battery

Abstract

The utility model discloses a battery, include: casing is equipped with accommodation cavity, winding electric core is located in the accommodation cavity, winding electric core has the week lateral surface, first end surface and second end surface, and first end surface and second end surface are opposite to set up in the length direction of winding electric core, and the week lateral surface includes first flat side and second flat side, and first flat side and second flat side are opposite to set up in the thickness direction of winding electric core, double -sided hot melt adhesive is pasted on winding electric core and is bonded with casing, and double -sided hot melt adhesive at least covers first end surface, first flat side and second end surface, and double -sided hot melt adhesive is provided with a plurality of through -holes. The battery is pasted by double -sided hot melt adhesive around winding electric core, and at least covers first end surface, first flat side and second end surface, increases the bonding area, improves the adhesion firmness to prevent drop failure, and sets up the through -hole exhaust on double -sided hot melt adhesive to avoid the bubble.

Description

Technical Field

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

[0002] Lithium-ion batteries, which contain lithium elements (including metallic lithium, lithium alloys, lithium ions, lithium polymers, etc.) in an electrochemical system, are widely used in consumer electronics and other fields due to their outstanding advantages such as high energy density, long cycle life and low self-discharge rate.

[0003] In the structural design of lithium batteries, aluminum-plastic film is usually used to encapsulate the bare cells. To ensure the stability of the bare cells within the aluminum-plastic film and to prevent them from shifting within the film due to external forces (such as drops), causing them to collide with the film and resulting in damage to their ends leading to short circuits, or even breaking through the film and causing leakage, existing technologies typically apply 1-2 double-sided hot melt adhesives to one side of the bare cells. The hot melt adhesives are used to bond the bare cells to the aluminum-plastic film, thereby fixing the position of the bare cells within the film.

[0004] However, as market demands for extended battery life continue to rise, lithium battery capacity is gradually increasing, leading to a corresponding increase in cell weight. In high-capacity cell scenarios, simply applying one or two layers of double-sided hot melt adhesive to one side is insufficient to withstand the significant impact of a drop. This fails to ensure a stable bond between the bare cell and the aluminum-plastic film, causing the bare cell to shift within the film and collide with it, easily resulting in battery failure. Increasing the area of ​​the double-sided hot melt adhesive to enhance adhesion results in air bubbles being generated during application due to the adhesive's thinness, severely impacting the final battery quality and performance stability. Utility Model Content

[0005] The main purpose of this invention is to propose a battery that improves the adhesion between the battery cell and the aluminum-plastic film of a high-capacity battery to prevent drop failure, while also preventing air bubbles from forming during adhesive application, thereby improving the overall quality and performance stability of the battery.

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

[0007] The housing has a receiving cavity;

[0008] A wound battery cell is disposed within the accommodating cavity. The wound battery cell has a peripheral side surface, a first end surface, and a second end surface. The first end surface and the second end surface are disposed opposite to each other in the length direction of the wound battery cell. The peripheral side surface includes a first flat side surface and a second flat side surface. The first flat side surface and the second flat side surface are disposed opposite to each other in the thickness direction of the wound battery cell.

[0009] Double-sided hot melt adhesive is applied to the wound battery cell and bonded to the housing. The double-sided hot melt adhesive covers at least the first end face, the first flat side face, and the second end face. The double-sided hot melt adhesive is provided with multiple through holes.

[0010] Optionally, in the length direction of the wound cell, one end of the double-sided hot melt adhesive extends beyond the first end face to the second flat side to form a head wrap; the other end of the double-sided hot melt adhesive extends beyond the second end face to the second flat side to form a bottom wrap.

[0011] Optionally, the excess distance at one end of the double-sided hot melt adhesive is D1, and the excess distance at the other end of the double-sided hot melt adhesive is D2, satisfying: 2mm < D1 ≤ 15mm, 2mm < D2 ≤ 15mm.

[0012] Optionally, the wound battery cell is welded with a first tab and a second tab, the first tab and the second tab extending from the first end face and spaced apart in the width direction of the wound battery cell;

[0013] One end of the double-sided hot melt adhesive is disposed through the gap between the first electrode and the second electrode.

