battery

Abstract

The utility model discloses a battery, include: casing is equipped with accommodation cavity, winding electric core is equipped in the accommodation cavity and has the circumference lateral surface, circumference lateral surface includes first flat side, first corner side, second flat side and second corner side, first flat side and second flat side are opposite to set up in the thickness direction of winding electric core, and first corner side and second corner side are opposite to set up in the width direction of winding electric core, double -sided hot melt adhesive is pasted on winding electric core along the circumference direction of winding electric core and is bonded with casing, and double -sided hot melt adhesive at least covers first corner side, first flat side and second corner side, and double -sided hot melt adhesive is provided with a plurality of through -holes. The battery is pasted along the circumference of winding electric core by double -sided hot melt adhesive, and at least covers first corner side, first flat side and second corner side, increases the bonding area, and 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, which includes a first flat side surface, a first corner side surface, a second flat side surface, and a second corner 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, and the first corner side surface and the second corner side surface are disposed opposite to each other in the width direction of the wound battery cell.

[0009] Double-sided hot melt adhesive is applied to the wound battery cell along the circumferential direction and bonded to the housing. The double-sided hot melt adhesive covers at least the first corner side, the first straight side, and the second corner side. The double-sided hot melt adhesive has multiple through holes.

[0010] Optionally, in the circumferential direction of the wound cell, one end of the double-sided hot melt adhesive extends beyond the first corner side to the second straight side, and the other end of the double-sided hot melt adhesive extends beyond the second corner side to the second straight side.

[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: 0mm < D1 ≤ 10mm, 0mm < D2 ≤ 10mm.

[0012] Optionally, the wound cell further has a first end face and a second end face, wherein the first end face and the second end face are disposed opposite to each other in the length direction of the wound cell;

[0013] Along the length of the wound cell, one side of the double-sided hot melt adhesive extends beyond the first corner side and the second corner side to the first end face, and the other side of the double-sided hot melt adhesive extends beyond the first corner side and the second corner side to the second end face.

[0014] Optionally, the excess distance on one side of the double-sided hot melt adhesive is D3, and the excess distance on the other side of the double-sided hot melt adhesive is D4, satisfying: 0.25mm≤D3≤5.75mm, 0.25mm≤D4≤5.75mm, and 0.5mm≤D3+D4≤6mm.

[0015] 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.

[0016] 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%.

[0017] Optionally, the battery cell further includes:

[0018] The first and second adhesive wraps are respectively attached to the opposite ends of the wound battery cell along its length.

[0019] The double-sided hot melt adhesive has a first clearance groove and a second clearance groove on its opposite sides. The first clearance groove avoids the first wrapping adhesive, and the second clearance groove avoids the second wrapping adhesive.

[0020] Optionally, the distance between the edge of the first wrapping adhesive and the wall of the first clearance groove is L1, satisfying: 0.5mm ≤ L1 ≤ 5mm; and / or,

[0021] The distance between the edge of the second wrapping adhesive and the wall of the second clearance groove is L2, which satisfies: 0.5mm≤L2≤5mm.

[0022] Optionally, the wound cell has a tab welding area;

[0023] The double-sided hot melt adhesive has a third clearance groove, and the projection area of ​​the third clearance groove in the thickness direction of the wound cell covers the tab welding area.

[0024] This novel battery increases the bonding area between the double-sided hot melt adhesive and the wound cell and the casing by applying double-sided hot melt adhesive along the circumference of the wound cell, covering at least the first corner side, the first straight side, and the second corner side. Compared to the prior art, which only applies 1-2 layers of double-sided hot melt adhesive on one side of the cell, this increases the effective resistance to the impact of drops, significantly improving the bonding strength between the cell and the casing in a large-capacity battery. This effectively prevents battery failure due to cell displacement impacting the aluminum-plastic film. Furthermore, multiple through-holes in the double-sided hot melt adhesive provide venting channels for internal air during the application process, preventing air bubbles from forming. This effectively avoids the impact of air bubbles on the quality and performance stability of the finished battery, thus improving the overall quality and performance stability of the battery and meeting market demand for large-capacity, high-performance lithium batteries. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a wound battery cell in one embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the wound battery cell in another embodiment of the present invention;

[0027] Figure 3 for Figure 2 A schematic diagram of the wound battery cell from another perspective in the embodiment;

[0028] Figure 4 This is a schematic diagram of the structure of the wound battery cell in another embodiment of the present invention;

[0029] Figure 5 for Figure 4 A schematic diagram of the structure of the double-sided hot melt adhesive on the wound battery cell in the embodiment;

