Battery

Abstract

This utility model relates to the field of battery manufacturing technology and discloses a battery including a core and tabs. At least one end of the core is configured as a tab connection end, which is formed by winding the head empty foil area of ​​the electrode sheet, and the central part of the tab connection end is configured as a hollow structure. The tab includes a connecting part and a lead-out part. The connecting part is configured as an arc-shaped structure and is connected to the sidewall of the hollow structure of the tab connection end. The connecting part is also connected to the lead-out part. This utility model can reduce the manufacturing cost of the battery while ensuring more uniform stress inside the battery electrode sheet and reducing the risk of electrode breakage.

Description

Technical Field

[0001] This utility model relates to the field of battery manufacturing technology, and specifically to a battery. Background Technology

[0002] Lithium-ion batteries, especially those aiming for high energy density, are increasingly using silicon-based materials as the negative electrode active material. However, silicon materials undergo dramatic volume expansion and contraction during battery charging and discharging.

[0003] Therefore, in existing technologies, cylindrical lithium-ion batteries typically employ different tab designs to connect the internal electrodes of the core to the external terminals. Common designs include tabs directly welded to the end face of the core (i.e., centrally located tabs) or full-tab structures covering the entire end face.

[0004] When using silicon anodes, the repeated expansion stress is directly transmitted to these connection structures. For center-mounted tab designs, stress tends to concentrate at and around the solder joints. Under the expansion and contraction cycles of the silicon anode, especially in pouch cells, these stress concentrations or complex structures can lead to anode breakage, resulting in rapid capacity decay or even battery failure. While all-tab structures theoretically offer a wider stress distribution, their manufacturing processes are typically more complex and expensive. Utility Model Content

[0005] In view of this, the present invention provides an electrode tab and a battery to solve the problem of ensuring more uniform stress inside the battery electrode and reducing the risk of electrode breakage while reducing manufacturing costs.

[0006] This utility model provides a battery, comprising:

[0007] The core has at least one end configured as a tab connection end, the tab connection end being formed by winding the head empty foil area of ​​the electrode sheet, and the center part of the tab connection end being configured as a hollow structure.

[0008] The electrode includes a connecting part and a lead-out part. The connecting part is configured as an arc-shaped structure and is connected to the side wall of the hollow structure of the electrode connecting end. The connecting part is connected to the lead-out part.

[0009] Beneficial effects: By designing the connection part of the electrode tab as an arc-shaped structure and directly connecting it to the sidewall of the hollow structure at the electrode tab connection end, this structure effectively disperses the huge expansion stress generated during the charging and discharging process of the silicon negative electrode. Compared with the traditional method of centrally welding the electrode tab to the end face of the core, the sidewall connection of the arc-shaped structure allows the stress to be evenly distributed along the circumferential direction, significantly reducing the risk of electrode breakage.

[0010] In one optional embodiment, the lead-out portion includes a first segment and a second segment, the first segment being connected to the connecting portion, the second segment being connected to the first segment, the first segment and the second segment being arranged at an angle, and the first segment being located within the inner perimeter area of ​​the connecting portion.

[0011] Beneficial effects: The lead-out section adopts a two-section design with an angled arrangement. Specifically, the first section connects to the connecting section, and the second section carries the tab adhesive. By confining both the first and second sections within the inner perimeter of the connecting section, a compact layout of the tab system is achieved. The L-shaped bending structure formed by the first and second sections shortens the current transmission path, reducing internal resistance. At the same time, it ensures that the entire tab is completely embedded within the core projection space, further optimizing axial dimensions, avoiding interference with the housing or other components, and improving space utilization and assembly reliability.

[0012] In one alternative implementation, the connection point between the first segment and the second segment is located at the center of the inner perimeter region of the connection portion, and the first segment and the second segment are perpendicular to each other.

[0013] Beneficial effects: By confining both the first segment and the second segment within the inner perimeter of the connecting portion, and by further enabling a compact layout of the electrode system, the first segment and the second segment can achieve this.

