Battery and electronic equipment

Abstract

According to the battery and the electronic equipment, in a packaging bag, a second side section and a third side section of a top wall form a step structure, a sealing part comprises a top seal, a side seal and an edge folding part, the top seal and the first side section are arranged in a stacked mode in the first direction, and the side seal and the side wall are arranged in a stacked mode in the second direction; the step structure provides a placement space for the folded edge parts connected to the top seal and the side seals, so that the folded edge parts can be fixed to the packaging body in a folded state. Wherein in the first direction, the projection of the folding part is at least partially overlapped with the projection of the third side section, the tab at least partially extends out of the top seal in the first direction, and the folding part does not exceed the edge of the tab in the first direction. According to the packaging bag, the folding part can be prevented from protruding out of the tab along the first direction after the battery is packaged, so that the occupied size of the packaging bag along the first direction is reduced, the packaging bag forms a more compact structure, and the volume waste in the battery packaging process is improved.

Description

Technical Field

[0001] This application relates to the technical field of electrochemical devices, and particularly to a battery and an electronic device. Background Art

[0002] With the wide application of secondary batteries, improving the energy density of secondary batteries has become the core pursuit of research and development. In secondary batteries, in order to achieve a higher volumetric energy density, it is necessary to minimize or compress unnecessary volume waste during the design phase to improve the volume utilization rate of the battery, which poses higher design requirements for the battery packaging structure. Summary of the Invention

[0003] Embodiments of this application provide a battery and an electronic device, which can improve the problem of volume waste caused by the battery packaging structure.

[0004] In a first aspect, embodiments of this application provide a battery, which includes an electrode assembly, a packaging bag, and an electrode tab. The electrode assembly is disposed in the internal space of the packaging bag, and the electrode tab is connected to the electrode assembly. The packaging bag includes a packaging main body and a sealing portion. The packaging main body includes a top wall and a side wall. The top wall includes a first side section, a second side section, and a third side section that are sequentially connected. One end of the third side section away from the second side section is connected to the side wall, and a stepped structure is formed between the second side section and the third side section; the sealing portion is disposed around the outer periphery of the packaging main body and connected to the packaging main body. The sealing portion includes a top seal, a side seal, and a folded edge portion; along a first direction, the top seal and the first side section are stacked; along a second direction, the side seal and the side wall are stacked, and the first direction is perpendicular to the second direction; the folded edge portion is connected to the top seal and the side seal and is in a folded state; wherein, along the first direction, the projection of the folded edge portion and the projection of the third side section at least partially overlap, the electrode tab at least partially extends out of the top seal along the first direction, and the folded edge portion does not extend beyond the edge of the electrode tab along the first direction.

[0005] Based on the above embodiments, by forming a stepped structure at the corner position of the packaging bag, the folded edge portion can be fixed to the packaging main body in a folded state, thereby reducing the size occupied by the packaging bag along the first direction. In this way, the packaging bag forms a more compact structure, achieving the purpose of reducing the battery size and improving the volume waste in battery packaging.

[0006] In some of these embodiments, the folded edge portion includes a plurality of straight sections, and the straight sections are perpendicular to the first direction; along the first direction, the plurality of straight sections are stacked and connected end to end in sequence.

[0007] Based on the above embodiments, the adjacent straight sections are connected end to end to form a continuous folding path, and the overall thickness of the folded edge portion 223 is uniform, thereby allowing the folded edge portion to be tightly packaged.

[0008] In some of these embodiments, when observed along the first direction, the folded edge portion is located between the side seal and the second side section.

[0009] Based on the above embodiment, along the second direction, the folded edge portion is embedded in the step structure to prevent the folded edge portion from protruding from the side seal along the second direction, thereby preventing the width dimension of the packaging bag from increasing.

[0010] In some embodiments, a projection of the hem portion along the first direction is located between a projection of the side seal along the first direction and a projection of the second side segment along the first direction.

[0011] Based on the above embodiment, along the second direction, the folded edge portion is embedded in the step structure to prevent the folded edge portion from protruding from the side seal along the second direction, thereby preventing the width dimension of the packaging bag from increasing.

[0012] In some embodiments, the folded edge portion also includes an adhesive layer; the folded edge portion also includes an adhesive layer; at least part of the adhesive layer fills the gap between two adjacent straight sections; and / or, at least part of the adhesive layer fills the gap between the folded edge portion and the third side section; and / or, at least part of the adhesive layer fills the gap between the folded edge portion and the second side section.

[0013] Based on the above embodiments, the adhesive force of the adhesive layer can offset the rebound force generated in the folded edge portion due to the bending of the packaging film, thereby positioning the straight sections of each layer to a preset position and preventing the folded edge portion from being released from the folded state due to the rebound force.

[0014] In some embodiments, the folded edge portion includes a first straight segment, a second straight segment and a third straight segment stacked in sequence along a first direction, the first straight segment is connected to the top seal, and the third straight segment is connected to the side seal.

