Electrochemical and electronic devices

Abstract

An electrochemical device and an electronic device, the electrochemical device includes a housing, an electrode assembly, and a first conductive plate. The housing includes a main body and a seal structure. The main body includes a first end wall and a second end wall arranged opposite to each other in a first direction, a first wall and a second wall arranged opposite to each other in a second direction, and a first side wall and a second side wall arranged opposite to each other in a third direction. The seal structure includes a first seal portion connected to the first end wall and a second seal portion connected to the first side wall. The first seal portion is folded back toward a connection point between the first wall and the first end wall, and / or the second seal portion is folded back toward a connection point between the first wall and the first side wall. The first conductive plate includes a first surface facing the first wall and a second surface facing the second wall. The insulating rubber connects the first conductive plate and the first seal portion, and includes a first layer connected to the first surface and a second layer connected to the second surface. The second region of the second layer overlaps the first layer, and the first region extends from the second region toward the electrode assembly and beyond the first layer.

Description

[Technical Field]

[0001] This application relates to the technical field of energy storage, and in particular to electrochemical devices and electronic devices comprising the same. [Background technology]

[0002] With the widespread use of consumer electronic products such as laptops, mobile phones, handheld game consoles, tablet computers, mobile power supplies, drones, and electric vehicles, users' requirements for electrochemical devices (e.g., lithium-ion batteries) are becoming increasingly stringent.

[0003]

[0003] An electrochemical device generally includes a housing, an electrode assembly disposed within the housing, and a conductive plate extending from the housing and electrically connected to the electrode assembly. When the electrochemical device is subjected to mechanical abuse such as dropping or rolling, stress may be concentrated on the conductive plate, causing breakage and further failure of the electrochemical device, which may affect the safety reliability and service life of the electrochemical device. Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the deficiencies of the prior art, the present invention aims to provide an electrochemical device that can avoid the deficiencies of the prior art. There is also a need to provide an electronic device that includes the above electrochemical device. [Means for solving the problem]

[0005] The electrochemical device according to the present application includes a housing, an electrode assembly, and a first conductive plate. The housing includes a main body and a seal structure connected to the main body. The electrode assembly is disposed inside the main body. The first conductive plate is electrically connected to the electrode assembly and protrudes from the housing through the seal structure. The direction in which the first conductive plate protrudes from the electrode assembly is defined as a first direction, the thickness direction of the electrode assembly is defined as a second direction, and a direction perpendicular to the first and second directions is defined as a third direction. The main body includes a first end wall and a second end wall arranged opposite each other in the first direction, a first wall and a second wall arranged opposite each other in the second direction, and a first side wall and a second side wall arranged opposite each other in the third direction. The seal structure includes a first seal connected to the first end wall and a second seal connected to the first side wall. The first conductive plate protrudes from the housing through the first seal. The first sealing portion is folded back toward a first connection point between the first wall and the first end wall, and / or the second sealing portion is folded back toward a second connection point between the first wall and the first side wall. The first conductive plate has a first surface and a second surface facing each other in the second direction, with the first surface within the body portion facing the first wall and the second surface within the body portion facing the second wall. The electrochemical device also includes an insulating rubber sealingly connecting the first conductive plate and the first sealing portion. The insulating rubber includes a first layer and a second layer, with the first layer connecting to the first surface and the second layer connecting to the second surface. The second layer includes a first region and a second region that are connected to each other in the first direction. When viewed in the second direction, the second region overlaps the first layer, and the first region extends from the second region toward the electrode assembly and beyond the first layer.

[0006] Considering that the direction in which the first conductive plate breaks is consistent with the bending direction of the seal structure, the present application extends the second layer covering the second surface of the insulating rubber so that the second layer includes a first region that exceeds the first layer in the first direction. When the electrochemical device is mechanically abused and the electrode assembly is rocked within the housing, on the one hand, the first region that exceeds the first layer can preferentially distribute at least a portion of the stress conducted toward the first conductive plate, improving the problem of stress concentration at the lower edge where the first conductive plate and the insulating rubber contact, thereby reducing the risk of the first conductive plate being fatigued and breaking due to stress. On the other hand, because the extended first region covers the first conductive plate, the toughness of the first conductive plate can be further increased, further reducing the risk of the first conductive plate being fatigued and breaking due to stress.

[0007] In some possible embodiments, the electrode assembly includes a first electrode sheet, the first electrode sheet including a laminated first current collector and a first active material layer, the first current collector including an exposed blank area in the first active material layer, and a first conductive plate welded to the blank area to increase connection strength of the first conductive plate.

