Electrochemical device and electrical apparatus

Abstract

An electrochemical device and an electrical apparatus. The electrochemical device comprises a housing, an electrode assembly, and a bonding member. The housing comprises a first sidewall. The electrode assembly is arranged in the housing and comprises a first side surface adjacent to the first sidewall, and the first side surface comprises a second region, a first region and a third region that are sequentially arranged in a first direction. The bonding member is located between the housing and the electrode assembly; the bonding member comprises a first side and a second side that are opposite to each other; the first side comprises a first bonding region bonded to the first sidewall; the second side comprises a second bonding region bonded to the second region, a third bonding region bonded to the third region, and a first non-bonding region located between the second bonding region and the third bonding region. In a second direction, the projection of the first bonding region overlaps with the first non-bonding region, and the second direction is the direction in which the first sidewall is opposite to the first side surface. The first non-bonding region arranged on the bonding member is not bonded to the first side surface, thereby being conducive to reducing the risk of damage to the electrode assembly.

Description

Electrochemical devices and electrical equipment Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to an electrochemical device and an electrical appliance. Background Technology

[0002] To mitigate the risks of internal short circuits and top seal breaches caused by the movement of internal electrode components during drops in electrochemical devices such as batteries, a double-sided adhesive layer is typically installed between the electrode components and the casing. One side adheres to the casing, while the other side adheres to the electrode components, thus suppressing their movement. This reduces the risk of failure during drops and improves the safety of the electrochemical device.

[0003] Summary of the Invention

[0004] However, the inventors of this application have discovered that the existing structure of bonding the electrode assembly to the housing with double-sided adhesive tape, although it can suppress the movement of the electrode assembly when the electrochemical device is dropped, poses a risk of tearing the foil on the outer ring of the electrode assembly, causing an internal short circuit.

[0005] In view of this, this application provides an electrochemical device and an electrical device, which aims to suppress the movement of the electrode assembly relative to the housing while reducing the risk of damage to the outer foil of the electrode assembly and improving the safety of the electrochemical device.

[0006] In a first aspect, this application provides an electrochemical device, comprising a housing, an electrode assembly, and an adhesive. The housing includes a first sidewall, and the electrode assembly is disposed within the housing. The electrode assembly includes a first sidewall adjacent to the first sidewall, and the first sidewall includes a first region, a second region, and a third region. Along a first direction, the first region is located between the second and third regions. The adhesive is located between the housing and the electrode assembly, and includes opposing first and second sides. The first side is adjacent to the housing, and the second side is away from the housing. The first side includes a first adhesive layer, which includes a first adhesive region bonded to the first sidewall. The second side includes a second adhesive layer and a third adhesive layer. The second adhesive layer includes a second adhesive region bonded to the second region, and the third adhesive layer includes a third adhesive region bonded to the third region. The surface of the second side includes a first non-adhesive region not bonded to the first region, which is located between the second and third adhesive regions. Along a second direction, the projection of the first adhesive layer overlaps with the first non-adhesive region, and the second direction is the direction in which the first sidewall and the first sidewall are opposite each other.

[0007] This application provides an adhesive component between the first side and the first sidewall. The housing and the electrode assembly are fixed in relative position by the first adhesive layer, the second adhesive layer and the third adhesive layer of the adhesive component. This helps to reduce the risk of the electrode assembly shifting when the electrochemical device is impacted. Furthermore, the adhesive component is provided with a first non-adhesive area that is not bonded to the first side. This helps to reduce the impact force transmitted from the adhesive component to the electrode assembly when the electrochemical device is impacted, thereby reducing the risk of damage to the outer electrode plate of the electrode assembly.

[0008] In some embodiments, the adhesive further includes a substrate layer, a first adhesive layer disposed on the surface of the substrate layer facing the housing, and a second and a third adhesive layer disposed on the surfaces of the substrate layer facing the electrode assembly. This arrangement eliminates the need for multiple layers of adhesive tape to bond the housing to the electrode assembly, thereby reducing the overall thickness of the electrochemical device and increasing its energy density.

[0009] In some embodiments, the surface of the first side further includes a second non-adhesive region and a third non-adhesive region not bonded to the first sidewall. Along a first direction, the first adhesive region is located between the second and third non-adhesive regions; along a second direction, the projection of the second non-adhesive region overlaps with the second adhesive region, and the projection of the third non-adhesive region overlaps with the third adhesive region. This arrangement reduces the tensile force exerted by the adhesive on the first sidewall when the electrochemical device is subjected to impact, thereby reducing the risk of damage to the outer electrode plate of the electrode assembly.

[0010] In some embodiments, along the second direction, the projection of the first non-adhesive region covers the projection of the first adhesive region, the projection of the second non-adhesive region covers the second adhesive region, and the projection of the third non-adhesive region covers the third adhesive region.

[0011] In some embodiments, along the first direction, the distance between the first adhesive area and the second adhesive area is greater than 0, and the distance between the first adhesive area and the third adhesive area is greater than 0. This arrangement allows the adhesive to have a portion that is neither bonded to the first sidewall nor to the first side surface. When the electrochemical device is subjected to impact, the force transmitted from the housing to the electrode assembly is absorbed by the local deformation dissipation of the adhesive, which suppresses the relative positional shift of the electrode assembly and the housing, while further reducing the force transmitted from the adhesive to the first side surface, thereby reducing the risk of damage to the outer electrode plate of the electrode assembly.

[0012] In some embodiments, along the second direction, the projection of the first adhesive area covers the first non-adhesive area, the projection of the first adhesive area overlaps with the second adhesive area, and the projection of the first adhesive area overlaps with the third adhesive area. This arrangement helps to increase the bonding area between the adhesive and the housing, and also allows the adhesive to have a portion that is simultaneously bonded to the first sidewall and the first side surface, thereby improving the bonding strength between the electrode assembly and the housing, further reducing the risk of relative positional movement between the electrode assembly and the housing, and effectively reducing the force transmitted by the adhesive to the first side surface.

[0013] In some embodiments, a portion of the substrate layer is exposed facing the electrode assembly to form a first non-adhesive region; a portion of the substrate layer is exposed facing the housing to form a second and a third non-adhesive region. This arrangement eliminates the need for multilayer adhesive tapes to prevent a portion of the adhesive from being bonded to the housing and a portion of the adhesive from being bonded to the first side, thereby helping to reduce the overall thickness of the electrochemical device and increase its energy density.