[0015] Based on the above embodiment, the folded edge portion is in a three-step folding state to minimize the number of straight sections stacked along the first direction, which not only reduces the number of stamping and bending times in the packaging process of the electrode 1, but also improves the interlayer extrusion between the multiple straight sections.

[0016] In some embodiments, along the first direction, the first straight section is located on the side of the second straight section facing away from the packaging body, and along the first direction, the projection of the first straight section at least partially covers the projection of the third straight section; or, along the first direction, the first straight section is located on the side of the second straight section facing the packaging body, and along the first direction, the projection of the third straight section at least partially covers the projection of the first straight section.

[0017] Based on the above embodiment, the first straight section is arranged outside the folded edge portion to improve the bending condition of the connection area between the first straight section and the top seal and optimize the bending stress. Alternatively, the third straight section is arranged outside the folded edge portion to make the appearance flatness between the folded edge portion and the side seal better.

[0018] In some embodiments, along the first direction, the thickness of the folded edge portion is S, and S satisfies: S≥0.25 mm.

[0019] Based on the above embodiment, the thickness S of the folded edge portion is controlled to meet the above range, so that a packaging bag with sufficient thickness is selected, so that the packaging bag has sufficient mechanical strength and deformation resistance.

[0020] In some embodiments, along the first direction, the distance from the electrode assembly to the first side segment is A, the distance from the electrode assembly to the third side segment is d1, and the width of the second side segment is d2, wherein d1+d2=A; the electrode assembly satisfies at least one of the following conditions:

[0021] (1) 1mm≤A≤5mm;

[0022] (2) 0.1mm≤d1≤4.85mm;

[0023] (3)0.15mm≤d2≤1.5mm.

[0024] Based on the above embodiment, by controlling A to meet the above range, a buffer space is provided for the volume expansion of the electrode assembly; by controlling d1 to meet the above range, the third side segment maintains a safe spacing distance from the electrode assembly, and a step structure with sufficient depth can be formed; by controlling d2 to meet the above range, the depth of the step structure is sufficient to accommodate at least part of the folded edge portion, so as to avoid the folded edge portion extending beyond the pole ear along the first direction, resulting in an increase in the battery length, and taking into account the spacing distance between the electrode assembly and the packaging body.

[0025] In some of these embodiments, the first side segment is parallel to the third side segment.

[0026] Based on the above embodiment, the depth of the depression at each location of the step structure is made substantially consistent, so as to better arrange the folded edge portion.

[0027] In some embodiments, along the second direction, the width of the third side segment is d3, and d3 satisfies: 0.3 mm≤d3≤5 mm.

[0028] Based on the above embodiments, sufficient size is reserved for the folded edge portion to avoid overlapping and squeezing of the folded edge portion and the top seal due to the step structure being too narrow, and to avoid excessive occupation of the volume of the packaging body due to the step structure being too wide.

[0029] In some embodiments, along the second direction, a distance from a side of the tab close to the folded edge portion to the second side segment is W, where W≥0.1 mm.

[0030] Based on the above embodiment, the tab is spaced apart from the step structure along the second direction to prevent the tab from blocking the folded package of the folded edge portion.

[0031] In some embodiments, along the first direction, the surface of the folded edge farthest from the third side segment is flush with the surface of the top seal away from the top wall; along the second direction, the surface of the folded edge farthest from the second side segment is flush with the surface of the side seal away from the side wall.

[0032] Based on the above embodiments, the surface of the flanging portion facing away from the third side segment along the first direction is flush with the top seal, and the surface of the flanging portion farthest from the second side segment along the second direction is flush with the side seal. The surface of the battery is flat and the dimensions are uniform everywhere. When the electrode assembly expands in volume, the flanging portion deforms synergistically with the top seal and the side seal, thereby effectively suppressing the concentration of expansion stress.

[0033] In a second aspect, an embodiment of the present application provides an electronic device, which includes a housing and a battery, and the battery is disposed in the internal space of the housing.

[0034] Based on a battery and an electronic device according to an embodiment of the present application, a stepped structure is formed between the second side segment and the third side segment of the top wall. The stepped structure provides an installation space for the sealing portion located in the corner area, so that the flanging portion can be fixed to the packaging main body in a folded state. Among them, the projection of the flanging portion along the first direction and the projection of the third side segment along the first direction at least partially overlap, and the flanging portion does not extend beyond the edge of the tab along the first direction. In this way, it is possible to prevent the flanging portion from protruding beyond the tab along the first direction after the battery is encapsulated, reduce the size occupied by the packaging bag along the first direction, make the packaging bag form a more compact structure, achieve the purpose of reducing the battery size, and improve the volume waste in battery packaging. Description of the Drawings

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] Figure 1 It is a schematic diagram of the packaging structure of a battery in the related art;

[0037] Figure 2 It is a schematic diagram of the structure of a battery in an unfolded state according to an embodiment of the present application;

[0038] Figure 3 It is a schematic cross-sectional view of a battery in an unfolded state according to an embodiment of the present application;

