Electrochemical device and electronic device
By designing shell regions with varying thicknesses and conductive component bonding structures, the problems of shell thickness affecting energy density and welding damage to electrodes were solved, achieving high energy density and reliability for the electrochemical device.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- NINGDE AMPEREX TECHNOLOGY LTD
- Filing Date
- 2024-03-26
- Publication Date
- 2026-07-30
AI Technical Summary
The thickness of the casing of an electrochemical device affects the energy density, and the welding process can damage electrode components, reducing reliability.
Design a housing assembly in which the thickness of a second region is greater than that of the first and third regions. The second region blocks welding energy from entering the receiving cavity during welding and improves the connection strength and safety of the electrode assembly through conductive and adhesive components.
It improves the energy density and reliability of electrochemical devices, reduces the risk of damage to electrode components during welding, and enhances safety and reliability.
Smart Images
Figure CN2024083708_30072026_PF_FP_ABST
Abstract
Description
Electrochemical devices and electronic devices Technical Field
[0001] This application relates to the field of energy storage technology, and more particularly to an electrochemical device and an electronic device having said electrochemical device. Background Technology
[0002] Electrochemical devices (such as button cells) are widely used in electronic mobile devices, power tools, and electric vehicles. Electrochemical devices typically consist of a housing and electrode assemblies housed within it. The housing itself has a certain thickness, which can affect the energy density of the electrochemical device. Furthermore, welding the housing can damage the electrode assemblies, reducing the reliability of the electrochemical device.
[0003] Summary of the Invention
[0004] This application provides an electrochemical device with improved energy density and reliability, as well as an electronic device having the above-described electrochemical device.
[0005] This application provides an electrochemical device, including a housing assembly and an electrode assembly. The housing assembly is made of metal. The housing assembly includes a first housing having a receiving cavity and a second housing covering the receiving cavity, with the electrode assembly disposed within the receiving cavity. The second housing and the electrode assembly are arranged in a first direction. In a second direction perpendicular to the first direction, the second housing includes a first region, a second region, and a third region connected sequentially. The third region is welded and fixed to the first housing. Viewed from the first direction, the first region overlaps with the electrode assembly, and the second and third regions 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 receiving cavity relative to the first and third regions along the first direction.
[0006] In this application, since the first region is thinner than the second region, it is beneficial to improve the space utilization rate inside the housing assembly, thereby increasing the energy density of the electrochemical device. At the same time, since the third region is welded to the first housing and the second region is thicker, the second region can prevent welding energy from entering the cavity through the weld between the third region and the first housing during welding, thereby reducing the risk of electrode assembly damage during welding and improving 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 also includes a conductive element, a first tab, and a second tab. The conductive element is at least partially disposed within the receiving cavity and exposed through the first opening. The first tab is electrically connected to the electrode assembly and the conductive element, and the second tab is electrically connected to the electrode assembly and the first housing. Therefore, the conductive element and the first housing can have opposite polarities, allowing the electrochemical device to supply power to external components.
[0008] Based on the first aspect, in some possible implementations, the conductive element includes a cover and a protrusion connected together. The cover is disposed in a first direction between the first region and the electrode assembly. The protrusion extends from the cover away from the electrode assembly into the first opening. This facilitates electrical connection between the protrusion and external components.
[0009] Based on the first aspect, in some possible implementations, the first region includes a first edge disposed around the first opening. Viewed from a first direction, the protrusion is separated from the first edge. Therefore, the risk of short circuits occurring between the first region and the protrusion during mechanical abuse can be reduced, 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 disposed in a first direction between the cover and the first region. The first adhesive member bonds the cover and the first region. The first adhesive member has a second opening. 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 to the first region, but also electrically isolates the cover and the first region through the first adhesive member, reducing the risk of short circuits between the first region and the cover during mechanical abuse, further improving the safety and reliability of the electrochemical device. In addition, the first adhesive member can also seal the gap between the second housing and the cover, reducing the risk of electrolyte flowing out of the receiving cavity through the space between the second housing and the cover.
[0011] Based on the first aspect, in some possible implementations, the cover includes a second edge. Viewed from a first direction, the second edge is closer to the protrusion than the second region, and the second edge is separate from the second region. The first adhesive includes a third edge disposed around the second opening and a fourth edge disposed away from the third edge. Viewed from a first direction, the fourth edge is closer to the protrusion than the second region, and the fourth edge is separate from the second region. Therefore, a portion of the first region is exposed in the cover and the first adhesive. When gas accumulates inside the electrochemical device, this portion of the first region can crack under the action of the gas, allowing the gas inside the casing 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, 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 inside the electrochemical device, the portion of the first region exposed to the cover and the first adhesive can be allowed to crack under the action of the gas, thereby achieving the purpose of pressure relief.