[0014] In one alternative embodiment, the lead-out portion and the connecting portion are constructed as an integral structure.

[0015] Beneficial effects: The one-piece molded lead-out and connection parts eliminate the weak interface area of ​​traditional separate welded tabs. Under extreme conditions of repeated expansion and contraction of the silicon anode, the one-piece structure avoids fatigue cracking of the solder joints, ensures the continuity of current transmission and mechanical connection strength, and significantly improves the reliability of the tabs in long-term use and the battery cycle life.

[0016] In one alternative embodiment, the winding core further includes:

[0017] A positive electrode and a negative electrode are provided, with the head empty foil area provided at opposite ends of the positive electrode and the negative electrode. A pair of electrode tabs are provided, and the pair of electrode tabs are respectively connected to the head empty foil area of ​​the positive electrode and the negative electrode.

[0018] Beneficial effects: The curved tabs on both the positive and negative electrodes ensure uniform stress distribution in both electrodes. The curved connection on the positive electrode side matches the expansion characteristics of the silicon negative electrode, synergistically maintaining the stability of the core structure; simultaneous optimization of both electrodes further balances the internal stress field, comprehensively suppressing the risk of electrode breakage and ensuring the overall reliability of the high-energy-density battery.

[0019] In one optional embodiment, both the positive electrode and the negative electrode include a current collector and a coating compounded to the current collector, and a head empty foil region is provided at one end along the width direction of the current collector, and the head empty foil region extends along the length direction of the current collector.

[0020] In one optional embodiment, the positive electrode and the negative electrode each have a starting end and a terminal end along their length direction, and the positive electrode and the negative electrode are wound around each other along the direction from the starting end to the terminal end to form the core.

[0021] Beneficial effects: The empty foil area extending along the width of the current collector provides a suitable welding substrate for the arc-shaped electrode tab connection. Through precise winding from the starting end to the end, the empty foil area naturally forms a hollow connection structure at the end of the core, ensuring a seamless connection between the arc-shaped electrode tab and the current collector. This design achieves structural synergy between the electrode sheet, the core, and the electrode tab, laying the foundation for uniform stress transmission.

[0022] In one optional embodiment, a first notch is provided at the end of the head empty foil area near the starting end, so that after the head empty foil area is wound, a hollow structure of the electrode connecting end is formed, and the connecting part is connected to the inner wall of the hollow structure of the electrode connecting end.

[0023] Beneficial effects: The layout of the empty foil area at both ends of the core precisely corresponds to the position of the bipolar tabs. The first notch design allows the empty foil area to automatically form a concave tab connection end face after winding. This structure creates an interface for welding the side walls of the arc-shaped tabs, avoiding the complex shaping process required for traditional flat end faces, significantly improving production yield and structural consistency, while also enhancing the core end's resistance to expansion and deformation.

[0024] In one optional embodiment, a second notch is provided at the end of the head empty foil area near the terminal, such that after the head empty foil area is wound, an arc-shaped notch is formed on the outer wall of the hollow structure of the electrode connection end, the connection part is connected to the outer wall of the hollow structure of the electrode connection end, and the connection part is located within the arc-shaped notch.

[0025] Beneficial effects: The second notch design automatically forms an external tab connection end with an arc-shaped notch in the empty foil area after winding. The arc-shaped notch creates an interface for welding the sidewalls of the arc-shaped tab, avoiding the complex shaping process required for traditional flat end faces, significantly improving production yield and structural consistency, while also enhancing the core end's resistance to expansion and deformation.

[0026] In one optional embodiment, a third notch is provided on the head empty foil area, the third notch being located between the first notch and the second notch, such that after the head empty foil area is wound, a connection notch is formed on the hollow structure of the electrode connection end, and the first segment passes through the connection notch.

[0027] Beneficial effect: The third notch design allows the empty foil area after winding to automatically form an external tab connection end with a connection notch, which allows the first segment to pass through, so that the second segment is located in the hollow structure of the tab connection end.