[0039] Figure 4 It is a schematic diagram of the packaging structure of a battery according to an embodiment of the present application;

[0040] Figure 5 It is Figure 4 A partial enlarged schematic diagram of the structure at A in

[0041] Figure 6 It is a front view schematic diagram of the packaging structure of a battery according to an embodiment of the present application;

[0042] Figure 7 is Figure 6 a partial enlarged structural schematic diagram at position B in

[0043] Figure 8 a structural schematic diagram of a hemming part of an embodiment of the present application;

[0044] Figure 9 a structural schematic diagram of a hemming part of another embodiment of the present application;

[0045] Figure 10 a structural schematic diagram of a hemming part of another embodiment of the present application;

[0046] Figure 11 a structural schematic diagram of a hemming part of another embodiment of the present application;

[0047] Figure 12 a structural schematic diagram of a hemming part of another embodiment of the present application.

[0048] Reference numerals:

[0049] 1. Battery;

[0050] 10. Electrode assembly; 20. Packaging bag; 21. Packaging main body; 210. Accommodating cavity; , Step structure; 211. Top wall; 2111. First side section; 2112. Second side section; 2113. Third side section; 212. Side wall; 22. Sealing part; 221. Top seal; 222. Side seal; 223. Hemming part; 223A. Straight section; , Adhesive layer; 2231. First straight section; 2232. Second straight section; 2233. Third straight section; 30. Tab. Detailed implementation manners

[0051] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0052] During the encapsulation process of the secondary battery cell, after the packaging bag is hot-pressed and sealed to form a sealing edge, the sealing edge is usually hemmed to reduce the assembly size of the battery. In the related art, there is a phenomenon that a certain part of the top seal and the side seal overlap in the corner area of the packaging bag, so that the hem of the top seal and the hem of the side seal interfere with each other. As Figure 1As shown, the inventor found that in actual manufacturing, it is usually chosen to fold the side seals and the middle area of the top seal, resulting in the sealing part in the corner area not being able to be fully folded and occupying a large space in the length direction of the battery. The sealing part in the corner area protrudes the tab in the length direction of the battery, resulting in a large volume waste, which is not conducive to the structural compactness and energy density improvement of the battery. Based on this, the embodiments of the present application provide a battery and an electronic device.

[0053] Please refer to Figures 2 - 3 , the battery 1 includes an electrode assembly 10, a packaging bag 20 and tabs 30. The packaging bag 20 includes a packaging main body 21 and a sealing part 22. The internal space of the packaging main body 21 forms a receiving cavity 210. Among them, the electrode assembly 10 is arranged in the receiving cavity 210. The battery 1 further includes an electrolyte, and the electrolyte is filled in the receiving cavity 210 and infiltrates the electrode assembly 10. The sealing part 22 is connected to the packaging main body 21 to make the receiving cavity 210 form a closed space, preventing the electrolyte in the receiving cavity 210 from overflowing.

[0054] The electrode assembly 10 includes a positive electrode plate, a negative electrode plate and a separator. The positive electrode plate, the separator and the negative electrode plate are stacked in sequence to form the electrode assembly 10, that is, the electrode assembly 10 is a stacked electrode assembly. Alternatively, the positive electrode plate, the separator and the negative electrode plate are stacked and wound in sequence to form the electrode assembly 10, that is, the electrode assembly 10 is a wound electrode assembly. In the embodiments of the present application, the stacking direction of the positive electrode plate, the separator and the negative electrode plate is the thickness direction of the battery.

[0055] The tabs 30 include a positive tab and a negative tab. The positive tab is electrically connected to the positive electrode plate, and the negative tab is electrically connected to the negative electrode plate. As Figure 2 shown, in the embodiments of the present application, the tabs 30 are connected to the electrode assembly 10, and the tabs 30 at least partially extend out of the packaging bag 20 along the length direction of the battery 1. The two tabs 30 are arranged side by side in the width direction of the battery 1. Among them, the two tabs 30 include a positive tab and a negative tab. The width direction, length direction and thickness direction of the battery 1 are perpendicular to each other in pairs.

[0056] Next, taking the length direction of the battery 1 as the first direction X, the width direction of the battery 1 as the second direction Y, and the thickness direction of the battery 1 as the third direction Z, the battery 1 of the embodiments of the present application will be introduced.

[0057] Please refer to Figure 4 and Figure 5, in the embodiments of the present application, the packaging body 21 includes a top wall 211 and a side wall 212. The top wall 211 includes a first side section 2111, a second side section 2112, and a third side section 2113 that are sequentially connected. One end of the third side section 2113 away from the second side section 2112 is connected to the side wall 212, and a stepped structure is formed between the second side section 2112 and the third side section 2113. It can be understood that the stepped structure provides a larger placement space for the sealing part 22 in the corner area, so that the protruding degree of the sealing part 22 in the corner area along the first direction X is lower after folding and shaping, thereby reducing the length dimension of the battery 1.