[0014] Optionally, the peripheral side surface further includes a first corner side surface and a second corner side surface, wherein the first corner side surface and the second corner side surface are disposed opposite to each other in the width direction of the wound cell;

[0015] The double-sided hot melt adhesive also covers the first corner side and the second corner side.

[0016] Optionally, in the circumferential direction of the wound cell, one side of the double-sided hot melt adhesive extends beyond the first corner side to the second straight side, and the other side of the double-sided hot melt adhesive extends beyond the second corner side to the second straight side.

[0017] Optionally, the other end of the double-sided hot melt adhesive is provided with two slits, which are spaced apart along the width direction of the wound cell, with one slit adjacent to the first corner side and the other adjacent to the second corner side.

[0018] Optionally, the outermost side of the wound cell has a winding tail end, and the double-sided hot melt adhesive is bonded to the winding tail end so that the winding tail end is fixed to the peripheral side of the wound cell.

[0019] Optionally, the ratio of the sum of the areas of the plurality of through holes to the area of ​​the double-sided hot melt adhesive is K, which satisfies: K≤50%.

[0020] Optionally, the wound cell has a tab welding area;

[0021] The double-sided hot melt adhesive has a relief groove, and the projection area of ​​the relief groove in the thickness direction of the wound cell covers the tab welding area.

[0022] This utility model battery uses double-sided hot melt adhesive to wrap around the surface of the wound battery cell, covering at least the first end face, the first flat side face, and the second end face. Compared to the prior art where only 1-2 layers of double-sided hot melt adhesive are applied to one side of the battery cell, this increases the bonding area between the double-sided hot melt adhesive and the wound battery cell and casing. This allows it to more effectively withstand the impact of gravity during drops, significantly improving the bonding strength between the battery cell and the casing inside the large-capacity battery. It also effectively prevents battery failure due to battery cell displacement impacting the aluminum-plastic film. Simultaneously, multiple through holes are provided on the double-sided hot melt adhesive to provide venting channels for internal air during the adhesive application process, preventing the formation of air bubbles. This effectively avoids the impact of air bubbles on the quality and performance stability of the finished battery, thereby improving the overall quality and performance stability of the battery and meeting the market demand for large-capacity, high-performance lithium batteries. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of a wound battery cell in one embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of the wound battery cell in another embodiment of the present invention;

[0025] Figure 3 for Figure 2 A schematic diagram of the wound battery cell from another perspective in the embodiment;

[0026] Figure 4 for Figure 2 A schematic diagram of the wound battery cell from another perspective in the embodiment;

[0027] Figure 5 for Figure 2 A schematic diagram of the structure of the double-sided hot melt adhesive on the wound battery cell in the embodiment;

[0028] Label Explanation:

[0029] label name label name 110 Winded battery cells 111 First end face 112 Second end face 113 First flat side 114 Second straight side 120 Double-sided hot melt adhesive 1201 Through hole 10 First pole ear 20 Second pole ear 115 First corner side 116 Second corner side 1202 gap 1203 clearance slot

[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 provides a battery, referring to... Figures 1 to 3 The battery includes:

[0036] The housing has a receiving cavity;

[0037] A wound battery cell 110 is disposed in a receiving cavity. The wound battery cell 110 has a peripheral side surface, a first end surface 111 and a second end surface 112. The first end surface 111 and the second end surface 112 are arranged opposite to each other in the length direction of the wound battery cell 110. The peripheral side surface includes a first flat side surface 113 and a second flat side surface 114. The first flat side surface 113 and the second flat side surface 114 are arranged opposite to each other in the thickness direction of the wound battery cell 110.

[0038] Double-sided hot melt adhesive 120 is applied to the wound cell 110 and bonded to the housing. The double-sided hot melt adhesive 120 covers at least the first end face 111, the first flat side face 113 and the second end face 112. The double-sided hot melt adhesive 120 is provided with multiple through holes 1201.

[0039] In this embodiment, the casing is preferably made of aluminum-plastic film to form the battery's encapsulation shell. The internal structure of the casing has a cavity for accommodating the wound cell 110. The wound cell 110 has a wound structure, formed by stacking and winding a positive electrode sheet, a separator, and a negative electrode sheet. The positive electrode sheet includes a positive current collector (such as aluminum foil) and a positive active material (such as lithium cobalt oxide, ternary materials, etc.) coated thereon. The negative electrode sheet includes a negative current collector (such as copper foil) and a negative active material (such as graphite) coated thereon. The separator is made of a polymer material with a microporous structure (such as polyethylene, polypropylene) to isolate the positive and negative electrode sheets while allowing lithium ions to pass through.