[0030] Figure 6 This is a schematic diagram of the structure of the wound battery cell in another embodiment of the present invention;

[0031] Figure 7 for Figure 6 A schematic diagram of the structure of the double-sided hot melt adhesive on the wound battery cell in the embodiment;

[0032] Label Explanation:

[0033]

[0034]

[0035] 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

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] This utility model embodiment proposes a battery cell, referring to... Figures 1 to 3 The battery cell includes:

[0041] The housing has a receiving cavity;

[0042] A wound battery cell 110 is disposed in a receiving cavity. The wound battery cell 110 has a peripheral side surface, which includes a first flat side surface 111, a first corner side surface 112, a second flat side surface 113, and a second corner side surface 114. The first flat side surface 111 and the second flat side surface 113 are arranged opposite to each other in the thickness direction of the wound battery cell 110, and the first corner side surface 112 and the second corner side surface 114 are arranged opposite to each other in the width direction of the wound battery cell 110.

[0043] Double-sided hot melt adhesive 120 is applied to the wound cell 110 along the circumferential direction and bonded to the housing. The double-sided hot melt adhesive 120 covers at least the first corner side 112, the first straight side 111 and the second corner side 114. The double-sided hot melt adhesive 120 is provided with a plurality of through holes 1201.

[0044] 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.

[0045] The wound battery cell 110 has a rectangular overall shape. In the circumferential direction (or winding direction) of the wound battery cell 110, the wound battery cell 110 has a circumferential side surface, which is formed by a first flat side surface 111, a first corner side surface 112, a second flat side surface 113, and a second corner side surface 114 connected sequentially along the circumferential direction of the wound battery cell 110. In the thickness direction of the wound battery cell 110, the first flat side surface 111 and the second flat side surface 113 are arranged opposite to each other, that is, the first flat side surface 111 and the second flat side surface 113 are located on opposite sides of the thickness direction of the wound battery cell 110. In the width direction of the wound battery cell 110, the first corner side surface 112 and the second corner side surface 114 are arranged opposite to each other, that is, the first corner side surface 112 and the second corner side surface 114 are located on opposite sides of the width direction of the wound battery cell 110.

[0046] The double-sided hot melt adhesive 120 is in the form of a strip or sheet, tightly adhered to the circumferential direction of the wound battery cell 110, and its coverage area includes at least the first corner side 112, the first straight side 111, and the second corner side 114, forming an adhesive structure surrounding a portion of the circumference 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 copolymer components, 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.

[0047] 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 applied around the circumference of the wound cell 110 and at least covers the first corner side 112, the first straight side 111, and the second corner side 114, the bonding area between the double-sided hot melt adhesive 120 and the wound cell 110 and the casing 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, preventing the wound cell 110 from shifting within the accommodating cavity, and preventing it from colliding with the casing 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.

[0048] In some embodiments, refer to Figures 1 to 3In the circumferential direction of the wound cell 110, one end of the double-sided hot melt adhesive 120 extends beyond the first corner side 112 to the second straight side 113, and the other end of the double-sided hot melt adhesive 120 extends beyond the second corner side 114 to the second straight side 113. In this embodiment, one end of the double-sided hot melt adhesive 120 extends beyond the edge of the first corner side 112 along the circumferential extension path of the wound cell 110, extending beyond a preset distance towards the second straight side 113, covering a portion of the second straight side 113 area; the other end of the double-sided hot melt adhesive 120 symmetrically extends beyond the edge of the second corner side 114, extending beyond the same preset distance towards the second straight side 113 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 straight side 113. Compared to the basic structure that only covers the first corner side 112, the first straight side 111, and the second corner side 114, this embodiment increases the bonding area by extending the two ends of the double-sided hot melt adhesive 120, thereby further improving the bonding strength between the internal cells and the casing of the large-capacity battery.

[0049] 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: 0mm < D1 ≤ 10mm, 0mm < D2 ≤ 10mm.

[0050] In this embodiment, the distance D1 extending beyond one end of the double-sided hot melt adhesive 120 is limited to 0mm < D1 ≤ 10mm. For example, the distance D1 extending beyond the first corner side 112 can be set to 2mm, 5mm, 8mm, or 10mm, depending on actual needs. The distance D2 extending beyond the other end of the double-sided hot melt adhesive 120 is limited to 0mm < D2 ≤ 10mm. For example, the distance D2 extending beyond the second corner side 114 can be set to 2mm, 5mm, 8mm, or 10mm, 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 straight side 113.