[0058] Please refer to Figures 6 - 7 , the sealing part 22 is disposed around the outer periphery of the packaging body 21 and connected to the packaging body 21. The sealing part 22 includes a top seal 221, a side seal 222, and a folded edge part 223. Along the first direction X, the top seal 221 is stacked with the first side section 2111. Along the second direction Y, the side seal 222 is stacked with the side wall 212. The folded edge part 223 is connected to the top seal 221 and the side seal 222, and the folded edge part 223 is in a folded state. Among them, the folded edge part 223 is in a folded state and at least partially located in the stepped structure: along the first direction X, the projection of the folded edge part 223 at least partially overlaps the projection of the third side section 2113, the tab 30 at least partially extends out of the top seal 221 along the first direction X, and the folded edge part 223 does not extend beyond the edge of the tab 30 along the first direction X. The folded edge part 223 will not occupy additional dimensions in the first direction X. After the folded edge part 223 is shaped and fixed to the packaging body 21, the length dimension of the packaging bag 20 can be reduced, and the packaging bag 20 forms a more compact structure, thereby achieving the purpose of reducing the size of the battery 1 and improving the volume waste in the battery 1 packaging.

[0059] Optionally, the packaging bag 20 includes a layer of packaging film. The packaging film wraps from one side of the electrode assembly 10 to the other side of the electrode assembly 10. After folding the film, a packaging body 21, a top seal 221, two side seals 222, and two folded edge parts 223 are formed. The electrode assembly 10 is disposed in the internal space of the packaging body 21. Among them, before folding the film, the packaging film is punched to form a packaging bag 20 with a stepped structure after folding the film.

[0060] In some of the embodiments, the first side section 2111 is parallel to the third side section 2113 so that the depression depths at various parts of the stepped structure are basically the same, thereby better placing the folded edge part 223. It should be noted that the first side section 2111 and the third side section 2113 are designed to be parallel in an ideal state. However, considering the processing accuracy and minor deviations in actual applications, a tolerance range of ±5° is allowed for the parallelism between the two. When there is a parallelism tolerance between the first side section 2111 and the third side section 2113, the distance should be measured along the direction perpendicular to the first side section 2111 with the first side section 2111 as the reference.

[0061] In some of these embodiments, along the first direction X, the distance from the electrode assembly 10 to the first side segment 2111 is A, the distance from the electrode assembly 10 to the third side segment 2113 is d1, and the width of the second side segment 2112 is d2, where d1 + d2 = A.

[0062] In some of these embodiments, A in the electrode assembly 10 satisfies: 1 mm ≤ A ≤ 5 mm. It should be noted that during the charge and discharge process of the battery 1, the electrode material (such as a silicon-based negative electrode) in the electrode assembly 10 will undergo volume expansion. Therefore, in the design and manufacturing, by spacing the electrode assembly 10 from the inner wall of the packaging body 21, a buffer space is provided for the volume expansion of the electrode assembly 10, avoiding deformation or rupture of the packaging bag 20 under pressure, and helping to reduce the pulverization of the electrode material or the extrusion of the separator caused by the expansion, delaying the capacity attenuation. In the embodiments of the present application, by controlling A to satisfy 1 mm ≤ A ≤ 5 mm, for example, A can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, or a range composed of any two of them, so as to provide sufficient buffer space for the volume expansion of the electrode assembly 10, and take into account the energy density of the battery 1, avoiding redundancy of the buffer space.

[0063] In some of these embodiments, d1 in the electrode assembly 10 satisfies: 0.1 mm ≤ d1 ≤ 4.85 mm. It can be understood that setting the stepped structure will cause the distance between the partial side wall of the top wall 211 for defining the third side segment 2113 and the electrode assembly 10 to be shortened. By controlling 0.1 mm ≤ d1 ≤ 4.85 mm, a safe spacing distance is maintained between the third side segment 2113 and the electrode assembly 10, and a stepped structure with sufficient depth can be formed.

[0064] In some of these embodiments, d2 in the electrode assembly 10 satisfies: 0.1 mm ≤ d2 ≤ 1.5 mm. The width of the second side segment 2112 being d2 reflects the depth of the stepped structure. Among them, by controlling d2 to satisfy 0.15 mm ≤ d2 ≤ 1.5 mm, the depth of the stepped structure is sufficient to accommodate at least part of the folded edge portion 223, so as to prevent the folded edge portion 223 from extending beyond the tab 30 along the first direction X, resulting in an increase in the length of the battery 1, and forming a suitable spacing between the electrode assembly 10 and the packaging body 21, leaving sufficient filling space for the electrolyte, and ensuring that the electrode assembly 10 is fully wetted.

[0065] In some of these embodiments, along the second direction Y, the width of the third side segment 2113 is d3, and d3 satisfies: 0.3 mm ≤ d3 ≤ 5 mm. The width d3 of the third side segment 2113 reflects the width of the step structure. By controlling d3 to satisfy 0.3 mm ≤ d3 ≤ 5 mm, sufficient dimensions are reserved for the flanging portion 223, avoiding the lamination and extrusion of the flanging portion 223 and the top seal 221 due to the too-narrow step structure, and avoiding the excessive occupation of the volume of the packaging main body 21 by the too-wide step structure, thereby affecting the injection amount of the electrolyte and being unfavorable to the electrochemical performance of the battery 1.

