Electrochemical device and electronic device

Abstract

An electrochemical device and an electronic device. The electrochemical device comprises a housing assembly (10) and an electrode assembly (20). The housing assembly (10) is made of metal. The housing assembly (10) comprises a first housing (11) having an accommodating cavity (S) and a second housing (12) covering the accommodating cavity (S); and the electrode assembly (20) is arranged in the accommodating cavity (S). The direction in which the second housing (12) and the electrode assembly (20) are arranged is a first direction (X); and in a second direction (Y) perpendicular to the first direction (X), the second housing (12) comprises a first region (121), a second region (122) and a third region (123), which are connected in sequence. The third region (123) is welded and fixed to the first housing (11). When observed in the first direction (X), the first region (121) overlaps with the electrode assembly (20), and the second region (122) and the third region (123) are both of a continuous annular structure. In the first direction (X), the thickness of the second region (122) is greater than the thickness of the first region (121) and is greater than the thickness of the third region (123), and the second region (122) extends into the accommodating cavity (S) in the first direction (X) relative to the first region (121) and the third region (123). The energy density and reliability of the electrochemical device having the above structure are improved.

Description

Electrochemical devices and electronic devices Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to an electrochemical device and an electronic device having the electrochemical device. Background Art

[0002] Electrochemical devices (such as button batteries) are widely used in electronic products such as mobile devices, power tools, and electric vehicles. These devices typically consist of a housing and an electrode assembly housed within it. The housing itself has a certain thickness, which affects the energy density of the electrochemical device. Furthermore, welding the housing can damage the electrode assembly, reducing the reliability of the electrochemical device.

[0003] Summary of the Invention

[0004] The present application provides an electrochemical device with improved energy density and reliability, and an electronic device having the electrochemical device.

[0005] The first aspect of the present application provides an electrochemical device, comprising a shell assembly and an electrode assembly. The shell assembly is made of metal. The shell assembly includes a first shell having a accommodating cavity and a second shell covering the accommodating cavity, and the electrode assembly is arranged in the accommodating cavity. The direction in which the second shell and the electrode assembly are arranged is a first direction. In a second direction perpendicular to the first direction, the second shell includes a first region, a second region and a third region connected in sequence. The third region is welded and fixed to the first shell. When viewed from the first direction, the first region overlaps with the electrode assembly, and the second region and the third region are both continuous annular structures. In the first direction, the thickness of the second region is greater than the thickness of the first region and greater than the thickness of the third region, and the second region extends into the accommodating cavity along the first direction compared to the first region and the third region.

[0006] In this application, the first region is thinner than the second region, which helps improve space utilization within the housing assembly and, in turn, increases the energy density of the electrochemical device. Furthermore, because the third region is welded to the first housing and the second region is thicker, the second region can block welding energy from entering the housing cavity through the weld between the third region and the first housing during welding. This reduces the risk of damage to the electrode assembly during welding and improves the reliability of the electrochemical device.

[0007] Based on the first aspect, in some possible implementations, the first region is provided with a first opening. The electrochemical device further includes a conductive member, a first tab, and a second tab. The conductive member is at least partially disposed within the accommodating cavity and exposed through the first opening. The first tab electrically connects the electrode assembly and the conductive member, and the second tab electrically connects the electrode assembly and the first housing. Therefore, the conductive member and the first housing can exhibit opposite electrical polarity, enabling the electrochemical device to supply power to external components.

[0008] Based on the first aspect, in some possible implementations, the conductive member includes a cover portion and a protrusion connected to each other. The cover portion is disposed between the first region and the electrode assembly in a first direction. The protrusion extends from a side of the cover portion facing away from the electrode assembly into the first opening. This facilitates electrical connection between the protrusion and an external component.

[0009] Based on the first aspect, in some possible implementations, the first region includes a first edge surrounding the first opening. When viewed from the first direction, the protrusion is separated from the first edge. This reduces the risk of short circuiting between the first region and the protrusion during mechanical abuse, thereby improving the safety and reliability of the electrochemical device.

