Battery cell and battery

Abstract

The utility model discloses a kind of battery and electric core, electric core includes: electric core body, electric core body includes mutually laminated winding setting anode pole piece, diaphragm and cathode pole piece, the opposite sides of electric core body along its width direction are formed with corner respectively;Corner of at least one side of electric core body is equipped with adhesive layer, adhesive layer is located between anode pole piece and diaphragm and extends along the height direction of electric core body and is set, one side of adhesive layer is bonded on one of anode pole piece and diaphragm, the other side is structured with bulge and with the other of anode pole piece and diaphragm abuts.The utility model electric core is set with adhesive layer with bulge between anode pole piece and diaphragm in the corner of electric core body, increase the gap of anode pole piece and diaphragm at corner, beneficial to electrolyte fully soak, avoid ion broken bridge, improve corner lithium analysis, and, can buffer extrusion force at corner, reduce active material drop on anode pole piece, reduce the risk of powder damage diaphragm, improve the security and reliability of battery.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and in particular to a battery cell and battery. Background Technology

[0002] Lithium batteries are batteries that contain lithium (including metallic lithium, lithium alloys, lithium ions, and lithium polymers) in their electrochemical system and are widely used in consumer products and other fields.

[0003] Among lithium batteries on the market, the mainstream cell types include stacked cells and wound cells. Stacked cells are formed by stacking positive and negative electrodes and separators in sequence, which has advantages such as regular structure and low internal resistance. Wound cells are formed by winding positive and negative electrodes and separators in sequence, which has certain advantages in terms of production efficiency and cost control, and therefore occupies a considerable share of the market.

[0004] However, due to the inherent structural characteristics of wound cells, a series of problems have emerged in practical applications. During charge-discharge cycles, the anode electrode of the cell is subjected to periodic mechanical stress, especially at the corners. Due to the tight structure formed by the winding of the cell, the gap between the anode electrode and the separator is relatively small, making it difficult for the electrolyte to fully wet this area. Consequently, during charge-discharge, ion transport channels are easily blocked, i.e., ion bridging occurs, leading to lithium plating at the corners. At the same time, the compressive force at the corners of the anode electrode can easily cause active material to detach, i.e., powder shedding. If the detached powder punctures and damages the separator, it can cause direct contact between the positive and negative electrodes inside the battery, resulting in a short circuit and seriously affecting the safety and reliability of the battery. Utility Model Content

[0005] The main purpose of this invention is to propose a battery cell that addresses the technical problem of small gaps between the anode plate and the separator at the corners of current wound battery cells, which easily leads to lithium plating at the corners and powder shedding that damages the separator.

[0006] To achieve the above objectives, this utility model proposes a battery cell, which includes:

[0007] The battery cell body includes an anode electrode, a separator, and a cathode electrode that are stacked and wound together, and corners are formed on opposite sides of the battery cell body along its width direction.

[0008] An adhesive layer is provided at at least one corner of the cell body. The adhesive layer is located between the anode electrode and the separator and extends along the height direction of the cell body. One side of the adhesive layer is bonded to one of the anode electrode and the separator, and the other side is constructed with a protrusion and abuts against the other of the anode electrode and the separator.

[0009] In some embodiments, the thickness of the adhesive layer is D1, and the thickness of the bulge is D3, satisfying: 0.4D1≤D3≤0.6D1.

[0010] In some embodiments, the side of the bulge facing away from the adhesive surface has a flat area, the width of the adhesive layer is W1, and the width of the flat area is W3, satisfying: 0≤W3≤0.4W1.

[0011] In some embodiments, the side of the bulge facing away from the adhesive surface has two opposing sloping areas, the flat area is located between the two sloping areas, the width of the adhesive layer is W1, and the width of the sloping area is W4, satisfying: 0.1W1≤W4≤0.3W1.

[0012] In some embodiments, the adhesive layer is constructed with micropores.

[0013] In some embodiments, the width of the adhesive layer is W1, and the radius of the corner is r, satisfying: 1.2πr≤W1≤2πr.