[0066] In some of these embodiments, along the second direction Y, the distance from the side of the tab 30 close to the flanging portion 223 to the second side segment 2112 is W, and W ≥ 0.1 mm, that is, the tab 30 is spaced from the step structure along the second direction Y to avoid the tab 30 blocking the folding and encapsulation of the flanging portion 223. When the battery 1 is encapsulated, the portion of the tab 30 located outside the packaging main body 21 is folded and disposed on one side of the packaging main body 21. Along the first direction X, the distance from the surface of the tab 30 farthest from the top seal 221 to the top seal 221 is H, and H satisfies H ≥ 0.1 mm. In actual manufacturing, H usually satisfies 0.2 mm ≤ H ≤ 0.6 mm. For example, H can take 0.2 mm, 0.4 mm, 0.6 mm or the range composed of any two of them. Of course, in some special designs, a larger H value can be selected according to the design requirements.

[0067] In some of these embodiments, the flanging portion 223 includes a plurality of straight segments 223A, and the straight segments 223A are perpendicular to the first direction X. Along the first direction X, the plurality of straight segments 223A are stacked and connected end to end in sequence. The flanging portion 223 forms a Z-shaped folding structure, and the adjacent straight segments 223A are connected end to end to form a continuous folding path. The overall thickness of the flanging portion 223 is uniform, thereby allowing the flanging portion 223 to be compactly encapsulated.

[0068] In some of these embodiments, the flanging portion 223 includes a plurality of folding segments stacked along the first direction X, and the adjacent folding segments are connected end to end to form a continuous folding path. The folding segments are at least partially curved surfaces, and the adjacent two folding segments form an arc-shaped connection region to reduce the stress concentration in the connection region during the folding process and reduce the risk of damage to the flanging portion 223.

[0069] In actual encapsulation, along the second direction Y, the middle region of the folding segment is straight, and the edge region is arc-shaped. For example, the middle region of the folding segment is adhesively fixed through an adhesive, thereby realizing the shaped encapsulation of the flanging portion 223 and being able to improve the stress concentration in the connection region between the adjacent folding segments.

[0070] In some embodiments, along the first direction X, the thickness of the folded edge portion 223 is S, and S satisfies: S≥0.25mm. In the packaging process, the folded edge portion 223 forms a three-order folding structure, and the thickness S of the folded edge portion 223 is controlled to satisfy S≥0.25mm, so that the packaging bag 20 with sufficient thickness is selected, so that the packaging bag 20 has sufficient mechanical strength and deformation resistance, and the risk of the packaging bag 20 breaking is reduced.

[0071] In some embodiments, when viewed along the first direction X, the folded edge portion 223 is located between the side seal 222 and the second side segment 2112. Along the second direction Y, the folded edge portion 223 is embedded in the step structure to prevent the folded edge portion 223 from protruding from the side seal 222 along the second direction Y, thereby preventing the width of the packaging bag 20 from increasing, thereby affecting the energy density of the battery 1.

[0072] In some embodiments, the projection of the folded edge 223 along the first direction X is located between the projection of the side seal 222 along the first direction X and the projection of the second side segment 2112 along the first direction X, that is, along the second direction Y, the folded edge 223 is embedded in the step structure to prevent the folded edge 223 from protruding from the side seal 222 along the second direction Y, thereby increasing the width of the packaging bag 20 and affecting the energy density of the battery 1.

[0073] It should be noted that, due to factors such as process tolerance and material deformation, the projection relationship of the folding edge portion 223 may have a certain range of positional offset in actual manufacturing, that is, there may be a slight deviation between the designed projection boundary and the actual contour. For example, in actual manufacturing, the folding edge portion 223 may exceed the step structure along the second direction Y.

[0074] In some embodiments, the folded edge portion 223 further includes an adhesive layer, and the adhesive force of the adhesive layer can offset the rebound force generated by the bending of the packaging film in the folded edge portion 223, thereby positioning the straight sections 223A of each layer to a preset position, and preventing the folded edge portion 223 from being released from the folded state due to the rebound force. In addition, the adhesive layer allows the folded edge portion 223 to form a stable structure, and even if the battery 1 is subjected to external impact or increases in volume due to internal chemical or physical changes, the folded state of the folded edge portion 223 remains stable, and the risk of delamination or opening is low.

[0075] Optionally, along the first direction X, the hem portion 223 is spaced apart from the second side segment 2112, and at least part of the adhesive layer is filled in the gap between the hem portion 223A and the second side segment 2112 to limit the movement of the hem portion 223A relative to the second side segment 2112. Optionally, along the first direction X, at least part of the adhesive layer is filled in the gap between two adjacent straight segments 223A to limit the relative movement between the two adjacent straight segments 223A. Optionally, at least part of the adhesive layer is filled in the gap between the hem portion 223 and the third side segment 2113. Among them, at least one straight segment 223A in the hem portion 223 is arranged towards the third side segment 2113, and the straight segment 223A is spaced apart from the third side segment 2113. Then, at least part of the adhesive layer is filled in the gap between the straight segment 223A and the third side segment 2113 to limit the movement of the straight segment 223A relative to the top wall 211.