[0051] In some embodiments, refer to Figure 3 The wound cell 110 also has a first end face 115 and a second end face 116, which are arranged opposite to each other in the length direction of the wound cell 110.

[0052] Along the length of the wound cell 110, one side of the double-sided hot melt adhesive 120 extends beyond the first corner side 112 and the second corner side 114 to the first end face 115, and the other side of the double-sided hot melt adhesive 120 extends beyond the first corner side 112 and the second corner side 114 to the second end face 116.

[0053] In this embodiment, the wound cell 110 has a first end face 115 and a second end face 116, which are arranged opposite to each other in the length direction (i.e., the axial direction of the winding shaft) of the wound cell 110. The double-sided hot melt adhesive 120 extends beyond the corner in the length direction of the wound cell 110. Specifically, the width of the double-sided hot melt adhesive 120 is greater than the length of the wound cell 110. In addition to covering the first corner side 112 and the second corner side 114, one side of the double-sided hot melt adhesive 120 extends toward the first end face 115, beyond the edge of the corner side, to cover the corner area of ​​the first end face 115, and the other side of the double-sided hot melt adhesive 120 extends toward the second end face 116, beyond the corner side, to cover the corner area of ​​the second end face 116. That is, the double-sided hot melt adhesive 120 covers the head corner and tail corner of the corner area of ​​the wound cell 110. If the corner of the wound cell 110 collides with the shell during the movement, the double-sided hot melt adhesive 120 can make flexible contact with the shell and play a certain buffering role, preventing the corner of the cell from deforming and causing short circuit of the positive and negative electrode plates or breaking through the shell and causing leakage.

[0054] In some embodiments, refer to Figure 3 The excess distance on one side of the double-sided hot melt adhesive 120 is D3, and the excess distance on the other side of the double-sided hot melt adhesive 120 is D4, satisfying the following conditions: 0.25mm≤D3≤5.75mm, 0.25mm≤D4≤5.75mm, 0.5mm≤D3+D4≤6mm.

[0055] In this embodiment, the excess distance D3 on one side of the double-sided hot melt adhesive 120 is limited to 0.25mm ≤ D3 ≤ 5.75mm, and the excess distance D4 on the other side of the double-sided hot melt adhesive 120 is limited to 0.25mm ≤ D4 ≤ 5.75mm. Simultaneously, 0.5mm ≤ D3 + D4 ≤ 6mm. For example, the excess distance D3 on one side of the double-sided hot melt adhesive 120 can be set to 0.25mm, and the excess distance D4 on the other side of the double-sided hot melt adhesive 120 can be set to 0.25mm, 2mm, 4mm, or 5.75mm; or, for another example, the excess distance D3 on one side of the double-sided hot melt adhesive 120 can be set to 2mm, and the excess distance D4 on the other side of the double-sided hot melt adhesive 120 can be set to 2mm, 3mm, or 4mm, which can be set according to actual needs.

[0056] 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.

[0057] 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 112 or the first straight side 111) 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.

[0058] 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.

[0059] 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.

[0060] In some embodiments, refer to Figure 4 and Figure 5 The battery cells also include:

[0061] The first adhesive 130 and the second adhesive 140 are respectively attached to the opposite ends of the wound cell 110 in its length direction;

[0062] The double-sided hot melt adhesive 120 is provided with a first clearance groove 121 and a second clearance groove 122 on opposite sides. The first clearance groove 121 avoids the first wrapping adhesive 130, and the second clearance groove 122 avoids the second wrapping adhesive 140.

[0063] In this embodiment, along the length of the wound cell 110, a first wrapping adhesive 130 is attached to one end of the wound cell 110, and a second wrapping adhesive 140 is attached to the other end of the wound cell 110. This strengthens the structural stability of the cell ends and prevents the cell from loosening. The number of the first wrapping adhesive 130 and the second wrapping adhesive 140 can be set according to actual needs; this embodiment does not limit this. A first clearance groove 121 and a second clearance groove 122 are respectively disposed on opposite sides of the double-sided hot melt adhesive 120, their positions corresponding to the projected areas of the first wrapping adhesive 130 and the second wrapping adhesive 140 in the thickness direction of the wound cell 110. Through the clearance groove design, the double-sided hot melt adhesive 120, when covering the periphery of the wound cell 110, forms a three-dimensional spatial complement with the end wrapping adhesive, avoiding overlapping adhesive layers that could lead to excessive thickness in localized areas and thus affecting the cell thickness.

