Electrochemical device and preparation method therefor, and electronic device

Abstract

An electrochemical device and a preparation method therefor, and an electronic device. The electrochemical device comprises a packaging pouch, an electrode assembly, and an electrically conductive plate, wherein the electrode assembly is disposed in the packaging pouch, and the electrically conductive plate is electrically connected to the electrode assembly. The packaging pouch comprises an accommodating portion for accommodating the electrode assembly and a sealing portion connected to the accommodating portion, the electrically conductive plate extending out of the packaging pouch from the sealing portion. A first direction is the thickness direction of the electrode assembly, and a second direction is perpendicular to the first direction and is a direction pointing from the electrode assembly to the electrically conductive plate. The accommodating portion comprises a first wall and a second wall, which are arranged opposite each other in the second direction. The accommodating portion further comprises a reinforcing portion. The reinforcing portion comprises at least one first protruding portion integrally disposed on the first wall. The first wall comprises a first surface and a second surface, which are arranged opposite each other in the second direction, and the first protruding portion forms a first protrusion on the first surface and forms a first recess on the second surface. The present application can ameliorate the deformation problem of the packaging pouch.

Description

Electrochemical devices and their preparation methods, electronic devices Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to an electrochemical device, a method for preparing the electrochemical device, and an electronic device having the electrochemical device. Background Technology

[0002] With the increasing popularity of consumer electronics products such as laptops, mobile phones, handheld game consoles, tablets, power banks, and drones, people are becoming more and more demanding in terms of the safety performance of electrochemical devices (such as pouch batteries).

[0003] Electrochemical devices typically consist of a packaging bag and an electrode assembly housed within the bag. In related technologies, recesses are formed in an aluminum-plastic film, the electrode assembly is placed within these recesses, and the film is then sealed to obtain the packaging bag. However, during subsequent manufacturing processes (such as hot pressing and vacuuming) and even during battery use, the portion of the packaging bag facing the head or tail of the electrode assembly is prone to collapse or other deformation. This not only results in poor appearance but also necessitates considering the internal space occupied by the collapse when designing the length of the electrode assembly, thus reducing the energy density of the electrochemical device. Summary of the Invention

[0004] In view of this, it is necessary to provide an electrochemical device and a method for preparing the same to improve the deformation problem of packaging bags. Furthermore, it is also necessary to provide an electronic device incorporating this electrochemical device.

[0005] This application provides an electrochemical device, including a packaging bag, an electrode assembly, and a conductive plate. The electrode assembly is disposed within the packaging bag, and the conductive plate is electrically connected to the electrode assembly. The packaging bag includes a receiving portion for accommodating the electrode assembly and a sealing portion connecting the receiving portion, with the conductive plate extending out of the packaging bag from the sealing portion. A first direction is the thickness direction of the electrode assembly, and a second direction is perpendicular to the first direction and is the direction in which the conductive plate protrudes from the electrode assembly. The receiving portion includes a first wall and a second wall disposed opposite to each other along the second direction. The receiving portion also includes a reinforcing portion. The reinforcing portion includes at least one first protrusion integrally disposed on the first wall. The first wall includes a first surface and a second surface disposed opposite to each other along the second direction, with the first protrusion forming a first protrusion on the first surface and a first recess on the second surface. Viewed from the second direction, the first protrusion and the first recess formed by the first protrusion overlap.

[0006] This application provides a first protrusion on the first wall. The first protrusion can improve the structural strength and deformation resistance of the first wall and reduce the risk of the first wall collapsing or undergoing other deformations. This not only improves the appearance of the electrochemical device, but also makes the dimensions of the receiving part along the second direction more stable. Therefore, when designing the dimensions of the electrode assembly along the second direction, it is not necessary to consider the internal space occupied when the first wall collapses, thereby improving the energy density of the electrochemical device.

[0007] Based on the first aspect, in some possible implementations, the first protrusion protrudes from the first wall in a direction away from the electrode assembly. Therefore, the first protrusion does not occupy the internal space of the packaging bag, and the first protrusion can also be used to accommodate part of the free electrolyte, improving the liquid storage capacity of the electrochemical device, thereby further improving the energy density and cycle performance of the electrochemical device.

[0008] Based on the first aspect, in some possible implementations, the sealing portion is connected to the second wall. Therefore, by providing the first protrusion on the first wall where no sealing portion is provided, the structural strength and deformation resistance of the first wall, which is more prone to deformation, are improved.

[0009] Based on the first aspect, in some possible implementations, the reinforcing portion further includes at least one second protrusion integrally formed on the second wall. The second wall includes a third surface and a fourth surface disposed opposite each other along a second direction, and the second protrusion forms a second protrusion on the third surface and a second recess on the fourth surface. Viewed from the second direction, the second protrusion and the second recess formed by the second protrusion overlap. Therefore, the second protrusion can improve the structural strength and deformation resistance of the second wall, reducing the risk of deformation of the second wall. This not only further improves the appearance of the electrochemical device, but also makes the dimensions of the housing portion more stable along the second direction.

[0010] Based on the first aspect, in some possible implementations, the sealing portion includes a first connecting edge integrally connected to the receiving portion. The second wall includes a first region and a second region respectively connected to the first connecting edge, the first region and the second region being located on opposite sides of the first connecting edge along a first direction. Along the first direction, the width of the first region is greater than the width of the second region. A second protrusion is provided in the first region. Therefore, by providing the second protrusion in the wider first region, the structural strength and deformation resistance of the first region, which is more prone to deformation, are improved.

[0011] Based on the first aspect, in some possible implementations, viewed from the second direction, the reinforcing portion (such as the first or second protrusion) is strip-shaped. The angle between the extending direction of the reinforcing portion and the third direction is α, where 45°≤α≤90°, and the third direction is perpendicular to both the first and second directions. Therefore, the deformation resistance of the first or second wall can be further improved, and the risk of electrochemical corrosion caused by easy breakage of the metal layer of the encapsulation film during the fabrication of the reinforcing portion can also be reduced. Moreover, when the extending direction of the reinforcing portion is inclined relative to the third direction, the reinforcing portion can be used to accommodate more free electrolyte, improving the electrolyte storage capacity of the electrochemical device.

[0012] Based on the first aspect, in some possible implementations, the width of the reinforcing part (such as the first or second protrusion) along the third direction is W, and the dimension of the first or second wall along the third direction is W0, where 0.1W0 ≤ W ≤ 0.9W0. Therefore, the reinforcing part can effectively improve the structural strength and deformation resistance of the first wall, and reduce the risk of deformation of the first or second wall.

