Battery and electric equipment
By setting a protective layer at the edge of the battery cell, the problem of easy scratching or damage at the edge of the battery cell is solved, the safety and insulation performance of the battery cell are improved, and the structural strength of the battery is enhanced.
Patent Information
- Application Number
- CN202423279003.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2026-03-06
- Estimated Expiration
- 2034-12-30
AI Technical Summary
In existing technologies, the edges of battery cells are prone to short circuits due to scratches or damage, and the wrapping technology cannot effectively protect the edges of the battery cells.
A protective layer is provided at the edge of the battery cell. The protective layer has an extension that extends to the outside of the battery cell body and is bonded to the casing or the surface of the battery cell to enhance the insulation performance and structural strength of the battery cell edge.
It effectively avoids scratches or damage to the edges of the battery cells, improves cell safety, prevents short circuits, and enhances the insulation performance and structural strength of the battery.
Smart Images
Figure CN223978061U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the technical field of batteries, specifically relating to batteries and electrical equipment. Background Technology
[0002] Lithium-ion batteries, as a new type of rechargeable battery, have advantages such as high energy density and power density, high operating voltage, light weight, small size, long cycle life, good safety, and environmental friendliness. They have broad application prospects in portable electrical appliances, power tools, large-scale energy storage, and electric transportation power supplies.
[0003] Currently, during the battery cell manufacturing process, adhesive wrapping is typically used at the edges of the cells to enhance structural stability. Specifically, adhesive tape is applied to the edges of the cell to prevent springback due to residual stress in the thickness direction, thus ensuring the safety and reliability of the cell during use. However, while adhesive wrapping can improve the structural stability of the cell to some extent, it does not provide protection for the cell's edges. The separator or anode material at the cell edges is often easily scratched or even damaged, potentially leading to short circuits and safety issues. Utility Model Content
[0004] The purpose of this utility model is to provide a battery and electrical device that addresses the shortcomings of the existing technology, solving the technical problem that the adhesive wrapping in the existing technology cannot protect the edges of the battery cell from scratches and damage, which easily leads to short circuits in the battery cell.
[0005] To achieve the above objectives, the present invention adopts the following technical solution:
[0006] In a first aspect, the present invention provides a battery comprising a casing and a bare cell. The casing has a receiving cavity, and the bare cell comprises a cell body and a tab portion. The cell body is housed in the receiving cavity, and the tab portion extends from one end of the cell body to the outside of the casing. Along the thickness direction of the cell body, a protective layer is disposed between the inner surface of the casing and the outer surface of the cell body. The protective layer is located in the edge region of the cell body and has an extension portion extending to the outside of the cell body. The protective layer is bonded to the inner surface of the casing; and / or, the protective layer is bonded to the outer surface of the cell body.
[0007] In some embodiments, the protective layer is a melt-blown insulating layer.
[0008] In some embodiments, along the thickness direction of the cell body, the cell body has two opposing outer surfaces, both of which are bonded to the protective layer, and the extension portions of the protective layer on the two outer surfaces overlap each other;
[0009] And / or, along the thickness direction of the cell body, the housing has two opposing inner surfaces, both of which are bonded to the protective layer, and the outer extensions of the protective layers on the two inner surfaces overlap each other.
[0010] In some embodiments, the distance K between the edge of the extension portion away from the cell body and the edge of the cell body satisfies the relationship: 0.8mm≤K≤1.5mm.
[0011] In some embodiments, the tab portion is provided with tab adhesive and tab protective adhesive, the tab protective adhesive covers the tab adhesive and the cell body, the tab protective adhesive and the tab adhesive have a first overlapping area, the extension portion extends to the first overlapping area, the first overlapping area (223) has a first side close to the cell body (21) and a second side away from the cell body (21), and the distance D between the second side and the edge of the cell body satisfies the relationship: K≤D.