[0014] In some embodiments, the length of the adhesive layer is L, and the width of the anode electrode is W2, satisfying: W2 < L ≤ 1.1W2; and / or,

[0015] The thickness of the adhesive layer is D1, which satisfies the condition: D1≤6μm.

[0016] In some embodiments, the adhesive layer includes a substrate layer and an adhesive layer disposed on the substrate layer;

[0017] The adhesive layer includes a plurality of spaced-apart adhesive points; and / or,

[0018] The thickness of the adhesive layer is D1, and the thickness of the bonding layer is D2, satisfying: 0.1D1≤D2≤0.2D1; and / or,

[0019] The area of ​​the adhesive layer is S1, and the area of ​​the bonding layer is S2, satisfying: 0.3S1≤S2≤0.6S1.

[0020] In some embodiments, the cell body has a winding axis;

[0021] The adhesive layer is bonded to the side of the anode electrode facing away from the winding axis; or, the adhesive layer is bonded to the side of the diaphragm facing the winding axis.

[0022] The present invention also proposes a battery comprising a casing and a battery cell as described above, wherein the battery cell is disposed in the casing.

[0023] This utility model battery cell has an adhesive layer at at least one corner of the cell body. The adhesive layer is located between the anode electrode and the separator and extends along the height direction of the cell body. One side of the adhesive layer is bonded to one of the anode electrode and the separator, while the other side has a raised structure that abuts against the other. The adhesive layer and its raised structure increase the gap between the anode electrode and the separator at the corner, which facilitates full wetting of the electrolyte, avoids ion bridging, improves lithium plating at the corner, and can buffer the squeezing pressure at the corner, reduce the shedding of active material from the anode electrode, reduce the risk of powder falling and damaging the separator, and improve the safety and reliability of the battery. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the battery cell structure in one embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the anode plate of the battery cell body before winding in one embodiment of the present invention;

[0026] Figure 3 This is a schematic diagram of the adhesive layer of the battery cell in one embodiment of the present invention;

[0027] Figure 4 This is a schematic diagram of the adhesive layer of the battery cell in another embodiment of the present invention;

[0028] Explanation of icon numbers:

[0029] 100 Battery cell body 110 Anode plate 120 diaphragm 130 Cathode plate 200 adhesive layer 201 bulge 2011 Straight area 2012 Slope area 210 Substrate layer 220 Adhesive layer 221 Adhesion points

[0030] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0031] The solutions in 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 a part of the embodiments of this utility model, and not all of them. 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.

[0032] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0033] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0034] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0035] This utility model embodiment proposes a battery cell, referring to... Figure 1 The battery cell includes:

[0036] The battery cell body 100 includes an anode electrode 110, a diaphragm 120 and a cathode electrode 130 that are stacked and wound together. Corners are formed on opposite sides of the battery cell body 100 along its width direction.

[0037] At least one corner of the cell body 100 is provided with an adhesive layer 200. The adhesive layer 200 is located between the anode electrode 110 and the separator 120 and extends along the height direction of the cell body 100. One side of the adhesive layer 200 is bonded to one of the anode electrode 110 and the separator 120, and the other side has a protrusion 201 and abuts against the other of the anode electrode 110 and the separator 120.

[0038] The battery cell body 100 involved in this embodiment serves as the basic structure of the battery cell, and is formed by stacking and winding the anode electrode 110, the separator 120, and the cathode electrode 130 in a specific order. The anode electrode 110 serves as the source of lithium ions during battery discharge, undergoing lithium ion insertion and extraction reactions during charging and discharging. The cathode electrode 130 is the storage location for lithium ions during charging and the receiving location for lithium ions during discharging. The separator 120 is located between the anode electrode 110 and the cathode electrode 130, playing a crucial role in isolating the positive and negative electrodes to prevent direct contact and short circuits, while simultaneously allowing lithium ions to pass through, ensuring the smooth progress of the electrochemical reaction.