[0013] Based on the first aspect, in some possible implementations, 0.5mm≤W≤95mm, thereby further improving the structural strength and deformation resistance of the first or second wall and reducing the risk of deformation of the first or second wall.

[0014] Based on the first aspect, in some possible implementations, the distance between two adjacent reinforcing portions on the first or second wall along a third direction is D, and the dimension of the first or second wall along the third direction is W0, where 0.1W0≤D≤0.9W0. Therefore, sufficient spacing between adjacent reinforcing portions reduces the risk of electrochemical corrosion caused by damage to the metal layer of the encapsulation film during reinforcing portion fabrication due to excessively dense reinforcing portions. Simultaneously, this spacing ensures that the aforementioned spacing is not excessive, allowing the reinforcing portions to effectively improve the structural strength and deformation resistance of the first or second wall, reducing the risk of deformation of the first or second wall.

[0015] Based on the first aspect, in some possible implementations, the length of the reinforcing part (such as the first protrusion or the second protrusion) is L, and the dimension of the first wall or the second wall along the first direction is L0, where 0.1L0≤L≤0.9L0. Therefore, while ensuring that the reinforcing part has a certain length, considering that the edges of the first wall or the second wall along the first direction may have rounded corner areas, by setting an upper limit for L, the reinforcing part can be formed in the straight areas of the first wall or the second wall other than the rounded corners. This allows the reinforcing part to fully exert its structural reinforcing function, thus effectively improving the structural strength and deformation resistance of the first wall or the second wall, and reducing the risk of deformation of the first wall or the second wall.

[0016] Based on the first aspect, in some possible implementations, 1mm≤L≤15mm, thereby further improving the structural strength and deformation resistance of the first or second wall and reducing the risk of deformation of the first or second wall.

[0017] Based on the first aspect, in some possible implementations, the height of the reinforcing part (such as the first protrusion or the second protrusion) is h1, 0.1 mm.

[0018] A second aspect of this application provides an electronic device comprising a receiving compartment and the aforementioned electrochemical device. The electrochemical device is disposed within the receiving compartment. The electronic device is powered by the aforementioned electrochemical device, and the problem of deformation of the packaging bag of the electrochemical device is improved.

[0019] A third aspect of this application provides a method for preparing the above-mentioned electrochemical device, comprising the following steps: providing a multilayer encapsulation material, the multilayer encapsulation material including a first encapsulation film and a second encapsulation film, the first encapsulation film including a first main body region and a first edge region connected together, and the second encapsulation film including a second main body region and a second edge region connected together; stamping at least the first main body region using a molding die, the molding die including a male die and a female die disposed opposite to each other, the male die including a first molding body, the female die including a second molding body, a molding part protruding from the first molding body or the second molding body, the first molding body and the second molding body cooperating to form a groove in the first main body region, the molding part forming a reinforcing part on the inner wall of the groove; electrically connecting an electrode assembly to a conductive plate, and placing the electrode assembly with the conductive plate in the groove; positioning the first encapsulation film and the second encapsulation film opposite to each other, and encapsulating the first edge region and the second edge region to form a sealing part, the conductive plate extending out of the sealing part from the packaging bag, and the second main body region and the first main body region with the groove forming a receiving part. The deformation problem of the packaging bag of the electrochemical device obtained by the above preparation method is improved. Attached Figure Description

[0020] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0021] Figure 1 is a schematic diagram of the structure of an electrochemical device according to an embodiment of this application when viewed from a first direction.

[0022] Figure 2A is a cross-sectional view along section line II-II of the electrochemical device shown in Figure 1 in some embodiments.

[0023] ​Figure 2B is a cross-sectional view along section line II-II of the electrochemical device shown in Figure 1 in some other embodiments.

[0024] Figure 3 is a schematic diagram of the electrochemical device shown in Figure 2A when viewed from the second direction.

[0025] Figure 4 is a schematic diagram of the electrochemical device in some other embodiments as viewed from the first direction.

[0026] Figure 5 is a cross-sectional view of an electrochemical device in some other embodiments.

[0027] Figure 6 is a schematic diagram of the electrochemical device shown in Figure 5 when viewed from the second direction.

[0028] Figure 7 is a schematic diagram of the electrochemical device shown in Figure 1 before encapsulation.

[0029] Figure 8 is a cross-sectional view of the first encapsulation membrane of the electrochemical device shown in Figure 7.

[0030] Figure 9 is a cross-sectional view of the second encapsulation membrane of the electrochemical device shown in Figure 7.

[0031] Figure 10 is a cross-sectional view of an electrochemical device according to another embodiment of this application.

[0032] Figure 11 is a cross-sectional view of an electrochemical device in some other embodiments.

[0033] Figure 12 is a cross-sectional view of an electrochemical device in some other embodiments.

[0034] Figure 13 is a flowchart of the preparation method of an electrochemical device according to an embodiment of this application.

[0035] Figure 14 is a schematic diagram of the molding die used in the preparation method shown in Figure 13 in some embodiments.

[0036] Figure 15 is a schematic diagram of the molding die used in the preparation method shown in Figure 13 in some other embodiments.

[0037] Figure 16 is a schematic diagram of the structure of an electronic device according to an embodiment of this application.

[0038] Key Component Symbols: Electronic device, 1; Packaging bag, 2; Receiving part, 11; Sealing part, 12; Electrode assembly, 20; First conductive plate, 30; First tab, 31; Second conductive plate, 40; Electrochemical device, 100, 200; First encapsulation film, 101; First protective layer, 101A; First metal layer, 101B; First polymer layer, 101C; Second encapsulation film, 102; Second protective layer, 102A; Second metal layer, 102B; Second polymer layer, 102C; Reinforcing part, 110; First wall, 111; First surface, 111A; Second surface, 111B; Second wall, 112; Third surface, 112A; Fourth surface, 112B; First protrusion, 113; Second protrusion, 114; First connecting edge, 120 ; Sealing area, 121; Transition area, 122; Molding mold, 300; Male mold, 301; Female mold, 302; Battery compartment, 1001; First main body area, 1011; First edge area, 1012; Second main body area, 1021; Second edge area, 1022; First protrusion, 1131; First depression, 1132; Second protrusion, 1141; Second depression, 1142; First region, 1121; Second region, 1122; First molding body, 3010; Second molding body, 3020; Molding part, 3030; Groove, R; Angle, α; Width, W; Spacing, D; Length, L; Height, h1; Dimension, W0, L0; First direction, X; First side, X1; Second side, X2; Second direction, Y; Third direction, Z.