[0012] In some embodiments, the thickness G of the protective layer satisfies the following relationship: 1.5μm≤G≤2.5μm;
[0013] And / or, along the thickness direction of the battery cell body, the protective layer and the battery cell body have a second overlapping area, the width L of the second overlapping area satisfies the relationship: 0.8cm≤L≤1.5cm.
[0014] In some embodiments, the protective layer has a porous structure.
[0015] In some embodiments, an adhesive layer is provided on the battery cell body, and the adhesive layer is offset from the protective layer.
[0016] In some embodiments, the cell body includes a first electrode, a second electrode, and a separator. The first electrode, the separator, and the second electrode are stacked and wound sequentially to form the cell body. Along the length direction of the cell body, the tabs are disposed at the top and / or bottom of the cell body, and the protective layer is disposed at the top and bottom of the cell body.
[0017] Alternatively, multiple first and second electrodes may be provided, with multiple first electrodes and multiple second electrodes stacked alternately, and a separator provided between adjacent first and second electrodes. Along the length direction of the cell body, the tabs are provided at the top and / or bottom of the cell body, and the protective layer is provided along the periphery of the cell body.
[0018] Secondly, this utility model provides an electrical device, including the battery described in the above embodiment.
[0019] Compared with the prior art, the beneficial effects achieved by this utility model are as follows:
[0020] This utility model's battery, through the combined use of a casing and a bare cell, has the cell body housed within the casing's cavity, with the tabs extending from one end of the cell body to the outside of the casing. This effectively ensures that the tabs can be electrically connected to an external power source, thereby guaranteeing battery performance. A protective layer is provided between the inner surface of the casing and the outer surface of the cell body. This protective layer is located at the edge region of the cell body and has an extension extending beyond the cell body. This not only effectively improves the insulation performance of the cell body's edges but also enhances the structural strength of the edges, effectively preventing scratches or even damage to the cell body's edges, thus avoiding short circuits in the bare cell. Furthermore, the extension also provides some protection against direct impact and damage from external objects to the cell body, further improving the safety of the bare cell.
[0021] Additional aspects and advantages of this invention 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 the invention. Attached Figure Description
[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 This is a schematic diagram of the structure of the battery of this utility model.
[0024] Figure 2 for Figure 1 A magnified structural diagram of point A in the middle.
[0025] Figure 3 This is a cross-sectional view of the battery of this utility model.
[0026] Figure 4 This is another structural schematic diagram of the battery of this utility model.
[0027] The reference numerals in the attached figures are explained as follows:
[0028] 100. Battery;
[0029] 10. Shell; 11. Inner surface;
[0030] 20. Bare battery cell; 21. Battery cell body; 211. Outer surface; 22. Electrode tab; 221. Electrode tab adhesive; 222. Electrode tab protective adhesive; 223. First overlapping area;
[0031] 30. Protective layer; 31. Extensional portion;
[0032] 40. Second overlapping region;
[0033] 50. Adhesive layer;
[0034] a. Along the thickness direction of the battery cell body; b. Along the length direction of the battery cell body. Detailed Implementation
[0035] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" as used throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.
[0036] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be interpreted as indicating or implying relative importance.
[0037] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0038] The following will be combined with the appendix Figures 1-4 The technical solutions in the embodiments of this utility model are clearly and completely described. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.
[0039] The electrical equipment of this utility model embodiment includes a battery 100. The electrical equipment can be automobiles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Automobiles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.; spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application embodiment does not impose any special limitations on the above-mentioned electrical equipment.
[0040] Please see Figures 1-4 The battery 100 of this utility model embodiment includes a housing 10 and a bare cell 20. The housing 10 has a receiving cavity. The bare cell 20 includes a cell body 21 and a tab 22. The cell body 21 is received in the receiving cavity. The tab 22 extends from one end of the cell body 21 to the outside of the housing 10. A protective layer 30 is provided between the inner surface 11 of the housing 10 and the outer surface 211 of the cell body 21 along the thickness direction a of the cell body 21. The protective layer 30 is located in the edge region of the cell body 21. The protective layer 30 has an extension 31 that extends to the outside of the cell body 21. The protective layer 30 is bonded to the inner surface 11 of the housing 10; and / or, the protective layer 30 is bonded to the outer surface 211 of the cell body 21.