[0040] The wound battery cell 110 has a rectangular overall shape. In the circumferential direction (or winding direction), the wound battery cell 110 has peripheral side surfaces, including a first flat side surface 113 and a second side surface. Specifically, in the thickness direction of the wound battery cell 110, the first flat side surface 113 and the second flat side surface 114 are positioned opposite each other, that is, the first flat side surface 113 and the second flat side surface 114 are located on opposite sides of the thickness direction of the wound battery cell 110. In addition to these peripheral side surfaces, the wound battery cell 110 also has a first end face 111 and a second end face 112. In the length direction of the wound battery cell 110, the first end face 111 and the second end face 112 are positioned opposite each other, that is, the first end face 111 and the second end face 112 are located at opposite ends of the length direction of the wound battery cell 110. Alternatively, it can be considered that in the length direction of the wound battery cell 110, the first end face 111 and the second end face 112 are located at opposite ends of the peripheral side surfaces.

[0041] The double-sided hot melt adhesive 120 is in the form of a strip or sheet, tightly adhered to the surface of the wound battery cell 110, and its coverage area includes at least the first end face 111, the first flat side face 113, and the second end face 112, forming an adhesive structure surrounding a portion of the surface of the wound battery cell 110, and simultaneously bonding to the housing (i.e., the cavity wall of the accommodating cavity). The double-sided hot melt adhesive 120 may include a substrate layer and an adhesive layer disposed on the substrate layer. The substrate layer may be made of PE, PET, or polyimide, and the adhesive layer may be a hot melt adhesive composed of rubber, PUR, EVA, or styrene-based block copolymers, including but not limited to these. The thickness of the double-sided hot melt adhesive 120 can be 0.01 mm to 0.05 mm, and can be set according to actual needs. Multiple through holes 1201 are uniformly or non-uniformly distributed on the double-sided hot melt adhesive 120. Their shapes can be circular, polygonal (such as rectangular), elliptical, etc. The hole diameter is designed according to the actual process requirements to ensure that internal air can be effectively discharged during the adhesive application process without affecting the bonding strength of the double-sided hot melt adhesive 120.

[0042] When the battery is subjected to external impacts such as drops, the wound cell 110 will be subjected to significant gravitational impact and inertial force. Since the double-sided hot melt adhesive 120 is attached around the surface of the wound cell 110 and at least covers the first end face 111, the first flat side face 113 and the second end face 112, the bonding area between the double-sided hot melt adhesive 120 and the wound cell 110 and the shell is increased. This allows the impact force to be dispersed and transmitted through a larger bonding surface, thereby effectively withstanding the gravitational impact during drops, avoiding the tendency of the wound cell 110 to shift within the accommodating cavity, and preventing it from colliding with the shell and causing failure. Meanwhile, during the application of the double-sided hot melt adhesive 120, the double-sided hot melt adhesive 120 is provided with multiple through holes 1201, which provide an exhaust channel for the internal air. The air can be smoothly discharged through the through holes 1201, avoiding the generation of air bubbles due to air being trapped between the double-sided hot melt adhesive 120 and the wound battery cell 110 or the housing, thus ensuring the tightness and reliability of the adhesive application.

[0043] In some embodiments, refer to Figures 1 to 3Along the length of the wound cell 110, one end of the double-sided hot melt adhesive 120 extends beyond the first end face 111 to the second flat side face 114 to form a head wrapping; the other end of the double-sided hot melt adhesive 120 extends beyond the second end face 112 to the second flat side face 114 to form a bottom wrapping. In this embodiment, one end of the double-sided hot melt adhesive 120 extends beyond the edge of the first end face 111 along the extension path around the wound cell 110, extending beyond a preset distance toward the second flat side face 114, covering a portion of the second flat side face 114 area; the other end of the double-sided hot melt adhesive 120 symmetrically extends beyond the edge of the second end face 112, extending beyond the same preset distance toward the second flat side face 114 on the same side, and the two ends of the double-sided hot melt adhesive 120 form a blank area of ​​a certain width on the second flat side face 114. Compared to a basic structure that only covers the first end face 111, the first flat side face 113, and the second end face 112, this embodiment increases the bonding area by extending the double-sided hot melt adhesive 120 at both ends, further improving the bonding strength between the battery cell and the casing inside the large-capacity battery. Furthermore, adhesive wrapping is formed at the head and tail of the battery cell to restrain the wound battery cell 110 and prevent it from loosening, eliminating the need for a separate adhesive wrapping structure for the wound battery cell 110, simplifying the structure and facilitating application.