[0039] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0040] The technical solutions in the embodiments of this application are described clearly and in detail below. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0041] The embodiments of this application will be described in detail below. However, this application may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided to provide a thorough and detailed understanding of this application to those skilled in the art.

[0042] Additionally, for brevity and clarity, the dimensions or thicknesses of various components and layers may be enlarged in the accompanying drawings. Throughout the text, the same numerical values ​​refer to the same elements. As used herein, the terms "and / or" and "and / or" include any and all combinations of one or more of the associated enumerated items. Furthermore, it should be understood that when element A is referred to as "connecting" element B, element A may be directly connected to element B, or there may be an intermediate element C and element A and element B may be indirectly connected to each other.

[0043] Furthermore, when describing the implementation of this application, the word "may" refers to "one or more implementations of this application".

[0044] The technical terms used herein are for the purpose of describing particular embodiments and are not intended to limit this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. It should be further understood that the term "comprising," as used in this specification, means the presence of the described features, values, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, values, steps, operations, elements, components, and / or combinations thereof.

[0045] Spatial terms, such as "above," may be used herein for convenience in describing the relationship between one element or feature and another element (or feature) or feature (or feature) illustrated in the figures. It should be understood that, in addition to the directions depicted in the figures, spatial terms are intended to include different orientations of the device or apparatus during use or operation. For example, if the device in the figure is flipped, an element described as "above" or "on" other elements or features would be oriented "below" or "under" other elements or features. Therefore, the exemplary term "above" can include both above and below orientations. It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, a first element, component, region, layer, or portion discussed below may be referred to as a second element, component, region, layer, or portion without departing from the teachings of the exemplary embodiments.

[0046] In this application, the design relationships of greater than, less than, or not equal to parameter values ​​need to exclude reasonable errors of the measuring equipment.

[0047] Referring to Figures 1 and 2A, one embodiment of this application provides an electrochemical device 100, which includes a packaging bag 10, an electrode assembly 20, an electrolyte (not shown), and a conductive plate. The electrode assembly 20 and the electrolyte are disposed within the packaging bag 10. The conductive plate may include a first conductive plate 30 and a second conductive plate 40. The first conductive plate 30 is electrically connected to the electrode assembly 20 or to the electrode assembly 20 via a first tab 31. The second conductive plate 40 is electrically connected to the electrode assembly 20 or to the electrode assembly 20 via a second tab (not shown). Furthermore, the first conductive plate 30 and the second conductive plate 40 extend out of the packaging bag 10 to connect to external components (not shown). A three-dimensional coordinate system is established based on two mutually perpendicular first directions X, second directions Y, and a third direction Z, where the first direction X is the thickness direction of the electrode assembly 20, the second direction Y is the direction in which the first conductive plate 30 or the second conductive plate 40 protrudes from the electrode assembly 20, and in some embodiments, the third direction Z is the direction from the first conductive plate 30 to the second conductive plate 40. Although the first direction X in Figure 2A has a specific vector direction to illustrate the thickness direction of the electrode assembly 20, it can be understood that the opposite direction can also be the thickness direction of the electrode assembly 20. Therefore, the first direction X has a first side X1 and a second side X2 facing opposite directions to the first side X1.

[0048] The packaging bag 10 includes a receiving portion 11 and a sealing portion 12 connecting the receiving portion 11. The electrode assembly 20 and electrolyte are disposed within the receiving portion 11. The receiving portion 11 includes a first wall 111 and a second wall 112 disposed opposite each other in a second direction Y. Referring to FIG3, at least a portion of the surface of the first wall 111 extends in the first direction X and the third direction Z. At least a portion of the surface of the second wall 112 extends in the first direction X and the third direction Z. In some embodiments, the sealing portion 12 is connected to the second wall 112, and the sealing portion 12 includes a first connecting edge 120 integrally connected to the receiving portion 11, the second wall 112 extending from the first connecting edge 120 along a second side X2. The first conductive plate 30 and the second conductive plate 40 can both extend out of the packaging bag 10 from the sealing portion 12. Referring to FIG4, in other embodiments, to meet the requirements of high-current charging and reduce the internal resistance of the electrode assembly 20, the width of the first tab 31 or the second tab in the third direction Z can be increased accordingly. At this time, there are two sealing parts 12, which are respectively connected to the first wall 111 and the second wall 112. The first conductive plate 30 and the second conductive plate 40 extend out of the packaging bag 10 from the two sealing parts 12. Therefore, the risk of short circuit caused by contact between the wide first tab 31 and the second tab can be reduced, and a larger welding operation space can be provided when welding the first conductive plate 30 and the second conductive plate 40 to the first tab 31 and the second tab respectively.

[0049] As shown in Figure 7, the packaging bag 10 includes a first sealing film 101 and a second sealing film 102 disposed opposite to each other in a first direction X. Both the first sealing film 101 and the second sealing film 102 are made of multilayer sealing materials. The first sealing film 101 includes a first main body region 1011 and a first edge region 1012 connected together, and the second sealing film 102 includes a second main body region 1021 and a second edge region 1022 connected together. The first main body region 1011 and the second main body region 1021 together constitute the receiving portion 11 of the packaging bag 10, and the first edge region 1012 and the second edge region 1022 are connected to together constitute the sealing portion 12 of the packaging bag 10. In some embodiments, the first sealing film 101 and the second sealing film 102 are an integral structure before sealing, and the first sealing film 101 and the second sealing film 102 are obtained by folding a single sealing film. As shown in Figure 8, the first sealing film 101 may include a first protective layer 101A, a first metal layer 101B, and a first polymer layer 101C stacked sequentially. The first polymer layer 101C is closer to the electrode assembly 20 than the first protective layer 101A. The first protective layer 101A can be made of a polymer resin, which can protect the first metal layer 101B, reducing the risk of damage to the first metal layer 101B due to external forces, and simultaneously delaying air penetration from the external environment, maintaining a normal operating environment inside the electrochemical device 100. In some embodiments, the material of the first protective layer 101A can be selected from at least one of polyethylene terephthalate, polybutylene terephthalate, polyvinylidene fluoride, polytetrafluoroethylene, polypropylene, polyamide, and polyimide. The first metal layer 101B can delay moisture penetration from the external environment and reduce damage to the electrode assembly 2020 caused by external forces. In some embodiments, the first metal layer 101B can be an aluminum foil layer or a steel foil layer. The first polymer layer 101C has the property of melting upon heating, can be used for encapsulation, and can reduce the risk of multilayer sheets being dissolved or swollen by organic solvents in the electrolyte. The first polymer layer 101C can also be used to reduce the risk of corrosion of the metal layer due to contact between the electrolyte in the electrolyte and the first metal layer 101B. In some embodiments, the first polymer layer 101C includes a first polymer material, which may be selected from at least one of polyethylene, polypropylene, polyurethane, and polyimide.

