Battery cells and batteries

Abstract

The application discloses an electric core and a battery. The electric core comprises a pole core, an insulation part and a top cover assembly. The pole core comprises a pole core body and a pole lug. The pole core body comprises a body part and a protruding part. A side surface of the body part along a second direction is a first surface. The pole lug is connected to the first surface. The protruding part is also connected to the first surface and is arranged in a first direction and spaced from the pole lug. The protruding part protrudes outward from the first surface along the second direction. The top cover assembly covers the first surface of the body part. The insulation part is arranged between the protruding part and the top cover assembly and wraps the protruding part. In this way, the volume of the electric core is increased to increase the capacity of the electric core, and the insulation performance is realized through the insulation part.

Description

Technical Field

[0001] This application belongs to the field of battery technology, specifically relating to a battery cell and a battery. Background Technology

[0002] With the rapid development of various electronic products, people not only have a rapidly growing demand for lithium-ion batteries, but also have higher requirements for the capacity of lithium batteries. People are eager for a significant increase in the capacity of existing lithium batteries.

[0003] In related technologies, batteries typically include a top cover, electrode cores, and a lower plastic layer. The positive and negative tabs of the electrode cores are connected to the positive and negative terminals of the top cover, and the lower plastic layer is located between the top cover and the electrode cores. However, existing lower plastic layers occupy internal space within the battery cell, leading to a decrease in the battery's energy density. Utility Model Content

[0004] This application aims to provide a battery cell and battery that can solve the problem that the energy density of the battery is reduced due to the plastic occupies part of the internal space of the battery cell.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, embodiments of this application propose a battery cell having a first direction and a second direction perpendicular to each other, the first direction being the length direction of the battery cell and the second direction being the height direction of the battery cell; the battery cell includes: an electrode core, an insulating portion, and a top cover assembly; the electrode core includes an electrode core body and an electrode tab, the electrode core body includes a body portion and a protrusion portion, one side surface of the body portion along the second direction is a first surface, the electrode tab is connected to the first surface, the protrusion portion is also connected to the first surface and is spaced apart from the electrode tab in the first direction, the protrusion portion protrudes outward from the first surface along the second direction; the top cover assembly covers the first surface of the body portion, the insulating portion is disposed between the protrusion portion and the top cover assembly and wraps around the protrusion portion.

[0007] Optionally, the top cover assembly includes a top cover body and a lower plastic layer, the lower plastic layer being disposed on the side of the top cover body near the electrode core; the number of electrode tabs is two, the two electrode tabs being spaced apart along the first direction; the number of protrusions is two, the two protrusions being disposed on both sides of one of the electrode tabs along the first direction, the lower plastic layer being disposed between the other electrode tab and the top cover body, and the lower plastic layer being connected to the top cover body and the first surface on both sides along the second direction.

[0008] Optionally, along the first direction, there is a first gap between the lower plastic and the adjacent protrusion, and the size of the first gap between the lower plastic and the adjacent protrusion is W1, which satisfies: 2mm≤W1≤5mm.

[0009] Optionally, the first surface has a first region and a second region other than the first region; the first region is connected to the tab, and the protrusion covers the second region.

[0010] Optionally, the top cover assembly includes an explosion-proof valve; the top cover body covers the first surface of the body portion and abuts against the insulating portion, and the explosion-proof valve is disposed in the top cover body; the protrusion is provided with a clearance space at a position corresponding to the explosion-proof valve, and the clearance space is opposite to the explosion-proof valve along the second direction.

[0011] Optionally, the height of the protrusion along the second direction is H, satisfying: 1.4mm≤H≤7mm.

[0012] Optionally, along the first direction, there is a second gap between the electrode tab and the adjacent protrusion, and the size of the second gap between the electrode tab and the adjacent protrusion is W2, which satisfies: 2mm≤W2≤5mm.

[0013] Optionally, the insulating part includes a first sub-insulating part and a second sub-insulating part; the top cover assembly is provided with a liquid injection hole, the first sub-insulating part is provided at the corresponding position of the top cover assembly and the liquid injection hole, the second sub-insulating part is provided at other positions of the top cover assembly except for the liquid injection hole, and the hardness of the first sub-insulating part is greater than the hardness of the second sub-insulating part.

[0014] Optionally, the insulating portion includes a first insulating layer and a thermally conductive layer; the first insulating layer is disposed on the side surface of the protrusion facing the top cover assembly, and the first insulating layer is used for insulation between the protrusion and the top cover assembly; the thermally conductive layer is disposed on the side surface of the insulating layer facing the top cover assembly, and the thermally conductive layer is used for heat conduction between the protrusion and the top cover assembly; or, the insulating portion includes an insulating and thermally conductive layer; the insulating and thermally conductive layer is disposed on the side surface of the protrusion facing the top cover assembly, and the insulating and thermally conductive layer is used for insulation and heat conduction between the protrusion and the top cover assembly.