[0014] In some embodiments, the adhesive further includes a first non-adhesive layer, a second non-adhesive layer, and a third non-adhesive layer. The first non-adhesive layer is adhered to the surface of the second adhesive layer and / or the third adhesive layer to form a first non-adhesive region. The second non-adhesive layer is adhered to the surface of the first adhesive layer opposite to the second region to form a second non-adhesive region. The third non-adhesive layer is adhered to the surface of the first adhesive layer opposite to the third region to form a third non-adhesive region. This allows for the direct coating of the first, second, and third adhesive layers onto the substrate layer. A second and third non-adhesive area are formed by bonding the second and third non-adhesive layers to the first adhesive layer. A first non-adhesive area is formed by bonding the first non-adhesive layer to the second and / or third adhesive layers. The area and position of the first, second, and third non-adhesive areas can be adjusted by modifying the area and position of the first, second, and third non-adhesive layers. This method of forming and adjusting the non-adhesive areas is simple, efficient, and cost-effective.

[0015] In some embodiments, the substrate layer includes a first substrate portion and a second substrate portion. The first substrate portion is provided with a second adhesive layer and a portion of a first adhesive layer, and the second substrate portion is provided with a third adhesive layer and a portion of a first adhesive layer. The first substrate portion and the second substrate portion are arranged along a first direction; or, the first substrate portion and the second substrate portion are arranged along a third direction, which is perpendicular to both the first direction and the second direction.

[0016] In some embodiments, the width of the electrode assembly is W along the first direction, and the length of the electrode assembly is L along the third direction, which is perpendicular to both the first and second directions.

[0017] In some embodiments, along the first direction, the distance between the center of the first bonding area and the center of the first side is D1, satisfying: D1≤0.1W. This helps to promote more uniform pulling of the shell on the electrode assembly, further suppress cell movement and reduce the risk of damage to the outer electrode sheet of the electrode assembly.

[0018] In some embodiments, along a third direction, the distance between the center of the first bonding area and the center of the first side is D2, satisfying: D2≤0.1L. This helps to promote more uniform pulling of the housing on the electrode assembly, further suppress cell movement and reduce the risk of damage to the outer electrode sheet of the electrode assembly.

[0019] In some embodiments, the width of the first bonding area along the first direction is W1, satisfying: 0.3W≤W1≤0.8W. When this condition is met, the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0020] In some embodiments, along a third direction, the length of the first bonding area is L1, satisfying: 0.4L≤L1≤0.8L. When this condition is met, the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0021] In some embodiments, along the first direction, the width of the second bonding area is w1, satisfying: 0.05W≤w1≤0.45W. When this condition is met, the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0022] In some embodiments, along the first direction, the width of the third bonding area is w2, satisfying: 0.05W≤w2≤0.45W. When this condition is met, the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0023] In some embodiments, along a third direction, the length of the first bonding area is L1 and the length of the second bonding area is l1, satisfying: l1≥0.4L1. When this condition is met, the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0024] In some embodiments, along a third direction, the length of the first bonding area is L1 and the length of the third bonding area is l2, satisfying: l2≥0.4L1. When this condition is met, the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0025] In some embodiments, the second bonding region includes a plurality of second sub-bonding regions spaced apart along a third direction. This helps to further reduce the risk of electrode assembly misalignment and the risk of damage to the outer electrode sheet of the electrode assembly.

[0026] In some embodiments, the third bonding region includes a plurality of third sub-bonding regions spaced apart along a third direction. This helps to further reduce the risk of electrode assembly misalignment and the risk of damage to the outer electrode sheet of the electrode assembly.

[0027] In some embodiments, along the first direction, the distance from the first adhesive area to one edge of the substrate layer is W2, satisfying: 0≤W2≤0.45W. When this condition is met, the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0028] In some embodiments, along the first direction, the distance from the first adhesive area to the other edge of the substrate layer is W3, satisfying: 0≤W3≤0.45W. When this condition is met, the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0029] In some embodiments, along a third direction, the distance from the first adhesive area to one edge of the substrate layer is L2, satisfying: 0≤L2≤0.4L1. When this condition is met, the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0030] In some embodiments, along a third direction, the distance from the first adhesive area to the other edge of the substrate layer is L3, satisfying: 0≤L3≤0.4L1. When this condition is met, the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0031] In some embodiments, the distance between the second bonding area and the first bonding area along the first direction is H1, satisfying: H1≤0.25W. When this condition is met, the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0032] In some embodiments, along the first direction, the distance between the third bonding area and the first bonding area is H2, satisfying: H2≤0.25W. When this condition is met, the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0033] In some embodiments, along the second direction, the projection of the first adhesive area and the second adhesive area have a first overlapping area, and the width of the first overlapping area along the first direction is q1, where q1 ≤ 0.32W. When this condition is met, the pass rate of the battery drop test is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0034] In some embodiments, along the second direction, the projection of the first bonding area and the third bonding area have a second overlapping area, and the width of the second overlapping area along the first direction is q2, where q2≤0.32W. When this condition is met, the pass rate of the battery drop test is better, which helps to reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0035] In some embodiments, the electrode assembly further includes a second side, a third side, and a fourth side. The second side is disposed opposite to the first side along a second direction, and the third side is disposed opposite to the fourth side along a first direction. The second adhesive layer is bonded to both the second region and the third side. This arrangement allows the adhesive to transmit the force of the housing to the third side of the electrode assembly. When the electrode assembly is a wound structure, the electrode sheet located on the arc-shaped third side is more likely to disperse the force transmitted by the adhesive, thereby helping to reduce the risk of damage to the outer ring electrode sheet of the electrode assembly. When the electrode assembly is a stacked structure, the adhesive is bonded to the edge of the diaphragm, positive electrode sheet, or negative electrode sheet on the third side, which is less likely to damage the electrode sheet of the electrode assembly and helps to suppress the relative sliding between the diaphragm and the positive or negative electrode sheet.

[0036] In some embodiments, the third adhesive layer is bonded to both the third region and the fourth side. This arrangement allows the adhesive to transfer the force of the housing to the fourth side of the electrode assembly. When the electrode assembly is a wound structure, the electrode located on the arc-shaped fourth side is more likely to disperse the force transferred by the adhesive, which helps to reduce the risk of damage to the outer electrode of the electrode assembly. When the electrode assembly is a stacked structure, the adhesive is bonded to the edge of the diaphragm, positive electrode, or negative electrode on the fourth side, which is less likely to damage the electrode of the electrode assembly and helps to suppress the relative sliding between the diaphragm and the positive or negative electrode.

[0037] In some embodiments, the second adhesive layer is bonded to the second side surface. This increases the bonding area between the adhesive and the electrode assembly, thereby improving the strength of the connection between the adhesive and the electrode assembly.

[0038] In some embodiments, the third adhesive layer is bonded to the second side, thereby increasing the bonding area between the adhesive and the electrode assembly, which helps to improve the strength of the connection between the adhesive and the electrode assembly.