[0008] In some possible embodiments, the first region and the first electrode sheet are spaced apart from each other in the first direction, thereby reducing the risk that the first region will cover part of the active material layer and affect the capacity of the electrochemical device.

[0009] In some possible embodiments, the width W1 of the first region in the third direction is smaller than the width W2 of the second region, thereby reducing the waste of insulating rubber material when the width W1 is too large.

[0010] In some possible embodiments, 2 mm≦W2−W1≦5 mm, which can reduce the risk that the first region cannot sufficiently cover the first conductive plate if the width W1 is too small, and can also reduce the waste of insulating rubber material if the width W1 is too large.

[0011] In some possible embodiments, in the third direction, the first region includes a first side and a second side that are relatively arranged, and where L1 is the distance between the first side and the first conductive plate and L2 is the distance between the second side and the first conductive plate, 0.1 mm≦L1≦0.6 mm and 0.1 mm≦L2≦0.6 mm are satisfied. In this way, if the distances L1 and L2 are too small, the risk that the first region will not sufficiently cover the first conductive plate can be reduced, and if the distances L1 and L2 are too large, waste of insulating rubber material can also be reduced.

[0012] In some possible embodiments, in the third direction, the first region includes a first side and a second side arranged opposite each other, the second region includes a third side connected to the first region, an arc angle is formed between the first side and the third side, and an arc angle is formed between the second side and the third side.

[0013] In some possible embodiments, where L0 is the length of the first region in the first direction, L0≧1 mm, such that the second layer is sufficiently longer than the first layer to allow the first region to better distribute at least a portion of the stress conducted toward the first conductive plate.

[0014] In some possible embodiments, L0≦3 mm. To ensure higher energy density, the volume of the battery is limited and it is necessary to minimize wasted space. If L0 is too large, the first region will cover the first electrode sheet, increasing the thickness of the electrochemical device and risking a decrease in volumetric energy density.

[0015] The present application also provides an electronic device including a housing box and the electrochemical device as described above, the electrochemical device being disposed in the housing box, the electronic device being powered by the electrochemical device, and having improved safety reliability and service life due to a reduced risk of breakage of the first conductive plate in the electrochemical device. [Brief explanation of the drawings]

[0016] [Figure 1]1 is a structural schematic diagram of an electrochemical device provided by an embodiment of the present application; [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of the electrochemical device shown in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line III-III of the electrochemical device shown in FIG. [Figure 4] 10A and 10B are structural schematic diagrams of electrochemical devices in some other embodiments. [Figure 5] FIG. 5 is a cross-sectional view taken along line VV of the electrochemical device shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI of the electrochemical device shown in FIG. [Figure 7] 3 is a front view of a portion of a first electrode sheet to which a first conductive plate is connected in the electrochemical device shown in FIG. 2. FIG. [Figure 8] FIG. 8 is a side view of the first conductive plate shown in FIG. 7. [Figure 9] 1 is a structural schematic diagram of an electronic device provided by an embodiment of the present application; [Figure 10] FIG. 10 is a cross-sectional view of the electronic device shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present application will be further described with reference to the above-mentioned drawings with respect to the following specific embodiments.

[0018] Hereinafter, technical aspects of the embodiments of the present application will be described clearly and in detail. Obviously, the described embodiments are only some of the embodiments of the present application, and not all of the embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art of the present application. The terms used in the specification of the present application are only for describing specific embodiments and are not intended to limit the present application.

[0019] The following detailed description of the present application will be given with reference to the preferred embodiments. However, the present application may be embodied in many different forms and should not be construed as being limited to the exemplary embodiments set forth herein. Instead, these exemplary embodiments are provided so that the present application will be fully and completely conveyed to those skilled in the art.

[0020] Additionally, for brevity and clarity, the figures may exaggerate the sizes or thicknesses of various components, layers. Like numbers refer to like elements throughout. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Furthermore, when element A is described as "connecting" element B, it should be understood that element A may be directly connected to element B, or there may be an intermediate element C, such that elements A and B may be indirectly connected to each other.

[0021] Furthermore, when describing embodiments of the present application, the use of "possible" means "one or more examples of the present application."

[0022] The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting of the present application. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. Furthermore, it should be understood that the term "comprises," as used herein, refers to the presence of stated features, values, steps, operations, elements, and / or components, but does not exclude the presence or increment of one or more other features, values, steps, operations, elements, components, and / or combinations thereof.