[0010] Based on the first aspect, in some possible implementations, the electrochemical device further includes a first adhesive member, which is disposed between the cover portion and the first region in a first direction. The first adhesive member bonds the cover portion and the first region. The first adhesive member is provided with a second opening. When viewed from the first direction, the first opening and the second opening overlap, and the protrusion is at least partially located within the second opening. The first adhesive member not only fixes the cover portion to the first region, but also electrically isolates the cover portion and the first region through the first adhesive member, thereby reducing the risk of contact short circuit between the first region and the cover portion during mechanical abuse, thereby further improving the safety and reliability of the electrochemical device. In addition, the first adhesive member can also seal the gap between the second shell and the cover portion, thereby reducing the risk of electrolyte flowing out of the accommodating cavity through the gap between the second shell and the cover portion.

[0011] Based on the first aspect, in some possible implementations, the cover includes a second edge. When viewed from the first direction, the second edge is closer to the protrusion than the second region, and the second edge is separated from the second region. The first adhesive member includes a third edge arranged around the second opening and a fourth edge arranged away from the third edge. When viewed from the first direction, the fourth edge is closer to the protrusion than the second region, and the fourth edge is separated from the second region. Therefore, a portion of the first region is exposed from the cover and the first adhesive member. When gas accumulates inside the electrochemical device, the portion of the first region can be cracked under the action of the gas, allowing the gas inside the shell to be released outward, achieving the purpose of pressure relief, thereby improving the safety and reliability of the electrochemical device.

[0012] Based on the first aspect, in some possible implementations, when viewed from the first direction, the distance between the second edge and the second region is 0.1 mm to 3 mm, and the distance between the fourth edge and the second region is 0.1 mm to 3 mm. Therefore, when gas accumulates within the electrochemical device, the portion of the first region exposed between the cover and the first adhesive member can be ruptured by the gas, thereby achieving the purpose of pressure relief.

[0013] Based on the first aspect, in some possible implementations, when viewed from the first direction, the third edge is connected to the protrusion, and the first adhesive member further extends into the first opening. Therefore, the portion of the first adhesive member located within the first opening can further isolate the first region from the protrusion, reducing the risk of short circuiting between the first region and the protrusion during mechanical abuse. Furthermore, the contact area between the conductive member and the first adhesive member is increased, thereby improving the bonding strength and sealing reliability of the first adhesive member.

[0014] Based on the first aspect, in some possible implementations, when viewed from the first direction, the fourth edge is further away from the protrusion than the second edge, and the first adhesive member also covers the second edge. Therefore, the contact area between the cover portion and the first adhesive member is increased, thereby further improving the bonding strength of the first adhesive member.

[0015] Based on the first aspect, in some possible implementations, the second region extends a height of 0.025 mm to 0.275 mm relative to the third region along the first direction. Thus, the second region can better block welding energy from entering the accommodating cavity through the weld between the third region and the first shell, thereby reducing the risk of damage to the electrode assembly during welding.

[0016] Based on the first aspect, in some possible implementations, the first housing includes a bottom wall and a side wall connected to the bottom wall. The third region is welded to the side wall. In the second direction, the width of the third region is equal to the width of the side wall, and the second region abuts the side wall. Thus, the second region can better block welding energy from entering the accommodating cavity through the weld between the third region and the first housing, thereby reducing the risk of damage to the electrode assembly during welding.

[0017] A second aspect of the present application further provides an electronic device comprising a battery compartment and an electrochemical device as described above, disposed within the battery compartment. The electronic device is powered by the electrochemical device, and the provision of the first region improves space utilization within the housing assembly, thereby increasing the energy density of the electrochemical device. Furthermore, the second region prevents welding energy from entering the housing cavity through the weld between the third region and the first housing during welding, thereby reducing the risk of damage to the electrode assembly during welding and improving the reliability of the electrochemical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0019] FIG1 is a schematic structural diagram of an electrochemical device according to one embodiment of the present application.

[0020] FIG. 2 is a schematic diagram of the electrochemical device shown in FIG. 1 when viewed from a first direction.

[0021] FIG3 is a cross-sectional view of the electrochemical device shown in FIG2 along line III-III in some embodiments.

[0022] FIG. 4 is a cross-sectional view of the electrochemical device shown in FIG. 2 along line III-III in some other embodiments.

[0023] FIG. 5 is a cross-sectional view of the electrochemical device shown in FIG. 2 along line III-III in some other embodiments.