[0076] In actual manufacturing, the setting position of the adhesive layer can be selected according to the processing technology. For example, during the encapsulation process of the battery 1, an adhesive is pre-coated on one side of the area where the sealing portion 22 is used to form the hem portion 223, and the sealing portion 22 is folded and pressed to form the above-mentioned top seal 221, side seal 222, and hem portion 223. Part of the adhesive is bonded between two adjacent straight segments 223A to form an adhesive layer, and another part of the adhesive is bonded between the third side segment 2113 and the straight segment 223A facing the third side segment 2113 to form an adhesive layer. Of course, it is also possible to perform perfusion filling in the encapsulation process so that the gaps between the hem portion 223A and the second side segment 2112, between any two adjacent straight segments 223A, and between the straight segment 223A and the third side segment 2113 are all provided with an adhesive layer.

[0077] It can be understood that, as a flexible medium, the adhesive layer can absorb the local stress generated when the straight segment 223A is folded. For example, the shear force at the bending part of two adjacent straight segments 223A can be avoided, and the stress is concentrated at the interface of the encapsulation film. Moreover, the adhesive layer can hinder the diffusion of cracks on the encapsulation film, improve the overall crack resistance of the hem portion 223, and contribute to improving the durability of the battery 1.

[0078] Please continue to refer to Figure 7 , the hem portion 223 includes a first straight segment 2231, a second straight segment 2232, and a third straight segment 2233 that are stacked in sequence along the first direction X. The first straight segment 2231 is connected to the top seal 221, and the third straight segment 2233 is connected to the side seal 222. That is, the hem portion 223 is in a three-stage folding state to minimize the number of straight segments 223A stacked along the first direction X. This not only reduces the number of stamping and bending times in the encapsulation process of the battery 1, simplifies the process flow, but also helps to reduce the thickness of the hem portion 223 along the first direction X, improves the interlayer extrusion between multiple straight segments 223A, and reduces stress concentration.

[0079] In the embodiment of the present application, the hem portion 223 can form different folding structures according to the order and direction of stamping and bending. Next, the hem portion 223 includes the above three straight sections 223A as an example, and the folding structure that may be formed by the hem portion 223 in the embodiment of the present application is introduced in conjunction with the accompanying drawings.

[0080] It should be noted that, in the folded state of the hem portion 223, the size of the first straight section 2231 along the third direction Z is substantially consistent with the width of the top seal 221 along the third direction Z, and the size of the third straight section 2233 along the third direction Z is substantially consistent with the width of the side seal 222 along the third direction Z. That is, along the third direction Z, the width of the top seal 221 and the side seal 222 directly affects the shape and size of each straight section 223A of the hem portion 223. When the folded edge portion 223 is in the folded state, along the third direction Z, the width of the top seal 221 is greater than the width of the side seal 222, and the first straight section 2231 protrudes from the third straight section 2233 along the third direction Z; the width of the top seal 221 is equal to the width of the side seal 222, and the first straight section 2231 is flush with the third straight section 2233 along the third direction Z; the width of the top seal 221 is less than the width of the side seal 222, and the third straight section 2233 protrudes from the first straight section 2231 along the third direction Z.

[0081] Further, the first straight section 2231 has a first edge line for connecting to the top seal 221 and a second edge line toward the side seal 222, and the third straight section 2233 has a third edge line for connecting to the side seal 222 and a fourth edge line toward the top seal 221. It can be understood that in different folding structures of the hem portion 223, the first edge line, the second edge line, the third edge line and the fourth edge line have different relative positional relationships.

[0082] See also Figure 5 , Figure 8 as well as Figure 9 , along the first direction X, the first straight section 2231 is located on the side of the second straight section 2232 away from the package body 21, so that the first straight section 2231 is arranged on the outside of the folding edge portion 223 to improve the bending condition of the connection area between the first straight section 2231 and the top seal 221, optimize the bending stress, and along the first direction X, the projection of the first straight section 2231 at least partially covers the projection of the third straight section 2233. Among them, the projection of the first straight section 2231 partially covers or completely covers the third straight section 2233.

[0083] In some embodiments, along the first direction X, the first straight section 2231 is located on the side of the second straight section 2232 away from the packaging body 21, and the projection of the first straight section 2231 completely covers the third straight section 2233. Figure 8As shown, along the third direction Z, the width of the top seal 221 is greater than or equal to the width of the side seal 222, the first straight section 2231 can cover the third straight section 2233 along the third direction Z, and the first edge line of the first straight section 2231 is substantially flush with the third edge line of the third straight section 2233, and the first straight section 2231 can cover the third straight section 2233 along the second direction Y. At this time, the first straight section 2231 is substantially rectangular, the third straight section 2233 is substantially triangular, and the projection of the first straight section 2231 completely covers the projection of the third straight section 2233. The folded edge portion 223 is at least partially disposed in the step structure to reduce the size of the packaging bag 20 along the first direction X, and the flatness of one side of the battery 1 along the first direction X is higher, so that it fits better with the installation wall.