[0028] In one optional embodiment, the central angle corresponding to the connecting part of the arc-shaped structure is A, wherein 90°≤A<360°, and the connecting part is configured as an open-loop structure with an opening for injecting electrolyte into the core.

[0029] Beneficial effects: The opening retained in the open-ring connector forms an electrolyte injection channel, overcoming the limitations of the closed-ring tab on the electrolyte injection process. This design combines the mechanical advantages of the ring structure with the requirements of electrolyte injection, eliminating the need for additional openings or complex electrolyte injection systems, thus ensuring battery performance while simplifying the manufacturing process and reducing production costs. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of a battery according to an embodiment of the present utility model;

[0032] Figure 2 This is a schematic diagram of the core structure in an embodiment of this utility model;

[0033] Figure 3 This is a schematic diagram of the electrode tab structure in an embodiment of this utility model;

[0034] Figure 4 This is a schematic diagram of the metal strip structure in an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the positive electrode sheet in an embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of the negative electrode sheet in an embodiment of the present invention;

[0037] Figure 7This is a schematic diagram of the structure of the base and welding head in an embodiment of this utility model.

[0038] Explanation of reference numerals in the attached figures:

[0039] 1. Core; 101. Tab connection end; 102. Positive electrode sheet; 103. Negative electrode sheet; 104. Current collector; 1041. Coating; 1042. Head empty foil area; 1043. First notch; 1044. Second notch; 1045. Third notch; 2. Tab; 201. Connecting part; 202. Lead-out part; 2021. First section; 2022. Second section; 203. Tab adhesive; 204. Opening; 3. Metal strip structure; 301. First side; 302. Second side; 4. Base; 401. Through groove; 5. Welding head; 501. Arc-shaped groove. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0041] The following is combined with Figures 1 to 7 The following describes embodiments of the present invention.

[0042] According to an embodiment of the present invention, a battery is provided, including a winding core 1 and tabs 2. At least one end of the winding core 1 is configured as a tab connection end 101, which is formed by winding the head empty foil area 1042 of the electrode sheet, and the center portion of the tab connection end 101 is configured as a hollow structure. The tab 2 includes a connecting portion 201 and a lead-out portion 202. The connecting portion 201 is configured as an arc-shaped structure and is connected to the side wall of the hollow structure of the tab connection end 101, and the connecting portion 201 is connected to the lead-out portion 202.

[0043] It should be noted that, as Figure 1 and Figure 2 As shown, both the tab connection end 101 of the core 1 and the connection portion 201 of the tab 2 can be configured as an arc-shaped structure, which allows the stress to be evenly distributed along the circumference. The lead-out portion 202 can extend along the axial direction of the connection portion 201 of the arc-shaped structure in a direction away from the core 1, so that the part of the lead-out portion 202 used for connecting with external devices is away from the core 1, which facilitates the operation of connecting with external devices.

[0044] In this embodiment, by designing the connecting portion 201 of the tab 2 as an arc-shaped structure and directly connecting it to the sidewall of the hollow structure of the tab connecting end 101 of the core 1, this structure effectively disperses the huge expansion stress generated during the charging and discharging of the silicon negative electrode. Compared with the traditional method of centrally welding the tabs on the end face of the core 1, the arc-shaped sidewall connection makes the stress evenly distributed along the circumferential direction, significantly reducing the risk of electrode breakage. At the same time, the arc-shaped connection makes full use of the axial space of the core 1, avoiding the additional occupation of the battery height by the traditional tab welding area, which helps to improve the battery energy density and simplify the internal structure.

[0045] In one embodiment, such as Figure 3 As shown, the lead-out portion 202 includes a first segment 2021 and a second segment 2022. The first segment 2021 includes a first end and a second end that are opposite each other. The first end of the first segment 2021 is connected to the connecting portion 201. The second segment 2022 is connected to the second end of the first segment 2021. The first segment 2021 and the second segment 2022 are arranged at an angle. The first segment 2021 is located within the inner perimeter area of ​​the connecting portion 201.