[0015] Secondly, embodiments of this application propose a battery including the battery cell described in the above embodiments.

[0016] In this embodiment, both the tabs and the protrusions are connected to the first surface, the protrusions are misaligned with the tabs, and at least part of the protrusions protrude outwards along a second direction. The top cover assembly covers the first surface of the body portion, and an insulating portion is disposed between the protrusions and the top cover assembly and encloses the protrusions. In this way, the capacity of the battery cell is increased by increasing its volume, and insulation performance is achieved through the insulating portion; that is, the insulation performance of the battery cell is ensured while increasing its energy density.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0019] Figure 1 This is a schematic diagram of a first type of battery cell according to an embodiment of this application;

[0020] Figure 2 This is a schematic diagram of the connection relationship between the first type of pole core and top cover assembly according to an embodiment of this application;

[0021] Figure 3 This is a schematic diagram of the connection relationship between the electrode core and the electrode tab according to a first embodiment of this application;

[0022] Figure 4 This is a schematic diagram of a first type of electrode according to an embodiment of this application;

[0023] Figure 5 This is a schematic diagram of a second type of battery cell according to an embodiment of this application;

[0024] Figure 6 This is a schematic diagram of the connection relationship between the second type of pole core and top cover assembly according to an embodiment of this application;

[0025] Figure 7 This is a schematic diagram of the connection relationship between the electrode core and the electrode tab according to the second embodiment of this application;

[0026] Figure 8 This is a schematic diagram of a second type of electrode sheet according to an embodiment of this application;

[0027] Figure 9 This is a schematic diagram of the connection relationship between the electrode core and the electrode tab according to the third embodiment of this application;

[0028] Figure 10 This is a schematic diagram of a third type of electrode sheet according to an embodiment of this application;

[0029] Figure 11This is a schematic diagram of an insulating part according to an embodiment of this application;

[0030] Figure 12 This is a schematic diagram of another insulating part according to an embodiment of this application.

[0031] Figure label:

[0032] 10-Electrode core; 11-Body part; 12-Protrusion; 121-Sub-protrusion; 13-Allowing space; 14-First surface; 15-Positive electrode plate; 16-Negative electrode plate; 20-Electrode tab; 21-Positive electrode tab; 211-Sub-positive electrode tab; 22-Negative electrode tab; 221-Sub-negative electrode tab; 30-Top cover assembly; 31-Top cover body; 32-Filter screen; 33-Explosion-proof valve; 34-Positive electrode post; 35-Negative electrode post; 36-Lower plastic; 37-Injection hole; 40-Insulation part; 41-First sub-insulation part; 42-Second sub-insulation part; X-First direction; Z-Second direction; Y-Third direction. Detailed Implementation

[0033] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0034] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0035] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are 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, and therefore should not be construed as a limitation of this application.

[0036] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0037] In the prior art, the lower plastic of the top cover assembly, as an insulating material, is usually placed between the electrode core and the top cover body to prevent short circuits between the negative electrode post or tab and the top cover body; at the same time, it can also control the distance between the electrode core and the top cover body, providing space for the tab to bend.

[0038] In existing technologies, the lower plastic layer almost completely covers the lower surface of the top cover body. While this provides insulation and protection, it also results in unnecessary material waste and occupies limited space inside the cell casing, thus increasing the battery's weight. Furthermore, the full-area coverage of the lower plastic layer hinders heat conduction between the top of the electrode core and the top cover body, impeding heat dissipation from the top of the electrode core.

[0039] The battery cells and batteries provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0040] like Figures 1 to 10 As shown in the embodiment of this application, a battery cell is proposed. The battery cell has a first direction X and a second direction Z that are perpendicular to each other. The first direction X is the length direction of the battery cell, and the second direction Z is the height direction of the battery cell. The battery cell includes: an electrode core 10, an insulating part 40, and a top cover assembly 30. The electrode core 10 includes an electrode core body and an electrode tab 20. The electrode core body includes a body part 11 and a protrusion 12. One side surface of the body part 11 along the second direction Z is a first surface 14. The electrode tab 20 is connected to the first surface 14. The protrusion 12 is also connected to the first surface 14 and is spaced apart from the electrode tab 20 in the first direction X. The protrusion 12 protrudes outward from the first surface 14 along the second direction Z. The top cover assembly 30 covers the first surface 14 of the body part 11. The insulating part 40 is disposed between the protrusion 12 and the top cover assembly 30 and wraps around the protrusion 12.