[0039] Due to its wound structure, the battery cell body 100 has corners on opposite sides in the width direction. An adhesive layer 200 is provided at at least one corner position (which can be the left, right, or both sides) of the battery cell body 100, and this adhesive layer 200 is located between the anode electrode 110 and the separator 120. For any corner of the battery cell body 100, the adhesive layer 200 can be a single layer, located between the anode electrode 110 and the separator 120 in one loop (e.g., the innermost loop, the innermost second loop, or the innermost third loop) at the corner position; or, the adhesive layer 200 can be multiple layers, with each layer located between different loops of the anode electrode 110 and the separator 120 at the corner position. The choice depends on the specific circumstances, and this embodiment does not impose any restrictions on this.

[0040] In actual manufacturing processes, the requirements of the process and the properties of the materials can be considered, such as... Figure 2 As shown, the adhesive layer 200 is bonded to the anode electrode 110, with the other side of the adhesive layer 200 abutting against the separator 120; or the adhesive layer 200 is bonded to the separator 120, with its other side abutting against the anode electrode 110. The adhesive layer 200 can be coated using methods such as dot coating, PVDF roll coating, or PVDF thermal lamination, and this embodiment does not limit this method. Furthermore, each of the exemplified coating methods has its advantages. For example, the adhesive layer 200 manufactured by PVDF roll coating is more compatible with the electrolyte system, and PVDF can enable lithium-ion conduction, avoiding interference with lithium-ion conduction; the adhesive layer 200 formed by PVDF thermal lamination can reduce the thickness of the adhesive layer 200 while maintaining good adhesion. In this embodiment, there are certain requirements for the adhesive force of the adhesive layer 200. Optionally, after the adhesive layer 200 is bonded to the anode plate 110 or the diaphragm 120, the peel force needs to reach 5gf to 20gf to ensure the stability of the bond and prevent it from falling off during charging and discharging.

[0041] The adhesive layer 200 extends along the height direction of the cell body 100 (which can also be considered as the width direction of the electrode or separator 120), and can function throughout the entire corner area. The material of the adhesive layer 200 needs to have good adhesion properties to ensure a firm bond with the anode electrode 110 or separator 120; at the same time, it should also have a certain degree of flexibility and chemical stability, so that it can exist stably for a long time in the battery's operating environment and will not react chemically with the electrolyte or other substances, thus affecting battery performance.

[0042] In the adhesive layer 200 structure at the corner of the cell body 100, the adhesive layer 200 adopts an irregular cross-sectional design with non-uniform thickness. Specifically, the side of the adhesive layer 200 facing the anode electrode 110 or the separator 120 is the bonding surface, realizing the bonding connection with the electrode or separator 120. The other side (non-bonding surface) of the adhesive layer 200 has a curved surface structure with a central bulge 201 and thinned edges. That is, along the thickness direction of the adhesive layer 200, the thickness of the central region is greater than that of the edge region, forming a cross-section similar to an arc or dome.

[0043] The raised area 201 of the adhesive layer 200 is precisely aligned with the center of the corner, forming a locally enlarged gap at the center of the corner, providing sufficient storage and diffusion space for the electrolyte. It can also absorb the concentrated extrusion pressure at the center of the corner through elastic deformation, reducing the risk of active material falling off the anode plate 110. At the same time, the edge areas of the adhesive layer 200 on both sides of the raised area 201 are thinned, which helps to reduce the impact of the thickness of the adhesive layer 200 on the overall thickness of the cell body 100.

[0044] During the charging and discharging process of a lithium battery, the electrolyte needs to fully wet all areas inside the cell to ensure that lithium ions can be smoothly transported between the anode electrode 110 and the cathode electrode 130. Because the gap between the anode electrode 110 and the separator 120 at the corner of a conventional wound cell is small, the electrolyte cannot fully wet the cell, leading to obstructed ion transport, ion bridging, and consequently, corner lithium plating. In this embodiment, the adhesive layer 200 and its raised structure 201 at the corner of the cell body 100 increase the gap between the anode electrode 110 and the separator 120 at the corner. This increased gap provides more sufficient wetting space for the electrolyte, allowing it to enter the corner area more smoothly and ensuring a smooth transport channel for lithium ions during charging and discharging. This effectively avoids ion bridging and improves the corner lithium plating problem.

