receiving cavity, and the outer end face W of the cover plate 11 is disposed away from the receiving cavity. The electrode assembly 20 is received in the receiving cavity. The housing 60 can be a steel shell, aluminum shell, etc., which, together with the cover plate 11, forms the receiving cavity for receiving the electrode assembly 20. The housing 60 and the cover plate 11 can be sealed together by welding, snap-fitting, or other methods.

[0173] Further in the embodiments, refer to Figure 2 The battery cell 100 also includes a thermally conductive covering 70, which is located in the receiving cavity and covers the electrode assembly 20. The thermally conductive covering 70 has thermal conductivity and can be graphene, thermally conductive plastic film (such as PP, PC, etc.).

[0174] At this time, the heat generated by the electrode assembly 20 is transferred to the outer shell 60 through the thermally conductive coating. The outer shell 60 can exchange heat with the external liquid cooling structure, thereby improving the heat exchange efficiency between the battery cell 100 and the liquid cooling structure, greatly reducing the working heat of the battery cell 100, and improving the reliability of the battery cell 100.

[0175] In a further embodiment, the battery cell 100 also includes an explosion-proof valve (not shown), which is disposed on the side of the housing 60 away from the end cover 10.

[0176] Furthermore, the battery provided in this application embodiment includes the battery cell 100 in any of the above embodiments. This battery possesses all the aforementioned beneficial effects.

[0177] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0178] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery cell (100), characterized in that, include: End cap (10) includes a cover plate (11) and multiple sets of pole posts disposed on the cover plate (11). Each set of pole posts includes two pole posts (12) with opposite polarities. All the pole posts (12) are arranged at intervals along the length direction (X) of the cover plate (11). The electrode assembly (20) includes an electrode tab end (J) facing the cover plate (11), and the electrode tab end (J) is provided with a plurality of electrodes (21); Each of the pole posts (12) has a first flow surface (GL1) and a second flow surface (GL2) disposed opposite to each other in the thickness direction (Z) of the cover plate (11), and each second flow surface (GL2) is connected to a pole tab (21); along the thickness direction (Z), the projected area of ​​the first flow surface (GL1) of each pole post (12) is smaller than the projected area of ​​the second flow surface (GL2); The total length G1 of the first flow surface (GL1) of all the pole posts (12) in the length direction (X), the total length G0 of the cover plate (11), and the total length G2 of the second flow surface (GL2) of all the pole posts (12) in the length direction (X) satisfy: 0.5G0<G1<G2<G0; The battery cell (100) includes an insulating support (50) disposed at the tab end (J); the insulating support (50) is provided with a hollow part (50u) that runs through the thickness direction (Z) of the cover plate (11), and the hollow part (50u) is sleeved around the tab (21); The cutout (50u) includes a support groove (u1) arranged in a strip shape. One end of the support groove (u1) is closed in its longitudinal direction, and the other end is constructed as an opening (u11). The insulating support (50) allows the tab (21) to be inserted into the support groove (u1) through the opening (u11). The opening (u11) of the support groove (u1) is funnel-shaped, and its large-diameter end is positioned away from the closed end of the support groove (u1) relative to its small-diameter end.

2. The battery cell (100) according to claim 1, characterized in that, Along the thickness direction (Z), the projected area S1 of the first flow surface (GL1) of all the pole posts (12) and the projected area S2 of the outer end face (W) of the cover plate (11) facing away from the electrode assembly (20) satisfy: 0.45S2≤S1<S2; and / or, Along the thickness direction (Z), the projected area S1' of the second flow surface (GL2) of all the pole posts (12) and the projected area S2 of the outer end face (W) of the cover plate (11) that is away from the electrode assembly (20) satisfy: 0.5S2≤S1'<S2.

3. The battery cell (100) according to any one of claims 1-2, characterized in that, The cover plate (11) is provided with a liquid injection hole (11a) that penetrates its outer end face (W), and each of the poles (12) protrudes from the outer end face (W); Along the length direction (X), a gap region (T) is formed between each pair of adjacent poles (12). The injection hole (11a) is arranged in part of the gap region (T). The size of the gap region (T) with the injection hole (11a) in the length direction (X) is m1, the diameter of the injection hole (11a) is D2, and the size of the gap region (T) without the injection hole (11a) in the length direction (X) is m2, satisfying: 0.4m1≤D2<m1; m2≤m1.

4. The battery cell (100) according to claim 1, characterized in that, Multiple tabs (21) are arranged side by side at intervals along the longitudinal direction of the support groove (u1); two insulating supports (50) are provided, with adjacent portions of the tabs (21) passing through the support groove (u1) of the same insulating support (50), and the remaining portions of the tabs (21) passing through the support groove (u1) of another insulating support (50); the support grooves (u1) of the two insulating supports (50) are spaced apart, and the openings (u11) are arranged opposite to each other.

5. The battery cell (100) according to claim 1, characterized in that, The cover plate (11) is provided with a liquid injection hole (11a). Along the thickness direction (Z) of the cover plate (11), the projection of the insulating support (50) is offset from the projection of the liquid injection hole (11a). And / or, the insulating support (50) is provided with a liquid passage hole (50v), the liquid passage hole (50v) connects the liquid injection hole (11a) and the electrode assembly (20), and is offset from the hollow position (50u); And / or, the insulating support (50) includes a first end face (d1) and a second end face (d2) disposed opposite to each other along the thickness direction (Z) of the cover plate (11), the first end face (d1) being configured as a planar structure that fits against the electrode assembly (20); the second end face (d2) is provided with a reinforcing rib (51), and the hollowed-out position (50u) is through which the reinforcing rib (51) passes.

6. The battery cell (100) according to any one of claims 1-2, characterized in that, The battery cell (100) further includes thermally conductive adhesive (40), which is located between the end cap (10) and the tab end (J), and the second flow surface (GL2) is located within the thermally conductive adhesive (40); and / or, The pole post (12) includes an adjacent mating section (12b) and a welding section (12c), and the first flow surface (GL1) is located at the end of the welding section (12c) away from the mating section (12b); the cover plate (11) includes a pole post hole (11b), and the end cap (10) includes a sealing element (13), the sealing element (13) is installed in the pole post hole (11b), and the sealing element (13) is provided with a first sealing groove (13e) that mates with the hole wall of the pole post hole (11b); the sealing element (13) has a mounting hole (13d), the mating section (12b) passes through the mounting hole (13d), and a second sealing groove (13i) that mates with the mating section (12b) is formed on the hole wall of the mounting hole (13d).

7. The battery cell (100) according to any one of claims 1-2, characterized in that, The battery cell (100) includes an insulating filler (30), which has a filling space (30h) and a clearance hole (30i) communicating with the filling space (30h). The insulating filler (30) has an opening (30m) at one end facing the tab end (J). The tab (21) extends into the filling space (30h) through the opening (30m). The terminal post (12) passes through the clearance hole (30i) and is connected to the tab (21) in the filling space (30h). The filling space (30h) is provided with thermally conductive adhesive (40), which covers the tab (21) and the terminal post (12).

8. A battery, characterized in that, Includes the battery cell (100) as described in any one of claims 1-7.

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