[0064] In some embodiments, the distance between the edge of the first wrapping adhesive 130 and the groove wall of the first clearance groove 121 is L1, satisfying: 0.5mm ≤ L1 ≤ 5mm; and / or,

[0065] The distance between the edge of the second wrapping adhesive 140 and the wall of the second clearance groove 122 is L2, which satisfies: 0.5mm≤L2≤5mm.

[0066] In this embodiment, the distances between the first wrapping adhesive 130 and the first clearance groove 121, and between the second wrapping adhesive 140 and the second clearance groove 122 are precisely defined. Specifically, the distance between the edge of the first wrapping adhesive 130 and the groove wall of the first clearance groove 121 is L1, satisfying 0.5mm≤L1≤5mm. For example, L1 can be set to 0.5mm, 2mm, 4mm, or 5mm, etc.; and / or, the distance between the edge of the second wrapping adhesive 140 and the groove wall of the second clearance groove 122 is L2, satisfying 0.5mm≤L2≤5mm. For example, L2 can be set to 0.5mm, 2mm, 4mm, or 5mm, etc. By controlling the distances within a suitable range, a small gap can be maintained between the wrapping adhesive and the clearance groove edge of the double-sided hot melt adhesive 120, which can prevent direct contact between the two and interference, while ensuring that the double-sided hot melt adhesive 120 has a large bonding area.

[0067] In some embodiments, refer to Figure 6 and Figure 7 The wound cell 110 has a tab welding area;

[0068] The double-sided hot melt adhesive 120 is provided with a third clearance groove 123, and the projection area of ​​the third clearance groove 123 in the thickness direction of the wound cell 110 covers the tab welding area.

[0069] In this embodiment, the tab welding area of ​​the wound cell 110 can be one or more, and correspondingly, one or more third clearance grooves can be provided on the double-sided hot melt adhesive 120. 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 third clearance groove 123 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 the third clearance groove 123 on the double-sided hot melt adhesive 120, the tab welding area (usually the thickest area of ​​the wound cell 110) is avoided, thereby preventing any impact on the thickness of the wound cell 110.

[0070] 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, which includes a first flat side surface, a first corner side surface, a second flat side surface, and a second corner 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, and the first corner side surface and the second corner side surface are disposed opposite to each other in the width direction of the wound battery cell. Double-sided hot melt adhesive is applied to the wound battery cell along the circumferential direction and bonded to the housing. The double-sided hot melt adhesive covers at least the first corner side, the first straight side, and the second corner side. The double-sided hot melt adhesive has multiple through holes.

2. The battery according to claim 1, characterized in that, In the circumferential direction of the wound cell, one end of the double-sided hot melt adhesive extends beyond the first corner side to the second straight side, and the other end of the double-sided hot melt adhesive extends beyond the second corner side to the second straight side.

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: 0mm < D1 ≤ 10mm, 0mm < D2 ≤ 10mm.

4. The battery according to claim 1, characterized in that, The wound cell also has a first end face and a second end face, the first end face and the second end face being disposed opposite to each other in the length direction of the wound cell; Along the length of the wound cell, one side of the double-sided hot melt adhesive extends beyond the first corner side and the second corner side to the first end face, and the other side of the double-sided hot melt adhesive extends beyond the first corner side and the second corner side to the second end face.

5. The battery according to claim 4, characterized in that, The excess distance on one side of the double-sided hot melt adhesive is D3, and the excess distance on the other side of the double-sided hot melt adhesive is D4, satisfying the following conditions: 0.25mm≤D3≤5.75mm, 0.25mm≤D4≤5.75mm, and 0.5mm≤D3+D4≤6mm.

6. 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.

7. 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%.

8. The battery according to any one of claims 1 to 7, characterized in that, Also includes: The first and second adhesive wraps are respectively attached to the opposite ends of the wound battery cell along its length. The double-sided hot melt adhesive has a first clearance groove and a second clearance groove on its opposite sides. The first clearance groove avoids the first wrapping adhesive, and the second clearance groove avoids the second wrapping adhesive.

9. The battery according to claim 8, characterized in that, The distance between the edge of the first wrapping adhesive and the wall of the first clearance groove is L1, satisfying: 0.5mm ≤ L1 ≤ 5mm; and / or, The distance between the edge of the second wrapping adhesive and the wall of the second clearance groove is L2, which satisfies: 0.5mm≤L2≤5mm.

10. The battery according to any one of claims 1 to 7, characterized in that, The wound battery cell has a tab welding area; The double-sided hot melt adhesive has a third clearance groove, and the projection area of ​​the third clearance groove in the thickness direction of the wound cell covers the tab welding area.

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