[0084] In some embodiments, along the first direction X, the first straight section 2231 is located on the side of the second straight section 2232 away from the packaging body 21, and the projection of the first straight section 2231 partially covers the third straight section 2233, and the folded edge portion 223 is at least partially disposed on the step structure to reduce the size of the packaging bag 20 along the first direction X. Figure 5 As shown, along the third direction Z, the width of the top seal 221 is smaller than the width of the side seal 222, and the third straight section 2233 protrudes from the first straight section 2231. At this time, the first straight section 2231 is roughly rectangular, and the third straight section 2233 is roughly trapezoidal. The projection of the first straight section 2231 partially covers the projection of the third straight section 2233. Figure 9 As shown, the first edge line of the first straight section 2231 and the third edge line of the third straight section 2233 are set at an angle. At this time, the first straight section 2231 is roughly triangular, the third straight section 2233 is roughly trapezoidal, and the projection of the first straight section 2231 partially covers the projection of the third straight section 2233.

[0085] See also Figures 10 - 12 , along the first direction X, the first straight section 2231 is located on the side of the second straight section 2232 facing the packaging body 21, and by arranging the third straight section 2233 on the outside of the folded edge portion 223, the folded edge portion 223 has a better appearance flatness between the side seals. Figures 10 - 12 As shown, along the first direction X, the projection of the third straight segment 2233 at least partially covers the projection of the first straight segment 2231 . The projection of the third straight segment 2233 partially covers or completely covers the projection of the first straight segment 2231 .

[0086] In some embodiments, along the first direction X, the first straight section 2231 is located on the side of the second straight section 2232 facing the packaging body 21, and the projection of the third straight section 2233 completely covers the projection of the first straight section 2231. Figure 10As shown, along the third direction Z, the width of the top seal 221 is less than or equal to the width of the side seal 222. The third straight section 2233 can cover the first straight section 2231 along the third direction Z, and the fourth edge line of the third straight section 2233 is substantially flush with the second edge line of the first straight section 2231. The third straight section 2233 can cover the first straight section 2231 along the second direction Y. At this time, the first straight section 2231 is substantially triangular, the third straight section 2233 is substantially rectangular, and the projection of the third straight section 2233 completely covers the projection of the first straight section 2231. At this time, the folded edge portion 223 is at least partially placed in the stepped structure to reduce the size of the packaging bag 20 along the first direction X.

[0087] In some embodiments, along the first direction X, the first straight section 2231 is located on the side of the second straight section 2232 facing the packaging body 21, and the projection of the third straight section 2233 partially covers the projection of the first straight section 2231. Part of the folded edge portion 223 is received in the stepped structure to reduce the size of the packaging bag 20 along the first direction X. As Figure 11 shown, along the third direction Z, the width of the top seal 221 is greater than the width of the side seal 222. The first straight section 2231 protrudes from the third straight section 2233 along the third direction Z. At this time, the first straight section 2231 is substantially triangular, the third straight section 2233 is substantially rectangular, and the projection of the third straight section 2233 partially covers the projection of the first straight section 2231. As Figure 12 shown, when the fourth edge line of the third straight section 2233 is at an angle with the second edge line of the first straight section 2231, the first straight section 2231 is substantially rectangular, the third straight section 2233 is substantially triangular (or trapezoidal), and the projection of the third straight section 2233 partially covers the projection of the first straight section 2231.

[0088] In some embodiments, along the first direction X, the surface of the folded edge portion 223 farthest from the third side section 2113 is flush with the surface of the top seal 221 facing away from the top wall 211. Along the second direction Y, the surface of the folded edge portion 223 farthest from the second side section 2112 is flush with the surface of the side seal 222 facing away from the side wall 212. In actual manufacturing, along the first direction X, the distance from the surface of the folded edge portion 223 farthest from the third side section 2113 to the top seal 221 is S1, and -0.5 mm ≤ S1 ≤ 0.5 mm. And, along the second direction Y, the distance from the surface of the folded edge portion 223 farthest from the second side section 2112 to the side seal 222 is S2, and -0.5 mm ≤ S2 ≤ 0.5 mm. In this way, the surface of the battery 1 is flat and the dimensions are uniform everywhere. When the electrode assembly 10 expands in volume, the folded edge portion 223 deforms synergistically with the top seal 221 and the side seal 222, thereby effectively suppressing the concentration of expansion stress.

[0089] In the embodiments of the present application, there are no particular limitations on the positive electrode plate, negative electrode plate, separator, positive electrode tab, negative electrode tab, and electrolyte. All kinds of elements known to those skilled in the art that can be used as the above components of the battery 1 are applicable to the present application.