[0050] As shown in Figure 9, the second encapsulation film 102 may include a second protective layer 102A, a second metal layer 102B, and a second polymer layer 102C stacked sequentially. It can be understood that when the first encapsulation film 101 and the second encapsulation film 102 are obtained by folding a single encapsulation film, the materials of the second protective layer 102A, the second metal layer 102B, and the second polymer layer 102C are the same as the materials of the first protective layer 101A, the first metal layer 101B, and the first polymer layer 101C, respectively. As shown in Figure 7, when preparing the packaging bag 10, a molding die 300 (shown in Figures 14 and 15) can be used to punch at least one groove R in the first main body region 1011 and the second main body region 1021. Then, the electrode assembly 20 is placed in the groove R, and the first encapsulation film 101 and the second encapsulation film 102 are placed opposite each other. Using the sealing head of the encapsulation device, a certain temperature and pressure are applied to the first edge region 1012 and the second edge region 1022 simultaneously, causing the first polymer layer 101C of the first edge region 1012 and the second polymer layer 102C of the second edge region 1022 to melt and bond together to form a sealing part 12. Figure 7 shows the groove R for accommodating the electrode assembly 20 obtained by punching the first main body region 1011. In other embodiments, the groove R can also be obtained by punching the first main body region 1011 and the second main body region 1021 separately. Therefore, when the first encapsulation film 101 and the second encapsulation film 102 are placed opposite each other, the two grooves R together form an accommodating space for accommodating the electrode assembly 20.

[0051] As shown in Figures 2A and 3, the receiving portion 11 further includes a reinforcing portion 110. The reinforcing portion 110 includes at least one first protrusion 113 integrally disposed on the first wall 111. Figure 3 shows that in some embodiments, the first wall 111 is integrally disposed with a plurality of first protrusions 113, and the plurality of first protrusions 113 are spaced apart along a third direction Z and are arranged substantially parallel. The first protrusions 113 protrude from the first wall 111 in a direction away from the electrode assembly 20. As shown in Figures 5 and 6, the first protrusions 113 may also protrude from the first wall 111 in a direction toward the electrode assembly 20. Specifically, the first wall 111 includes a first surface 111A and a second surface 111B disposed opposite to each other along a second direction Y, with the second surface 111B facing the electrode assembly 20. As shown in Figures 2A and 3, when the first protrusion 113 protrudes from the first wall 111 in a direction away from the electrode assembly 20, the first protrusion 113 forms a first protrusion 1131 on the first surface 111A and a first recess 1132 on the second surface 111B. As shown in Figures 5 and 6, when the first protrusion 113 protrudes from the first wall 111 in a direction toward the electrode assembly 20, the first protrusion 113 forms a first recess 1132 on the first surface 111A and a first protrusion 1131 on the second surface 111B. Viewed from the second direction Y, the first protrusion 1131 and the first recess 1132 formed by the first protrusion 113 overlap.

[0052] In this embodiment, when the molding die 300 punches a groove R into the first main body area 1011, the molding die 300 simultaneously forms a first protrusion 113 on the inner wall of the groove R. In some embodiments, the inner wall of the groove R is the first wall 111. As shown in FIG2A, the first wall 111 includes a second connecting edge 1110 connecting the second encapsulation film 102. When the first encapsulation film 101 and the second encapsulation film 102 are folded from a single encapsulation film, the second connecting edge 1110 is also the fold between the first encapsulation film 101 and the second encapsulation film 102. The first protrusion 113 connects to the second connecting edge 1110 in the first direction X. As shown in FIG2B, in some embodiments, if the fold between the first encapsulation film 101 and the second encapsulation film 102 changes or the molding method of the first protrusion 113 is changed, the first protrusion 113 may also be separated from the second connecting edge 1110 in the first direction X.

[0053] In this embodiment, a first protrusion 113 is provided on the first wall 111. The first protrusion 113 can improve the structural strength and deformation resistance of the first wall 111, reducing the risk of collapse or other deformation of the first wall 111. This not only improves the appearance of the electrochemical device 100, but also makes the dimension of the receiving part 11 along the second direction Y more stable. Therefore, when designing the dimension of the electrode assembly 20 along the second direction Y, it is not necessary to consider the internal space occupied by the first wall 111 when it collapses, thereby improving the energy density of the electrochemical device 100. In particular, when the sealing part 12 is connected to the second wall 112, the sealing part 12 and the first conductive plate 30 and the second conductive plate 40 sandwiched in the sealing part 12 can play a certain structural reinforcement role for the second wall 112. By providing the first protrusion 113 on the first wall 111 without the sealing part 12, the structural strength and deformation resistance of the first wall 111, which is more prone to deformation, are improved. Moreover, when the first protrusion 113 protrudes from the first wall 111 in a direction away from the electrode assembly 20, the first protrusion 113 will not occupy the internal space of the packaging bag 10, and the first protrusion 113 can also be used to accommodate part of the free electrolyte, thereby improving the liquid storage capacity of the electrochemical device 100, and thus further improving the energy density and cycle performance of the electrochemical device 100.

[0054] As shown in Figures 3 and 6, in some embodiments, viewed from the second direction Y, the first protrusion 113 can be a strip, circle, ellipse, triangle, square, trapezoid, rhombus, or other polygonal shape. In this embodiment, to further improve the structural strength of the first wall 111 and facilitate manufacturing, the first protrusion 113 can be set as a strip. The angle between the extension direction of the first protrusion 113 and the third direction Z is defined as α, where 45°≤α≤90°. Wherein, when the extension direction of the first protrusion 113 is inclined relative to the third direction Z, the aforementioned angle α refers to the acute angle formed between the extension direction of the first protrusion 113 and the third direction Z. By limiting the lower limit of the included angle α, not only can the deformation resistance of the first wall 111 be further improved (for example, when the compressive force on the electrochemical device 100 has a component force along the first direction X, the deformation resistance of the first wall 111 under this component force can be improved), but the risk of electrochemical corrosion caused by easy breakage of the first metal layer 101B or the second metal layer 102B during the fabrication of the first protrusion 113 can also be reduced. Moreover, when the extension direction of the first protrusion 113 is inclined relative to the third direction Z, that is, when 45°≤α<90°, the first protrusion 113 can be used to accommodate more free electrolyte, thereby improving the liquid storage capacity of the electrochemical device 100.