[0041] Compared with the prior art, the battery 100 of this utility model embodiment, through the cooperative use of the casing 10 and the bare cell 20, with the cell body 21 of the bare cell 20 housed within the receiving cavity of the casing 10, and the tab 22 extending from one end of the cell body 21 to the outside of the casing 10, effectively ensures that the tab 22 can be electrically connected to an external power source, thereby ensuring the performance of the battery 100. By providing a protective layer 30 between the inner surface 11 of the casing 10 and the outer surface 211 of the cell body 21, and the protective layer 30 being disposed in the edge region of the cell body 21, having an extension portion 31 extending to the outside of the cell body 21, not only can the insulation performance of the edge of the cell body 21 be effectively improved, but also the structural strength of the edge of the cell body 21 can be improved, effectively preventing scratches or even damage to the edge of the cell body 21, thereby preventing short circuits of the bare cell 20. In addition, the extension portion 31 can also prevent direct impact and damage to the cell body 21 from external objects to a certain extent, further improving the safety of the bare cell 20.
[0042] It is understood that the protective layer 30 is bonded to the inner surface 11 of the housing 10; and / or, the protective layer 30 is bonded to the outer surface 211 of the cell body 21. That is, the protective layer 30 can be bonded to the inner surface 11 of the housing 10, the protective layer 30 can also be bonded to the outer surface 211 of the cell body 21, and the protective layer 30 can also be bonded to both the inner surface 11 of the housing 10 and the outer surface 211 of the cell body 21. This effectively improves the design flexibility of the protective layer 30, allowing its placement to be flexibly adjusted according to actual needs. Specifically, the protective layer 30 can be bonded to the inner surface 11 of the housing 10 alone to ensure that the bare cell 20 is effectively isolated and protected after being installed in the housing 10. Similarly, the protective layer 30 can also be applied separately to the outer surface 211 of the cell body 21 as an isolation barrier between the bare cell 20 and the external environment, further enhancing the insulation performance and safety of the battery 100.
[0043] In particular, when both the inner surface 11 of the casing 10 and the outer surface 211 of the cell body 21 are bonded to the protective layer 30, the cell body 21 can be fixed to the casing 10 by the protective layer 30, effectively preventing the bare cell 20 from shaking and further ensuring the safety performance of the battery 100.
[0044] Understandably, the casing 10 is made of aluminum-plastic film, a multi-layer composite film known for its high barrier properties, good formability, and resistance to electrolyte corrosion. The aluminum-plastic film consists of a nylon layer, an intermediate aluminum layer, and a polypropylene layer from the outside in. During the production and assembly of the battery 100, the battery 100 is typically encapsulated using heat sealing. This involves applying pressure to the aluminum-plastic film using a hot press mold, melting the polypropylene layer of the aluminum-plastic film over a certain period. After cooling, the polypropylene layers adhere and solidify, thus achieving the purpose of encapsulating the battery 100.
[0045] In some embodiments, the protective layer 30 is a melt-blown insulating layer. Specifically, the protective layer 30 is disposed on the inner surface 11 of the housing 10 and / or the outer surface 211 of the cell body 21 by melt-blowing, which can effectively ensure that the protective layer 30 forms a good fit with the housing 10 or the cell body 21.
[0046] Furthermore, the meltblown insulation layer employs an electrospinning process, enabling precise control over its position and thickness. The material of the meltblown insulation layer can be an adhesive, such as polypropylene, or a hot melt adhesive. This effectively allows the meltblown insulation layer to be thermally bonded to the polypropylene layer of the housing 10, ensuring a tight bond between the meltblown insulation layer and the housing 10. When the meltblown insulation layer is made of polypropylene, the meltblown insulation layer and the polypropylene layer of the housing 10 can be thermally bonded under the same thermal fusion conditions, enhancing the overall structural strength and sealing performance.