[0041] It should be noted that the battery cell also has a casing (not shown in the figure), which contains a cavity and an electrolyte. The electrode core 10 is placed inside the cavity. Both the body portion 11 and the protrusion 12 of the electrode core 10 contain active materials that can chemically react with the electrolyte inside the cavity. The top cover assembly 30 covers the opening of the cavity. In addition, the battery cell also has a third-direction Y, where the third-direction Y is the width direction of the battery cell.

[0042] In this embodiment, the tab 20 and the protrusion 12 are both connected to the first surface 14, the protrusion 12 is misaligned with the tab 20, and the protrusion 12 at least partially protrudes outward along the second direction Z. The top cover assembly 30 covers the first surface of the body portion 11, and the insulating portion 40 is disposed between the protrusion 12 and the top cover assembly 30 and wraps around the protrusion 12. In this way, the capacity of the battery cell is increased by increasing the volume of the battery cell, and the insulation performance is achieved by the insulating portion 40; that is, the insulation performance of the battery cell is ensured while increasing the energy density of the battery cell.

[0043] Specifically, this application can set the thickness of the insulating part 40 to be less than the thickness of the lower plastic in a conventional battery cell, thereby utilizing the thickness difference between the two to improve the energy density of the battery cell; that is, this application gradually reduces the use of one positive electrode lower plastic, or one negative electrode lower plastic, or all of the lower plastic, and sets protrusions at corresponding positions, and insulates and wraps the protrusions, thereby improving the energy density of the battery cell while ensuring the insulation performance of the battery cell.

[0044] It should be noted that this application can reduce or eliminate the use of the lower plastic corresponding to any positive or negative electrode in the battery cell, or the lower plastic can be omitted from both the positive and negative electrodes, thereby increasing the energy density of the battery cell; in addition, in order to make the insulating part 40 have a smaller thickness, insulating tape, insulating paper, and spraying insulating liquid can be used to insulate the protrusion 12.

[0045] Furthermore, the insulating portion 40 is positioned between the protrusion 12 and the top cover assembly 30, specifically covering the potential short-circuit risk area near the electrode tab, achieving precise local insulation and avoiding the redundancy of full coverage with traditional plastic. Simultaneously, the protrusion 12 protrudes outward along the second direction Z, forming a structural complement to the top cover assembly 30. This prevents the electrode core 10 from shaking within the casing, improving its impact resistance, and also facilitates heat conduction between the top of the electrode core 10 and the top cover assembly 30, enhancing the battery's cycle performance and safety.

[0046] It is understandable that, such as Figure 1 and Figure 3 As shown, the first surface 14 is the side surface of the body portion 11 along the second direction Z that is close to the top cover assembly 30. The body portion 11 also has a second surface disposed opposite to the first surface 14, which is close to the bottom of the receiving cavity.

[0047] Optionally, such as Figures 1 to 4As shown, the top cover assembly 30 includes a top cover body 31 and a lower plastic 36; the lower plastic 36 is disposed on the side of the top cover body 31 near the electrode core 10; there are two electrode tabs 20, which are spaced apart along the first direction X; there are two protrusions 12, which are respectively disposed on both sides of one electrode tab 20 along the first direction X; the lower plastic 36 is disposed between the other electrode tab 20 and the top cover body 31, and the lower plastic 36 is connected to the top cover body 31 and the first surface 14 on both sides along the second direction Z.

[0048] In this embodiment, two tabs 20 are spaced apart along a first direction X, and two protrusions 12 are respectively disposed on both sides of one tab 20 along the first direction X. A lower plastic 36 is disposed between the other tab 20 and the top cover body 31. This allows for different insulation methods to be used for tabs 20 located in different positions, enabling more flexible adaptation to the position of the tabs 20 and thus saving space.

[0049] Furthermore, this application can reduce or eliminate the use of the lower plastic corresponding to any positive or negative electrode in the battery cell, or eliminate the use of the lower plastic for both the positive and negative electrodes, thereby increasing the energy density of the battery cell.