[0039] In some embodiments, the first side further includes a fourth region and a fifth region. Along a third direction, the first region is located between the fourth and fifth regions. The second side further includes a fourth adhesive layer and a fifth adhesive layer. The fourth adhesive layer includes a fourth adhesive region bonded to the fourth region; the fifth adhesive layer includes a fifth adhesive region bonded to the fifth region. Along a third direction, a first non-adhesive region is located between the fourth and fifth adhesive regions. The third direction is perpendicular to both the first and second directions. This helps to further reduce the risk of electrode assembly shifting during impacts to the electrochemical device and the risk of damage to the outer electrode plates of the electrode assembly.

[0040] In some embodiments, the fourth bonding region includes a plurality of fourth sub-bonding regions spaced apart along the first direction. This helps to further reduce the risk of electrode assembly misalignment and the risk of damage to the outer electrode sheet of the electrode assembly.

[0041] In some embodiments, the fifth bonding region includes a plurality of fifth sub-bonding regions spaced apart along a first direction. This helps to further reduce the risk of electrode assembly misalignment and the risk of damage to the outer electrode sheet of the electrode assembly.

[0042] In some embodiments, the electrode assembly further includes a fifth side and a sixth side disposed opposite each other along a third direction, and a fourth adhesive layer is also bonded to the fifth side. This helps to further reduce the risk of electrode assembly misalignment and the risk of damage to the outer electrode sheet of the electrode assembly.

[0043] In some embodiments, the fourth adhesive layer is also bonded to the second side. This increases the bonding area between the adhesive and the electrode assembly, thereby improving the strength of the connection between the adhesive and the electrode assembly.

[0044] In some embodiments, the fifth adhesive layer is also bonded to the sixth side. This helps to further reduce the risk of electrode assembly movement and the risk of damage to the outer electrode sheet of the electrode assembly.

[0045] In some embodiments, the fifth adhesive layer is also bonded to the second side. This increases the bonding area between the adhesive and the electrode assembly, thereby improving the strength of the connection between the adhesive and the electrode assembly.

[0046] A second aspect of this application provides an electrical device including the electrochemical device in any of the above embodiments. The risk of the electrochemical device shifting during drop tests and the risk of damage to the electrode components are reduced, thereby improving the reliability of the electrical device. Attached Figure Description

[0047] Figure 1 is a schematic diagram of the structure of an electrochemical device provided in an embodiment of this application.

[0048] Figure 2 is a schematic diagram of the decomposition of the electrochemical device in Figure 1.

[0049] Figure 3 is a cross-sectional view of an electrochemical device provided in an embodiment of this application.

[0050] Figure 4 is a cross-sectional view of the adhesive and electrode assembly provided in an embodiment of this application.

[0051] Figure 5 is a cross-sectional view of the adhesive and electrode assembly provided in another embodiment of this application.

[0052] Figure 6 is a side view of an adhesive provided in an embodiment of this application.

[0053] Figure 7 is a side view of an adhesive provided in another embodiment of this application.

[0054] Figure 8 is a side view of an adhesive provided in another embodiment of this application.

[0055] Figure 9 is a side view of an adhesive provided in another embodiment of this application.

[0056] Figure 10 is a side view of an adhesive provided in another embodiment of this application.

[0057] Figure 11 is a top view of the adhesive and electrode assembly provided in an embodiment of this application.

[0058] Figure 12 is a top view of the adhesive and electrode assembly provided in another embodiment of this application.

[0059] Figure 13 is a schematic diagram of an electrical device provided in an embodiment of this application.

[0060] Key Component Symbols: Electrochemical Device 100; Shell 10; First Sidewall 11; Second Sidewall 12; Third Sidewall 13; Fourth Sidewall 14; Fifth Sidewall 15; Sixth Sidewall 16; Electrode Assembly 20; First Side 21; First Region 211; Second Region 212; Third Region 213; Second Side 22; Third Side 23; Fourth Side 24; Fifth Side 25; Sixth Side 26; Adhesive Component 30; First Side 31; First Adhesive Layer 311; First Adhesive Area 3111; Second Non-Adhesive Area 312; Third Non-Adhesive Area 313; Second Side 32; First Non-Adhesive Area 321; Second Adhesive Layer 322; Second Adhesive Area 3221; Third Adhesive Layer 323; Third Adhesive Area 3231; First Non-Adhesive Layer 33; Second Non-Adhesive Layer 34; Third Non-Adhesive Layer 35First overlapping region 36 Second overlapping region 37 Substrate layer 301 First substrate part 3011 Second substrate part 3012 Electrode 50 Equipment body 200 Electrical equipment 1000 First direction X Second direction Y Third direction Z Detailed Implementation

[0061] The technical solutions in the embodiments of this application will be described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0062] It should be noted that, in this application, the center of a region refers to the centroid of its planar shape when the region is a continuous whole. Understandably, the centroid of the planar shape can be determined by a suspension method: suspend the planar shape with a thin thread, draw a straight line vertically from the starting point of the thread, suspend the planar shape again with a different endpoint than the first time, and draw another straight line using the same method. The intersection of these two lines is the centroid of the planar shape. When the region consists of multiple discrete regions, the center of the region is the center of the smallest circumcircle containing all the discrete regions. Understandably, the smallest circumcircle is the circle with the smallest radius that contains all the discrete regions.

[0063] Understandably, when a component is considered to be "connected" to another component, it can be directly connected to the other component or may have an intervening component. When a component is considered to be "placed" on another component, it can be directly placed on the other component or may have an intervening component. The terms "top," "bottom," and similar expressions used in this article are for illustrative purposes only.

[0064] The terms “first”, “second”, etc., are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implying the quantity, specific order, or primary and secondary relationship of the indicated technical features.

[0065] The term "perpendicular" is used to describe the ideal state between two components. In actual production or use, two components can exist in a state that is approximately perpendicular. The two parts described as "perpendicular" do not have to be absolute straight lines or planes, but can be roughly straight lines or planes. From a macroscopic perspective, if the overall direction of extension is a straight line or plane, the component can be considered a "straight line" or "plane".

[0066] It should be understood that the dimensions and thicknesses of the components shown in the accompanying drawings are for better understanding and more convenient description, and this application is not limited to the dimensions and thicknesses shown in the accompanying drawings.

[0067] 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 herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0068] Some embodiments of this application will now be described with reference to the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0069] Please refer to Figures 1 and 2. This application embodiment provides an electrochemical device 100, which includes a housing 10, an electrode assembly 20, and an adhesive member 30. The electrode assembly 20 is disposed within the housing 10, and the adhesive member 30 is disposed within the housing 10, located between the housing 10 and the electrode assembly 20, and the adhesive member 30 adheres to the housing 10 and the electrode assembly 20.

[0070] In some embodiments, referring to Figures 1 and 2, the housing 10 includes a first sidewall 11 and a second sidewall 12 disposed opposite to each other, and the electrode assembly 20 is located between the first sidewall 11 and the second sidewall 12.