[0023] Spatially related terms, such as "above," may be used herein for brevity to describe the relationship of one element or feature to another element(s) or feature(s), as illustrated in the figures. It should be understood that these spatially related terms are intended to encompass different orientations of a device or apparatus in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures were inverted, elements described as "above" or "on" other elements or features would be oriented "below" or "below" the other elements or features. Thus, the exemplary term "above" can encompass an orientation of above and below. Terms such as first, second, and third may be used herein to describe various elements, components, regions, layers, and / or portions, but it should be understood that 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. Thus, a first element, component, region, layer or section discussed below could be described as a second element, component, region, layer or section without departing from the teachings of the example embodiments.

[0024] As shown in FIGS. 1 to 3 , an electrochemical device 100 according to one embodiment of the present disclosure includes a housing 10, an electrode assembly 20, a first conductive plate 30, and a second conductive plate 40. The electrode assembly 20 is located within the housing 10. The first conductive plate 30 and the second conductive plate 40 are both electrically connected to the electrode assembly 20 and protrude from the housing 10. The first conductive plate 30 and the second conductive plate 40 can be connected to an external device (not shown). In some embodiments, the electrode assembly 20 may have a wound structure. Specifically, as shown in FIGS. 2 and 3 , the electrode assembly 20 includes a first electrode sheet 21, a second electrode sheet 22, and a separation film 23. The first electrode sheet 21, the separation film 23, and the second electrode sheet 22 are sequentially stacked and wound. The separation film 23 is used to prevent direct contact between the first electrode sheet 21 and the second electrode sheet 22, thereby reducing the risk of short-circuiting the electrode assembly 20. The first conductive plate 30 is electrically connected to the first electrode sheet 21, and the second conductive plate 40 is electrically connected to the second electrode sheet 22. In some other embodiments, the electrode assembly 20 may have a laminated structure, i.e., the first electrode sheet 21, the separator film 23, and the second electrode sheet 22 may be laminated in sequence.

[0025] The first electrode sheet 21 includes a first active material layer 211, a first current collector 210, and a second active material layer 212, which are stacked together. In some embodiments, the first current collector 210 includes a blank area 2100 exposed to the first active material layer 211. The first conductive plate 30 includes a first surface 31 and a second surface 32 arranged opposite each other. The first conductive plate 30 is welded to the blank area 2100 via the second surface 32, thereby increasing the connection strength between the first conductive plate 30 and the first current collector 210. Here, the blank area 2100 refers to a region of the first current collector 210 where the first active material layer 211 is not provided. The blank area 2100 may be formed by applying the first active material layer 211 to the first current collector 210 and then cleaning the first active material layer 211 at a position corresponding to the blank area 2100 to expose a portion of the first current collector 210, or by applying a foaming agent to a position corresponding to the blank area 2100, applying the first active material layer 211, and then heating the foaming agent to remove the foaming agent and the first active material layer 211 attached thereto. In some other embodiments, the first conductive plate 30 may be formed integrally with the first current collector 210 (i.e., the first conductive plate 30 is formed by cutting the first current collector 210).

[0026] The second electrode sheet 22 includes a third active material layer 221, a second current collector 220, and a fourth active material layer 222, which are stacked. The first active material layer 211 faces the third active material layer 221, and the second active material layer 212 faces the fourth active material layer 222. The second conductive plate 40 may be welded to or integrally formed with the second current collector 220. In some embodiments, the first electrode sheet 21 is a negative electrode sheet, and the second electrode sheet 22 is a positive electrode sheet. In other embodiments, the first electrode sheet 21 is a positive electrode sheet, and the second electrode sheet 22 is a negative electrode sheet.

[0027] As shown in FIGS. 1 to 3 , the housing 10 includes a main body 11 and a seal structure 12. The electrode assembly 20 is provided within the main body 11. When manufacturing the housing 10, a sheet of sealing film is folded in half, and a sealing head of a sealing device is used to simultaneously apply a certain temperature and pressure to the edge of the folded sealing film, thereby obtaining the seal structure 12. The direction in which the first conductive plate 30 or the second conductive plate 40 protrudes from the electrode assembly 20 (i.e., the direction from the electrode assembly 20 to the first conductive plate 30 or the second conductive plate 40) is defined as a first direction X, the thickness direction of the electrode assembly 20 is defined as a second direction Y, and the direction perpendicular to the first direction X and the second direction Y is defined as a third direction Z. The third direction Z is also the direction from the second conductive plate 40 toward the first conductive plate 30.