[0047] It is understandable that when the bare cell 20 is melt-blown, the melt-blown insulating layer can be bonded to the outer surface 211 of the cell body 21; when the casing 10 is melt-blown, the melt-blown insulating layer can be bonded to the inner surface 11 of the casing 10.
[0048] Please see Figure 1 as well as Figures 3-4 In some embodiments, along the thickness direction a of the cell body 21, the cell body 21 has two opposing outer surfaces 211, both of which are bonded to the protective layer 30, and the extensions 31 of the protective layer 30 on the two outer surfaces 211 overlap each other; and / or, along the thickness direction a of the cell body 21, the housing 10 has two opposing inner surfaces 11, both of which are bonded to the protective layer 30, and the extensions 31 of the protective layer 30 on the two inner surfaces 11 overlap each other.
[0049] By bonding both outer surfaces 211 to the protective layer 30, and / or bonding both inner surfaces 11 to the protective layer 30, the protective layer 30 is effectively disposed on the two opposite outer surfaces 211 of the cell body 21, which can further increase the insulation strength of the bare cell 20 and reduce the risk of short circuit. Simultaneously, the overlapping of the extensions 31 of the protective layer 30 on the two outer surfaces 211 and / or the extensions 31 of the protective layer 30 on the two inner surfaces 11 not only further improves the structural strength of the edge of the cell body 21 and enhances the safety of the bare cell 20, but also ensures the flatness of the edge of the cell body 21. This not only facilitates the assembly and fixation of the battery 100, but also improves the overall aesthetics of the battery 100.
[0050] Please see Figures 1-2 as well as Figure 4In some embodiments, the distance K between the edge of the extension portion 31 away from the cell body 21 and the edge of the cell body 21 satisfies the relationship: 0.8mm ≤ K ≤ 1.5mm. By setting the distance K between the edge of the extension portion 31 away from the cell body 21 and the edge of the cell body 21, this distance K cannot be too large or too small. When the distance K is too large, i.e., K > 1.5mm, the dimension of the extension portion 31 extending to the outside of the cell body 21 is large, increasing the overall size of the bare cell 20. This results in the bare cell 20 occupying more space within the casing 10, reducing the space utilization rate of the battery 100, thereby reducing the energy density of the battery 100. When the distance K is too small, i.e., K < 0.8mm, the dimension of the extension portion 31 extending to the outside of the cell body 21 is insufficient, which may lead to poor insulation performance and structural strength improvement of the edge of the cell body 21, and the edge of the cell body 21 may still be scratched or damaged. Therefore, by ensuring that the distance K between the edge of the extension portion 31 away from the edge of the cell body 21 and the edge of the cell body 21 satisfies the relationship: 0.8mm≤K≤1.5mm, the space utilization rate of the battery 100 can be effectively ensured and the energy density of the battery 100 can be improved. At the same time, it can also effectively improve the insulation performance and structural strength of the edge of the cell body 21, avoid scratches or even damage to the edge of the cell body 21, and thus avoid short circuits of the bare cell 20.
[0051] Furthermore, the distance K between the edge of the extension portion 31 away from the edge of the cell body 21 and the edge of the cell body 21 is 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm or 1.5mm, but is not limited to the listed values, and other values within the range are also applicable.