[0050] In some embodiments, such as Figure 1 and Figure 2 As shown, the top cover assembly 30 also includes a positive terminal 34 and a negative terminal 35; the positive terminal 34 and the negative terminal 35 are inserted into the top cover body 31, and the two tabs 20 are the positive tab 21 and the negative tab 22, respectively. The positive terminal 34 and the positive tab 21 are electrically connected, and the negative terminal 35 and the negative tab 22 are electrically connected. A protrusion 12 is provided on both sides of the negative tab 22 along the first direction X, and a lower plastic 36 is provided between the electrode core 10 where the negative tab 22 is located and the top cover body 31. The lower plastic 36 has a clearance hole for the positive terminal 34 to pass through. Thus, by providing the lower plastic 36 on one side of the positive tab 21 and the protrusion 12 on one side of the negative tab 22, the arrangement constraints between the positive tab 21 and the negative tab 22 are accommodated, and the excessive thickness caused by using only the lower plastic 36 is avoided, resulting in a more compact fit between the top cover body 31 and the electrode core 10.

[0051] It should be noted that, in this embodiment of the application, protrusions 12 may be provided on both sides of the positive electrode tab 21 along the first direction X, and a lower plastic 36 may be provided between the negative electrode tab 22 and the top cover body 31. This embodiment of the application does not impose any limitations on this.

[0052] In some embodiments, such as Figure 1 and Figure 2As shown, the top cover assembly 30 also includes a filter screen 32 and an explosion-proof valve 33; the explosion-proof valve 33 is disposed in the top cover body 31, and the filter screen 32 is disposed between the explosion-proof valve 33 and the electrode core 10. When the battery cell experiences thermal runaway, the filter screen 32 can filter the impurities that have passed through the explosion-proof valve 33 when the battery cell runs away, thereby allowing gas to pass through the explosion-proof valve 33 and preventing blockage.

[0053] In some embodiments, such as Figure 1 and Figure 4 As shown, the electrode core 10 includes multiple positive electrode plates 15, multiple negative electrode plates 16, and multiple sub-protrusions 121. The positive electrode tab 21 includes multiple sub-positive electrode tabs 211, and the negative electrode tab 22 includes multiple sub-negative electrode tabs 221. Sub-positive electrode tabs 211 are connected to the positive electrode plates 15, and sub-negative electrode tabs 221 are connected to the negative electrode plates 16. Along the first direction X, the positive electrode plate 15 has two sub-protrusions 121 on the side away from the sub-positive electrode tabs 211, and the negative electrode plate 16 has sub-protrusions 121 on both sides of the sub-negative electrode tabs 221. Multiple positive electrode plates 15 and multiple negative electrode plates 16 are stacked sequentially to form a body portion 11, multiple sub-protrusions 121 are stacked to form a protrusion portion 12, multiple sub-positive electrode tabs 211 are stacked to form a positive electrode tab 21, and multiple sub-negative electrode tabs 221 are stacked to form a negative electrode tab 22.

[0054] In some embodiments, the positive electrode 15 and the negative electrode 16 are first cut into the shape shown below. Figure 4 The shape shown is then formed by stacking and hot-pressing the positive electrode 15 and the negative electrode 16; subsequently, the sub-positive electrode tab 211 and sub-negative electrode tab 221 are respectively gathered and ultrasonically welded to form a shape as shown. Figure 2 and Figure 3 The positive electrode tab 21 and negative electrode tab 22 are shown. Finally, the positive electrode tab 21 and negative electrode tab 22 are laser welded to the positive electrode post 34 and negative electrode post 35, respectively. Furthermore, after the positive electrode tab 21 and negative electrode tab 22 are welded to the positive electrode post 34 and negative electrode post 35, insulating tape can be applied to the surface of the positive electrode tab 21 and negative electrode tab 22 near the top cover body 31 to prevent the positive electrode tab 21 and negative electrode tab 22 from contacting the top cover body 31 and short-circuiting when the electrode core 10 is closed.

[0055] Optionally, such as Figure 1 As shown, along the first direction X, there is a first gap between the lower plastic 36 and the adjacent protrusion 12. The size of the first gap between the lower plastic 36 and the adjacent protrusion 12 is W1, which satisfies: 2mm≤W1≤5mm.

[0056] In this embodiment, the size W1 of the first gap between the lower plastic 36 and the adjacent protrusion 12 is set within a certain range. This avoids the problem of interference between the protrusion 12 and the lower plastic 36 during production and assembly if W1 is too small, and also avoids powder shedding caused by friction between the sidewall of the protrusion 12 and the lower plastic 36 if W1 is too small. On the other hand, an excessively large W1 would reduce the gap utilization rate, decrease the size of the electrode core 10, and thus reduce the energy density of the battery cell.

[0057] For example, W1 can be set to any value such as 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, or any range between any two values.

[0058] It should be noted that, as Figure 1 and Figure 2 As shown, W1 refers to the distance between the left edge of the lower plastic 36 and the right edge of the protrusion 12 located on the right side of the negative electrode tab 22.