[0044] In some embodiments, refer to Figure 1 The distance extending beyond one end of the double-sided hot melt adhesive 120 is D1, and the distance extending beyond the other end of the double-sided hot melt adhesive 120 is D2, satisfying: 2mm<D1≤15mm, 2mm<D2≤15mm.

[0045] In this embodiment, the distance D1 extending beyond one end of the double-sided hot melt adhesive 120 is limited to 2mm < D1 ≤ 15mm. For example, the distance D1 extending beyond the first end face 111 can be set to 2mm, 6mm, 10mm, or 12mm, depending on actual needs. The distance D2 extending beyond the other end of the double-sided hot melt adhesive 120 is limited to 2mm < D2 ≤ 15mm. For example, the distance D2 extending beyond the second end face 112 can be set to 2mm, 6mm, 10mm, or 12mm, depending on actual needs. Optionally, D1 = D2, so that the double-sided hot melt adhesive 120 forms a symmetrical partial coverage area on the second flat side surface 114.

[0046] In some embodiments, refer to Figures 1 to 3 The wound cell 110 is welded with a first tab 10 and a second tab 20. The first tab 10 and the second tab 20 extend from the first end face 111 and are spaced apart in the width direction of the wound cell 110.

[0047] One end of the double-sided hot melt adhesive 120 passes through the gap between the first tab 10 and the second tab 20.

[0048] In this embodiment, one of the first tab 10 and the second tab 20 is a positive tab, welded to the positive electrode sheet in the wound cell 110, and the other is a negative tab, welded to the negative electrode sheet in the wound cell 110, used to realize the electrical connection between the internal and external circuits of the battery. One end of the double-sided hot melt adhesive 120 passes through the gap between the first tab 10 and the second tab 20, forming a "sandwich" interlocking structure. Specifically, when the double-sided hot melt adhesive 120 covers the first end face 111 of the wound cell 110, its extended portion passes through the gap between the two tabs and continues to extend towards the second flat side 114 to form the head wrapping adhesive. The width of this gap is greater than the width of the double-sided hot melt adhesive 120, ensuring that the double-sided hot melt adhesive 120 can pass smoothly without squeezing the tabs, while a certain process gap is reserved between them to avoid stress concentration between the tabs and the double-sided hot melt adhesive 120.

[0049] In some embodiments, refer to Figures 2 to 4 The peripheral side also includes a first corner side 115 and a second corner side 116, which are arranged opposite to each other in the width direction of the wound cell 110.

[0050] The double-sided hot melt adhesive 120 also covers the first corner side 115 and the second corner side 116.

[0051] In this embodiment, the peripheral side surface of the wound cell 110 is formed by sequentially connecting a first straight side surface 113, a first corner side surface 115, a second straight side surface 114, and a second corner side surface 116 along the circumferential direction of the wound cell 110. Specifically, in the width direction of the wound cell 110, the first corner side surface 115 and the second corner side surface 116 are positioned opposite each other, i.e., the first corner side surface 115 and the second corner side surface 116 are located on opposite sides of the width direction of the wound cell 110. Double-sided hot melt adhesive 120 also covers the first corner side surface 115 and the second corner side surface 116, increasing the bonding area with the wound cell 110 and the housing, and improving the bonding stability between the wound cell 110 and the housing.