[0024] FIG. 6 is a cross-sectional view of the electrochemical device shown in FIG. 2 along line III-III in some other embodiments.

[0025] FIG7 is a schematic structural diagram of an electrochemical device provided in some other embodiments.

[0026] FIG8 is a schematic structural diagram of an electronic device according to an embodiment of the present application.

[0027] Explanation of Main Component Symbols Electronic device 1 Housing assembly 10 First housing 11 Second housing 12 Explosion-proof valve 13 Electrode assembly 20 First pole piece 21 Second pole piece 22 Separator 23 First pole tab 30 Second pole tab 40 Conductive member 50 Cover 51 Protrusion 52 First adhesive 60 Electrochemical device 100 Battery compartment 101 Bottom wall 111 Side wall 112 First region 121 Second region 122 Third region 123 First current collector 210 First active material layer 211 Second current collector 220 Second active material layer 221 Second edge 511 Second opening 600 Third edge 601 Fourth edge 602 First opening 1210 First edge 1211 Accommodating chamber S Thickness T1, T2, T3, T4 Width W1, W2, W3 Distance D1, D2 First direction X Second direction Y

[0028] The following specific implementation methods will further illustrate the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application are described clearly and in detail below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those 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 the purpose of describing specific embodiments and are not intended to limit the present application.

[0030] Below, embodiments of the present application will be described in detail. However, the present application may be embodied in many different forms and should not be construed as limited to the exemplary embodiments illustrated herein. Rather, these exemplary embodiments are provided to make the present application thorough and detailed for those skilled in the art.

[0031] In addition, for the sake of brevity and clarity, the size or thickness of various components or layers may be exaggerated in the accompanying drawings. Throughout the text, the same numerical value refers to the same element. As used herein, the terms "and / or" and "and / or" include any and all combinations of one or more related enumerated items. In addition, it should be understood that when element A is referred to as "connecting" element B, element A can be directly connected to element B, or there may be an intermediate element C and element A and element B can be indirectly connected to each other.

[0032] Further, when describing embodiments of the present application, the use of “may” refers to “one or more embodiments of the present application.”

[0033] The technical terms used herein are for the purpose of describing specific embodiments and are not intended to limit this application. As used herein, the singular is intended to include the plural, unless the context clearly indicates otherwise. It should be further understood that the term "comprising", when used in this specification, refers to the presence of the described features, values, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, values, steps, operations, elements, components and / or combinations thereof.

[0034] Spatial related terms, such as "on" etc., can be used herein for convenient description, to describe the relationship between an element or feature and another element (multiple elements) or feature (multiple features) as illustrated in the figure. It should be understood that, in addition to the directions described in the figure, spatial related terms are intended to include different directions of equipment or devices in use or operation. For example, if the equipment in the figure is turned over, the elements described as "above" or "on" other elements or features will be oriented "below" or "below" other elements or features. Therefore, the exemplary term "on" can include the direction above and below. It should be understood that although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are used to distinguish an element, component, region, layer or part from another element, component, region, layer or part. Therefore, the first element, component, region, layer or part discussed below can be referred to as the second element, component, region, layer or part, without departing from the teachings of the exemplary embodiments.

[0035] As used herein, "parallel" and "perpendicular" are used to describe an ideal state between two components. In actual production or use, two components may be approximately parallel or perpendicular to each other. For example, in combination with numerical descriptions, parallel can refer to the angle between two straight lines being within ±10°, parallel can also refer to the dihedral angle between two planes being within ±10°, and parallel can also refer to the angle between a straight line and a plane being within ±10°. Perpendicular can refer to the angle between two straight lines being within 90±10°, perpendicular can also refer to the dihedral angle between two planes being within 90±10°, and perpendicular can also refer to the angle between a straight line and a plane being within 90±10°. The two components described as "parallel" or "perpendicular" may not be absolutely straight lines or planes, but may be roughly straight lines or planes. From a macroscopic perspective, a component can be considered a "straight line" or "plane" if its overall extension direction is a straight line or plane.

[0036] In this application, the relationship between parameter values ​​that is greater than, less than, or not equal to the design relationship needs to exclude the reasonable error of the measuring equipment.