[0071] In some embodiments, referring to Figures 1 and 2, the housing 10 further includes a third sidewall 13, a fourth sidewall 14, a fifth sidewall 15, and a sixth sidewall 16. The third sidewall 13 and the fourth sidewall 14 are disposed opposite each other along a first direction X, the first sidewall 11 and the second sidewall 12 are disposed opposite each other along a second direction Y, and the fifth sidewall 15 and the sixth sidewall 16 are disposed opposite each other along a third direction Z. The first direction X is perpendicular to both the second direction Y and the third direction Z. The first sidewall 11, the second sidewall 12, the third sidewall 13, the fourth sidewall 14, the fifth sidewall 15, and the sixth sidewall 16 enclose a space for housing the electrode assembly 20.

[0072] In some embodiments, the housing 10 is an aluminum-plastic film, but the housing 10 is not limited to aluminum-plastic film.

[0073] In some embodiments, the electrode assembly 20 includes a positive electrode, a negative electrode, and a separator. The positive electrode, the negative electrode, and the separator can be stacked to form a stacked structure, or the positive electrode, the negative electrode, and the separator can be stacked and then wound to form a wound structure.

[0074] In some embodiments, the positive electrode includes a positive current collector and a positive active material layer disposed on the positive current collector; the negative electrode includes a negative current collector and a negative active material layer disposed on the negative current collector.

[0075] In some embodiments, a portion of the positive current collector is provided with a positive active material layer, and a portion of the positive current collector is not provided with a positive active material layer; a portion of the negative current collector is provided with a negative active material layer, and a portion of the negative current collector is not provided with a negative active material layer.

[0076] The positive and negative current collectors can be metal layers. As an example, the positive current collector can be a metal layer including at least one of aluminum, nickel, tantalum, and titanium, such as aluminum foil. The positive active material layer includes a positive active material, which can include at least one of lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium manganese iron phosphate, or lithium manganese oxide. The negative current collector can be a metal layer including at least one of copper, nickel, tantalum, and titanium, such as copper foil. The negative active material layer includes a negative active material, which can include at least one of graphite, hard carbon, soft carbon, silicon, silicon-oxygen materials, and silicon-carbon materials.

[0077] In some embodiments, the outermost ring of the electrode assembly 20 has a positive current collector layer without a positive active material layer, and the positive current collector is aluminum foil.

[0078] In some embodiments, please refer to FIG3, the electrode assembly 20 includes a first side surface 21 adjacent to the first sidewall 11. The first side surface 21 includes a first region 211, a second region 212 and a third region 213. Along the first direction X, the first region 211 is located between the second region 212 and the third region 213.

[0079] In some embodiments, referring to FIG3, the electrode assembly 20 further includes a second side surface 22, a third side surface 23, and a fourth side surface 24. Along the second direction Y, the first side surface 21 is disposed opposite to the second side surface 22, and the first side surface 21 is adjacent to the first sidewall 11 relative to the second side surface 22. The second side surface 22 is disposed away from the first sidewall 11. The third side surface 23 and the fourth side surface 24 are disposed opposite to each other along the first direction X. When the electrode assembly 20 is a wound structure, the third side surface 23 and the fourth side surface 24 are arc-shaped sides.

[0080] In some embodiments, referring to FIG2, the electrode assembly 20 further includes a fifth side 25 and a sixth side 26, which are disposed opposite each other along a third direction Z.

[0081] In some embodiments, referring to Figures 1 and 2, the electrochemical device 100 further includes a tab 50 connected to the electrode assembly 20. Along the third direction Z, the tab 50 extends from the fifth side 25 or the sixth side 26 of the electrode assembly 20 out of the housing 10 to draw out the polarity of the electrode assembly 20. When the tab 50 is connected to the positive electrode of the electrode assembly 20, it is a positive tab 50; when the tab 50 is connected to the negative electrode of the electrode assembly 20, it is a negative tab 50. The tab 50 can be made of copper or aluminum, without specific limitations.

[0082] In some embodiments, referring to FIG3, the adhesive member 30 includes a first side 31 and a second side 32 disposed opposite to each other. The first side 31 is adjacent to the housing 10 relative to the second side 32, and the second side 32 is away from the housing 10. The first side 31 includes a first adhesive layer 311, which includes a first adhesive region 3111 bonded to the first sidewall 11. The second side 32 includes a second adhesive layer 322 and a third adhesive layer 323. The second adhesive layer 322 includes a second adhesive region 3221 bonded to the second region 212, and the third adhesive layer 323 includes a third adhesive region 3231 bonded to the third region 213. The surface of the second side 32 includes a first non-adhesive region 321 not bonded to the first region 211, which is located between the second adhesive region 3221 and the third adhesive region 3231. Along the second direction Y, the projection of the first adhesive region 3111 overlaps with the first non-adhesive region 321. The second direction Y is the direction in which the first sidewall 11 and the first side surface 21 are opposite each other.

[0083] This application provides an adhesive 30 between the first side surface 21 and the first side wall 11. The housing 10 and the electrode assembly 20 are fixed in relative position by the first adhesive layer 311, the second adhesive layer 322 and the third adhesive layer 323 of the adhesive 30. This helps to reduce the risk of the electrode assembly 20 shifting when the electrochemical device 100 is impacted. Furthermore, the adhesive 30 is provided with a first non-adhesive area 321 that is not adhered to the first side surface 21. This helps to reduce the impact force transmitted from the adhesive 30 to the electrode assembly 20 when the electrochemical device 100 is impacted, thereby reducing the risk of damage to the outer electrode sheet of the electrode assembly 20.

[0084] In some embodiments, the first adhesive layer 311, the second adhesive layer 322, and the third adhesive layer 323 may be adhesive materials that are adhesive without activation at room temperature; the first adhesive layer 311, the second adhesive layer 322, and the third adhesive layer 323 may also be adhesive materials that are not adhesive at room temperature but whose adhesiveness is activated after a hot pressing process.

[0085] In some embodiments, the second bonding region 3221 includes a plurality of second sub-bonding regions spaced Z-spaced along a third direction. In some embodiments, the third bonding region 3231 includes a plurality of third sub-bonding regions spaced Z-spaced along a third direction. This helps to further reduce the risk of misalignment of the electrode assembly 20 and the risk of damage to the outer electrode sheet of the electrode assembly 20.

[0086] In some embodiments, referring to FIG4, the second adhesive layer 322 is bonded to both the second region 212 and the third side surface 23. This arrangement allows the adhesive 30 to transmit the force of the housing 10 to the third side surface 23 of the electrode assembly 20. When the electrode assembly 20 is a wound structure, the electrode sheet located on the arc-shaped third side surface 23 is more likely to disperse the force transmitted by the adhesive 30, thereby helping to reduce the risk of damage to the outer electrode sheet of the electrode assembly 20. When the electrode assembly 20 is a stacked structure, the adhesive 30 is bonded to the edge of the diaphragm, positive electrode sheet, or negative electrode sheet on the third side surface 23, which is less likely to cause damage to the electrode sheet of the electrode assembly 20 and helps to suppress the relative sliding between the diaphragm and the positive or negative electrode sheet.