[0046] It should be noted that the extension direction of the first segment 2021 of the lead-out portion 202 is parallel to the radial direction of the connecting portion 201 of the arc-shaped structure. Specifically, the first end and the second end of the first segment 2021 are arranged opposite to each other along its extension direction. The first end of the first segment 2021 is connected to the connecting portion 201, and the second end of the first segment 2021 is arranged along the radial direction of the connecting portion 201 pointing towards the center of the connecting portion 201, so that the second segment 2022 of the lead-out portion 202 can be located within the inner perimeter area of ​​the connecting portion 201.

[0047] Understandably, the extension direction of the second segment 2022 can be set parallel to or coincide with the circumferential direction of the lead-out portion 202.

[0048] Optionally, the included angle between the first segment 2021 and the second segment 2022 of the lead-out portion 202 can be set to 90°.

[0049] Optionally, the included angle between the first segment 2021 and the second segment 2022 of the lead-out portion 202 can be set to a range of 60° to 120°.

[0050] In this embodiment, the lead-out portion 202 adopts a two-section design with an included angle. Specifically, the first section 2021 is connected to the connecting portion 201, and the second section 2022 carries the tab adhesive 203. By confining both the first section 2021 and the second section 2022 within the inner perimeter area of ​​the connecting portion 201, a compact layout of the tab 2 system is achieved. The L-shaped bending structure formed by the first section 2021 and the second section 2022 shortens the current transmission path and reduces internal resistance. At the same time, it also ensures that the tab 2 is completely embedded within the projection space of the core 1, further optimizing the axial dimensions, avoiding interference with the housing or other components, and improving space utilization and assembly reliability.

[0051] In one embodiment, such as Figure 3 As shown, the second segment 2022 is equipped with tab adhesive 203.

[0052] It should be noted that the tab adhesive 203 is located in the middle of the second segment 2022 or at the end away from the first segment 2021.

[0053] In this embodiment, the tab adhesive 203 can block the path of electrolyte leakage through the gap between the metal and the casing, while preventing external moisture from entering the battery and ensuring the stability of the internal chemical environment of the battery. Placing the tab adhesive 203 in the second section 2022 of the lead-out portion 202 keeps the tab adhesive 203 away from the high-temperature welding area, avoiding the risk of heat damage.

[0054] In one embodiment, the connection point between the first segment 2021 and the second segment 2022 is located at the center of the inner perimeter area of ​​the connection portion 201, and the first segment 2021 and the second segment 2022 are perpendicular to each other.

[0055] In this embodiment, both the first segment 2021 and the second segment 2022 are confined within the inner perimeter of the connecting portion 201, and the first segment 2021 and the second segment 2022 can further achieve a compact layout of the tab system.

[0056] In one embodiment, such as Figure 4 As shown, the lead-out part 202 and the connecting part 201 are constructed as an integral structure.

[0057] It should be noted that the tab 2 can be configured as an L-shaped metal strip structure 3, including a first side 301 and a second side 302 connected together, with the first side 301 and the second side 302 set at an angle. The tab 2 is formed by bending the L-shaped metal strip structure 3. Specifically, the portion of the first side 301 of the L-shaped metal strip structure 3 away from the second side 302 is bent to form an arc-shaped structure. The bent portion is the connecting part 201. The portion of the first side 301 of the L-shaped metal strip structure 3 close to the second side 302 and not bent is the first segment 2021. The second side 302 of the L-shaped metal strip structure 3 is the second segment 2022.

[0058] In this embodiment, the integrally formed lead-out portion 202 and connecting portion 201 eliminate the weak interface area of ​​the traditional separate welded electrode tab 2. Under the extreme working conditions of repeated expansion and contraction of the silicon anode, the integral structure avoids fatigue cracking of the solder joint, ensures the continuity of current transmission and mechanical connection strength, and greatly improves the reliability of the electrode tab 2 in long-term use and the battery cycle life.