[0037] Referring to Figures 1 to 3, one embodiment of the present application provides an electrochemical device 100, comprising a shell assembly 10, an electrode assembly 20 and an electrolyte (not shown). The shell assembly 10 is made of metal. The shell assembly 10 includes a first shell 11 and a second shell 12. The first shell 11 has a accommodating chamber S, and the electrode assembly 20 and the electrolyte are both arranged in the accommodating chamber S. Specifically, the first shell 11 may include a bottom wall 111 and a side wall 112 connected to the periphery of the bottom wall 111, and the bottom wall 111 and the side wall 112 are together arranged to form the accommodating chamber S. The first direction X is defined as the direction in which the second shell 12 and the electrode assembly 20 are arranged. When viewed from the first direction X, the second shell 12 covers the accommodating chamber S. When viewed from the first direction X, the bottom wall 111 can be roughly circular, and the second shell 12 can also be roughly circular. The bottom wall 111 and the second shell 12 can be arranged in parallel and both are perpendicular to the first direction X. One end of the side wall 112 is connected to the bottom wall 111, and the other end is welded and fixed to the second shell 12, so that a roughly cylindrical accommodating cavity S is formed in the first shell 11. In some embodiments, the electrochemical device 100 can be a button cell or a cylindrical battery, and the shell assembly 10 is entirely made of steel. For example, the first shell 11 is made of steel, the second shell 12 is also made of steel, and the bottom wall 111 and the side wall 112 of the first shell 11 are integrally formed. Furthermore, the shell assembly 10 can include the elements Fe and C. The shell assembly 10 can also include one or more of the elements Ni, Co, Al, Mn, Cr, Cu, Mg, Mo, S, Si, Ti, V, Pb, Sb, N, and P. Referring to Figure 7, in other embodiments, the electrochemical device 100 can also be a square shell battery.

[0038] As shown in FIG3 , the electrode assembly 20 may be a laminated structure, comprising a plurality of first electrode sheets 21, a plurality of second electrode sheets 22, and a plurality of isolation membranes 23. In the laminated structure, the first electrode sheets 21 and the second electrode sheets 22 are stacked alternately in sequence, with one second electrode sheet 22 provided between each two adjacent first electrode sheets 21, and one first electrode sheet 21 provided between each two adjacent second electrode sheets 22. The isolation membrane 23 is disposed between adjacent first electrode sheets 21 and second electrode sheets 22. The isolation membrane 23 is used to prevent direct contact between the first electrode sheets 21 and the second electrode sheets 22, thereby reducing the possibility of a contact short circuit between the first electrode sheets 21 and the second electrode sheets 22. The first electrode tab 30 is electrically connected to the first electrode sheet 21 and extends out of the first electrode sheet 21, and the second electrode tab 40 is electrically connected to the second electrode sheet 22 and extends out of the second electrode sheet 22. As shown in FIG4 , in other embodiments, the electrode assembly 20 may also be a wound structure.

[0039] As shown in Figures 3 and 4, in a second direction Y perpendicular to the first direction X, the second shell 12 includes a first region 121, a second region 122, and a third region 123 connected in sequence. The second shell 12 is welded to the first shell 11 (e.g., the sidewall 112 of the first shell 11) via the third region 123. For example, the third region 123 can be welded to the first shell 11 by laser welding, electron beam welding, arc welding, ultrasonic welding, etc. As shown in Figure 2, when viewed from the first direction X, the first region 121 overlaps with the electrode assembly 20, and the second region 122 and the third region 123 are both continuous ring structures. For example, when the electrochemical device 100 is a button battery, when viewed from the first direction X, the second region 122 and the third region 123 are both continuous circular ring structures. When the electrochemical device 100 is a square shell battery, when viewed from the first direction X, the second region 122 and the third region 123 are both continuous rectangular ring structures. 2 does not show the outer contour of the electrode assembly 20 for the sake of simplicity. In an embodiment of the present application, when observed from the first direction X, the outer contour of the electrode assembly 20 may overlap with the second region 122 (such as being connected to the inner edge of the second region 122), or may be separated from the second region 122. This application does not impose any restrictions.