[0055] As shown in Figures 3 and 6, in some embodiments, the width of the first protrusion 113 along the third direction Z is W, and the dimension of the first wall 111 along the third direction Z is W0, where 0.1W0 ≤ W ≤ 0.9W0. Therefore, the first protrusion 113 can effectively improve the structural strength and deformation resistance of the first wall 111, reducing the risk of deformation of the first wall 111. Further, the width can be set to 0.5mm ≤ W ≤ 95mm, thereby further improving the structural strength and deformation resistance of the first wall 111 and reducing the risk of deformation of the first wall 111.

[0056] As shown in Figures 3 and 6, in some embodiments, the distance between two adjacent first protrusions 113 along the third direction Z is D, and the dimension of the first wall 111 along the third direction Z is W0, where 0.1W0 ≤ D ≤ 0.9W0. Therefore, by setting a lower limit for D, sufficient spacing is ensured between two adjacent first protrusions 113, reducing the risk of electrochemical corrosion caused by the first metal layer 101B or the second metal layer 102B being easily damaged during the fabrication of the first protrusions 113 due to excessive density of the first protrusions 113. Simultaneously, by setting an upper limit for D, the aforementioned spacing is prevented from becoming excessively large, allowing the first protrusions 113 to effectively improve the structural strength and deformation resistance of the first wall 111, reducing the risk of deformation of the first wall 111.

[0057] As shown in Figures 3 and 6, in some embodiments, the length of the first protrusion 113 along its extension direction is L, and the dimension of the first wall 111 along the first direction X is L0, where 0.1L0≤L≤0.9L0. Therefore, while ensuring the first protrusion 113 has a certain length, it can be formed in the straight area of ​​the first wall 111, excluding the rounded corners. This allows the first protrusion 113 to fully exert its structural strengthening function, effectively improving the structural strength and deformation resistance of the first wall 111 and reducing the risk of deformation. Furthermore, the length can be set to 1mm≤L≤15mm to further improve the structural strength and deformation resistance of the first wall 111 and reduce the risk of deformation.

[0058] As shown in Figures 2A and 5, in some embodiments, the first protrusion 113 protrudes from the first wall 111 by a height h1, which is 0.1 mm.

[0059] ​Referring to Figure 10, another embodiment of this application provides an electrochemical device 200, which differs from the electrochemical device 100 described above in that the reinforcing portion 110 further includes at least one second protrusion 114 integrally disposed on the second wall 112. In some embodiments, the second wall 112 is integrally disposed with a plurality of second protrusions 114, and the plurality of second protrusions 114 are spaced apart along a third direction Z and are arranged substantially parallel. The second protrusions 114 protrude from the first wall 111 in a direction away from the electrode assembly 20. As shown in Figure 11, the second protrusions 114 may also protrude from the second wall 112 in a direction toward the electrode assembly 20. Specifically, the second wall 112 includes a third surface 112A and a fourth surface 112B disposed opposite to each other along a second direction Y, with the fourth surface 112B facing the electrode assembly 20. As shown in Figure 10, when the second protrusion 114 protrudes from the first wall 111 in a direction away from the electrode assembly 20, the second protrusion 114 forms a second protrusion 1141 on the third surface 112A and a second recess 1142 on the fourth surface 112B. As shown in Figure 11, when the second protrusion 114 protrudes from the second wall 112 in a direction toward the electrode assembly 20, the second protrusion 114 forms a second recess 1142 on the third surface 112A and a second protrusion 1141 on the fourth surface 112B. Viewed from the second direction Y, the second protrusion 1141 and the second recess 1142 formed by the second protrusion 114 overlap.

[0060] In this embodiment, a second protrusion 114 is provided on the second wall 112. The second protrusion 114 can improve the structural strength and deformation resistance of the second wall 112, reducing the risk of collapse or other deformation of the second wall 112. This not only further improves the appearance of the electrochemical device 200, but also makes the dimensions of the receiving portion 11 along the second direction Y more stable. In particular, when the second protrusion 114 protrudes from the second wall 112 in a direction away from the electrode assembly 20, the second protrusion 114 will not occupy the internal space of the packaging bag 10, and the second protrusion 114 can also be used to contain part of the free electrolyte. This not only improves the liquid storage capacity of the electrochemical device 200, but also reduces the impact of the free electrolyte on the second wall 112 during mechanical abuse (such as drops, collisions, etc.), reduces the risk of leakage caused by the sealing portion 12 connected to the second wall 112 being blown open by the free electrolyte, and improves the safety performance of the electrochemical device 200.

[0061] The width of the second protrusion 114 along the third direction Z, the spacing between two adjacent second protrusions 114 along the third direction Z, the length of the second protrusion 114, and the protruding height of the second protrusion 114 can be referenced to the corresponding dimensions of the first protrusion 113, which will not be elaborated here. For example, the width of the second protrusion 114 can be approximately equal to the width of the first protrusion 113, the spacing between the first protrusions 113 can be approximately equal to the spacing between the first protrusions 113, the length of the second protrusion 114 can be approximately equal to the length of the first protrusion 113, and the height of the second protrusion 114 can be approximately equal to the height of the first protrusion 113. In some embodiments, when the second protrusion 114 protrudes from the second wall 112 in the direction toward the electrode assembly 20, since the sealing portion 12 can provide a certain structural reinforcement to the second wall 112, the length of the second protrusion 114 can also be set to be less than the length of the first protrusion 113. Thus, while enabling the second protrusion 114 to improve the structural strength and deformation resistance of the second wall 112, the impact of the second protrusion 114 on the energy density of the electrochemical device 200 is reduced.