[0059] In one embodiment, such as Figure 1 As shown, the core 1 also includes a positive electrode 102 and a negative electrode 103. The positive electrode 102 and the negative electrode 103 are provided with head empty foil areas 1042 at their opposite ends. A pair of tabs 2 are provided, and the pair of tabs 2 are respectively connected to the head empty foil areas 1042 of the positive electrode 102 and the negative electrode 103.

[0060] Understandably, the pair of tabs 2 are respectively set as positive tabs and negative tabs, wherein the positive tab is connected to the positive electrode plate 102 and the negative tab is connected to the negative electrode plate 103.

[0061] In this embodiment, the positive electrode 102 and the negative electrode 103 are respectively equipped with arc-shaped tabs 2, so that both electrodes of the battery can obtain the ability to uniformly distribute stress. The arc-shaped connection on the positive electrode side can match the expansion characteristics of the silicon negative electrode and jointly maintain the structural stability of the core 1; the synchronous optimization of the two electrodes further balances the internal stress field, comprehensively suppresses the risk of electrode breakage, and ensures the overall reliability of the high-energy-density battery.

[0062] In one embodiment, such as Figure 5 and Figure 6 As shown, both the positive electrode 102 and the negative electrode 103 include a current collector 104 and a coating 1041 composited in the current collector 104. A head empty foil region 1042 is provided at one end along the width direction of the current collector 104, and the head empty foil region 1042 extends along the length direction of the current collector 104.

[0063] It should be noted that the current collector 104, as the conductive framework of the electrode, plays a core role in current collection and transmission. The positive current collector 104 is typically made of aluminum foil, which can form a dense oxide film under high pressure, resisting electrolyte corrosion and meeting conductivity requirements. The negative current collector 104 is mostly made of copper foil, which has lower resistivity, avoids alloying with lithium, and has ductility suitable for the expansion of the silicon negative electrode. The coating 1041 provides a site for electrochemical reactions. The head empty foil area 1042 is located at one end of the width direction of the current collector 104, extending along the length direction, and is the exposed metal foil area without coating 1041. It can serve as the base for welding the tab 2 at the end of the winding core 1. When the silicon negative electrode expands, the electrode stress is evenly transferred to the arc-shaped tab 2 through the empty foil area, preventing the coating 1041 area from directly breaking under stress. Furthermore, the extension direction of the head empty foil area 1042 is consistent with the winding direction, ensuring that multiple layers of empty foil are precisely stacked to form an arc-shaped welding surface after winding.

[0064] In one embodiment, such as Figure 5 and Figure 6 As shown, the positive electrode 102 and the negative electrode 103 each have a starting end and a terminal end along their length direction. The positive electrode 102 and the negative electrode 103 are wound around each other along the direction from the starting end to the terminal end to form a core 1.

[0065] It should be noted that an empty foil area is also provided at the end of the positive electrode 102, and the empty foil area extends along the width direction of the positive electrode 102. This is a commonly used empty foil area design in the prior art. It can be used together with the head empty foil area 1042, or this empty foil area can be omitted and only the head empty foil area 1042 can be used.

[0066] In this embodiment, the head empty foil area 1042 extending along the width direction of the current collector 104 provides a suitable welding substrate for the connection of the arc-shaped electrode tab 2. Through precise winding from the starting end to the end, the empty foil area naturally forms a hollow connection structure at the end of the core 1, ensuring a seamless connection between the arc-shaped electrode tab 2 and the current collector 104. This design achieves structural synergy between the electrode sheet, the core 1, and the electrode tab 2, laying the foundation for uniform stress transmission.

[0067] In one embodiment, a first notch 1043 is provided at the end of the head empty foil area 1042 near the starting end, so that after the head empty foil area 1042 is wound, a hollow structure of the tab connection end 101 is formed, and the connection part 201 is connected to the inner sidewall of the hollow structure of the tab connection end 101.