[0045] Furthermore, during the charge-discharge cycle of the battery cell, the corner of the anode electrode 110 is subjected to significant compressive force, which can easily cause the active material on the anode electrode 110 to detach. The adhesive layer 200 in this embodiment has a certain degree of flexibility, which can buffer the compressive force at the corner. When the anode electrode 110 is subjected to compressive force, the adhesive layer 200 and its protrusions 201 can absorb part of the pressure through their own elastic deformation, reducing the direct compressive force on the anode electrode 110, thereby reducing the detachment of active material from the anode electrode 110, lowering the risk of powder shedding and damage to the separator 120, and effectively improving the safety and reliability of the battery.

[0046] In some embodiments, refer to Figure 3The thickness of the adhesive layer 200 is D1, and the thickness of the raised section 201 is D3, satisfying the condition: 0.4D1≤D3≤0.6D1. In this embodiment, the thickness of the adhesive layer 200 is D1, and the height D3 of the raised section 201 can be set within the range of 0.4D1 to 0.6D1. For example, the height D3 of the raised section 201 can be set to 0.4D1, 0.5D1, 0.6D1, etc., selected according to actual needs. Setting the height D3 of the raised section 201 within the range of 0.4D1 to 0.6D1 provides a moderate thickness, effectively widening the gap at the center of the corner without causing the overall thickness of the adhesive layer 200 to exceed the limit or the edges to be excessively thinned, thus ensuring structural stability.

[0047] In some embodiments, refer to Figure 3 The raised area 201 forms a flat area 2011. The width of the adhesive layer 200 is W1, and the width of the flat area 2011 is W3, satisfying: 0≤W3≤0.4W1.

[0048] In this embodiment, optionally, the flat region 2011 is located on the side of the raised 201 facing away from the adhesive surface of the adhesive layer 200 (i.e., the non-adhesive surface facing the diaphragm 120 or the anode electrode 110), and is a planar structure with uniform thickness. Along the winding direction of the cell body 100, the width of the adhesive layer 200 is W1, and the width W3 of the flat region 2011 can be set in the range of 0 to 0.4W1. For example, the width W3 of the flat region 2011 can be set to 0.2W1, 0.4W1, etc., selected according to actual needs. The width W3 of the flat region 2011 is set in the range of 0 to 0.4W1, which is a moderate width and can avoid affecting the overall thickness of the cell body 100 due to excessive width.

[0049] In some embodiments, the bulge 201 further forms two oppositely arranged sloping regions 2012, and a straight region 2011 is located between the two sloping regions 2012. The width of the adhesive layer 200 is W1, and the width of the sloping region 2012 is W4, satisfying: 0.1W1≤W4≤0.3W1.

[0050] In this embodiment, the ramp region 2012 is also located on the side of the protrusion 201 facing away from the adhesive surface of the adhesive layer 200 (i.e., the non-adhesive surface facing the diaphragm 120 or the anode electrode 110), and is distributed on opposite sides of the flat region 2011, forming a ramp structure with gradually changing thickness. Along the winding direction of the cell body 100, the width of the adhesive layer 200 is W1, and the width W4 of the ramp region 2012 can be set within the range of 0.1W1 to 0.3W1. For example, the width W4 of the ramp region 2012 can be set to 0.1W1, 0.2W1, 0.3W1, etc., selected according to actual needs. Setting the width W4 of the ramp region 2012 within the range of 0.1W1 to 0.3W1 provides a moderate width, avoiding uneven transitions due to excessive narrowness and affecting the overall thickness of the cell body 100 due to excessive width.