[0052] Please see Figure 1 as well as Figures 3-4 In some embodiments, the tab portion 22 is provided with tab adhesive 221 and tab protective adhesive 222. The tab protective adhesive 222 covers the tab adhesive 221 and the cell body 21. The tab protective adhesive 222 and the tab adhesive 221 have a first overlapping region 223. The first overlapping region 223 has a first side close to the cell body 21 and a second side away from the cell body 21. The extension portion 31 extends to the first overlapping region 223, and the distance D between the second side and the edge of the cell body 21 satisfies the relationship: K≤D. Through the provision of tab adhesive 221 and tab protective adhesive 222, both tab adhesive 221 and tab protective adhesive 222 cover part of the tab portion 22. The tab protective adhesive 222 is used to cover the welding joint of the tab portion 22 to prevent the welding burrs of the tab portion 22 from puncturing the separator and causing a short circuit in the battery 100. The tab 22 is heat-fused to the casing 10 by tab adhesive 221, which ensures the sealing effect of the battery 100 and can also effectively prevent the tab 22 from directly contacting the casing 10 and causing a short circuit.
[0053] Furthermore, by setting a distance K between the edge of the extension portion 31 away from the edge of the cell body 21 and the edge of the cell body 21, when this distance K is greater than the distance D between the second side and the edge of the cell body 21 (i.e., K > D), after the battery 100 is packaged, the extension portion 31 becomes too long, and the top sealing edge of the battery 100 becomes excessively thick, resulting in poor sealing or sealing of the battery 100. This may lead to safety hazards such as electrolyte leakage and gas expansion inside the battery 100. Therefore, when K ≤ D, the insulation performance and structural strength of the edge of the cell body 21 can be effectively improved while ensuring the packaging effect of the battery 100, preventing scratches or even damage to the edge of the cell body 21, thereby preventing short circuits in the bare cell 20.
[0054] Please see Figure 3 In some embodiments, the thickness G of the protective layer 30 satisfies the relationship: 1.5μm ≤ G ≤ 2.5μm. The thickness G of the protective layer 30 cannot be too large or too small. When the thickness G of the protective layer 30 is too large, i.e., G > 2.5μm, the overall size of the battery 100 increases, reducing the space utilization of the battery 100 and consequently reducing the energy density of the battery 100. When the thickness G of the protective layer 30 is too small, i.e., G < 1.5μm, the thickness G of the protective layer 30 is too thin, resulting in poor insulation performance. Furthermore, insufficient thickness G cannot improve the structural strength of the edge of the cell body 21. Therefore, ensuring the thickness G of the insulating layer satisfies the relationship: 1.5μm ≤ G ≤ 2.5μm, it can effectively improve the insulation performance and structural strength of the edge of the cell body 21 while ensuring the energy density of the battery 100, preventing scratches or even damage to the edge of the cell body 21, thereby preventing short circuits in the bare cell 20.
[0055] Furthermore, the thickness G of the protective layer 30 is 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, 2 μm, 2.1 μm, 2.2 μm, 2.3 μm, 2.4 μm, or 2.5 μm. However, it is not limited to the listed values, and other values within the range are also applicable.
[0056] Please see Figure 1 and Figure 4In some embodiments, along the thickness direction a of the cell body 21, the protective layer 30 and the cell body 21 have a second overlapping region 40. The width L of the second overlapping region 40 satisfies the relationship: 0.8cm ≤ L ≤ 1.5cm. The setting of the second overlapping region 40 effectively ensures sufficient contact area between the cell body 21 and the protective layer 30, thereby enhancing the insulation performance of the bare cell 20. Furthermore, the width L of the second overlapping region 40 cannot be too large or too small. When the width L of the second overlapping region 40 is too large, the amount of protective layer 30 used increases, which not only increases production costs but may also increase the overall weight of the battery 100, thereby reducing the energy density of the battery 100. When the width L of the second overlapping region 40 is too small, the contact area between the protective layer 30 and the cell body 21 is insufficient, and the insulation and protection effects of the protective layer 30 on the cell body 21 are weak. Therefore, by ensuring that the width L of the second overlapping region 40 satisfies the relationship 0.8cm≤L≤1.5cm, the insulation performance and structural strength of the edge of the cell body 21 can be effectively improved, preventing scratches or even damage to the edge of the cell body 21, thereby avoiding short circuits in the bare cell 20. At the same time, this saves production costs and ensures the energy density of the battery 100.