[0068] In this embodiment, the layout of the head empty foil area 1042 at both ends of the core 1 precisely corresponds to the position of the bipolar tab 2. The first notch 1043 is designed so that the empty foil area automatically forms the connection end face of the concave tab 2 after winding. This structure creates an interface for welding the side wall of the arc-shaped tab 2, avoiding the complex shaping process required for traditional flat end faces, significantly improving production yield and structural consistency, while strengthening the anti-expansion deformation capability of the end of the core 1.

[0069] In one embodiment, a second notch 1044 is provided at the end of the head empty foil area 1042 near the terminal, so that after the head empty foil area 1042 is wound, an arc-shaped notch is formed on the outer wall of the hollow structure of the electrode connection end 101, and the connecting part 201 is connected to the outer wall of the hollow structure of the electrode connection end 101, and the connecting part 201 is located inside the arc-shaped notch.

[0070] In this embodiment, the second notch 1044 is designed to automatically form an external tab connection end 101 with an arc-shaped notch in the empty foil area after winding. The arc-shaped notch creates an interface for welding the side wall of the arc-shaped tab 2, avoiding the complex shaping process required by traditional flat end faces, significantly improving production yield and structural consistency, while strengthening the resistance to expansion deformation at the end of the core.

[0071] In one embodiment, a third notch 1045 is provided on the head empty foil area 1042. The third notch 1045 is located between the first notch 1043 and the second notch 1044, so that after the head empty foil area 1042 is completed, a connection notch is formed on the hollow structure of the tab connection end 101, and the first segment 2021 passes through the connection notch.

[0072] Optionally, multiple third notches 1045 may be spaced out on the head empty foil area 1042.

[0073] In this embodiment, the third notch 1045 is designed so that the empty foil area after winding automatically forms an external tab connection end 101 with a connection notch, which allows the first segment 2021 to pass through, so that the second segment 2022 is located in the hollow structure of the tab connection end 101.

[0074] By cutting through the current collector 104, a first notch 1043, a second notch 1044, and a third notch 1045 can be formed.

[0075] In one embodiment, the central angle of the arc-shaped connecting part 201 is A, where 90°≤A<360°. The connecting part 201 is configured as an open-loop structure with an opening 204, which is used to inject electrolyte into the core 1.

[0076] Optionally, the central angle of the arc-shaped connecting part 201 is 90°.

[0077] Optionally, the central angle of the arc-shaped connecting part 201 is 180°.

[0078] Optionally, the central angle of the arc-shaped connecting part 201 is 358°, which is the preferred central angle of the connecting part 201, making it closest to the complete ring structure.

[0079] Understandably, the opening 204 of the connecting part 201 includes two opposing end faces, one of which can be connected to the first segment 2021.

[0080] It should be noted that the opening 204 of the connecting part 201 is the end face of the first side 301 of the L-shaped metal strip structure 3 that is away from the second side 302. After being bent, the gap between it and the side of the first side 301 is also noted.

[0081] In this embodiment, the opening 204 retained in the open-ring connector 201 forms an electrolyte injection channel, overcoming the limitations of the closed annular tab 2 on the electrolyte injection process. This design combines the mechanical advantages of the annular structure with the electrolyte injection requirements, eliminating the need for additional openings or complex electrolyte injection systems, thus ensuring battery performance, simplifying the manufacturing process, and reducing production costs.

[0082] In one embodiment, such as Figure 7 As shown, it also includes a base 4 and welding heads 5. The base 4 is a disc-shaped structure with a through groove 401 in its center. The through groove 401 is a strip-shaped structure, and one end of the through groove 401 extends along the radius of the base 4, penetrating the circumference of the base 4. The through groove 401 is used to accommodate the first section 2021 of the lead-out part 202, and the outer circumference of the base is adapted to the inner sidewall of the connecting part 201. A pair of welding heads 5 are provided, and each welding head 5 is provided with an arc-shaped groove 501. The arc-shaped grooves 501 on the pair of welding heads 5 can cooperate with each other to form a circular structure, and can be sleeved on the outside of the tab connecting end 101 of the core 1, so as to limit the tab connecting end 101 of the core 1.