[0013] Based on the first aspect, in some possible implementations, viewed from the first direction, the third edge connects to the protrusion, and the first adhesive also extends into the first opening. Therefore, the portion of the first adhesive located within the first opening can further isolate the first region and the protrusion, reducing the risk of short circuits between the first region and the protrusion during mechanical abuse. Furthermore, the increased contact area between the conductive element and the first adhesive improves the bonding strength and sealing reliability of the first adhesive.
[0014] Based on the first aspect, in some possible implementations, viewed from the first direction, the fourth edge is farther from the protrusion than the second edge, and the first adhesive also covers the second edge. Therefore, the contact area between the cover and the first adhesive increases, thereby further improving the adhesive strength of the first adhesive.
[0015] Based on the first aspect, in some possible implementations, the second region extends at a height of 0.025 mm to 0.275 mm in the first direction relative to the third region. This allows the second region to better prevent welding energy from entering the cavity through the weld between the third region and the first housing, 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. A 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 against the side wall. Therefore, the second region can better prevent welding energy from entering the 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 this application also provides an electronic device including a battery compartment and the aforementioned electrochemical device disposed within the battery compartment. The electronic device is powered by the electrochemical device, and the arrangement of the first region facilitates improved space utilization within the housing assembly, thereby increasing the energy density of the electrochemical device. Simultaneously, the second region can prevent welding energy from entering the receiving cavity through the weld seam 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. Attached Figure Description
[0018] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0019] Figure 1 is a schematic diagram of the structure of an electrochemical device according to an embodiment of this application.
[0020] Figure 2 is a schematic diagram of the electrochemical device shown in Figure 1 as viewed from the first direction.
[0021] Figure 3 is a cross-sectional view along III-III of the electrochemical device shown in Figure 2 in some embodiments.
[0022] Figure 4 is a cross-sectional view along III-III of the electrochemical device shown in Figure 2 in some other embodiments.
[0023] Figure 5 is a cross-sectional view along III-III of the electrochemical device shown in Figure 2 in some other embodiments.
[0024] Figure 6 is a cross-sectional view along III-III of the electrochemical device shown in Figure 2 in some other embodiments.
[0025] Figure 7 is a schematic diagram of the structure of an electrochemical device provided in some other embodiments.
[0026] Figure 8 is a schematic diagram of the structure of an electronic device according to an embodiment of this application.
[0027] Key Component Symbols: Electronic Device 1; Housing Assembly 10; First Housing 11; Second Housing 12; Explosion-proof Valve 13; Electrode Assembly 20; First Electrode 21; Second Electrode 22; Separator 23; First Tab 30; Second Tab 40; Conductive Component 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; Receiving Cavity S; Thickness T1, T2, T3, T4; Width W1, W2, W3; Distance D1, D2; First Direction X; Second Direction Y
[0028] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation
[0029] The technical solutions in the embodiments of this application are described clearly and in detail below. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit this application.
[0030] The embodiments of this application will be described in detail below. However, this application may be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided to provide a thorough and detailed understanding of this application to those skilled in the art.
[0031] Additionally, for brevity and clarity, the dimensions or thicknesses of various components and layers may be enlarged in the accompanying drawings. Throughout the text, the same numerical values refer to the same elements. As used herein, the terms "and / or" and "and / or" include any and all combinations of one or more of the associated enumerated items. Furthermore, it should be understood that when element A is referred to as "connecting" element B, element A may be directly connected to element B, or there may be an intermediate element C and element A and element B may be indirectly connected to each other.
[0032] Furthermore, when describing the implementation of this application, the word "may" refers to "one or more implementations of this application".
[0033] The technical terms used herein are for the purpose of describing particular embodiments and are not intended to limit this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. It should be further understood that the term "comprising," as used in this specification, means the presence of the described features, values, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, values, steps, operations, elements, components, and / or combinations thereof.
[0034] Spatial terms, such as "above," may be used herein for convenience in describing the relationship between one element or feature and another element (or feature) or feature (or feature) illustrated in the figures. It should be understood that, in addition to the directions depicted in the figures, spatial terms are intended to include different orientations of the device or apparatus during use or operation. For example, if the device in the figure is flipped, an element described as "above" or "on" other elements or features would be oriented "below" or "under" other elements or features. Therefore, the exemplary term "above" can include both above and below orientations. It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or portion from another element, component, region, layer, or portion. Therefore, a first element, component, region, layer, or portion discussed below may be referred to as a second element, component, region, layer, or portion without departing from the teachings of the exemplary embodiments.