[0087] In some embodiments, as shown in FIG5, the second adhesive layer 322 is bonded to the second side surface 22. This arrangement increases the bonding area between the adhesive 30 and the electrode assembly 20, thereby improving the firmness of the connection between the adhesive 30 and the electrode assembly 20.

[0088] In some embodiments, referring to FIG4, the third adhesive layer 323 is bonded to both the third region 213 and the fourth side surface 24. This arrangement allows the adhesive 30 to transmit the force of the housing 10 to the fourth side surface 24 of the electrode assembly 20. When the electrode assembly 20 is a wound structure, the electrode sheet located on the arc-shaped fourth side surface 24 is more likely to disperse the force transmitted by the adhesive 30, which helps to reduce the risk of damage to the outer electrode sheet of the electrode assembly 20. When the electrode assembly 20 is a stacked structure, the adhesive 30 is bonded to the edge of the diaphragm, positive electrode sheet, or negative electrode sheet on the fourth side surface 24, which is less likely to damage the electrode sheet of the electrode assembly 20 and helps to suppress the relative sliding between the diaphragm and the positive or negative electrode sheet.

[0089] In some embodiments, as shown in FIG5, the third adhesive layer 323 is bonded to the second side 22. This arrangement increases the bonding area between the adhesive 30 and the electrode assembly 20, thereby improving the firmness of the connection between the adhesive 30 and the electrode assembly 20.

[0090] In the embodiment where the second adhesive layer 322 is bonded to both the second region 212 and the third side 23, and the third adhesive layer 323 is bonded to both the third region 213 and the fourth side 24, the adhesive member 30 transmits the force of the housing 10 to both sides of the electrode assembly 20 in the first direction X, which is beneficial to improving the uniformity of the force on the electrode assembly 20.

[0091] In some embodiments, the first side 21 further includes a fourth region and a fifth region. Along the third direction Z, the first region 211 is located between the fourth and fifth regions. The second side 32 further includes a fourth adhesive layer and a fifth adhesive layer. The fourth adhesive layer includes a fourth adhesive region bonded to the fourth region; the fifth adhesive layer includes a fifth adhesive region bonded to the fifth region. Along the third direction Z, a first non-adhesive region 321 is located between the fourth and fifth adhesive regions. The third direction Z is perpendicular to both the first direction X and the second direction Y. This helps to further reduce the risk of the electrode assembly 20 shifting when the electrochemical device is subjected to impact and the risk of damage to the outer electrode sheet of the electrode assembly 20.

[0092] In some embodiments, the fourth bonding region includes a plurality of fourth sub-bonding regions spaced apart along the first direction X. In some embodiments, the fifth bonding region includes a plurality of fifth sub-bonding regions spaced apart along the first direction X. This helps to further reduce the risk of displacement of the electrode assembly 20 and the risk of damage to the outer electrode sheet of the electrode assembly 20.

[0093] In some embodiments, the electrode assembly further includes a fifth side and a sixth side disposed opposite each other along a third direction, and a fourth adhesive layer is also bonded to the fifth side. In some embodiments, the fifth adhesive layer is also bonded to the sixth side. This helps to further reduce the risk of displacement of the electrode assembly 20 and the risk of damage to the outer electrode sheet of the electrode assembly 20.

[0094] In some embodiments, the fourth adhesive layer is also bonded to the second side surface 22. In some embodiments, the fifth adhesive layer is also bonded to the second side surface 22. This arrangement increases the bonding area between the adhesive member 30 and the electrode assembly 20, thereby improving the strength of the connection between the adhesive member 30 and the electrode assembly 20.

[0095] In some embodiments, referring to Figures 3 and 6, the first side 31 further includes a second non-adhesive region 312 and a third non-adhesive region 313 that are not bonded to the first sidewall 11. Along the first direction X, the first adhesive region 3111 is located between the second non-adhesive region 312 and the third non-adhesive region 313. Along the second direction Y, the projection of the second non-adhesive region 312 overlaps with the second adhesive region 3221, and the projection of the third non-adhesive region 313 overlaps with the third adhesive region 3231. This arrangement reduces the tensile force of the adhesive 30 on the first side 21 when the electrochemical device 100 is subjected to impact, thereby reducing the risk of damage to the outer electrode sheet of the electrode assembly 20.

[0096] In some embodiments, referring to Figures 3 and 6, along the second direction Y, the projection of the first non-adhesive region 321 covers the projection of the first adhesive region 3111, the projection of the second non-adhesive region 312 covers the projection of the second adhesive region 3221, and the projection of the third non-adhesive region 313 covers the projection of the third adhesive region 3231.

[0097] In some embodiments, referring to Figures 3 and 6, along the first direction X, the distance between the first adhesive area 3111 and the second adhesive area 3221 is greater than 0, and the distance between the first adhesive area 3111 and the third adhesive area 3231 is greater than 0. This arrangement allows the adhesive 30 to have a portion that is neither bonded to the first sidewall 11 nor to the first side surface 21. When the electrochemical device 100 is subjected to an impact, the force from the housing 10 is absorbed by the local deformation dissipation of the adhesive 30 during the transmission of force from the housing 10 to the electrode assembly 20. This suppresses the relative positional shift of the electrode assembly 20 and the housing 10, while further reducing the force transmitted from the adhesive 30 to the first side surface 21, thereby reducing the risk of damage to the outer electrode sheet of the electrode assembly 20.

[0098] In some other embodiments, referring to Figures 7 and 8, along the second direction Y, the projection of the first adhesive area 3111 covers the first non-adhesive area 321, the projection of the first adhesive area 3111 overlaps with the second adhesive area 3221, and the projection of the first adhesive area 3111 overlaps with the third adhesive area 3231. This arrangement helps to increase the bonding area between the adhesive component 30 and the housing 10, and also allows the adhesive component 30 to have a portion that is simultaneously bonded to the first sidewall 11 and the first side surface 21, thereby improving the bonding strength between the electrode assembly 20 and the housing 10, further reducing the risk of relative positional movement between the electrode assembly 20 and the housing 10, and effectively reducing the force transmitted by the adhesive component 30 to the first side surface 21. It can be understood that in this embodiment, the second non-adhesive area 312 and the third non-adhesive area 313 may or may not exist.

[0099] In some embodiments, referring to Figures 3, 6 to 8, the adhesive 30 further includes a substrate layer 301. A first adhesive layer 311 is disposed on the surface of the substrate layer 301 facing the housing 10, and a second adhesive layer 322 and a third adhesive layer 323 are disposed on the surface of the substrate layer 301 facing the electrode assembly 20. This arrangement eliminates the need for multilayer adhesive tape to bond the housing 10 to the electrode assembly 20, thereby reducing the overall thickness of the electrochemical device 100 and increasing its energy density.