[0051] In some embodiments, the adhesive layer 200 is constructed with micropores. In this embodiment, the microporous structure of the adhesive layer 200 can be formed by foaming, template method, or solvent evaporation method, so that the adhesive layer 200 has both mechanical support and ion conduction functions. The porosity of the adhesive layer 200 can be set in the range of 30% to 45%, for example, the porosity of the adhesive layer 200 can be set to 30%, 38%, 45%, etc., selected according to actual needs. The porosity involved is the percentage between the volume of the micropores and the total volume of the adhesive layer 200. The micropores are three-dimensionally interconnected with a concentrated pore size distribution, providing flow channels for lithium ions. Lithium ions can quickly pass through the adhesive layer 200 through the micropores, avoiding the hindrance of ion migration by the adhesive layer 200 material itself, which helps to improve the electrolyte wetting effect at corner positions. In addition, the micropores inside the adhesive layer 200 form an elastic buffer structure. During charging and discharging, the mechanical stress generated by the expansion of the anode electrode 110 can be absorbed by the compression deformation of the micropores, which helps to improve the buffering effect. Alternatively, from another perspective, the air permeability of the adhesive layer 200 can be between 60s / 100mL and 160s / 100mL. For example, the air permeability of the adhesive layer 200 can be set to 60s / 100mL (i.e., the passage time of 100mL of gas is 60s), 110s / 100mL (i.e., the passage time of 100mL of gas is 110s), 160s / 100mL (i.e., the passage time of 100mL of gas is 160s), etc. In other words, the adhesive layer 200 has good air permeability, ensuring lithium ion throughput and thus avoiding hindering ion migration.

[0052] In some embodiments, the width of the adhesive layer 200 is W1, and the radius of the corner is r, satisfying: 1.2πr ≤ W1 ≤ 2πr. In this embodiment, the corner of the cell body 100 can be regarded as an arc structure with a radius of r. Along the winding direction of the cell body 100, the width W1 of the adhesive layer 200 is set in the range of 1.2πr to 2πr, where π is the mathematical constant pi. For example, the width W1 of the adhesive layer 200 can be set to 1.2πr, 1.6πr, 2πr, etc., selected according to actual needs. This is because if W1 < 1.2πr, the adhesive layer 200 may not be able to completely cover the curved surface of the corner, resulting in the edge area of ​​the corner not being protected; if W1 > 2πr, the adhesive layer 200 will extend to the planar stacked area of ​​the cell body, forming a thickness stack after winding, increasing the overall thickness of the cell. Therefore, the width range of 1.2πr to 2πr allows the adhesive layer 200 to accurately cover the corner area in the winding direction of the cell body 100, while avoiding the cell body stack (i.e., flat area) as much as possible, so as to avoid the overall thickness of the cell due to the stacking of adhesive layers 200.

[0053] In some embodiments, the length of the adhesive layer 200 is L, and the width of the anode electrode 110 is W2, satisfying: W2 < L ≤ 1.1W2; and / or,

[0054] The thickness of adhesive layer 200 is D1, which satisfies: D1≤6μm.

[0055] In this embodiment, optionally, the width of the anode electrode 110 along the height direction of the cell body 100 is W2, and the length L of the adhesive layer 200 is set within the range of W2 to 1.1W2. For example, the length L of the adhesive layer 200 can be set to W2, 1.05W2, 1.1W2, etc., selected according to actual needs. When L > W2, the adhesive layer 200 can completely cover the entire height range of the corner in the height direction, ensuring that the top and bottom edges of the corner are covered by the adhesive layer 200; at the same time, L ≤ 1.1W2 ensures that the excess of the adhesive layer 200 beyond the edge of the electrode is controlled within 10%, avoiding material waste due to excessive extension or interference with other structures.

[0056] Optionally, the thickness D1 of the adhesive layer 200 can be set within a range of 6μm. For example, the thickness D1 of the adhesive layer 200 can be set to 4μm, 5μm, 6μm, etc., depending on the actual needs. By controlling the thickness D1 of the adhesive layer 200 within 6μm, the excessive thickness at the corners can be avoided while ensuring its buffering effect.