[0035] As used in this article, "parallel" and "perpendicular" are used to describe the ideal state between two components. In actual production or use, two components may exist in a state that is approximately parallel or perpendicular. For example, combined with numerical descriptions, parallel can refer to the angle between two straight lines within ±10°, the dihedral angle between two planes within ±10°, or the angle between a straight line and a plane within ±10°. Perpendicular can refer to the angle between two straight lines within 90±10°, the dihedral angle between two planes within 90±10°, or the angle between a straight line and a plane within 90±10°. The two components described as "parallel" or "perpendicular" do not have to be absolutely straight lines or planes; they can be approximately 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".
[0036] In this application, the design relationships of greater than, less than, or not equal to parameter values need to exclude reasonable errors of the measuring equipment.
[0037] Please refer to Figures 1 to 3. One embodiment of this application provides an electrochemical device 100, including a housing assembly 10, an electrode assembly 20, and an electrolyte (not shown). The housing assembly 10 is made of metal. The housing assembly 10 includes a first housing 11 and a second housing 12. The first housing 11 has a receiving cavity S, in which the electrode assembly 20 and the electrolyte are disposed. Specifically, the first housing 11 may include a bottom wall 111 and a side wall 112 connected to the periphery of the bottom wall 111, the bottom wall 111 and the side wall 112 together forming the receiving cavity S. A first direction X is defined as the direction in which the second housing 12 and the electrode assembly 20 are arranged. Viewed from the first direction X, the second housing 12 covers the receiving cavity S. Viewed from the first direction X, the bottom wall 111 may be generally circular, and the second housing 12 may also be generally circular. The bottom wall 111 and the second housing 12 may be arranged parallel to each other and both perpendicular to the first direction X. One end of the sidewall 112 is connected to the bottom wall 111, and the other end is welded and fixed to the second housing 12, so that a generally cylindrical receiving cavity S is formed inside the first housing 11. In some embodiments, the electrochemical device 100 can be a coin cell or a cylindrical cell, and the housing assembly 10 is made entirely of steel. For example, the first housing 11 is made of steel, the second housing 12 is also made of steel, and the bottom wall 111 and the sidewall 112 of the first housing 11 are integrally formed. Further, the housing assembly 10 may include the elements Fe and C, and the housing assembly 10 may 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 some other embodiments, the electrochemical device 100 may also be a prismatic cell.
[0038] As shown in Figure 3, the electrode assembly 20 can be a stacked structure, comprising multiple first electrodes 21, multiple second electrodes 22, and multiple insulating films 23. In the stacked structure, the first electrodes 21 and second electrodes 22 are stacked alternately, with one second electrode 22 between every two adjacent first electrodes 21 and one first electrode 21 between every two adjacent second electrodes 22. The insulating films 23 are disposed between adjacent first electrodes 21 and second electrodes 22, preventing direct contact between the first electrodes 21 and second electrodes 22, thereby reducing the possibility of short circuits. First tabs 30 are electrically connected to and extend from the first electrodes 21, and second tabs 40 are electrically connected to and extend from the second electrodes 22. As shown in Figure 4, in some embodiments, the electrode assembly 20 can also be a wound structure.
[0039] As shown in Figures 3 and 4, in the second direction Y, perpendicular to the first direction X, the second housing 12 includes a first region 121, a second region 122, and a third region 123 connected in sequence. The second housing 12 is welded to the first housing 11 (e.g., the sidewall 112 of the first housing 11) via the third region 123. For example, the third region 123 can be welded to the first housing 11 by laser welding, electron beam welding, arc welding, ultrasonic welding, etc. As shown in Figure 2, viewed from the first direction X, the first region 121 overlaps with the electrode assembly 20, and both the second region 122 and the third region 123 are continuous annular structures. For example, when the electrochemical device 100 is a coin cell, viewed from the first direction X, both the second region 122 and the third region 123 are continuous circular annular structures. When the electrochemical device 100 is a prismatic cell, viewed from the first direction X, both the second region 122 and the third region 123 are continuous rectangular annular structures. Figure 2 is simplified and does not show the outer contour of the electrode assembly 20. In the embodiments of this application, when viewed 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 housing 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 receiving cavity S in the first direction X relative to the first region 121 and the third region 123. As shown in Figures 3 and 4, since the second region 122 extends into the receiving cavity S in the first direction X, the surface of the second housing 12 facing the electrode assembly 20 is a stepped surface, while the surface of the second housing 12 away from the electrode assembly 20 can be a plane. 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 to 0.05 mm to 0.3 mm, and the thickness T3 of the third region 123 to 0.025 to 0.15 mm. The thickness T1 of the first region 121 can be approximately the same as or different from the thickness T3 of the third region 123.