[0062] In some cases, the sealing portion 12 needs to be bent onto the second wall 112 to reduce the size of the electrochemical device 100 in the second direction Y. Specifically, the sealing portion 12 may include a sealing region 121 and a transition region 122 connected in the second direction Y, the transition region 122 also being connected to the receiving portion 11. The connection point between the transition region 122 and the receiving portion 11 is the aforementioned first connecting edge 120. Along the first direction X, the thickness of the transition region 122 is less than the thickness of the receiving portion 11 and greater than the thickness of the sealing region 121. At the transition region 122, the first polymer layer 101C of the first encapsulation film 101 is close to the second polymer layer 201C of the second encapsulation film 102, but the second polymer layer 201C is not adhered. When the sealing portion 12 is bent onto the second wall 112, the bend can actually be located in the transition region 122, thereby reducing the impact on the encapsulation strength of the sealing portion 12. When the second protrusion 114 protrudes from the first wall 111 in a direction away from the electrode assembly 20, the height h1 of the protrusion of the second protrusion 114 is set to satisfy: 0.1

[0063] ​As shown in Figure 12, in some embodiments, the structure of the second wall 112 can be modified. For example, the second wall 112 may include a first region 1121 and a second region 1122 respectively connected to the first connecting edge 120, with the first region 1121 and the second region 1122 located on both sides of the first connecting edge 120 along a first direction X. Specifically, the first region 1121 extends from the first connecting edge 120 along a first side X1, and the second region 1122 extends from the first connecting edge 120 along a second side X2. Along the first direction X, the width of the first region 1121 is greater than the width of the second region 1122. That is, the first region 1121 is a deep pit surface, and the second region 1122 is a shallow pit surface. In this case, the second protrusion 114 is provided in the first region 1121, thereby improving the structural strength and deformation resistance of the first region 1121, which is more prone to deformation. It is understood that in other embodiments, without considering the complexity of the manufacturing process, the second protrusion 114 can also be provided in the second region 1122, thereby further improving the structural strength and deformation resistance of the second wall 112 and reducing the risk of deformation of the second wall 112.

[0064] The electrochemical devices 100 and 200 of this application can be lithium secondary batteries, including lithium metal secondary batteries, lithium-ion secondary batteries, lithium polymer secondary batteries or lithium-ion polymer secondary batteries.

[0065] Referring to Figure 13, this application also provides a method for preparing the above-described electrochemical device 100 (or electrochemical device 200) according to one embodiment. Depending on different requirements, the order of steps in the preparation method can be changed, and some steps can be omitted or combined. The preparation method includes the following steps:

[0066] Step S1: Provide a multilayer encapsulation material, which includes a first encapsulation film 101 and a second encapsulation film 102. The first encapsulation film 101 includes a first body region 1011 and a first edge region 1012 connected to each other, and the second encapsulation film 102 includes a second body region 1021 and a second edge region 1022 connected to each other.

[0067] Step S2, the first main body area 1011 is stamped and formed by the forming mold 300.

[0068] Referring to Figure 14, the molding die 300 includes a male die 301 and a female die 302 disposed opposite to each other. The male die 301 includes a first molding body 3010, and the female die 302 includes a second molding body 3020. A molding portion 3030 protrudes from either the first molding body 3010 or the second molding body 3020. The first encapsulation film 101 can be placed on the second molding body 3020, and then the first molding body 3010 is pressed in a direction toward the second molding body 3020, so that the first main body area 1011 of the first encapsulation film 101 is pressed into the cavity of the second molding body 3020, forming a groove R. During the above-mentioned stamping process, the molding portion 3030 can simultaneously form a reinforcing portion 110 on the inner wall of the groove R. As shown in Figure 2A, in some embodiments, the inner wall of the groove R is the first wall 111.

[0069] For example, when it is necessary to form a reinforcing portion 110 protruding in the direction toward the electrode assembly 20 on the first wall 111, as shown in FIG14, a first molding body 3010 having a molding portion 3030 on its surface can be used. Thus, when the first molding body 3010 is stamped to form a groove R in the direction toward the second molding body 3020, the molding portion 3030 on the first molding body 3010 can simultaneously form the protruding reinforcing portion 110 on the inner wall of the groove R. Since the molding portion 3030 stamps the reinforcing portion 110 on the inner wall of the groove R, referring to FIGS. 2A and 7, along the first direction X, the reinforcing portion 110 is connected to one edge of the inner wall of the groove R.

[0070] When it is necessary to form a reinforcing portion 110 protruding in the direction away from the electrode assembly 20 on the first wall 111, as shown in FIG15, a second molding body 3020 having a molding portion 3030 on its surface can be used. In this way, when the first molding body 3010 stamps and forms a groove R in the direction toward the second molding body 3020, the molding portion 3030 on the second molding body 3020 can simultaneously form a recessed reinforcing portion 110 on the inner wall of the groove R.

[0071] Step S3: Connect the electrode assembly 20 to the conductive plate and place the electrode assembly 20 with the conductive plate in the groove R.

[0072] In step S4, the first encapsulation film 101 and the second encapsulation film 102 are placed opposite each other, and the first edge region 1012 and the second edge region 1022 are encapsulated to form a sealing part 12. The conductive plate extends out of the packaging bag 10 from the sealing part 12, and the second main body region 1021 and the first main body region 1011 with the groove R form a receiving part 11.

[0073] Referring to Figure 16, one embodiment of this application also provides an electronic device 1, which includes a battery compartment 1001 and the aforementioned electrochemical device 100 (or electrochemical device 200) disposed within the battery compartment 1001. The electrochemical device 100 of this application is applicable to electronic devices 1 in various fields. The electronic device 1 is powered by the aforementioned electrochemical device 100, and the deformation problem of the packaging bag 10 of the electrochemical device 100 is improved. In one embodiment, the electronic device 1 of this application may be, but is not limited to, a laptop computer, a pen input computer, a mobile computer, an e-book player, a portable telephone, a portable fax machine, a portable copier, a portable printer, a stereo headset, a video recorder, an LCD TV, a portable cleaner, a portable C-type device, a mini CD-ROM, a transceiver, an electronic notepad, a calculator, a memory card, a portable recorder, a radio, a backup power supply, a motor, a car, a motorcycle, an electric bicycle, a bicycle, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, household large-capacity batteries, and lithium-ion capacitors, etc.

[0074] The present application will be described in detail below through specific embodiments and comparative examples. The electrochemical device 100 is a stacked lithium-ion secondary battery, which is used as an example to illustrate the present application in conjunction with specific preparation processes and testing methods. Those skilled in the art should understand that the preparation methods described in this application are merely examples, and any other suitable preparation methods are within the scope of this application.