[0059] Optionally, such as Figure 1 and Figure 6 As shown, the first surface 14 has a first region and a second region other than the first region; the first region is connected to the tab 20, and the protrusion 12 covers the second region.

[0060] In this embodiment, the tab 20 is connected to the first region, and the protrusion 12 covers the second region. This ensures that the conductive space required for connecting the tab 20 and the protective area required for the protrusion 12 do not overlap, maximizing the use of the surface space of the electrode core 10 and further improving the internal compactness of the cell.

[0061] It should be noted that the connection area between the tab 20 and the core 10 can be in part of the first area or can completely cover the first area. This embodiment of the application does not impose any restrictions here.

[0062] In some embodiments, the tab 20 and the body 11 can be separate designs or integrally formed; the embodiments of this application do not impose any limitations on this.

[0063] In some embodiments, the present application can be applied to upright battery packs and inverted battery packs; wherein, an inverted battery pack refers to a battery cell top cover assembly 30 being placed downwards, i.e., the battery cell top cover assembly 30 facing the ground. In an inverted battery, the protrusion 12 can also disperse the pressure of the body portion 11 on the tab 20, preventing the tab 20 from tearing.

[0064] Optionally, such as Figure 5 and Figure 6As shown, the top cover assembly 30 includes an explosion-proof valve 33; the top cover body 31 covers the first surface 14 of the body portion 11 and abuts against the insulating portion 40, and the explosion-proof valve 33 is disposed in the top cover body 31; the protrusion 12 is provided with a clearance space 13 at a position corresponding to the explosion-proof valve 33, and the clearance space 13 is opposite to the explosion-proof valve 33 along the second direction Z.

[0065] In this embodiment, the top cover body 31 abuts against the insulating portion 40, and the explosion-proof valve 33 located in the top cover body 31 is aligned with the clearance space 13 in the protrusion 12. This allows the explosion-proof valve 33 to quickly respond and release pressure when there is abnormal pressure inside the battery cell, improving the battery's safety performance under extreme conditions. Furthermore, the clearance space 13 only provides partial clearance for the area of ​​the explosion-proof valve 33, while the protrusion 12 remains connected to the top cover body 31 through the insulating portion 40 in other areas. This coordinated design of precise clearance and full-area insulation satisfies the functional requirements of the explosion-proof valve 33 without affecting the overall insulation protection effect.

[0066] In some embodiments, such as Figure 6 and Figure 7 As shown, when the explosion-proof valve 33 is located in the middle of the top cover body 31, a clearance space 13 is provided in the protrusion 12 located between the positive electrode 21 and the negative electrode 22. Of course, if the explosion-proof valve 33 is located on any side of the top cover body 31 along the first direction X, the clearance space 13 is also located on any side of the protrusion 12 along the first direction X.

[0067] In some embodiments, the clearance space 13 is suitable for batteries with large capacity and large gas production during cell thermal runaway, such as ternary high-nickel batteries.

[0068] In some embodiments, such as Figure 5 and Figure 8 As shown, the electrode core 10 includes multiple positive electrode plates 15, multiple negative electrode plates 16, and multiple sub-protrusions 121. The positive electrode tab 21 includes multiple sub-positive electrode tabs 211, and the negative electrode tab 22 includes multiple sub-negative electrode tabs 221. Sub-positive electrode tabs 211 are connected to the positive electrode plates 15, and sub-negative electrode tabs 221 are connected to the negative electrode plates 16. Along the first direction X, the positive electrode plate 15 has a sub-protrusion 121 at a position corresponding to the sub-negative electrode tab 221, and sub-protrusions 121 are provided on both sides of the sub-positive electrode tab 211. The negative electrode 16 has a sub-protrusion 121 on both sides of the sub-negative electrode tab 221, and the negative electrode 16 has a sub-protrusion 121 at the corresponding position to the sub-positive electrode tab 211; multiple positive electrode plates 15 and multiple negative electrode plates 16 are stacked in sequence to form the main body 11, multiple sub-protrusions 121 are stacked to form a protrusion 12, multiple sub-positive electrode tabs 211 are stacked to form a positive electrode tab 21, and multiple sub-negative electrode tabs 221 are stacked to form a negative electrode tab 22.

[0069] In some embodiments, such as Figure 9and Figure 10 As shown, the clearance space 13 can also be omitted in the protrusion 12, that is, the protrusion 12 located between the positive electrode tab 21 and the negative electrode tab 22 can be continuously provided. The continuously provided protrusion 12 is suitable for small-capacity batteries with a small amount of gas production during cell thermal runaway, such as lithium iron phosphate batteries.