[0041] When manufacturing the housing assembly 10, a flat plate of metal is first provided, and one surface of it 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 a second region 122. The above manufacturing method is only an example and is not intended to limit the structure of the housing assembly 10 of this application.
[0042] In this application, since the first region 121 is thinner than the second region 122, it is beneficial to improve the space utilization rate inside the housing assembly 10, thereby increasing the energy density of the electrochemical device 100. Simultaneously, since the third region 123 is welded to the first housing 11 and the second region 122 is thicker, the second region 122 can prevent welding energy (such as laser, electron beam, or electric arc) from entering the 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. This application allows for the thinning of a metal plate of a certain thickness to fabricate the first region 121 and the third region 123, which reduces the processing difficulty.
[0043] In some embodiments, the height of the second region 122 relative to the third region 123 extending along the first direction X (i.e., the difference between T2 and T3) is 0.025 mm to 0.275 mm, thereby allowing the second region 122 to better block welding energy from entering the receiving cavity S through the weld between the third region 123 and the first housing 11, thus reducing the risk of damage to the electrode assembly 20 during welding. Further, the width W2 of the second region 122 in the second direction Y can be set to 0.1 mm to 3 mm, such that the width of the second region 122 is sufficient to block welding energy from entering the receiving cavity S through the weld between the third region 123 and the first housing 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 against the sidewall 112. Because the second region 122 abuts against the sidewall 112, it better prevents welding energy from entering the cavity S through the weld between the third region 123 and the first housing 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 can 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 has a first opening 1210. The electrochemical device 100 also includes a conductive element 50, a first tab 30, and a second tab 40. The conductive element 50 is entirely made of conductive material. The conductive element 50 is at least partially disposed within the receiving cavity S and exposed through the first opening 1210. The first tab 30 is electrically connected to the electrode assembly 20 and the conductive element 50, and the second tab 40 is electrically connected to the electrode assembly 20 and the first housing 11. For example, the first tab 30 is electrically connected to the first current collector 210 of the first electrode 21, and the second tab 40 is electrically connected to the second current collector 220 of the second electrode 22. In some embodiments, the first tab 30 may be welded to the conductive element 50, thereby improving the connection strength between the first tab 30 and the conductive element 50. The second electrode 40 can also be welded and fixed to the first housing 11, thereby improving the connection strength between the second electrode 40 and the first housing 11. More specifically, when the housing assembly 10 is made entirely of steel, the second electrode 40 can be welded and fixed to the bottom wall 111 or side wall 112 of the first housing 11. This allows the conductive element 50 to have opposite polarities to the first housing 11, enabling the electrochemical device 100 to supply power to external components (not shown). Specifically, when the first electrode 21 is a positive electrode and the second electrode 22 is a negative electrode, the conductive element 50 is positive, and the first housing 11 is negative. In some embodiments, the material of the conductive element 50 can be selected from metals such as aluminum, copper, steel, and nickel, or their alloys. Viewed from the first direction X, the first opening 1210 can be circular. In other embodiments, the shape of the first opening 1210 can also be changed, such as elliptical, square, hexagonal, etc.
[0046] The conductive element 50 may include a cover portion 51 and a protrusion 52 connected together. The cover portion 51 is disposed between the first region 121 and the electrode assembly 20 in a first direction X. A first 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 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 away from the cover portion 51 may be substantially flush with the surface of the second cover body away from the cover portion 51, thereby improving the flatness of the appearance 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. Viewed from 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 also be separate structures. The shapes of the cover portion 51 and the protrusion 52 may also be varied, such as elliptical, square, hexagonal, etc.
[0047] In some embodiments, the first region 121 includes a first edge 1211 disposed around the first opening 1210. Viewed from the first direction X, the protrusion 52 is separated from the first edge 1211. This reduces the risk of short circuit between the first region 121 and the protrusion 52 during mechanical abuse (such as vibration or impact), thereby improving the safety and reliability of the electrochemical device 100.