[0040] In the first direction X, the thickness T2 of the second region 122 of the second shell 12 is greater than the thickness T1 of the first region 121 and greater than the thickness T3 of the third region 123. The second region 122 extends into the accommodating cavity S along the first direction X, compared to the first and third regions 121, 123. As shown in Figures 3 and 4, because the second region 122 extends into the accommodating cavity S along the first direction X, the surface of the second shell 12 facing the electrode assembly 20 is a stepped surface, while the surface of the second shell 12 facing away from the electrode assembly 20 can be a flat surface. In some embodiments, the thickness T1 of the first region 121 can be set to 0.025 to 0.15 mm, the thickness T2 of the second region 122 can be set to 0.05 to 0.3 mm, and the thickness T3 of the third region 123 can be set to 0.025 to 0.15 mm. The thickness T1 of the first region 121 can be substantially the same as the thickness T3 of the third region 123, or they can be different.

[0041] When manufacturing the housing assembly 10, a flat metal plate is first provided. One surface is thinned to form a first region 121 and a third region 123. The unthinned area between the first region 121 and the third region 123 forms the second region 122. The above manufacturing method is merely an example and is not intended to limit the structure of the housing assembly 10 of this application.

[0042] In the present application, since the first region 121 is thinner than the second region 122, it is beneficial to improve the space utilization inside the housing assembly 10, thereby improving the energy density of the electrochemical device 100. At the same time, since the third region 123 is welded to the first housing 11 and the second region 122 is thicker, the second region 122 can block welding energy (such as laser, electron beam, arc) from entering the accommodating cavity S through the weld between the third region 123 and the first housing 11 during welding, thereby reducing the risk of damage to the electrode assembly 20 during welding and improving the service life of the electrochemical device 100. In the present application, thinning can be performed on a metal flat plate with a certain thickness to process the first region 121 and the third region 123, which helps to reduce the difficulty of processing.

[0043] In some embodiments, the height of the second region 122 relative to the third region 123 along the first direction X (i.e., the difference between T2 and T3) is 0.025 mm to 0.275 mm. This allows the second region 122 to better block welding energy from entering the accommodating cavity S through the weld between the third region 123 and the first shell 11, thereby reducing the risk of damage to the electrode assembly 20 during welding. Furthermore, the width W2 of the second region 122 in the second direction Y can be set to 0.1 mm to 3 mm, so that the width of the second region 122 is sufficient to block welding energy from entering the accommodating cavity S through the weld between the third region 123 and the first shell 11.

[0044] In some embodiments, in the second direction Y, the width W3 of the third region 123 is equal to the width W1 of the sidewall 112, and the second region 122 abuts the sidewall 112. Because the second region 122 abuts the sidewall 112, it can better block welding energy from entering the accommodating cavity S through the weld between the third region 123 and the first shell 11, thereby reducing the risk of damage to the electrode assembly 20 during welding. In some embodiments, the width W3 of the third region 123 can be set to 0.025 mm to 0.25 mm. It will be understood that the third region 123 is an annular structure, and the width W3 of the third region 123 refers to the difference between the outer radius and the inner radius of the third region 123. Similarly, the width W1 of the sidewall 112 refers to the difference between the outer radius and the inner radius of the sidewall 112.

[0045] As shown in Figures 3 and 4, in some embodiments, the first region 121 is provided with a first opening 1210. The electrochemical device 100 further includes a conductive member 50, a first electrode tab 30, and a second electrode tab 40. The conductive member 50 is entirely made of a conductive material. The conductive member 50 is at least partially disposed within the accommodating cavity S and is exposed at the first opening 1210. The first electrode tab 30 electrically connects the electrode assembly 20 and the conductive member 50, and the second electrode tab 40 electrically connects the electrode assembly 20 and the first shell 11. For example, the first electrode tab 30 is electrically connected to the first current collector 210 of the first electrode sheet 21, and the second electrode tab 40 is electrically connected to the second current collector 220 of the second electrode sheet 22. In some embodiments, the first electrode tab 30 can be welded and fixed to the conductive member 50, thereby improving the connection strength between the first electrode tab 30 and the conductive member 50. The second electrode tab 40 can also be welded to the first housing 11, thereby improving the connection strength between the second electrode tab 40 and the first housing 11. More specifically, when the housing assembly 10 is entirely made of steel, the second electrode tab 40 can be welded to the bottom wall 111 or the side wall 112 of the first housing 11. This allows the conductive member 50 to have opposite polarities to the first housing 11, allowing the electrochemical device 100 to power external components (not shown). When the first electrode sheet 21 is a positive electrode sheet and the second electrode sheet 22 is a negative electrode sheet, the conductive member 50 has a positive polarity and the first housing 11 has a negative polarity. In some embodiments, the conductive member 50 can be made of a metal such as aluminum, copper, steel, nickel, or alloys thereof. When viewed from the first direction X, the first opening 1210 can be circular. In other embodiments, the shape of the first opening 1210 can be varied, such as elliptical, square, hexagonal, etc.