[0028] The main body 11 includes a first end wall 111 and a second end wall 112 that are disposed opposite each other in the first direction X. The surface on which the first end wall 111 is located extends in the second direction Y and the third direction Z, and the surface on which the second end wall 112 is located extends in the second direction Y and the third direction Z. The main body 11 further includes a first wall 113 and a second wall 114 that are disposed opposite each other in the second direction Y. The surface on which the first wall 113 is located extends in the first direction X and the third direction Z, and the surface on which the second wall 114 is located extends in the first direction X and the third direction Z. The first wall 113 is connected between the first end wall 111 and the second end wall 112 in the first direction X. The second wall 114 is connected between the first end wall 111 and the second end wall 112 in the first direction X. A first surface 31 of the first conductive plate 30 located within the main body 11 faces the first wall 113, and a second surface 32 of the first conductive plate 30 located within the main body 11 faces the second wall 114. The main body 11 further includes a first side wall 115 and a second side wall 116 opposed to each other in the third direction Z. The surface on which the first side wall 115 is located extends in the first direction X and the second direction Y, and the surface on which the second side wall 116 is located extends in the first direction X and the second direction Y. The first side wall 115 is connected between the first end wall 111 and the second end wall 112 in the first direction X. The second side wall 116 is connected between the first end wall 111 and the second end wall 112 in the first direction X.

[0029] The seal structure 12 includes a first seal portion 121 connected to the first end wall 111 and a second seal portion 122 connected to the first side wall 115. The first conductive plate 30 and the second conductive plate 40 both protrude from the housing 10 through the first seal portion 121. In some embodiments, the seal structure 12 may further include a third seal portion 123 connected to the second side wall 116.

[0030] In the present application, in order to increase the space utilization rate and energy density of the electrochemical device, at least a portion of the seal structure 12 is folded back in a direction approaching the first wall 113. As shown in FIGS. 1 to 3 , in some embodiments, the first seal portion 121 can be folded back to the first end wall 111. Specifically, the first seal portion 121 is folded back in a direction approaching a first connection point C1 between the first wall 113 and the first end wall 111. At this time, the direction in which the first conductive plate 30 protrudes within the first seal portion 121 changes. Furthermore, the first direction X is the direction in which the first conductive plate 30 protrudes from the electrode assembly 20 (i.e., the direction from the electrode assembly 20 to the first conductive plate 30), and is also the direction in which the first conductive plate 30 protrudes from within the first seal portion 121 when the first seal portion 121 is folded back to a state perpendicular to the first end wall 111 (when the first seal portion 121 is not folded back). In this application, the first connection point C1 refers to the position where both the first wall 113 and the first end wall 111 are connected, and the first connection point C1 may be an arc surface extending entirely along the third direction Z, or may be a straight line extending along the third direction Z.

[0031] As shown in FIGS. 4 to 6 , in some other embodiments, the second seal portion 122 can be folded up to the first side wall 115, eliminating the need to fold the first seal portion 121. This reduces the dimension of the electrochemical device 100 in the third direction Z, thereby improving space utilization and energy density. Specifically, the second seal portion 122 is folded back toward the second connection point C2 between the first wall 113 and the first side wall 115. In the present application, the second connection point C2 refers to the position where both the first wall 113 and the first side wall 115 are connected. The second connection point C2 may be an arcuate surface extending entirely along the first direction X, or a straight line extending along the first direction X. When the seal structure 12 further includes a third seal portion 123, the third seal portion 123 may be folded back toward the third connection point C3 between the first wall 113 and the second side wall 116. In this application, the third connection point C3 refers to the position where both the first wall 113 and the second side wall 116 are connected, and the third connection point C3 may be an arc surface extending entirely along the first direction X, or may be a straight line extending along the first direction X.

[0032] In another embodiment, the first sealing portion 121 is folded to the first end wall 111 and the second sealing portion 122 is folded to the first side wall 115, thereby simultaneously reducing the dimensions of the electrochemical device 100 in the first direction X and the third direction Z.

[0033] 2, 7, and 8. The electrochemical device 100 further includes a first insulating rubber 50. The first insulating rubber 50 hermetically connects the first conductive plate 30 and the first sealing portion 121 and maintains electrical insulation between the first conductive plate 30 and the housing 10. Specifically, the first insulating rubber 50 fills any gaps that may exist between the first conductive plate 30 and the first sealing portion 121, thereby hermetically connecting the first conductive plate 30 and the housing 10 and reducing the possibility of separation between the first conductive plate 30 and the first sealing portion 121 during subsequent use. In some embodiments, the material of the first insulating rubber 50 is selected from at least one of polypropylene, polyethylene, polyethylene terephthalate, polyethylene naphthalate, a polypropylene-modified material, and a polyethylene-modified material. As shown in FIG. 1, the electrochemical device 100 may further include a second insulating rubber 60. The second insulating rubber 60 connects the second conductive plate 40 and the first seal portion 121 to seal them, and can also electrically insulate the second conductive plate 40 from the housing 10 .