[0100] Understandably, the first adhesive layer 311, the second adhesive layer 322, and the third adhesive layer 323 can be formed by coating an adhesive substance onto a predetermined area of ​​the substrate layer 301; or the first adhesive layer 311, the second adhesive layer 322, and the third adhesive layer 323 can be formed by coating the substrate layer 301 with adhesive substance on both sides and then removing the adhesive substance from a portion of it.

[0101] In some embodiments, the material of the substrate layer 301 may include any one of PET (polyethylene terephthalate), PVC (polyvinyl chloride), or PI (polyimide).

[0102] In some embodiments, referring to Figures 3, 6 to 8, a portion of the surface of the substrate layer 301 facing the electrode assembly 20 is exposed to form a first non-adhesive region 321; a portion of the surface of the substrate layer 301 facing the housing 10 is exposed to form a second non-adhesive region 312 and a third non-adhesive region 313. This configuration eliminates the need for multilayer adhesive tape to prevent a portion of the adhesive element 30 from adhering to the housing 10 and a portion of the adhesive element 30 from adhering to the first side surface 21, thereby reducing the overall thickness of the electrochemical device 100 and increasing its energy density.

[0103] Understandably, a masking material can be pre-applied to the surface of the substrate layer 301, and then the adhesive material can be applied to the substrate layer 301. The surface covered with the masking material forms the first non-adhesive area 321, the second non-adhesive area 312, and the third non-adhesive area 313, which are exposed without the adhesive material. Alternatively, the adhesive material can be applied to both sides of the substrate layer 301 and then the adhesive material can be removed from a local surface, exposing the surface of the substrate layer 301 where the adhesive material has been removed, thus forming the first non-adhesive area 321, the second non-adhesive area 312, and the third non-adhesive area 313.

[0104] In some embodiments, referring to FIG9, the adhesive 30 further includes a first non-adhesive layer 33, a second non-adhesive layer 34, and a third non-adhesive layer 35. The first non-adhesive layer 33 is adhered to the surface of the second adhesive layer 322 and / or the third adhesive layer 323 to form a first non-adhesive region 321. The second non-adhesive layer 34 is adhered to the surface of the first adhesive layer 311 on the side opposite to the second region 212 to form a second non-adhesive region 312. The third non-adhesive layer 35 is adhered to the surface of the first adhesive layer 311 on the side opposite to the third region 213 to form a third non-adhesive region 313. In this way, after the first adhesive layer 311, the second adhesive layer 322, and the third adhesive layer 323 are directly coated on the substrate layer 301, the first non-adhesive area 321, the second non-adhesive area 312, and the third non-adhesive area 313 are formed by bonding the first non-adhesive layer 33, the second non-adhesive layer 34, and the third non-adhesive layer 35. By adjusting the area and position of the first non-adhesive layer 33, the second non-adhesive layer 34, and the third non-adhesive layer 35, the area and position of the first non-adhesive area 321, the second non-adhesive area 312, and the third non-adhesive area 313 can be adjusted. This makes the method of forming and adjusting the non-adhesive area simple, efficient, and low-cost.

[0105] Understandably, the first non-adhesive layer 33, the second non-adhesive layer 34, and the third non-adhesive layer 35 can be layers with no adhesive material on both sides. The first non-adhesive layer 33, the second non-adhesive layer 34, and the third non-adhesive layer 35 can also be layers with adhesive material on one side and no adhesive material on the other side. For example, the side of the first non-adhesive layer 33 facing the first adhesive layer 311 has adhesive material, and the side of the first non-adhesive layer 33 away from the first adhesive layer 311 has no adhesive material.

[0106] In some embodiments, referring to FIG10, the substrate layer 301 includes a first substrate portion 3011 and a second substrate portion 3012, both of which are independent parts. The first substrate portion 3011 is provided with a second adhesive layer 322 and a portion of a first adhesive layer 311, and the second substrate portion 3012 is provided with a third adhesive layer 323 and a portion of a first adhesive layer 311. The first substrate portion 3011 and the second substrate portion 3012 are arranged along a first direction. This helps to reduce the risk of damage to the outer electrode sheet of the electrode assembly 20.

[0107] In some other embodiments, the first substrate portion 3011 and the second substrate portion 3012 are arranged along a third direction Z. This helps to reduce the risk of damage to the outer electrode sheet of the electrode assembly 20.

[0108] Understandably, the surface of the first substrate portion 3011 facing the first region 211 and the surface of the second substrate portion 3012 facing the first region 211 together form the first non-adhesive region 321.

[0109] In some embodiments, referring to FIG11, the width of the electrode assembly 20 along the first direction X is W, the length of the electrode assembly 20 along the third direction Z is L, and the distance between the center of the first bonding area 3111 and the center of the first side surface 21 along the first direction X is D1, satisfying: D1≤0.1W. This is beneficial for the adhesive 30 to suppress cell movement and reduce the risk of damage to the outer electrode sheet of the electrode assembly 20.

[0110] In some embodiments, referring to FIG11, the distance between the center of the first bonding area 3111 and the center of the first side surface 21 along the third direction Z is D2, which satisfies: D2≤0.1L. This is beneficial for the adhesive 30 to suppress cell movement and reduce the risk of damage to the outer electrode sheet of the electrode assembly 20.

[0111] To verify the influence of each adhesive and non-adhesive region of the adhesive component 30 on the electrochemical device 100, the following experiments were conducted:

[0112] A lithium-ion pouch battery with a rectangular maximum projection surface is selected. The length L of the internal wound electrode assembly 20 of the lithium-ion pouch battery is 87 mm, the width W is 64 mm, and the thickness is 4.8 mm.

[0113] In Examples 1 to 20, the adhesive component 30 includes a first adhesive layer 311, a second adhesive layer 322, a third adhesive layer 323, and a first adhesive region 3111, a second adhesive region 3221, and a third adhesive region 3231. The first adhesive region 3111 coincides with the center of the first side surface 21. In the first side surface 21, along the first direction X, the distance from the first adhesive region 3111 to one edge of the substrate layer 301 is W2, the distance from the first adhesive region 3111 to the other edge of the substrate layer 301 is W3, the distance between the second adhesive region 3221 and the first adhesive region 3111 is H1, and the distance between the third adhesive region 3231 and the first adhesive region 3111 is H2. Along the third direction Z, the distance from the first adhesive region 3111 to one edge of the substrate layer 301 is L2, and the distance from the first adhesive region 3111 to the other edge of the substrate layer 301 is L3.

[0114] In Example 17, the second bonding area 3221 includes two second sub-bonding areas spaced apart along the third direction Z, with a spacing of 4mm between the two second sub-bonding areas; the third bonding area 3231 includes two third sub-bonding areas spaced apart along the third direction Z, with a spacing of 4mm between the two third sub-bonding areas.