[0057] In some embodiments, refer to Figure 4 The adhesive layer 200 includes a substrate layer 210 and an adhesive layer 220 disposed on the substrate layer 210;

[0058] The adhesive layer 220 includes a plurality of spaced-apart adhesive points 221; and / or,

[0059] The thickness of adhesive layer 200 is D1, and the thickness of adhesive layer 220 is D2, satisfying: 0.1D1≤D2≤0.2D1; and / or,

[0060] The area of ​​adhesive layer 200 is S1, and the area of ​​adhesive layer 220 is S2, satisfying: 0.3S1≤S2≤0.6S1.

[0061] In this embodiment, the adhesive layer structure at the corner of the battery cell body 100, such as Figure 3 As shown, the adhesive layer 200 adopts a composite structure of a substrate layer 210 and an adhesive layer 220. The substrate layer 210 serves as a supporting body, located between the anode electrode 110 and the separator 120, extending along the height direction of the cell body 100 and covering the corner area. The adhesive layer 220 is attached to the surface of the substrate layer 210, fixing the adhesive layer 200 to the anode electrode 110 or the separator 120 through adhesion. A protrusion 201 is formed on the substrate layer 210 and located on the side of the substrate layer 210 facing away from the adhesive layer 220.

[0062] Optionally, such as Figure 4 As shown, the adhesive layer 220 can adopt a structure with spaced adhesive points 221. Specifically, multiple adhesive points 221 are arranged regularly or irregularly on the surface of the substrate layer 210, forming a discontinuous adhesive interface. Furthermore, the shape of the adhesive points 221 can be designed as circular, strip-shaped, grid-shaped, etc., and the spacing is optimized according to parameters such as corner curvature and adhesive layer 200 thickness. The gaps formed between the adhesive points 221 allow lithium ions to pass through, helping to improve the lithium ion throughput.

[0063] Optionally, such as Figure 4 As shown, the thickness of the adhesive layer 200 is D1, and the thickness D2 of the adhesive layer 220 can be set within the range of 0.1D1 to 0.2D1. For example, the thickness D2 of the adhesive layer 220 can be set to 0.1D1, 0.15D1, 0.2D1, etc., depending on actual needs. The thickness D2 of the adhesive layer 220 should not be less than 0.1D1 to ensure sufficient adhesive material and prevent the adhesive layer 200 from detaching due to excessive thinness. At the same time, the thickness D2 of the adhesive layer 220 should not exceed 0.2D1 to ensure that the thickness ratio of the substrate layer 210 reaches 80% to 90%, allowing the substrate layer 210 to fully utilize its flexibility and structural support, absorbing the extrusion pressure at the corners through elastic deformation, thus providing buffer protection for the anode electrode 110 and preventing the loss of its buffering function due to excessive thinness of the substrate layer 210.

[0064] Optionally, the area of ​​the adhesive layer 200 is S1, and the area S2 of the adhesive layer 220 can be set within the range of 0.3S1 to 0.6S1. For example, the area S2 of the adhesive layer 220 can be set to 0.3S1, 0.45S1, 0.6S1, etc., depending on actual needs. The area S2 of the adhesive layer 220 is not less than 0.3S1, ensuring that the adhesive layer 200 has sufficient bonding area and preventing the adhesive layer 200 from detaching due to an insufficiently small area. At the same time, the area S2 of the adhesive layer 220 does not exceed 0.6S1, forming sufficient gaps for lithium ions to pass through.

[0065] In some embodiments, refer to Figure 1 The battery cell body 100 has a winding axis;

[0066] The adhesive layer 200 is bonded to the side of the anode electrode 110 facing away from the winding axis; or, the adhesive layer 200 is bonded to the side of the diaphragm 120 facing the winding axis.