[0057] Furthermore, the width L of the second overlapping region 40 is 0.8cm, 0.9cm, 1cm, 1.1cm, 1.2cm, 1.3cm, 1.4cm, or 1.5cm. However, it is not limited to the listed values; other values within the range are also applicable.
[0058] In some embodiments, the protective layer 30 has a porous structure. By providing a porous protective layer 30, the protective layer 30 can absorb and store a certain amount of electrolyte, thereby improving the wetting effect of the electrolyte, ensuring the cycle performance of the battery 100, and extending the service life of the battery 100.
[0059] Please see Figure 1 and Figure 4 In some embodiments, an adhesive layer 50 is provided on the cell body 21, and the adhesive layer 50 is staggered from the protective layer 30. The adhesive layer 50 effectively prevents the bare cell 20 from springing back due to residual stress in the thickness direction, thereby ensuring the safety and reliability of the bare cell 20 during use. Furthermore, by staggering the adhesive layer 50 from the protective layer 30, the overlap of the adhesive layer 50 and the protective layer 30 is effectively avoided, thus preventing an increase in the thickness of the battery 100 and ensuring the energy density of the battery 100.
[0060] In some embodiments, the cell body 21 includes a first electrode, a second electrode, and a separator. The first electrode, separator, and second electrode are stacked and wound sequentially to form the cell body 21. Along the length direction b of the cell body 21, tabs 22 are disposed at the top and / or bottom of the cell body 21, and a protective layer 30 is disposed at the top and bottom of the cell body 21. Alternatively, multiple first and second electrodes are provided, with multiple first electrodes and multiple second electrodes alternately stacked. A separator is disposed between adjacent first and second electrodes. Along the length direction b of the cell body 21, tabs 22 are disposed at the top and / or bottom of the cell body 21, and a protective layer 30 is disposed along the periphery of the cell body 21. With the above structural configuration, the protective layer 30 can be flexibly configured according to different bare cell 20 structures. When the bare cell 20 is a wound structure, the protective layer 30 is disposed at the top and bottom of the cell body 21. When the bare cell 20 is a stacked structure, the protective layer 30 is disposed along the periphery of the cell body 21. This effectively enables the protective layer 30 to better adapt to different bare cell structures 20, ensuring the insulation performance and structural strength of the edge of the cell body 21, preventing scratches or even damage to the edge of the cell body 21, thereby preventing short circuits in the bare cell 20.
[0061] Understandably, the first and second electrodes have opposite polarities, with one being a positive electrode and the other a negative electrode. The tab portion 22 includes a first tab and a second tab, with opposite polarities. The first tab is disposed on the first electrode, and the second tab is disposed on the second electrode. Specifically, one of the first and second tabs is disposed on the top of the cell body 21, and the other is disposed on the bottom of the cell body 21. Alternatively, the first and second tabs are spaced apart on the top of the cell body 21. Or, the first and second tabs are spaced apart on the bottom of the cell body 21.
[0062] Understandably, during the manufacturing process of the bare cell 20, since the main function of the separator is to isolate the positive and negative electrodes and prevent them from directly contacting each other and causing a short circuit, the size of the separator is generally greater than or equal to the size of the positive electrode and / or the size of the negative electrode. That is, the length of the separator is greater than or equal to the length of the positive electrode, and the width of the separator is greater than or equal to the length of the positive electrode; and / or, the length of the separator is greater than or equal to the length of the negative electrode, and the width of the separator is greater than or equal to the length of the negative electrode.
[0063] Under this design logic, in this utility model, the extension of the epitaxial portion 31 to the outside of the cell body 21 actually refers to the extension of the epitaxial portion 31 to the outside of the edge of the separator. The distance K between the edge of the epitaxial portion 31 away from the cell body 21 and the edge of the cell body 21 actually refers to the distance between the edge of the epitaxial portion 31 away from the separator and the edge of the separator. Similarly, the distance D between the edge of the tab adhesive 221 away from the cell body 21 and the edge of the cell body 21 actually refers to the distance between the edge of the tab adhesive 221 away from the separator and the edge of the separator.