[0052] In some embodiments, refer to Figure 3In the circumferential direction of the wound cell 110, one side of the double-sided hot melt adhesive 120 extends beyond the first corner side 115 to the second straight side 114, and the other side of the double-sided hot melt adhesive 120 extends beyond the second corner side 116 to the second straight side 114. In this embodiment, one side of the double-sided hot melt adhesive 120 extends beyond the edge of the first corner side 115 along the circumferential extension path of the wound cell 110, extending a predetermined distance towards the second straight side 114, covering a portion of the second straight side 114 area; the other side of the double-sided hot melt adhesive 120 symmetrically extends beyond the edge of the second corner side 116, extending the same predetermined distance towards the second straight side 114 on the same side, forming a blank area of ​​a certain width on both sides of the double-sided hot melt adhesive 120 on the second straight side 114. This embodiment increases the bonding area by extending the double-sided hot melt adhesive 120 on both sides, further improving the bonding strength between the internal cell and the casing of the large-capacity battery.

[0053] In some embodiments, refer to Figure 2 , Figure 3 and Figure 5 The other end of the double-sided hot melt adhesive 120 has two slits 1202, which are spaced apart along the width direction of the wound cell 110. One slit is adjacent to the first corner side 115, and the other is adjacent to the second corner side 116. In this embodiment, the two slits 1202 at the end of the double-sided hot melt adhesive 120 effectively solve the process problem in the bottom wrapping process. During battery assembly, the arc structure at the corner of the cell causes local stress concentration in the adhesive paper during the wrapping process, resulting in wrinkles. The presence of the slits 1202 allows the double-sided hot melt adhesive 120 to have a deformable margin at the corner. When the adhesive paper is wrapped around the corner, the adhesive paper on both sides of the slits 1202 can fit the arc surface more flexibly. Through the appropriate opening and closing of the slits 1202, the stress during the wrapping process is released. Meanwhile, a smooth adhesive tape application ensures effective contact area between the hot melt adhesive and the battery cell and casing, avoiding localized bonding failures caused by wrinkles, further improving the stability and reliability of the battery's internal structure, and reducing product defect rates caused by process defects.

[0054] In some embodiments, the outermost side of the wound cell 110 has a winding tail end, and double-sided hot melt adhesive 120 is bonded to the winding tail end so that the winding tail end is fixed to the peripheral side of the wound cell 110.

[0055] The wound cell 110 is formed by winding a positive electrode sheet, a separator, and a negative electrode sheet. Its outermost winding tail end (i.e., the edge of the end electrode sheet after winding) is exposed on the peripheral side. Because this tail end is not completely embedded inside the winding body, there is a risk of loosening. Double-sided hot melt adhesive 120 is directly bonded to the winding tail end, and the adhesive layer firmly attaches the tail end to the peripheral side of the wound cell 110 (such as the first corner side 115 or the first straight side 113) through the adhesive layer. This replaces the separately set finishing adhesive in the traditional process, saves the separate process step of finishing adhesive, and improves production efficiency.

[0056] In some embodiments, the ratio of the sum of the areas of multiple through holes 1201 to the area of ​​the double-sided hot melt adhesive 120 is K, satisfying that K ≤ 50%. In this embodiment, the area ratio of the through holes 1201 on the double-sided hot melt adhesive 120 is optimized. Specifically, the ratio of the sum of the areas of multiple through holes 1201 to the area of ​​the double-sided hot melt adhesive 120 is K, and K ≤ 50%. This technical solution achieves multi-dimensional improvement in cell performance by precisely limiting the area ratio of the through holes 1201. From a structural design perspective, the area ratio of the through holes 1201 does not exceed 50%, ensuring that the double-sided hot melt adhesive 120 has sufficient bonding area while reasonably setting up venting channels. If the area of ​​the through hole 1201 is too large, it will significantly reduce the actual contact area between the hot melt adhesive and the wound cell 110 and the casing, resulting in a decrease in bonding strength and making it difficult to effectively fix the wound cell 110 when the battery is subjected to external impact. However, when the area of ​​the through hole 1201 is controlled within 50%, the hot melt adhesive can maintain a sufficient bonding area to ensure that the impact force can be dispersed and transmitted through the large bonding surface, preventing the wound cell 110 from being displaced in the accommodating cavity due to external force and preventing it from colliding with the casing and failing.