[0048] In some embodiments, the electrochemical device 100 further includes a first adhesive member 60 disposed in a first direction X between the cover portion 51 and the first region 121. Since the first region 121 is thinner than the second region 122 by a thickness T1, at least a portion of the first adhesive member 60 can be accommodated within the space reserved after the first region 121 is thinned, thereby improving the space utilization rate inside the housing assembly 10 and thus increasing the energy density of the electrochemical device 100. In some embodiments, at least a portion of the cover portion 51 can also be accommodated within the space reserved after the first region 121 is thinned, thereby further increasing the energy density of the electrochemical device 100. The first adhesive member 60 bonds the cover portion 51 and the first region 121, fixing the cover portion 51 to the first region 121. Furthermore, the cover portion 51 and the first region 121 are electrically isolated by the first adhesive member 60, reducing the risk of short circuits between the first region 121 and the cover portion 51 during mechanical abuse, further improving the safety and reliability of the electrochemical device 100. Additionally, the first adhesive 60 can seal the gap between the second housing 12 and the cover 51, thereby reducing the risk of electrolyte leakage from the receiving cavity S between the second housing 12 and the cover 51 during normal use of the electrochemical device 100. The first adhesive 60 is provided with a second opening 600. 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 sequentially from the side of the cover 51 away from the electrode assembly 20 into the second opening 600 and the first opening 1210. The first adhesive 60 may include at least one of polyethylene, polypropylene, propylene-ethylene copolymer, polyetheretherketone, polyvinylidene fluoride, or polytetrafluoroethylene. The thickness T4 of the first adhesive 60 may be from 0.025 mm to 0.15 mm.
[0049] In some embodiments, the cover 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 the second region 122, and the second edge 511 is separated from the second region 122. Further, 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 the second region 122, and the fourth edge 602 is separated from the second region 122. By setting both the second edge 511 and the fourth edge 602 to be separated from the second region 122, a portion of the first region 121 is exposed in the cover 51 and the first adhesive member 60. Therefore, when gas accumulates inside the electrochemical device 100, the first region 121 exposed in the cover 51 and the first adhesive 60 can crack under the action of gas, so that the gas inside the shell can be released through the crack, thereby reducing the pressure in the containment cavity S and achieving the purpose of depressurization, thereby improving the safety and reliability of the electrochemical device 100.
[0050] In some embodiments, when 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 the above distances, when gas accumulates inside the electrochemical device 100, the portion of the first region 121 exposed between the cover 51 and the first adhesive 60 can be allowed to crack under the action of the gas, thereby achieving the purpose of pressure relief.
[0051] Referring to Figure 5, in some embodiments, an explosion-proof valve 13 can be additionally provided at other locations on the housing assembly 10. For example, the explosion-proof valve 13 can be provided on the bottom wall 111 or side wall 112 of the first housing 11. The explosion-proof valve 13 can be a through-hole formed on the bottom wall 111 or side wall 112 of the first housing 11 by laser etching, and the shape and depth of the explosion-proof valve 13 can be set according to specific needs. Therefore, when the internal pressure of the electrochemical device 100 reaches a certain level, the explosion-proof valve 13 will crack due to stress concentration, achieving the purpose of pressure relief. At this time, it is also possible to set the second edge 511 to be in contact with the second region 122 when viewed from the first direction X. Since the contact area between the first region 121 and the first adhesive 60 is increased, the bonding strength and sealing reliability of the first adhesive 60 can be improved.
[0052] As shown in Figures 3 and 4, in some embodiments, when viewed from the first direction X, the third edge 601 of the first adhesive member 60 is substantially flush with the first edge 1211 of the second housing 12. That is, when viewed from the first direction X, the first opening 1210 and the second opening 600 can completely overlap. Referring to Figure 6, in other embodiments, the position of the third edge 601 of the first adhesive member 60 can also be changed. For example, when viewed from the first direction X, the third edge 601 of the first adhesive member 60 can also be connected to the protrusion 52, that is, the first adhesive member 60 covers and adheres to the sidewall of the protrusion 52. The first adhesive member 60 further extends into the first opening 1210. Therefore, the portion of the first adhesive member 60 located within the first opening 1210 can further isolate the first region 121 and the protrusion 52, reducing the risk of short circuit between the first region 121 and the protrusion 52 during mechanical abuse, and further improving the safety and reliability of the electrochemical device 100. Moreover, the increased contact area between the conductive element 50 and the first adhesive element 60 further improves the bonding strength and sealing reliability of the first adhesive element 60.