[0090] The embodiments of the present application provide an electronic device, which includes a housing and the battery in any of the foregoing embodiments. The battery is disposed in the internal space of the housing. Therefore, the electronic device provided by the present application has good performance in use.

[0091] The present application does not particularly limit the type of the electronic device, and it can be any electronic device known in the prior art. In some embodiments, the electronic device may include, but is not limited to, a laptop computer, a pen-input computer, a mobile computer, an e-book player, a portable phone, a portable fax machine, a portable copier, a portable printer, a headset stereo, a video recorder, a liquid crystal TV, a portable cleaner, a portable CD player, a minidisc, a transceiver, an electronic notepad, a calculator, a memory card, a portable recorder, a radio, a backup power supply, a motor, an automobile, a motorcycle, a moped, a bicycle, a lighting fixture, a toy, a game console, a clock, a power tool, a flashlight, a camera, a large household battery, and a lithium-ion capacitor, etc.

[0092] In the drawings of the present embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the present application, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0093] The foregoing are only the preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery, characterized in that: The invention comprises an electrode assembly, a packaging bag and a tab, wherein the electrode assembly is arranged in the inner space of the packaging bag, the tab is connected to the electrode assembly, and the packaging bag comprises: A packaging body, comprising a top wall and a side wall, wherein the top wall comprises a first side segment, a second side segment and a third side segment connected in sequence, an end of the third side segment away from the second side segment is connected to the side wall, and the second side segment and the third side segment form a step structure; and A sealing portion is arranged around the outer circumference of the packaging body and connected to the packaging body, the sealing portion includes a top seal, a side seal and a folded edge portion; along a first direction, the top seal and the first side segment are stacked; along a second direction, the side seal and the side wall are stacked, the first direction is perpendicular to the second direction; the folded edge portion is connected to the top seal and the side seal, and is in a folded state; Wherein, along the first direction, the projection of the folded edge portion at least partially overlaps with the projection of the third side segment, the pole lug at least partially extends out of the top seal along the first direction, and the folded edge portion does not exceed the edge of the pole lug along the first direction.

2. The battery according to claim 1, characterized in that The folded edge portion includes a plurality of straight sections, and the straight sections are perpendicular to the first direction; Along the first direction, a plurality of the straight sections are stacked and connected end to end in sequence.

3. The battery according to claim 1, characterized in that When viewed along the first direction, the folded edge portion is located between the side seal and the second side section.

4. The battery according to claim 1, characterized in that The projection of the folded edge portion along the first direction is located between the projection of the side seal along the first direction and the projection of the second side section along the first direction.

5. The battery according to claim 2, characterized in that The folded edge portion further includes an adhesive layer; At least part of the adhesive layer fills the gap between two adjacent straight sections; and / or, At least part of the adhesive layer fills the gap between the folded edge portion and the third side segment; and / or, At least a portion of the adhesive layer fills the gap between the folded edge portion and the second side segment.

6. The battery according to claim 2, characterized in that The folded edge portion includes a first straight section, a second straight section and a third straight section stacked in sequence along the first direction, the first straight section is connected to the top seal, and the third straight section is connected to the side seal.

7. The battery according to claim 6, characterized in that Along the first direction, the first straight section is located on a side of the second straight section away from the packaging body, and along the first direction, a projection of the first straight section at least partially covers a projection of the third straight section; or, Along the first direction, the first straight section is located on a side of the second straight section facing the packaging body, and along the first direction, a projection of the third straight section at least partially covers a projection of the first straight section.

8. The battery according to claim 1, characterized in that Along the first direction, the thickness of the folded edge portion is S, and S satisfies: S≥0.25 mm.

9. The battery according to claim 1, characterized in that Along the first direction, the distance from the electrode assembly to the first side segment is A, the distance from the electrode assembly to the third side segment is d1, and the width of the second side segment is d2, wherein d1+d2=A; The electrode assembly satisfies at least one of the following conditions: (1) 1mm≤A≤5mm; (2) 0.1mm≤d1≤4.85mm; (3)0.15mm≤d2≤1.5mm.

10. The battery according to claim 1, characterized in that The first side section is parallel to the third side section.

11. The battery according to claim 1, characterized in that Along the second direction, the width of the third side segment is d3, and d3 satisfies: 0.3 mm≤d3≤5 mm.

12. The battery according to claim 1, characterized in that Along the second direction, a distance from a side of the pole ear close to the folded edge portion to the second side segment is W, where W is ≥ 0.1 mm.

13. The battery according to claim 1, characterized in that Along the first direction, the surface of the folded edge portion farthest from the third side segment is flush with the surface of the top seal facing away from the top wall; Along the second direction, a surface of the folded edge portion farthest from the second side segment is flush with a surface of the side seal facing away from the side wall.

14. An electronic device, characterized in that: include: case; as well as The battery according to any one of claims 1 to 13, wherein the battery is disposed in the internal space of the shell.

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