[0034] As shown in FIGS. 2, 7, and 8, the first insulating rubber 50 includes a first layer 51 and a second layer 52. The first layer 51 is connected to the first surface 31, and the second layer 52 is connected to the second surface 32. When viewed from the second direction Y, the first layer 51 may be substantially rectangular, and the second layer 52 may be substantially T-shaped. The second layer 52 includes a first region 521 and a second region 522 that are connected to each other in the first direction X. When viewed from the second direction Y, the second region 522 overlaps with the first layer 51, and the first region 521 extends from the second region 522 toward the electrode assembly 20. That is, when viewed from the second direction Y, the second layer 52 extends from the region where it overlaps with the first layer 51 toward the electrode assembly 20 until it exceeds the first layer 51.

[0035] In the prior art, the lower edge where the first conductive plate and the insulating rubber contact is the starting point of the bond, making it prone to stress concentration. When an electrochemical device is subjected to mechanical abuse, the electrode assembly swings within the housing, pulling on the first conductive plate. This stress is then transmitted to the first conductive plate, making it prone to stress concentration at the lower edge where the first conductive plate and the insulating rubber meet, resulting in fatigue fracture of the first conductive plate. Furthermore, through multiple experiments, the inventors of the present application have found that the fracture direction of the first conductive plate coincides with the bending direction of the sealing structure. For example, when the sealing structure is bent toward the first wall, mechanical abuse causes the first conductive plate to typically begin to fracture from the second surface toward the first surface due to stress. That is, the second surface is the surface where the first conductive plate begins to fracture due to stress.

[0036] Therefore, in the present application, the second layer 52 covering the second surface 32 of the first insulating rubber 50 is extended so that the second layer 52 includes a first region 521 extending beyond the first layer 51 in the first direction X. When the electrochemical device 100 is subjected to mechanical abuse, causing the electrode assembly 20 to rock within the housing 10, the first region 521 extending beyond the first layer 51 can preferentially distribute at least a portion of the stress conducted toward the first conductive plate 30, alleviating the problem of stress concentration at the lower edge of the first conductive plate 30 that contacts the first insulating rubber 50, thereby reducing the risk of fatigue fracture of the first conductive plate 30 due to stress. Meanwhile, because the extended first region 521 covers the first conductive plate 30 and increases the area of ​​the first conductive plate 30 covered by the first insulating rubber 50, the toughness of the first conductive plate 30 can be further increased, further reducing the risk of fatigue fracture of the first conductive plate 30 due to stress. The second insulating rubber 60 may have a structure similar to that of the first insulating rubber 50 in order to reduce the risk of fatigue fracture of the second conductive plate 40 due to stress.

[0037] 7, the first region 521 and the first electrode sheet 21 are spaced apart in the first direction X. That is, when viewed from the second direction Y or the third direction Z, the first region 521 and the first electrode sheet 21 do not overlap. This reduces the risk that the first region 521 will cover a portion of the active material layer and affect the capacity of the electrochemical device 100.

[0038] 7 and 8 , in some embodiments, the length of the first region 521 in the first direction X is set to L0 (L0≧1 mm), allowing the second layer 52 to be a sufficient distance from the first layer 51, and at least a portion of the stress transmitted toward the first conductive plate 30 to be better dispersed to the first region 521. Furthermore, the length L0 of the first region 521 may be set to satisfy 1 mm≦L0≦3 mm. To ensure higher energy density, the volume of the battery is limited, and wasted space should be minimized. If L0 is too large, the first region 521 will cover the first electrode sheet 21, increasing the thickness of the electrochemical device 100 and potentially reducing the volumetric energy density.

[0039] As shown in FIG. 7 , in some embodiments, the width W1 of the first region 521 is smaller than the width W2 of the second region 522 in the third direction Z. This reduces the waste of insulating material in the first insulating rubber 50 due to the width W1 of the first region 521 being too large. Furthermore, 2 mm≦W2−W1≦5 mm may be satisfied. For example, in some specific embodiments, W2−W1 may be 2 mm, 3 mm, 4 mm, or 5 mm. This reduces the risk that the first region 521 will not adequately cover the first conductive plate 30 if the width W1 is too small, and also reduces the waste of insulating material in the first insulating rubber 50 if the width W1 is too large.