[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 approximately 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 changed. For example, when viewed from the first direction X, the fourth edge 602 is further away from the protrusion 52 than the second edge 511, and the first adhesive member 60 also covers the second edge 511. Due to the increased contact area between the cover portion 51 and the first adhesive member 60, the adhesive strength of the first adhesive member 60 can be further improved.
[0054] The electrochemical device 100 of this application includes all devices capable of undergoing electrochemical reactions. Specifically, the electrochemical device 100 includes all types of primary cells, secondary cells, fuel cells, solar cells, and capacitors (e.g., supercapacitors). Optionally, the electrochemical device 100 can be a lithium secondary battery, including lithium metal secondary batteries, lithium-ion secondary batteries, lithium polymer secondary batteries, and lithium-ion polymer secondary batteries.
[0055] Referring to Figure 8, one embodiment of this application also provides an electronic device 1, including a battery compartment 101 and the aforementioned electrochemical device 100 disposed within the battery compartment 101. The electronic device 1 is powered by the aforementioned electrochemical device 100, which has improved energy density and reliability. In one embodiment, the electronic device 1 of this application may be, but is not limited to, a laptop computer, a pen-based computer, a mobile computer, an e-book player, a portable telephone, a portable fax machine, a portable copier, a portable printer, a stereo headset, a video recorder, an LCD TV, a portable cleaner, a portable CD player, a mini CD-ROM, a transceiver, an electronic notebook, a calculator, a memory card, a portable recorder, a radio, a backup power supply, a motor, a car, a motorcycle, an electric bicycle, a bicycle, lighting fixtures, toys, game consoles, clocks, power tools, flashlights, cameras, household large-capacity batteries, and lithium-ion capacitors, etc.
[0056] The above-disclosed embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of this application. Therefore, any equivalent variations made in accordance with this application are still within the scope of this application.
Claims
1. An electrochemical device comprising a housing assembly and an electrode assembly, wherein the housing assembly is made of metal, the housing assembly includes a first housing having a receiving cavity and a second housing covering the receiving cavity, and the electrode assembly is disposed within the receiving cavity, wherein, The second housing and the electrode assembly are arranged in a first direction. In a second direction perpendicular to the first direction, the second housing includes a first region, a second region, and a third region connected in sequence. The third region is welded and fixed to the first housing. When viewed from the first direction, the first region overlaps with the electrode assembly. 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 receiving cavity in the first direction relative to the first region and the third region.
2. The electrochemical device as claimed in claim 1, wherein, The first region has a first opening, and the electrochemical device further includes a conductive element, a first tab, and a second tab. The conductive element is at least partially disposed within the receiving cavity and exposed through the first opening. The first tab is electrically connected to the electrode assembly and the conductive element, and the second tab is electrically connected to the electrode assembly and the first housing.
3. The electrochemical device as described in claim 2, wherein, The conductive element includes a cover and a protrusion connected to each other. The cover is disposed between the first region and the electrode assembly in the first direction, and the protrusion extends from the side of the cover away from the electrode assembly into the first opening.
4. The electrochemical device as described in claim 3, wherein, The first region includes a first edge surrounding the first opening, and when viewed from the first direction, the protrusion is separated from the first edge.
5. The electrochemical device as described in claim 3, wherein, The electrochemical device further includes a first adhesive member disposed between the cover and the first region in the first direction, wherein the first adhesive member adheres to the cover and the first region. The first adhesive has 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.
6. The electrochemical device as claimed in claim 5, wherein, The cover includes a second edge, which, when viewed from the first direction, is closer to the protrusion than the second region, and is separated from the second region; The first adhesive includes a third edge disposed around the second opening and a fourth edge disposed 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.
7. The electrochemical device as claimed in claim 6, wherein, 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.
8. The electrochemical device as claimed in claim 6, wherein, Viewed from the first direction, the third edge is connected to the protrusion, and the first adhesive also extends into the first opening.
9. The electrochemical device as claimed in claim 6, wherein, Viewed from the first direction, the fourth edge is further away from the protrusion than the second edge, and the first adhesive also covers the second edge.
10. The electrochemical device according to any one of claims 1 to 9, wherein, The second region extends at a height of 0.025 mm to 0.275 mm relative to the third region along the first direction.
11. The electrochemical device according to any one of claims 1 to 9, wherein, The first housing includes a bottom wall and a side wall connected to the bottom wall. The third region is welded and fixed 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 against the side wall.
12. An electronic device, wherein, It includes a battery compartment and an electrochemical device as described in any one of claims 1 to 11 disposed within the battery compartment.