[0115] In Example 18, please refer to FIG. 12. The bonding area between the bonding member 30 and the electrode assembly 20 is in a "hui" character shape. The second side 32 includes a fourth bonding area and a fifth bonding area that are bonded to the first side 21. Along the third direction Z, the first non-bonding area 321 is located between the fourth bonding area and the fifth bonding area. The third direction Z is perpendicular to the first direction X and the second direction Y pairwise. The widths of the fourth bonding area and the fifth bonding area are equal to the width w1 of the second bonding area 322 or the width w2 of the third bonding area 3231.

[0116] In Example 19 and Example 20, along the second direction Y, the projection of the first bonding area 3111 and the second bonding area 3221 have a first overlapping area 36. The width of the first overlapping area 36 along the first direction X is q1. The projection of the first bonding area 3111 and the third bonding area 3221 have a second overlapping area 37. The width of the second overlapping area 37 along the first direction X is q2.

[0117] The dimensional parameters of the bonding member 30 in the above embodiments are shown in Table 1 below.

[0118] In the comparative example, a double-sided tape with a length of 60.9 mm and a width of 38 mm is used to bond the first side wall 11 and the first side 21.

[0119] For each group, 20 batteries are taken for a drop pass rate comparison experiment. The batteries are set to be tested according to the drop sequence of six sides and four corners, and the drop height is 1.8 m. After the drop is completed, observe whether the housing 10 is broken or leaks liquid, and count the number of batteries with the housing 10 broken or leaking liquid. If the housing 10 is not broken or leaking liquid, then disassemble the lithium-ion soft-pack battery and observe whether the outer electrodes of the electrode assembly 20 are torn or damaged, and count the number of batteries with the outer electrodes torn or damaged. Among them, if the housing 10 is not broken and does not leak liquid, and the outer electrodes do not have tearing or damage, it is determined to pass the test; otherwise, it is determined not to pass the test. Pass rate = number of passes / 20 × 100%.

[0120] Table 1: Test results of dimensional changes of each bonding layer in the bonding member 30

[0121] In some embodiments, please refer to FIG. 12 and Table 1. Along the first direction X, the width of the first bonding area 3111 is W1, satisfying: 0.3W ≤ W1 ≤ 0.8W. As can be seen from Table 1, when the condition 0.3W ≤ W1 ≤  0.8W is satisfied, the pass rate of the battery drop test is better, which is beneficial to reducing the risk of the electrode assembly 20 moving around and the risk of damage to the outer electrodes of the electrode assembly 20.

[0122] In some embodiments, referring to Figure 12 and Table 1, the length of the first bonding area 3111 along the third direction Z is L1, satisfying: 0.4L≤L1≤0.8L. As can be seen from Table 1, when the condition 0.4L≤L1≤0.8L is met, the battery drop test pass rate is better, which helps reduce the risk of electrode assembly 20 shifting and the risk of damage to the outer electrode sheet of electrode assembly 20.

[0123] In some embodiments, referring to Figure 12 and Table 1, along the third direction Z, the length of the first bonding area 3111 is L1, the length of the second bonding area 3221 is l1, and the length of the third bonding area 3231 is l2, satisfying: l1≥0.4L1 and / or l2≥0.4L1. When the above conditions are met, the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly 20 shifting and the risk of damage to the outer electrode sheet of electrode assembly 20. In Embodiments 1 to 16, and Embodiments 19 to 20, l1=l2=L1. In Embodiment 17, l1=l2=56mm, the length of l1 does not include the 4mm interval between the two second sub-bonding areas, the length of l2 does not include the 4mm interval between the two third sub-bonding areas, and along the third direction Z, the length of each second sub-bonding area and the length of each third sub-bonding area are both 28mm. In Embodiment 18, l1=l2=L1+L2+L3.

[0124] In some embodiments, please refer to Figure 12 and Table 1, satisfying 0≤L2≤0.4L1 and / or 0≤L3≤0.4L1. When the above conditions are met, it can be seen from Table 1 that the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly 20 moving around when the electrochemical device is impacted and the risk of damage to the outer electrode sheet of electrode assembly 20.

[0125] In some embodiments, referring to Figure 12 and Table 1, along the first direction X, the width of the second adhesive region 3221 is w1, and the width of the third adhesive region 3231 is w2, satisfying: 0.05W ≤ w1 ≤ 0.45W and / or 0.05W ≤ w2 ≤ 0.45W. This configuration improves the battery drop test pass rate and helps reduce the risk of electrode assembly 20 shifting and damage to the outer electrode sheet of the electrode assembly 20. In embodiments 10 to 15, the second adhesive layer 322 is bonded to the second region 212, the third side 23, and / or the second side 22, and the third adhesive layer 323 is bonded to the third region 213, the fourth side 24, and / or the second side 22.

[0126] In some embodiments, please refer to Figures 3, 12 and Table 1, and the following conditions are met: W2≤0.45W and / or W3≤0.45W. When this condition is met, it can be seen from Table 1 that the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly 20 shifting and the risk of damage to the outer electrode sheet of electrode assembly 20.

[0127] In some embodiments, please refer to Figure 12 and Table 1, satisfying: H1≤0.25W and / or H2≤0.25W. When this condition is met, it can be seen from Table 1 that the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly 20 shifting and the risk of damage to the outer electrode sheet of electrode assembly 20.

[0128] In some embodiments, referring to Figures 8, 12 and Table 1, the following conditions are met: q1 ≤ 0.32W and / or q2 ≤ 0.32W. When this condition is met, it can be seen from Table 1 that the battery drop test pass rate is better, which helps to reduce the risk of electrode assembly 20 shifting and the risk of damage to the outer electrode sheet of electrode assembly 20.

[0129] Please refer to Figure 13. An embodiment of this application also provides an electrical device 1000, which includes the electrochemical device 100 described above.

[0130] In some embodiments, please refer to FIG13, the electrical device 1000 further includes a device body 200, and an electrochemical device 100 is installed on the device body 200 for supplying power to the device body 200.

[0131] In some embodiments, the electrical device 1000 may be a Bluetooth headset, Bluetooth speaker, mobile phone, laptop, tablet computer, e-book player, electric toy, game console, video recorder, portable recorder, radio, smartwatch, lamp, or calculator, etc., which will not be listed here.

[0132] Since the electrical equipment 1000 adopts the technical solution of any embodiment of the electrochemical device 100, it has at least the beneficial effects brought about by the technical solution of any embodiment of the electrochemical device 100, which will not be described in detail here.