[0040] As shown in FIG. 7 , in some embodiments, the first region 521 includes a first side 5211 and a second side 5212 that are disposed opposite each other in the third direction Z. If the distance between the first side 5211 and the first conductive plate 30 is L1 and the distance between the second side 5212 and the first conductive plate 30 is L2, then 0.1 mm≦L1≦0.6 mm and 0.1 mm≦L2≦0.6 mm are satisfied. For example, in some specific embodiments, L1 and L2 may be 0.1 mm, 0.3 mm, 0.5 mm, or 0.6 mm, respectively. In this way, if the distances L1 and L2 are too small, the risk of the first region 521 not being able to fully cover the first conductive plate 30 can be reduced. Furthermore, if the distances L1 and L2 are too large, the waste of insulating material in the first insulating rubber 50 can be reduced.

[0041] In some embodiments, the second region 522 includes a third side 5220 that connects to the first region 521. The radius of the arc angle formed between the first side 5211 and the third side 5220 is R1, and the radius of the arc angle formed between the second side 5212 and the third side 5220 is R2, where 0 mm≦R1≦0.05 mm and 0 mm≦R2≦0.05 mm are satisfied. Setting the arc angles reduces the risk of stress concentration occurring at the intersection between the first side 5211 and the third side 5220 and the intersection between the second side 5212 and the third side 5220. Furthermore, by setting the magnitudes of the radii R1 and R2 of the arc angles, it is possible to reduce the risk of stress concentration at the points where the first side 5211 and the third side 5220 intersect and where the second side 5212 and the third side 5220 intersect, and it is also possible to reduce the risk that if the radii R1 and R2 are too large, the length L0 of the first region 521 will increase accordingly and cover part of the active material layer.

[0042] As shown in FIGS. 2 and 3 , in some embodiments, the electrochemical device 100 further includes an adhesive layer 70 positioned within the housing 10. The adhesive layer 70 bonds the electrode assembly 20 to the first wall 113. The adhesive layer 70 is used to secure the electrode assembly 20 to the housing 10 and reduces shaking of the electrode assembly 20 within the housing 10 during mechanical abuse. In some embodiments, the material of the adhesive layer 70 is selected from at least one of polypropylene, polyethylene, polyethylene terephthalate, polyethylene naphthalate, a polypropylene-modified material, and a polyethylene-modified material. Specifically, the adhesive layer 70 may be double-sided tape or a hot melt adhesive. In some specific embodiments, the outermost layer of the electrode assembly 20 may be a separator film 23. The adhesive layer 70 bonds the separator film 23 to the first wall 113.

[0043] Here, the electrochemical device 100 of the present application includes all devices capable of causing an electrochemical reaction. Specifically, the electrochemical device 100 includes all types of primary batteries, secondary batteries, fuel cells, solar cells, and capacitors (e.g., supercapacitors). Optionally, the electrochemical device 100 may be a lithium secondary battery, including a lithium metal secondary battery, a lithium ion secondary battery, a lithium polymer secondary battery, and a lithium ion polymer secondary battery.

[0044] 9 and 10, an embodiment of the present application further provides an electronic device 1, including a battery box 101 and an electrochemical device 100 disposed in the battery box 101. The electronic device 1 is powered by the electrochemical device 100. The risk of the first conductive plate 30 in the electrochemical device 100 being broken is reduced, thereby improving safety reliability and service life.

[0045] 10 , in some embodiments, the electronic device 1 further includes an adhesive layer 102 for adhering the second wall 114 of the electrochemical device 100 to the battery box 101. The adhesive layer 102 is used to secure the electrochemical device 100 within the battery box 101 and reduces the electrochemical device 100 from shaking within the battery box 101 during mechanical abuse. In some embodiments, the material of the adhesive layer 102 is selected from at least one of polypropylene, polyethylene, polyethylene terephthalate, polyethylene naphthalate, a polypropylene-modified material, and a polyethylene-modified material. Specifically, the adhesive layer 102 may be a double-sided tape or a hot melt adhesive.

[0046] The electrochemical device 100 of the present application can be applied to electronic devices 1 in various fields. In one embodiment, the electronic device 1 of the present application may be, but is not limited to, a notebook computer, a pen-input computer, a mobile computer, an electronic book player, a portable telephone, a portable facsimile machine, a portable copier, a portable printer, a head-mounted stereo, a video recorder, an LCD television, a portable cleaner, a portable CD player, a minidisc, a transceiver, an electronic organizer, a calculator, a memory card, a portable recorder, a radio, a backup power supply, an electrical appliance, an automobile, a motorcycle, an electric-assisted bicycle, a bicycle, a lighting fixture, a toy, a game console, a clock, an electric tool, a flash, a camera, a large-scale household storage battery, and a lithium-ion capacitor.