[0064] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention.
Claims
1. A battery, characterized by: The battery cell includes a shell (10) and a bare battery cell (20), the shell (10) has a receiving cavity, the bare battery cell (20) includes a battery cell body (21) and a tab portion (22), the battery cell body (21) is received in the receiving cavity, the tab portion (22) extends from one end of the battery cell body (21) to the outside of the shell (10), along the thickness direction (a) of the battery cell body (21), the inner surface (11) of the shell (10) and the outer surface (211) of the battery cell body (21) are provided with a protective layer (30), the protective layer (30) is located at the edge region of the battery cell body (21), the protective layer (30) has an extension part (31) extending to the outside of the battery cell body (21), wherein the protective layer (30) is bonded to the inner surface (11) of the shell (10); and / or the protective layer (30) is bonded to the outer surface (211) of the battery cell body (21).
2. The battery of claim 1, wherein: The protective layer (30) is a melt-blown insulation layer.
3. The battery of claim 1, wherein: Along the thickness direction (a) of the battery cell body (21), the battery cell body (21) has two opposite outer surfaces (211), both of which are bonded to the protective layer (30), and the extension parts (31) of the protective layers (30) of the two outer surfaces (211) overlap each other; And / or, along the thickness direction (a) of the battery cell body (21), the shell (10) has two opposite inner surfaces (11), both of which are bonded to the protective layer (30), and the extension parts (31) of the protective layers (30) of the two inner surfaces (11) overlap each other.
4. The battery of claim 1, wherein: The distance K between the extension part (31) of the protective layer (30) and the edge of the battery cell body (21) satisfies the relationship: 0.8mm≤K≤1.5mm.
5. The battery of claim 4, wherein: The tab portion (22) is provided with a tab rubber (221) and a tab protection rubber (222), the tab protection rubber (222) covers the tab rubber (221) and the battery cell body (21), the tab protection rubber (222) has a first overlapping area (223) with the tab rubber (221), the first overlapping area (223) has a first edge close to the battery cell body (21) and a second edge away from the battery cell body (21), the extension part (31) extends to the first overlapping area (223), and the distance D between the second edge and the edge of the battery cell body (21) satisfies the relationship: K≤D.
6. The battery of claim 1, wherein: The thickness G of the protective layer (30) satisfies the relationship: 1.5μm≤G≤2.5μm; And / or, along the thickness direction (a) of the battery cell body (21), the protective layer (30) has a second overlapping area (40) with the battery cell body (21), the width L of the second overlapping area (40) satisfies the relationship: 0.8cm≤L≤1.5cm.
7. The battery of claim 1, wherein: The protective layer (30) has a porous structure.
8. The battery of claim 1, wherein: The battery core body (21) is provided with a glue layer (50), and the glue layer (50) is arranged staggeredly with the protective layer (30).
9. The battery according to any one of claims 1 to 8, characterized in that: The battery core body (21) comprises a first pole piece, a second pole piece and a diaphragm, the first pole piece, the diaphragm and the second pole piece are stacked and wound in sequence to form the battery core body (21), along the length direction (b) of the battery core body (21), the tab part (22) is arranged at the top and / or bottom of the battery core body (21), and the protective layer (30) is arranged at the top and bottom of the battery core body (21). Alternatively, the first pole piece and the second pole piece are each provided with a plurality of the first pole pieces and the second pole pieces are arranged alternately in layers, the diaphragm is arranged between adjacent first pole pieces and second pole pieces, along the length direction (b) of the battery core body (21), the tab part (22) is arranged at the top and / or bottom of the battery core body (21), and the protective layer (30) is arranged along the circumferential side of the battery core body (21).
10. An electrical device, characterized by: The battery comprises the battery as claimed in any one of claims 1-9.