[0067] In the winding structure of the battery cell body 100, the winding axis is defined as the central axis of the battery cell winding formation, and the anode electrode 110, separator 120, and cathode electrode 130 are stacked and wound around this axis. By bonding the adhesive layer 200 to the side of the anode electrode 110 facing away from the winding axis, or by bonding the adhesive layer 200 to the side of the separator 120 facing the winding axis, the adhesive layer 200 can support the anode electrode 110 from the outside to the inside, thereby effectively suppressing the expansion of the anode electrode 110 during charging and discharging, buffering the extrusion pressure at the corners, and improving the safety and reliability of the battery.

[0068] This utility model embodiment also proposes a battery, which includes a casing and a battery cell as described in the foregoing embodiments, with the battery cell disposed within the casing. The specific structure of the battery cell is as described in the foregoing embodiments. Since this battery adopts all the technical solutions of all the foregoing embodiments, it possesses at least all the technical effects brought about by the technical solutions of the foregoing embodiments, and will not be elaborated upon here. The battery can be a lithium battery.

[0069] The above description is only a part or preferred embodiment of this utility model. Neither the text nor the drawings should limit the scope of protection of this utility model. All equivalent structural transformations made using the content of this utility model specification and drawings under the overall concept of this utility model, or direct / indirect applications in other related technical fields, are included within the scope of protection of this utility model.

Claims

1. A battery cell, characterized in that, include: The battery cell body (100) includes an anode electrode (110), a separator (120) and a cathode electrode (130) that are stacked and wound together. The battery cell body (100) has corners formed on opposite sides along its width direction. At least one corner of the cell body (100) is provided with an adhesive layer (200). The adhesive layer (200) is located between the anode electrode (110) and the separator (120) and extends along the height direction of the cell body (100). One side of the adhesive layer (200) is bonded to one of the anode electrode (110) and the separator (120), and the other side is constructed with a protrusion (201) and abuts against the other of the anode electrode (110) and the separator (120).

2. The battery cell according to claim 1, characterized in that, The thickness of the adhesive layer (200) is D1, and the thickness of the bulge (201) is D3, satisfying: 0.4D1≤D3≤0.6D1.

3. The battery cell according to claim 1, characterized in that, The raised area (201) has a flat area (2011), the width of the adhesive layer (200) is W1, and the width of the flat area (2011) is W3, satisfying: 0≤W3≤0.4W1.

4. The battery cell according to claim 3, characterized in that, The bulge (201) also forms two oppositely arranged sloping areas (2012), and the straight area (2011) is located between the two sloping areas (2012). The width of the adhesive layer (200) is W1, and the width of the sloping area (2012) is W4, satisfying: 0.1W1≤W4≤0.3W1.

5. The battery cell according to claim 1, characterized in that, The adhesive layer (200) has micropores.

6. The battery cell according to claim 1, characterized in that, The width of the adhesive layer (200) is W1, and the radius of the corner is r, satisfying: 1.2πr≤W1≤2πr.

7. The battery cell according to claim 1, characterized in that, The length of the adhesive layer (200) is L, and the width of the anode electrode (110) is W2, satisfying: W2 < L ≤ 1.1W2; and / or, The thickness of the adhesive layer (200) is D1, which satisfies: D1≤6μm.

8. The battery cell according to any one of claims 1 to 7, characterized in that, The adhesive layer (200) includes a substrate layer (210) and an adhesive layer (220) disposed on the substrate layer (210); The adhesive layer (220) includes a plurality of spaced adhesive points (221); and / or, The thickness of the adhesive layer (200) is D1, and the thickness of the bonding layer (220) is D2, satisfying: 0.1D1≤D2≤0.2D1; and / or, The area of ​​the adhesive layer (200) is S1, and the area of ​​the bonding layer (220) is S2, satisfying: 0.3S1≤S2≤0.6S1.

9. The battery cell according to any one of claims 1 to 7, characterized in that, The battery cell body (100) has a winding axis; The adhesive layer (200) is bonded to the side of the anode electrode (110) facing away from the winding axis; or, the adhesive layer (200) is bonded to the side of the diaphragm (120) facing the winding axis.

10. A battery, characterized in that, It includes a housing and a battery cell as described in any one of claims 1 to 9, wherein the battery cell is disposed in the housing.

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