[0047] The performance of the electrochemical device provided herein will be described below using specific examples and comparative examples. The electrochemical device will be a lithium ion soft-pack battery as an example, and the present invention will be described in conjunction with specific manufacturing processes and test methods. Those skilled in the art should understand that the manufacturing methods described herein are merely examples, and that all other suitable manufacturing methods are within the scope of the present invention.

[0048] Example 1 The first electrode sheet 21 is manufactured. The negative electrode active materials, artificial graphite, conductive carbon black (Super P), and styrene butadiene rubber (SBR), are mixed in a weight ratio of 96:1.5:2.5, and deionized water is added as a solvent to prepare a 70 wt% slurry. The mixture is then uniformly stirred. The slurry is uniformly applied to one surface of a 10 μm-thick copper foil and dried at 110°C to obtain a 150 μm-thick first active material layer 211. The above process is repeated on the other surface of the copper foil to obtain a 150 μm-thick second active material layer 212. A first conductive plate 30 is welded to the blank area 2100 of the first electrode sheet 21. The first conductive plate 30 is made of nickel (Ni).

[0049] The second electrode sheet 22 was fabricated. The positive electrode active materials, lithium cobalt oxide (LiCoO), conductive carbon black (Super P), and polyvinylidene fluoride (PVDF), were mixed in a weight ratio of 97.5:1.0:1.5, and N-methylpyrrolidone (NMP) was added as a solvent to prepare a slurry with a solid content of 75 wt%. The mixture was then uniformly stirred. The slurry was uniformly applied to one surface of a 12 μm-thick aluminum foil and dried at 90°C to obtain a 100 μm-thick third active material layer 221. The above process was repeated on the other surface of the aluminum foil to obtain a 100 μm-thick fourth active material layer 222. A second conductive plate 40 was welded to the blank area of ​​the second electrode sheet 22. The second conductive plate 40 was made of aluminum (Al).

[0050] To prepare the electrolyte, organic solvents ethylene carbonate (EC), methyl ethyl carbonate (EMC), and diethyl carbonate (DEC) were mixed in a mass ratio of EC:EMC:DEC = 30:50:20 in a dry argon atmosphere. Lithium hexafluorophosphate (LiPF6) was then added and dissolved in the organic solvent, and the mixture was mixed uniformly to obtain an electrolyte with a lithium salt concentration of 0.8 mol / L.

[0051] In manufacturing a lithium-ion battery, the first insulating rubber 50 and the second insulating rubber 60 are connected to the first conductive plate 30 and the second conductive plate 40, respectively. Here, in the first direction X, the length of the first layer 51 of each first insulating rubber 50 is 5 mm, and the length of the second layer 52 is 6 mm. That is, in this embodiment, the second layer 52 is extended along the first direction X so that the length of the second layer 52 beyond the first layer 51 (i.e., the length L0 of the first region 521) is 1 mm. Next, the first electrode sheet 21, the separator film 23, and the second electrode sheet 22 are sequentially stacked and wound to obtain the electrode assembly 20. The separator film 23 is a polyethylene (PE) film with a thickness of 15 μm. The pit-formed aluminum-plastic film (150 μm thick) is placed in an assembly jig, with the pit side facing up, and the electrode assembly 20 is placed in the pit. An electrolyte is injected into the pits in the aluminum-plastic film, and the first conductive plate 30 and the second conductive plate 40 are pulled out of the aluminum-plastic film, then chemically converted and packaged to form the housing 10, and the first sealing portion 121 of the housing 10 is folded toward the first connection point C1 to obtain a lithium-ion battery.

[0052] <Example 2> The difference between Example 2 and Example 1 is that the length of the second layer 52 in the first direction X is 7 mm, and the length L0 of the first region 521 is 2 mm.

[0053] Example 3 The difference between Example 3 and Example 1 is that the length of the second layer 52 in the first direction X is 8 mm, and the length L0 of the first region 521 is 3 mm.

[0054] Example 4 The difference between Example 4 and Example 1 is that the length of the second layer 52 in the first direction X is 5.5 mm, and the length L0 of the first region 521 is 0.5 mm.

[0055] <Comparative Example 1> The difference between Comparative Example 1 and Example 1 is that the length of the first layer 51 and the second layer 52 are both 5 mm.

[0056] <Comparative Example 2> The difference between Comparative Example 2 and Example 2 is that the positions of the first layer 51 and the second layer 52 in Example 2 are interchanged.