[0046] The conductive member 50 may include a connected cover portion 51 and a protrusion 52. The cover portion 51 is positioned between the first region 121 and the electrode assembly 20 in the first direction X. The first electrode tab 30 may be connected to the surface of the cover portion 51 facing the electrode assembly 20. The protrusion 52 extends from the side of the cover portion 51 facing away from the electrode assembly 20 into the first opening 1210, facilitating electrical connection between the protrusion 52 and external components. As shown in Figures 3 and 4, the surface of the protrusion 52 facing away from the cover portion 51 may be substantially flush with the surface of the second cover body facing away from the cover portion 51, thereby improving the smoothness of the electrochemical device 100 and facilitating electrical connection between the protrusion 52 and external components. In some embodiments, the cover portion 51 and the protrusion 52 may be integrally formed. When viewed in the first direction X, both the cover portion 51 and the protrusion 52 may be circular. In other embodiments, the cover portion 51 and the protrusion 52 may be separate structures. The shapes of the cover portion 51 and the protrusion 52 may also vary, such as oval, square, hexagonal, etc.

[0047] In some embodiments, the first region 121 includes a first edge 1211 disposed around the first opening 1210. The protrusion 52 is separated from the first edge 1211 when viewed from the first direction X. This reduces the risk of short circuiting between the first region 121 and the protrusion 52 during mechanical abuse (e.g., vibration or collision), thereby improving the safety and reliability of the electrochemical device 100.

[0048] In some embodiments, the electrochemical device 100 further includes a first adhesive 60 disposed between the cover 51 and the first region 121 in the first direction X. Because the first region 121 is thinner than the second region 122 in thickness T1 after thinning, at least a portion of the first adhesive 60 can be accommodated within the space reserved after the thinning of the first region 121, thereby improving space utilization within the housing assembly 10 and, in turn, increasing the energy density of the electrochemical device 100. In some embodiments, at least a portion of the cover 51 can also be accommodated within the space reserved after the thinning of the first region 121, further improving the energy density of the electrochemical device 100. The first adhesive 60 bonds the cover 51 and the first region 121, securing them to each other. Furthermore, the first adhesive 60 electrically isolates the cover 51 and the first region 121, reducing the risk of short circuits between the first region 121 and the cover 51 during mechanical abuse, further enhancing the safety and reliability of the electrochemical device 100. In addition, the first adhesive member 60 can also seal the gap between the second housing 12 and the cover 51, thereby reducing the risk of electrolyte flowing out of the accommodating chamber S through the gap between the second housing 12 and the cover 51 during normal use of the electrochemical device 100. The first adhesive member 60 has a second opening 600. When viewed from the first direction X, the first opening 1210 and the second opening 600 overlap, and the protrusion 52 is at least partially located within the second opening 600. As shown in Figures 3 and 4, the protrusion 52 extends from the side of the cover 51 facing away from the electrode assembly 20 to the second opening 600 and the first opening 1210, respectively. The first adhesive member 60 can include at least one of polyethylene, polypropylene, propylene-ethylene copolymer, polyetheretherketone, polyvinylidene fluoride, or polytetrafluoroethylene. The thickness T4 of the first adhesive member 60 can be 0.025 mm to 0.15 mm.