[0083] By limiting the electrode tab 2 and the electrode tab connection end 101 of the core 1 respectively by the base 4 and the welding head 5, the electrode tab 2 and the electrode tab connection end 101 of the core 1 are then welded, which can ensure welding accuracy and stability.

[0084] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A battery, characterized in that, include: The core (1) has at least one end configured as a tab connection end (101), the tab connection end (101) is formed by winding the head empty foil area (1042) of the electrode sheet, and the center part of the tab connection end (101) is configured as a hollow structure. The tab (2) includes a connecting part (201) and a lead-out part (202). The connecting part (201) is configured as an arc-shaped structure and is connected to the side wall of the hollow structure of the tab connecting end (101). The connecting part (201) is connected to the lead-out part (202).

2. The battery according to claim 1, characterized in that, The lead-out portion (202) includes a first segment (2021) and a second segment (2022). The first segment (2021) is connected to the connecting portion (201), and the second segment (2022) is connected to the first segment (2021). The first segment (2021) and the second segment (2022) are arranged at an angle, and the first segment (2021) is located within the inner perimeter area of ​​the connecting portion (201).

3. The battery according to claim 2, characterized in that, The connection point between the first segment (2021) and the second segment (2022) is located at the center of the inner perimeter area of ​​the connecting part (201), and the first segment (2021) and the second segment (2022) are perpendicular to each other.

4. The battery according to claim 2, characterized in that, The core (1) includes: A positive electrode (102) and a negative electrode (103) are provided, with the head empty foil area (1042) provided at opposite ends of the positive electrode (102) and the negative electrode (103). A pair of tabs (2) are provided, and the pair of tabs (2) are respectively connected to the head empty foil area (1042) of the positive electrode (102) and the negative electrode (103).

5. The battery according to claim 4, characterized in that, Both the positive electrode (102) and the negative electrode (103) include a current collector (104) and a coating (1041) composited on the current collector (104). A head empty foil area (1042) is provided at one end along the width direction of the current collector (104), and the head empty foil area (1042) extends along the length direction of the current collector (104).

6. The battery according to claim 5, characterized in that, The positive electrode (102) and the negative electrode (103) each have a starting end and a terminal end along their length direction. The positive electrode (102) and the negative electrode (103) are wound around each other along the direction from the starting end to the terminal end to form the core (1).

7. The battery according to claim 6, characterized in that, The head empty foil area (1042) is provided with a first notch (1043) at the end near the starting end, so that after the head empty foil area (1042) is wound, it forms the hollow structure of the tab connection end (101), and the connection part (201) is connected to the inner wall of the hollow structure of the tab connection end (101).

8. The battery according to claim 7, characterized in that, The head empty foil area (1042) is provided with a second notch (1044) near the end of the terminal, so that after the head empty foil area (1042) is wound, an arc-shaped notch is formed on the outer wall of the hollow structure of the electrode connecting end (101). The connecting part (201) is connected to the outer wall of the hollow structure of the electrode connecting end (101), and the connecting part (201) is located in the arc-shaped notch.

9. The battery according to claim 8, characterized in that, A third notch (1045) is provided on the head empty foil area (1042). The third notch (1045) is located between the first notch (1043) and the second notch (1044), so that after the head empty foil area (1042) is wound, a connection notch is formed on the hollow structure of the electrode connection end (101), and the first segment (2021) passes through the connection notch.

10. The battery according to claim 1, characterized in that, The connecting part (201) of the arc structure has a center angle of A, where 90°≤A<360°. The connecting part (201) is configured as an open-loop structure with an opening (204), and the opening (204) is used to inject electrolyte into the core (1).

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