[0057] Next, 10 batteries from each of the example and comparative examples were taken out and subjected to a drop test, with the corresponding test results recorded in Table 1. The drop test steps were: 1) placing the battery on a jig; 2) conducting a drum test using a 0.5 m high drum for 5,000 tests; 3) after 2,500 tests were completed, the battery voltage was measured and recorded, and the battery's appearance was inspected. If leakage or fire occurred, the test was stopped; 4) if no abnormalities were found, the drum test was continued for the remaining 2,500 tests. After completion, the voltage was measured and recorded to determine whether the first conductive plate 30 had broken.

[0058] [Table 1]

[0059] Note: Pass rate X / 10 means that out of 10 samples tested, X number passed the drop test.

[0060] As can be seen from the data in Table 1, compared to Comparative Example 1, Examples 1 to 4 improve the situation in which the first conductive plate 30 breaks by extending the second layer 52 of the first insulating rubber 50, thereby increasing the pass rate of the battery in the drop test. As can be seen from Comparative Example 2, when the positions of the first layer 51 and the second layer 52 of the first insulating rubber 50 in Example 2 were swapped, the breakage of the first conductive plate 30 was not improved. Here, compared to Example 4, the length L0 of the first region 521 in Examples 1 to 3 was 1 mm or more, and therefore the pass rate of the battery in the drop test was relatively improved.

[0061] Finally, the above examples are only used to explain the technical aspects of the present application, but do not limit the present application. Although the present application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that the technical aspects of the present application can be modified or equivalently substituted without departing from the scope of the technical aspects of the present application.

Claims

1. 1. An electrochemical device comprising: a housing, an electrode assembly, and a first conductive plate; the housing includes a main body and a seal structure connected to the main body; the electrode assembly is disposed within the body; the first conductive plate is electrically connected to the electrode assembly; a direction in which the first conductive plate protrudes from the electrode assembly is defined as a first direction, a thickness direction of the electrode assembly is defined as a second direction, and a direction perpendicular to the first and second directions is defined as a third direction; the main body portion includes a first end wall and a second end wall disposed opposite to each other in the first direction, a first wall and a second wall disposed opposite to each other in the second direction, and a first side wall and a second side wall disposed opposite to each other in the third direction, the seal structure includes a first seal portion connected to the first end wall and a second seal portion connected to the first side wall; the first conductive plate protrudes from the housing beyond the first seal portion; the first seal portion is folded back in a direction approaching the first wall, and the second seal portion is folded back in a direction approaching the first wall, the first conductive plate includes a first surface and a second surface facing each other in the second direction, the first surface within the body portion facing the first wall, and the second surface within the body portion facing the second wall; the electrochemical device further includes an insulating rubber that connects the first conductive plate and the first seal portion so as to seal; the insulating rubber includes a first layer and a second layer, the first layer is contiguous with the first surface, and the second layer is contiguous with the second surface; the second layer includes a first region and a second region connected to each other in the first direction; When viewed from the second direction, within the main body portion, the second region overlaps the first layer, and the first region extends from the second region toward the electrode assembly and beyond the first layer.

2. 2. The electrochemical device of claim 1, wherein the electrode assembly includes a first electrode sheet, the first electrode sheet including a first current collector and a first active material layer stacked together, the first current collector including a blank area exposed in the first active material layer, and the first conductive plate being welded to the blank area.

3. 3. The electrochemical device according to claim 2, wherein the first region and the first electrode sheet are spaced apart from each other in the first direction.

4. 2. The electrochemical device according to claim 1, wherein a width W1 of the first region is smaller than a width W2 of the second region in the third direction.

5. 5. The electrochemical device according to claim 4, wherein 2 mm≦W2−W1≦5 mm is satisfied.

6. 5. The electrochemical device according to claim 4, wherein, in the third direction, the first region includes a first side and a second side that are arranged opposite each other, and when a distance between the first side and the first conductive plate is L1 and a distance between the second side and the first conductive plate is L2, the following relationships are satisfied: 0.1 mm≦L1≦0.6 mm, 0.1 mm≦L2≦0.6 mm.

7. In the third direction, the first region includes a first side and a second side that are opposed to each other, and the second region includes a third side that is connected to the first region, 5. The electrochemical device according to claim 4, wherein an arc angle is formed between the first side and the third side, and an arc angle is also formed between the second side and the third side.

8. 2. The electrochemical device according to claim 1, wherein, when the length of the first region in the first direction is L0, L0≧1 mm is satisfied.

9. 9. The electrochemical device according to claim 8, wherein L0≦3 mm is satisfied.

10. An electronic device including a containment box, The electronic device further comprises the electrochemical device according to any one of claims 1 to 9, which is provided in the housing box.

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