[0070] Optionally, such as Figure 3 , Figure 7 and Figure 9 As shown, the height of the protrusion 12 along the second direction Z is H, which satisfies: 1.4mm≤H≤7mm.

[0071] In this embodiment, the height H of the protrusion 12 along the second direction Z is within a certain range. Thus, when H≥1.4mm, the protrusion 12 has sufficient compressive mechanical strength to withstand the compression stress during the assembly of the top cover assembly 30 and the expansion force during the battery charging and discharging process, avoiding connection failure caused by deformation; when H≤7mm, it prevents the protrusion 12 from excessively protruding and occupying the longitudinal space inside the cell, taking into account both insulation safety and energy density.

[0072] In some embodiments, the lower plastic 36 includes a lower plastic body and lower plastic bosses connected to each other, with the lower plastic bosses located on both sides of the lower plastic body; the height of the lower plastic body along the second direction Z is generally 0.4mm-2mm, and the height of the lower plastic bosses along the second direction Z is generally 1mm-5mm. This application uses an insulating portion 40 instead of the lower plastic to achieve insulation between the electrode core 10 and the top cover assembly 30, thereby increasing the size of the electrode core 10 by improving the thickness difference between the insulating portion 40 and the lower plastic, thus increasing the energy density of the electrode core 10.

[0073] For example, H can be set to any value or a range between any two values, such as 1.4mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm.

[0074] In some embodiments, the height H of the protrusions 12 along the second direction Z can be set to be consistent or partially consistent. For example, the height of the protrusions 12 located between the positive electrode tab 21 and the negative electrode tab 22 can be set to 7 mm, and the height of the protrusions 12 located on both sides of the cell along the first direction X can be set to 9 mm.

[0075] Optionally, such as Figure 3 , Figure 7 and Figure 9 As shown, along the first direction X, there is a second gap between the tab 20 and the adjacent protrusion 12. The size of the second gap between the tab 20 and the adjacent protrusion 12 is W2, which satisfies: 2mm≤W2≤5mm.

[0076] In this embodiment, the size W2 of the second gap between the tab 20 and the adjacent protrusion 12 is set within a certain range. This avoids the problem of powder shedding caused by friction between the sidewall of the protrusion 12 and the tab 20 due to an excessively small W2; on the other hand, an excessively large W2 will reduce the gap utilization rate, reduce the size of the electrode core 10, and thus reduce the energy density of the battery cell.

[0077] For example, W2 can be set to any value such as 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, or any range between any two values.

[0078] Optionally, such as Figure 1 , Figure 2 and Figure 6 As shown, the insulating part 40 includes a first sub-insulating part 41 and a second sub-insulating part 42 that are connected to each other; the top cover assembly 30 is provided with an injection hole 37, the first sub-insulating part 41 is provided at the corresponding position of the protrusion 12 and the injection hole 37, and the second sub-insulating part 42 is provided in the remaining part of the protrusion 12 except for the corresponding position of the injection hole 37. The hardness of the first sub-insulating part 41 is greater than the hardness of the second sub-insulating part 42.

[0079] In this embodiment, the first sub-insulating part 41 is disposed at the corresponding position of the top cover assembly 30 and the protrusion 12, and the second sub-insulating part 42 is disposed in the remaining part of the protrusion 12 excluding the corresponding position of the injection hole 37. The hardness of the first sub-insulating part 41 is greater than the hardness of the second sub-insulating part 42. In this way, the hardness of the first sub-insulating part 41 can prevent the electrolyte from impacting the protrusion 12 during injection, avoiding powder shedding from the electrode core body and preventing the separator located between the positive electrode plate 15 and the negative electrode plate 16 from being pushed into the cell, causing a short circuit problem caused by direct contact between the positive electrode plate 15 and the negative electrode plate 16 at the top of the cell.

[0080] It should be noted that hardness refers to the ability of a localized area to resist the indentation of a hard object into its surface; in this application, hardness refers to the ability of the first sub-insulating part 41 to resist the impact of electrolyte.

[0081] Optionally, such as Figure 2 and Figure 11 As shown, the insulating portion 40 includes a first insulating layer 43 and a heat-conducting layer 44; the first insulating layer 43 is disposed on the side surface of the protrusion 12 facing the top cover assembly 30, and the first insulating layer 43 is used for insulation between the protrusion 12 and the top cover assembly 30; the heat-conducting layer 44 is disposed on the side surface of the first insulating layer 43 facing the top cover assembly 30, and the heat-conducting layer 44 is used for heat conduction between the protrusion 12 and the top cover assembly 30.