[0057] In terms of process performance, the limitation of this area ratio effectively balances venting efficiency and hot melt adhesive integrity. When K≤50%, the through hole 1201 can provide sufficient venting channels for air generated during the application of double-sided hot melt adhesive 120, avoiding the formation of air bubbles due to air trapped between the hot melt adhesive and the wound cell 110 or the housing; at the same time, the retained solid portion of the hot melt adhesive can maintain stable bonding performance, ensuring the tightness and reliability of the adhesive application, and forming a solid connection structure between the double-sided hot melt adhesive 120 and the cell and housing.

[0058] In some embodiments, refer to Figure 3 and Figure 5 The wound cell 110 has a tab welding area;

[0059] The double-sided hot melt adhesive 120 is provided with a relief groove 1203, and the projection area of ​​the relief groove 1203 in the thickness direction of the wound cell 110 covers the tab welding area.

[0060] In this embodiment, the tab welding area of ​​the wound cell 110 can be one or more, and correspondingly, one or more clearance grooves 1203 on the double-sided hot melt adhesive 120 can be provided. Furthermore, the tab welding area can be a welding area for welding the positive tab or a welding area for welding the negative tab. The clearance groove 1203 is formed at the position of the double-sided hot melt adhesive 120 corresponding to the tab welding area, and its projected area in the thickness direction of the wound cell 110 completely covers the tab welding area. By forming clearance grooves 1203 on the double-sided hot melt adhesive 120 to avoid the tab welding area (usually the thickest area of ​​the wound cell 110), the thickness of the wound cell 110 is prevented from being affected.

[0061] 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, characterized in that, include: The housing has a receiving cavity; A wound battery cell is disposed within the accommodating cavity. The wound battery cell has a peripheral side surface, a first end surface, and a second end surface. The first end surface and the second end surface are disposed opposite to each other in the length direction of the wound battery cell. The peripheral side surface includes a first flat side surface and a second flat side surface. The first flat side surface and the second flat side surface are disposed opposite to each other in the thickness direction of the wound battery cell. Double-sided hot melt adhesive is applied to the wound battery cell and bonded to the housing. The double-sided hot melt adhesive covers at least the first end face, the first flat side face, and the second end face. The double-sided hot melt adhesive is provided with multiple through holes.

2. The battery according to claim 1, characterized in that, Along the length of the wound cell, one end of the double-sided hot melt adhesive extends beyond the first end face to the second flat side to form a head wrap; the other end of the double-sided hot melt adhesive extends beyond the second end face to the second flat side to form a bottom wrap.

3. The battery according to claim 2, characterized in that, The distance extending beyond one end of the double-sided hot melt adhesive is D1, and the distance extending beyond the other end of the double-sided hot melt adhesive is D2, satisfying: 2mm < D1 ≤ 15mm, 2mm < D2 ≤ 15mm.

4. The battery according to claim 1, characterized in that, The wound battery cell is welded with a first tab and a second tab, which extend from the first end face and are spaced apart in the width direction of the wound battery cell. One end of the double-sided hot melt adhesive is disposed through the gap between the first electrode and the second electrode.

5. The battery according to claim 4, characterized in that, The peripheral side also includes a first corner side and a second corner side, wherein the first corner side and the second corner side are arranged opposite to each other in the width direction of the wound cell; The double-sided hot melt adhesive also covers the first corner side and the second corner side.

6. The battery according to claim 5, characterized in that, In the circumferential direction of the wound cell, one side of the double-sided hot melt adhesive extends beyond the first corner side to the second straight side, and the other side of the double-sided hot melt adhesive extends beyond the second corner side to the second straight side.

7. The battery according to claim 5, characterized in that, The other end of the double-sided hot melt adhesive has two slits, which are spaced apart along the width direction of the wound cell. One of the slits is adjacent to the first corner side, and the other is adjacent to the second corner side.

8. The battery according to claim 1, characterized in that, The outermost side of the wound cell has a winding tail end, and the double-sided hot melt adhesive is bonded to the winding tail end so that the winding tail end is fixed to the peripheral side of the wound cell.

9. The battery according to claim 1, characterized in that, The ratio of the sum of the areas of the plurality of through holes to the area of ​​the double-sided hot melt adhesive is K, which satisfies: K≤50%.

10. The battery according to any one of claims 1 to 9, characterized in that, The wound battery cell has a tab welding area; The double-sided hot melt adhesive has a relief groove, and the projection area of ​​the relief groove in the thickness direction of the wound cell covers the tab welding area.

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