[0049] In some embodiments, the cover portion 51 includes a second edge 511. The second edge 511 is the outer edge of the entire conductive member 50 when viewed from the first direction X. When viewed from the first direction X, the second edge 511 is closer to the protrusion 52 than to the second region 122, and the second edge 511 is separated from the second region 122. Furthermore, the first adhesive member 60 includes a third edge 601 disposed around the second opening 600 and a fourth edge 602 disposed away from the third edge 601. The third edge 601 is the inner edge of the entire first adhesive member 60 when viewed from the first direction X, and the fourth edge 602 is the outer edge of the entire first adhesive member 60 when viewed from the first direction X. When viewed from the first direction X, the fourth edge 602 is closer to the protrusion 52 than to the second region 122, and the fourth edge 602 is separated from the second region 122. By separating the second edge 511 and the fourth edge 602 from the second region 122, a portion of the first region 121 is exposed between the cover portion 51 and the first adhesive member 60. Therefore, when gas accumulates inside the electrochemical device 100, the portion of the first region 121 exposed between the cover 51 and the first adhesive member 60 can be ruptured by the gas, allowing the gas inside the shell to be released through the rupture, causing the pressure in the accommodating chamber S to drop, achieving the purpose of pressure relief, thereby improving the safety and reliability of the electrochemical device 100.

[0050] In some embodiments, as viewed from the first direction X, the distance D1 between the second edge 511 and the second region 122 is 0.1 mm to 3 mm, and the distance D2 between the fourth edge 602 and the second region 122 is 0.1 mm to 3 mm. By setting these distances, when gas accumulates within the electrochemical device 100, the portion of the first region 121 exposed between the cover 51 and the first adhesive member 60 is facilitated to rupture under the action of the gas, thereby achieving the purpose of pressure relief.

[0051] Referring to Figure 5 , in other embodiments, an explosion-proof valve 13 may be provided at other locations within the housing assembly 10. For example, the explosion-proof valve 13 may be provided on the bottom wall 111 or side wall 112 of the first housing 11. The explosion-proof valve 13 may be a slit formed by laser etching through a portion of the first housing 11 on the bottom wall 111 or side wall 112 of the first housing 11. The shape and depth of the explosion-proof valve 13 may be customized to meet specific requirements. Therefore, when the internal pressure of the electrochemical device 100 reaches a certain level, the explosion-proof valve 13 may rupture due to stress concentration, thereby achieving pressure relief. In this case, the second edge 511 may also be arranged to abut the second region 122 when viewed from the first direction X. This increases the contact area between the first region 121 and the first adhesive member 60, thereby enhancing the bonding strength and sealing reliability of the first adhesive member 60.

[0052] As shown in Figures 3 and 4 , in some embodiments, the third edge 601 of the first adhesive 60 is substantially flush with the first edge 1211 of the second housing 12 when viewed from the first direction X. That is, the first opening 1210 and the second opening 600 may completely overlap when viewed from the first direction X. Referring to Figure 6 , in other embodiments, the position of the third edge 601 of the first adhesive 60 may be modified. For example, when viewed from the first direction X, the third edge 601 of the first adhesive 60 may be connected to the protrusion 52, that is, the first adhesive 60 covers and adheres to the sidewall of the protrusion 52. The first adhesive 60 further extends into the first opening 1210. Therefore, the portion of the first adhesive 60 located within the first opening 1210 further isolates the first region 121 from the protrusion 52, reducing the risk of short circuiting between the first region 121 and the protrusion 52 during mechanical abuse, further improving the safety and reliability of the electrochemical device 100. Moreover, since the contact area between the conductive member 50 and the first adhesive member 60 is increased, the adhesive strength and sealing reliability of the first adhesive member 60 can be further improved.

[0053] As shown in Figures 3 and 4 , in some embodiments, when viewed from the first direction X, the fourth edge 602 of the first adhesive member 60 is substantially flush with the second edge 511 of the cover portion 51. Referring to Figure 6 , in other embodiments, the position of the fourth edge 602 of the first adhesive member 60 can be modified. For example, when viewed from the first direction X, the fourth edge 602 can be further away from the protrusion 52 than the second edge 511, while the first adhesive member 60 still covers the second edge 511. This increases the contact area between the cover portion 51 and the first adhesive member 60, thereby further enhancing the bonding strength of the first adhesive member 60.

[0054] The electrochemical device 100 of the present application includes all devices capable of generating 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). Alternatively, 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.