[0133] Furthermore, those skilled in the art should recognize that the above embodiments are merely illustrative of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. An electrochemical device, characterized in that, include: A housing, the housing including a first sidewall; An electrode assembly is disposed within the housing. The electrode assembly includes a first side surface adjacent to the first sidewall. The first side surface includes a first region, a second region, and a third region. Along a first direction, the first region is located between the second region and the third region. An adhesive element is located between the housing and the electrode assembly. The adhesive element includes a first side and a second side opposite to each other. The first side is adjacent to the housing, and the second side is opposite to the housing. The first side includes a first adhesive layer, which includes a first adhesive region bonded to a first sidewall. The second side includes a second adhesive layer and a third adhesive layer. The second adhesive layer includes a second adhesive region bonded to a second region, and the third adhesive layer includes a third adhesive region bonded to a third region. The surface of the second side includes a first non-adhesive region not bonded to the first region, which is located between the second adhesive region and the third adhesive region. Along the second direction, the projection of the first adhesive area overlaps with the first non-adhesive area, and the second direction is the direction in which the first sidewall is opposite to the first side surface.

2. The electrochemical device according to claim 1, characterized in that, The adhesive further includes a substrate layer, the first adhesive layer is disposed on the surface of the substrate layer facing the housing, and the second adhesive layer and the third adhesive layer are disposed on the surface of the substrate layer facing the electrode assembly.

3. The electrochemical device according to claim 2, characterized in that, The surface of the first side also includes a second non-adhesive area and a third non-adhesive area that are not bonded to the first sidewall. Along the first direction, the first adhesive area is located between the second non-adhesive area and the third non-adhesive area. Along the second direction, the projection of the second non-adhesive area overlaps with the second adhesive area, and the projection of the third non-adhesive area overlaps with the third adhesive area.

4. The electrochemical device according to claim 3, characterized in that, Along the second direction, the first non-adhesive area covers the projection of the first adhesive area, the projection of the second non-adhesive area covers the second adhesive area, and the projection of the third non-adhesive area covers the third adhesive area. Along the first direction, the distance between the first adhesive area and the second adhesive area is greater than 0, and the distance between the first adhesive area and the third adhesive area is greater than 0.

5. The electrochemical device according to claim 2, characterized in that, Along the second direction, the projection of the first adhesive area covers the first non-adhesive area, the projection of the first adhesive area overlaps with the second adhesive area, and the projection of the first adhesive area overlaps with the third adhesive area.

6. The electrochemical device according to claim 3, characterized in that, The adhesive component satisfies any of the following conditions: (1) A portion of the surface of the substrate layer facing the electrode assembly is exposed to form the first non-adhesive region; a portion of the surface of the substrate layer facing the housing is exposed to form the second non-adhesive region and the third non-adhesive region; (2) The adhesive further includes a first non-adhesive layer, a second non-adhesive layer and a third non-adhesive layer, wherein the first non-adhesive layer is bonded to the surface of the second adhesive layer and / or the third adhesive layer to form the first non-adhesive area; The second non-adhesive layer is bonded to the surface of the first adhesive layer on the side opposite to the second region to form the second non-adhesive region; The third non-adhesive layer is bonded to the surface of the first adhesive layer on the side opposite to the third region to form the third non-adhesive region.

7. The electrochemical device according to claim 2, characterized in that, The substrate layer includes a first substrate portion and a second substrate portion. The first substrate portion is provided with the second adhesive layer and a portion of the first adhesive layer, and the second substrate portion is provided with the third adhesive layer and a portion of the first adhesive layer. The substrate layer satisfies any one of the following conditions: (1) The first substrate portion and the second substrate portion are arranged along the first direction; (2) The first substrate portion and the second substrate portion are arranged along a third direction, which is perpendicular to the first direction and the second direction.

8. The electrochemical device according to claim 1, characterized in that, Along the first direction, the width of the electrode assembly is W; along the third direction, the length of the electrode assembly is L; the third direction is perpendicular to both the first and second directions; the electrochemical device satisfies at least one of the following conditions: (1) Along the first direction, the distance between the center of the first adhesive area and the center of the first side surface is D1, which satisfies: D1≤0.1W; (2) Along the third direction, the distance between the center of the first bonding area and the center of the first side surface is D2, which satisfies: D2≤0.1L; (3) Along the first direction, the width of the first bonding area is W1, which satisfies: 0.3W≤W1≤0.8W; (4) Along the third direction, the length of the first bonding area is L1, which satisfies: 0.4L≤L1≤0.8L; (5) Along the first direction, the width of the second bonding area is w1, which satisfies: 0.05W≤w1≤0.45W; (6) Along the first direction, the width of the third bonding area is w2, which satisfies: 0.05W≤w2≤0.45W; (7) Along the third direction, the length of the first bonding area is L1, and the length of the second bonding area is l1, satisfying: l1≥0.4L1; (8) Along the third direction, the length of the first adhesive region is L1, and the length of the third adhesive region is l2, satisfying: l2≥0.4L1; (9) The second bonding area includes a plurality of second sub-bonding areas spaced apart along the third direction; (10) The third bonding area includes a plurality of third sub-bonding areas spaced apart along the third direction.

9. The electrochemical device according to claim 8, characterized in that, The adhesive further includes a substrate layer, the first adhesive layer is disposed on the surface of the substrate layer facing the housing, and the second adhesive layer and the third adhesive layer are disposed on the surface of the substrate layer facing the electrode assembly; Along the first direction, the distance from the first adhesive area to one edge of the substrate layer is W2, the distance from the first adhesive area to the other edge of the substrate layer is W3, the distance between the second adhesive area and the first adhesive area is H1, and the distance between the third adhesive area and the first adhesive area is H2. Along the third direction, the distance from the first adhesive area to one edge of the substrate layer is L2, and the distance from the first adhesive area to the other edge of the substrate layer is L3. The adhesive component satisfies at least one of the following conditions: (1) W2 ≤ 0.45W; (2) W3 ≤ 0.45W; (3) L2≤0.4L1: (4) L3≤0.4L1; (5) H1≤0.25W; (6) H2 ≤ 0.25W; (7) Along the second direction, the projection of the first adhesive area and the second adhesive area have a first overlapping area, and the width of the first overlapping area along the first direction is q1, q1≤0.32W; (8) Along the second direction, the projection of the first adhesive area and the third adhesive area have a second overlapping area, and the width of the second overlapping area along the first direction is q2, q2≤0.32W.

10. The electrochemical device according to claim 1, characterized in that, The electrode assembly further includes a second side, a third side, and a fourth side, wherein the second side and the first side are disposed opposite to each other along the second direction, and the third side and the fourth side are disposed opposite to each other along the first direction, satisfying at least one of the following conditions: (1) The second adhesive layer is bonded to both the second region and the third side surface; (2) The third adhesive layer is bonded to both the third region and the fourth side surface.

11. The electrochemical device according to claim 10, characterized in that, At least one of the following conditions must be met: (1) The second adhesive layer is bonded to the second side surface; (2) The third adhesive layer is bonded to the second side surface.

12. An electrical appliance, characterized in that, Includes the electrochemical device as described in any one of claims 1 to 11.

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