[0082] In this embodiment, a first insulating layer 43 is provided between the protrusion 12 and the top cover assembly 30. This forms a sandwich-like insulation structure of "protrusion 12 - first insulating layer 43 - top cover assembly 30," improving the dielectric strength of the insulation and making it suitable for higher voltage or more demanding operating conditions. Furthermore, the first insulating layer 43, acting as a flexible medium, fills the rigid contact surface between the protrusion 12 and the top cover assembly 30, absorbing mechanical stress generated during assembly pressing or cell expansion, and reducing the propagation of microcracks in the protrusion 12 due to long-term pressure.

[0083] Furthermore, by disposing of the thermally conductive layer 44 on the surface of the first insulating layer 43 facing the top cover assembly 30, a directional thermally conductive channel is established between the first insulating layer 43 and the top cover assembly 30. This allows the heat generated by the electrode core 10 to be quickly dissipated through the path of the protrusion 12-thermally conductive layer 44-top cover assembly 30, thereby reducing the internal hot spot temperature of the cell and improving battery cycle life and fast charging performance. In addition, the thermally conductive layer 44, as a flexible interface material, can fill the microscopic uneven gaps between the first insulating layer 43 and the top cover assembly 30, reducing contact thermal resistance and ensuring efficient heat transfer. At the same time, its elastic properties can absorb the expansion difference between the top cover assembly 30 and the electrode core 10 caused by temperature changes, avoiding mechanical stress concentration caused by rigid connection and improving structural stability under long-term thermal cycling.

[0084] In some embodiments, the thermally conductive layer 44 may be made of at least one of silicon dioxide, silicon carbide, aluminum oxide, aluminum nitride, magnesium oxide, and boron nitride.

[0085] In some embodiments, the first insulating layer 43 may be made of at least one of epoxy resin, polyurethane, and polyolefin. The first insulating layer 43 may also be insulating tape. Before the tabs 20 are welded, the outer surface of the protrusion 12 is wrapped with high-temperature resistant insulating tape to prevent the positive electrode 15 and negative electrode 16 from contacting and rubbing with the top cover body 31 when the battery is subjected to vibration and impact, which could lead to damage, powder shedding, and short circuits.

[0086] Optionally, such as Figure 2 and Figure 12 As shown, the insulating part 40 includes an insulating and heat-conducting layer 45; the insulating and heat-conducting layer 45 is disposed on the side surface of the protrusion 12 facing the top cover assembly 30, and the insulating and heat-conducting layer 45 is used for insulation and heat conduction between the protrusion 12 and the top cover assembly 30.

[0087] In this embodiment, an insulating and thermally conductive layer 45 is disposed on the surface of the protrusion 12 facing the top cover assembly 30. This allows the insulating and thermally conductive layer 45 to simultaneously achieve insulation and thermal conductivity, thereby improving integration.

[0088] Specifically, the material particles for making the heat-conducting layer and the material particles for the insulating layer can be mixed and formed into an insulating and thermally conductive adhesive by injection molding. The insulating and thermally conductive adhesive can then be applied to the surface of the protrusion 12 facing the top cover body 31.

[0089] In some embodiments, the insulating portion 40 may further include a buffer layer disposed on the side surface of the insulating and thermally conductive layer 45 facing the top cover assembly 30, and the buffer layer is used for buffering between the protrusion 12 and the top cover assembly 30.

[0090] Optionally, embodiments of this application propose a battery that includes the battery cell described in the above embodiments.

[0091] In this embodiment, the tab 20 and the protrusion 12 are both connected to the first surface 14, the protrusion 12 is misaligned with the tab 20, and the protrusion 12 at least partially protrudes outward along the second direction Z. The top cover assembly 30 covers the first surface of the body portion 11, and the insulating portion 40 is disposed between the protrusion 12 and the top cover assembly 30 and wraps around the protrusion 12. In this way, the capacity of the battery cell is increased by increasing the volume of the battery cell, and the insulation performance is achieved by the insulating portion 40; that is, the insulation performance of the battery cell is ensured while increasing the energy density of the battery cell.

[0092] Furthermore, the insulating portion 40 is positioned between the protrusion 12 and the top cover assembly 30, specifically covering the potential short-circuit risk area near the electrode tab, achieving precise local insulation and avoiding the redundancy of full coverage with traditional plastic. Simultaneously, the protrusion 12 protrudes outward along the second direction Z, forming a structural complement to the top cover assembly 30. This prevents the electrode core 10 from shaking within the casing, improving its impact resistance, and also facilitates heat conduction between the top of the electrode core 10 and the top cover body 31, enhancing the battery's cycle performance and safety.