[0055] Referring to FIG8 , one embodiment of the present application further provides an electronic device 1 comprising a battery compartment 101 and the electrochemical device 100 disposed within the battery compartment 101 . The electronic device 1 is powered by the electrochemical device 100, which has improved energy density and reliability. In one embodiment, the electronic device 1 of the present application may be, but is not limited to, a laptop computer, a pen-type computer, a mobile computer, an e-book player, a portable phone, a portable fax machine, a portable copier, a portable printer, a head-mounted stereo headset, a video recorder, an LCD television, a portable cleaner, a portable CD player, a mini-disc, a transceiver, an electronic notepad, a calculator, a memory card, a portable recorder, a radio, a backup power supply, a motor, an automobile, a motorcycle, a power-assisted bicycle, a bicycle, a lighting fixture, a toy, a game console, a clock, an electric tool, a flashlight, a camera, a large household battery, and a lithium-ion capacitor.

[0056] The above disclosure is only a preferred embodiment of the present application, and certainly cannot be used to limit the present application. Therefore, equivalent changes made based on the present application are still within the scope covered by the present application.

Claims

1. An electrochemical device comprising a housing assembly and an electrode assembly, wherein the housing assembly is made of metal and comprises a first housing having a housing cavity and a second housing covering the housing cavity, wherein the electrode assembly is disposed in the housing cavity, The second shell and the electrode assembly are arranged in a first direction. In a second direction perpendicular to the first direction, the second shell includes a first region, a second region, and a third region connected in sequence, and the third region is welded and fixed to the first shell. When viewed from the first direction, the first region overlaps with the electrode assembly, and the second region and the third region are both continuous annular structures. In the first direction, the thickness of the second region is greater than that of the first region and greater than that of the third region. The second region extends into the accommodation cavity along the first direction compared to the first region and the third region.

2. The electrochemical device according to claim 1, wherein The first region is provided with a first opening, and the electrochemical device further includes a conductive member, a first pole tab and a second pole tab. The conductive member is at least partially provided in the accommodating cavity and exposed at the first opening. The first pole tab electrically connects the electrode assembly and the conductive member, and the second pole tab electrically connects the electrode assembly and the first shell.

3. The electrochemical device according to claim 2, wherein The conductive member includes a cover portion and a convex portion connected to each other. The cover portion is arranged between the first area and the electrode assembly in the first direction. The convex portion extends from a side of the cover portion away from the electrode assembly to the first opening.

4. The electrochemical device according to claim 3, wherein The first region includes a first edge disposed around the first opening, and the protrusion is separated from the first edge when viewed from the first direction.

5. The electrochemical device according to claim 3, wherein The electrochemical device further includes a first adhesive member, the first adhesive member being disposed between the cover portion and the first region in the first direction, the first adhesive member bonding the cover portion and the first region; The first adhesive member is provided with a second opening. When viewed from the first direction, the first opening and the second opening overlap, and the protrusion is at least partially located in the second opening.

6. The electrochemical device according to claim 5, wherein The cover portion includes a second edge, and when viewed from the first direction, the second edge is closer to the protrusion than the second area, and the second edge is separated from the second area; The first adhesive member includes a third edge arranged around the second opening and a fourth edge arranged away from the third edge. When viewed from the first direction, the fourth edge is closer to the protrusion than the second area, and the fourth edge is separated from the second area.

7. The electrochemical device according to claim 6, wherein Observed from the first direction, the distance between the second edge and the second region is 0.1 mm to 3 mm, and the distance between the fourth edge and the second region is 0.1 mm to 3 mm.

8. The electrochemical device according to claim 6, wherein When viewed from the first direction, the third edge is connected to the protrusion, and the first adhesive component further extends into the first opening.

9. The electrochemical device according to claim 6, wherein When viewed from the first direction, the fourth edge is farther away from the protrusion than the second edge, and the first adhesive component also covers the second edge.

10. The electrochemical device according to any one of claims 1 to 9, wherein A height of the second region relative to the third region extending along the first direction is 0.025 mm to 0.275 mm.

11. The electrochemical device according to any one of claims 1 to 9, wherein The first shell includes a bottom wall and a side wall connected to the bottom wall. The third area is welded and fixed to the side wall. In the second direction, the width of the third area is equal to the width of the side wall. The second area abuts against the side wall.

12. An electronic device, wherein: The invention comprises a battery compartment and an electrochemical device according to any one of claims 1 to 11 arranged in the battery compartment.

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