[0075] Example 1

[0076] (1) Preparation of the negative electrode sheet: The negative electrode active materials, artificial graphite, conductive carbon black (Super P), and styrene-butadiene rubber (SBR), were mixed in a weight ratio of 96:1.5:2.5. Deionized water was added as a solvent to prepare a slurry with a solid content of 50 wt%, and the mixture was stirred evenly. The slurry was uniformly coated on one surface of a copper foil with a thickness of 8 μm, leaving an empty foil area at the edge of the copper foil. The foil was dried at 110 °C to obtain a negative electrode sheet with a single-sided coating of negative electrode active material layer with a coating thickness of 100 μm. The above steps were repeated on the other surface of the negative electrode sheet to obtain a negative electrode sheet with a double-sided coating of negative electrode active material layer. Then, the excess empty foil area was removed by laser die-cutting to obtain the negative electrode tab.

[0077] (2) Preparation of the positive electrode sheet: Lithium cobalt oxide (LiCoO2), conductive carbon black (Super P), and polyvinylidene fluoride (PVDF) were mixed in a weight ratio of 97.5:1.0:1.5. N-methylpyrrolidone (NMP) was added as a solvent to prepare a slurry with a solid content of 75 wt%, and the mixture was stirred evenly. The slurry was uniformly coated on one surface of an aluminum foil with a thickness of 10 μm, leaving an empty foil area at the edge of the aluminum foil. The foil was dried at 90 °C to obtain a positive electrode sheet with a positive active material layer thickness of 90 μm. The above steps were repeated on the other surface of the positive current collector aluminum foil to obtain a positive electrode sheet with a positive active material layer coated on both sides. Then, the excess empty foil area was removed by laser die-cutting to obtain the positive electrode tab.

[0078] (3) Preparation of electrolyte: In a dry argon atmosphere, the organic solvents ethylene carbonate (EC), ethyl methyl carbonate (EMC) and diethyl carbonate (DEC) are first mixed in a mass ratio of EC:EMC:DEC = 30:50:20. Then, lithium salt lithium hexafluorophosphate (LiPF6) is added to the organic solvent to dissolve and mix evenly to obtain an electrolyte with a lithium salt concentration of 1.15 mol / L.

[0079] (4) Assembly of the electrode assembly: The negative electrode, the separator, and the positive electrode are stacked sequentially to obtain the electrode assembly. The separator is a 5μm thick polyethylene (PE) film. The positive and negative electrode tabs are welded to the first and second conductive plates respectively by adapter welding. The first conductive plate is made of aluminum, and the second conductive plate is made of nickel. The first encapsulation film (aluminum-plastic film, 115μm thick) is punched into a groove using a forming mold. The forming mold simultaneously forms a certain number of mutually spaced first protrusions on the inner wall of the groove. Then the electrode assembly is placed in the groove.

[0080] (5) Liquid injection and encapsulation: Electrolyte is injected into the groove of the first encapsulation film, the first encapsulation film and the second encapsulation film are arranged opposite to each other, and the first edge area and the second edge area are encapsulated to obtain a packaging bag. The first protrusion is integrally disposed on the first wall of the packaging bag and protrudes from the first wall in the direction away from the electrode assembly. The first conductive plate and the second conductive plate extend out of the packaging bag from the second wall to obtain the secondary battery shown in Figures 1 to 3.

[0081] Example 2

[0082] The difference from Embodiment 1 is that the first protrusion is replaced by a second protrusion integrally disposed on the second wall of the packaging bag, and the second protrusion protrudes from the second wall in a direction away from the electrode assembly.

[0083] Comparative Example 1

[0084] The difference from Embodiment 1 is that a traditional molding die is used to punch a groove in the first packaging film, so that the packaged bag does not have a first recess.

[0085] Then, the secondary batteries prepared in each embodiment and comparative example were subjected to energy density test, drop test and cycle performance test, and the test results are recorded in Table 1.

[0086] The energy density testing procedure includes: charging the secondary battery at a constant current of 0.7C to 4.50V at a test temperature of 25℃, then charging it at a constant voltage of 4.50V to 0.05C, letting it stand for 5 minutes, discharging it at a constant current of 0.2C to 3.0V, and letting it stand for 5 minutes to obtain the discharge capacity D of the secondary battery. After charging the secondary battery at a constant current of 0.7C to 3.95V, and then charging it at a constant voltage of 3.95V to 0.05C, the length, width, and height of the secondary battery are measured using a laser thickness gauge to calculate the volume V of the secondary battery. The energy density (ED) = D / V, with units of Wh / L.

[0087] The drop test procedure is as follows: 1) Under environmental conditions of 23±2℃, record the open-circuit voltage and internal resistance of the secondary battery (the testing instrument is a voltage-resistance tester, manufacturer: Dongguan Lijia Precision Instrument Co., Ltd., model: LNG-SY1-0020-DQ); 2) Place the secondary battery into the clamping chamber, and use an automatic drop device to drop the clamping chamber containing the secondary battery sequentially from a position of 1m onto the concrete base, with the bottom, left, right, back, front, and top surfaces of the clamping chamber as one landing surface. The cycle consists of 3 rounds of drops, totaling 18 times; 3) The clamp head is dropped from a position of 1.5m onto the concrete base in sequence, with the bottom, left, right, back, front, and top surfaces as one round of landing. One cycle consists of 3 rounds of drops, totaling 18 times; 4) The voltage of the secondary battery is measured after each round of drops. If the secondary battery catches fire or explodes, the drop is stopped; otherwise, the drop continues; 5) After the drop test is completed, observe whether the first or second wall of the packaging bag has collapsed. If not, the secondary battery is considered to have passed the drop test.

[0088] The cycle performance test is a capacity retention test, and the test steps are as follows: 1) At a test temperature of 25℃, the secondary battery is left to stand for 5 minutes, then charged at a constant current of 3.4C to 4.25V, then charged at 2C to 4.4V, then charged at 1C to 4.50V, then charged at a constant voltage of 4.50V to 0.05C, and then discharged at a constant current of 0.5C to 3.0V. The discharge capacity C of the secondary battery is recorded. 11 ;2) After 400 cycles of the above 3.4C charge / 0.5C discharge cycle, record the discharge capacity C of the secondary battery. 12 Calculate the capacity retention rate (%) after 400 cycles = C12 / C 11 ×100%.

[0089] Table 1

[0090] In the table above, the drop test pass rate of 9 / 10 indicates that 9 out of 10 secondary batteries tested passed the test. The meanings of other percentage values ​​follow the same logic.