[0093] In specific applications, the battery can be at least one of lithium-ion batteries, solid-state batteries, lead-acid batteries, and nickel-metal hydride batteries. Those skilled in the art can choose according to actual needs, and the embodiments of this application do not limit this.

[0094] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0095] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery cell, the battery cell having a first direction (X) and a second direction (Z) perpendicular to each other, the first direction (X) being the length direction of the battery cell, and the second direction (Z) being the height direction of the battery cell; characterized in that, The battery cell includes: an electrode core (10), an insulation part (40), and a top cover assembly (30); The electrode core (10) includes an electrode core body and an electrode tab (20). The electrode core body includes a body portion (11) and a protrusion portion (12). The surface of the body portion (11) along the second direction (Z) is a first surface (14). The electrode tab (20) is connected to the first surface (14). The protrusion portion (12) is also connected to the first surface (14) and is spaced apart from the electrode tab (20) in the first direction (X). The protrusion portion (12) protrudes outward from the first surface (14) along the second direction (Z). The top cover assembly (30) covers the first surface (14) of the body portion (11). The insulating portion (40) is disposed between the protrusion portion (12) and the top cover assembly (30) and wraps around the protrusion portion (12).

2. The battery cell according to claim 1, characterized in that, The top cover assembly (30) includes a top cover body (31) and a lower plastic (36), wherein the lower plastic (36) is disposed on the side of the top cover body (31) near the pole core (10); The number of the electrode tabs (20) is two, and the two electrode tabs (20) are arranged at intervals along the first direction (X); There are two protrusions (12), and the two protrusions (12) are respectively disposed on both sides of one of the tabs (20) along the first direction (X). The lower plastic (36) is disposed between the other tab (20) and the top cover body (31). The lower plastic (36) is connected to the top cover body (31) and the first surface (14) on both sides along the second direction (Z).

3. The battery cell according to claim 2, characterized in that, Along the first direction (X), there is a first gap between the lower plastic (36) and the adjacent protrusion (12), and the size of the first gap between the lower plastic (36) and the adjacent protrusion (12) is W1, which satisfies: 2mm≤W1≤5mm.

4. The battery cell according to claim 3, characterized in that, The first surface (14) has a first region and a second region other than the first region; The first region is connected to the tab (20), and the protrusion (12) covers the second region.

5. The battery cell according to claim 4, characterized in that, The top cover assembly (30) includes an explosion-proof valve (33); The top cover body (31) covers the first surface (14) of the body part (11) and abuts against the insulating part (40), and the explosion-proof valve (33) is disposed in the top cover body (31); The protrusion (12) has a clearance space (13) at a position corresponding to the explosion-proof valve (33), and the clearance space (13) is opposite to the explosion-proof valve (33) along the second direction (Z).

6. The battery cell according to claim 1, characterized in that, The height of the protrusion (12) along the second direction (Z) is H, which satisfies: 1.4mm≤H≤7mm.

7. The battery cell according to claim 1, characterized in that, Along the first direction (X), there is a second gap between the tab (20) and the adjacent protrusion (12), and the size of the second gap between the tab (20) and the adjacent protrusion (12) is W2, which satisfies: 2mm≤W2≤5mm.

8. The battery cell according to claim 1, characterized in that, The insulating part (40) includes a first sub-insulating part (41) and a second sub-insulating part (42) that are connected to each other; The top cover assembly (30) is provided with an injection hole (37). The first sub-insulating part (41) is provided at the corresponding position of the protrusion (12) and the injection hole (37). The second sub-insulating part (42) is provided in the remaining part of the protrusion (12) excluding the corresponding position of the injection hole (37). The hardness of the first sub-insulating part (41) is greater than the hardness of the second sub-insulating part (42).

9. The battery cell according to any one of claims 1-7, characterized in that, The insulating portion (40) includes a first insulating layer (43) and a heat-conducting layer (44); the first insulating layer (43) is disposed on the side surface of the protrusion (12) facing the top cover assembly (30), and the first insulating layer (43) is used for insulation between the protrusion (12) and the top cover assembly (30); the heat-conducting layer (44) is disposed on the side surface of the first insulating layer (43) facing the top cover assembly (30), and the heat-conducting layer (44) is used for heat conduction between the protrusion (12) and the top cover assembly (30); Alternatively, the insulating portion (40) may include an insulating and thermally conductive layer (45); the insulating and thermally conductive layer (45) is disposed on the side surface of the protrusion (12) facing the top cover assembly (30), and the insulating and thermally conductive layer (45) serves for insulation and thermal conduction between the protrusion (12) and the top cover assembly (30).

10. A battery, characterized in that, The battery cell includes any one of claims 1-9.

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