[0091] As shown in Table 1, compared to Comparative Example 1, Examples 1-3 have reinforcing portions on the first and second walls, respectively, which improves the structural strength and deformation resistance of the first and second walls, resulting in a higher drop test pass rate for the secondary batteries. Compared to Example 3, the reinforcing portions (i.e., the first protrusions) in Examples 1-2 protrude away from the electrode assembly, thus not occupying internal space in the packaging bag and also accommodating some free electrolyte, resulting in higher energy density and cycle capacity protection rate for the secondary batteries.

[0092] Example 4-26

[0093] The difference from Embodiment 1 is the values ​​of the included angle α, width W, length L, or height h1 of the first protrusion.

[0094] Then, energy density tests and drop tests were conducted on the secondary batteries prepared in each embodiment and comparative example, and the test results are recorded in Table 2.

[0095] Table 2

[0096] As shown in Table 2, compared to Example 7, the included angle α of the first protrusion in Examples 1 and 4-6 satisfies 45°≤α≤90°, which improves the structural strength and deformation resistance of the first wall, resulting in a higher drop test pass rate for the secondary battery. Furthermore, because the extension direction of the first protrusion in Examples 1 and 4-5 is inclined, the first protrusion can accommodate more free electrolyte, thus resulting in a higher cycle capacity retention rate for the secondary battery.

[0097] Compared to Examples 12-13, the width W of the first protrusion in Examples 1 and 8-11 satisfies: 0.1W0≤W≤0.9W0, which improves the structural strength and deformation resistance of the first wall, thus resulting in a higher pass rate for the drop test of the secondary battery.

[0098] Compared to Examples 18-19, the length L of the first protrusion in Examples 1 and 14-17 satisfies: 0.1L0≤L≤0.9L0, which improves the structural strength and deformation resistance of the first wall, thus resulting in a higher pass rate for the drop test of the secondary battery.

[0099] Compared to Examples 25-26, the height h1 of the first protrusion in Examples 1 and 20-24 satisfies: 0.1mm.

[0100] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with this application are still within the scope of this application.​

Claims

1. An electrochemical device comprising a packaging bag, an electrode assembly, and a conductive plate, wherein the electrode assembly is disposed within the packaging bag, and the conductive plate is electrically connected to the electrode assembly, wherein... The packaging bag includes a receiving portion for accommodating the electrode assembly and a sealing portion connecting the receiving portion, and the conductive plate extends out of the packaging bag from the sealing portion; The first direction is the thickness direction of the electrode assembly, and the second direction is perpendicular to the first direction and is the direction in which the conductive plate protrudes from the electrode assembly. The receiving portion includes a first wall and a second wall disposed opposite to each other along the second direction. The receiving portion further includes a reinforcing portion, the reinforcing portion including at least one first protrusion integrally disposed on the first wall, the first wall including a first surface and a second surface disposed opposite to each other along the second direction, the first protrusion forming a first protrusion on the first surface and forming a first depression on the second surface, and when viewed from the second direction, the first protrusion and the first depression formed by the first protrusion overlap.

2. The electrochemical device as claimed in claim 1, wherein, The first protrusion protrudes from the first wall in a direction away from the electrode assembly.

3. The electrochemical device as described in claim 1 or 2, wherein, The sealing part is connected to the second wall.

4. The electrochemical device as described in claim 3, wherein, The reinforcing part further includes at least one second protrusion integrally disposed on the second wall. The second wall includes a third surface and a fourth surface disposed opposite to each other along the second direction. The second protrusion forms a second protrusion on the third surface and a second depression on the fourth surface. When viewed from the second direction, the second protrusion and the second depression formed by the second protrusion overlap.

5. The electrochemical device as described in claim 4, wherein, The sealing portion includes a first connecting edge integrally connected to the receiving portion, and the second wall includes a first region and a second region respectively connected to the first connecting edge. The first region and the second region are respectively located on both sides of the first connecting edge along the first direction. Along the first direction, the width of the first region is greater than the width of the second region. The at least one second protrusion is provided in the first region.

6. The electrochemical device according to any one of claims 1 to 5, wherein, Viewed from the second direction, the reinforcing part is strip-shaped; the angle between the extending direction of the reinforcing part and the third direction is α, 45°≤α≤90°, and the third direction is perpendicular to the first direction and the second direction respectively.

7. The electrochemical device as claimed in claim 6, wherein, The width of the reinforcing part along the third direction is W, and the dimension of the first wall or the second wall along the third direction is W0, where 0.1W0≤W≤0.9W0.

8. The electrochemical device as claimed in claim 7, wherein, 0.5mm≤W≤95mm.

9. The electrochemical device according to any one of claims 6 to 8, wherein, The distance between two adjacent reinforcing parts on the first wall or the second wall along the third direction is D, and the dimension of the first wall or the second wall along the third direction is W0, where 0.1W0≤D≤0.9W0.

10. The electrochemical device according to any one of claims 6 to 9, wherein, The length of the reinforcing part is L, and the dimension of the first wall or the second wall along the first direction is L0, where 0.1L0≤L≤0.9L0.

11. The electrochemical device of claim 10, wherein, 1mm≤L≤15mm.

12. The electrochemical device according to any one of claims 1 to 11, wherein, The height of the protruding reinforcement is h1, where 0.1 ≤ h1 ≤ 2 mm.

13. An electronic device comprising a receiving compartment, wherein, The electronic device further includes an electrochemical device as described in any one of claims 1 to 12, the electrochemical device being disposed within the containment chamber.

14. A method for preparing an electrochemical device as described in any one of claims 1 to 12, wherein, Includes the following steps: A multilayer encapsulation material is provided, the multilayer encapsulation material including a first encapsulation film and a second encapsulation film, the first encapsulation film including a first body region and a first edge region connected together, and the second encapsulation film including a second body region and a second edge region connected together; At least the first main body area is stamped by a forming mold, the forming mold including a male mold and a female mold arranged opposite to each other, the male mold including a first forming body, the female mold including a second forming body, a forming part protruding on the first forming body or the second forming body, the first forming body and the second forming body cooperating to form a groove on the first main body area, the forming part forming the reinforcing part on the inner wall of the groove; The electrode assembly is electrically connected to the conductive plate, and the electrode assembly with the conductive plate is placed in the groove; as well as The first encapsulation film and the second encapsulation film are placed opposite each other, and the first edge area and the second edge area are encapsulated to form the sealing portion. The conductive plate extends out of the packaging bag from the sealing portion. The second body area and the first body area with the groove form the receiving portion.

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