Electrochemical device and electronic device

Abstract

An electrochemical device includes a housing, an electrode assembly, and an insulating sleeve. The electrode assembly is in a jelly-roll structure, and a first tab of the electrode assembly includes a current collector and a tab. The current collector includes a first edge and a second edge opposite to each other in a first direction. The tab includes a first connecting region connecting the first edge and a second connecting region connecting the first connecting region. The electrode assembly includes a first end surface and a second end surface opposite to each other in the first direction, and the second connecting region forms the first end surface. The insulating sleeve includes a first region and a second region integrally connected. The first region covers the first connecting region, and the second region is disposed on the second connecting region and has a first opening. The electrode assembly includes a first portion and a second portion connected in a second direction, the first portion contains the first connecting region, and the second portion is separated from the insulating sleeve. A width of the first portion is less than a width of the second portion. An electronic device is also provided. The present application can improve the reliability and service life of the electrochemical device.

Description

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 secondary batteries) are widely used in electronic mobile devices, power tools and electric vehicles, and people have increasingly higher requirements for the reliability and safety of electrochemical devices.

[0003] Electrochemical devices typically consist of a housing and an electrode assembly housed within the housing. The electrode assembly includes current collectors and tabs connecting to the current collectors. During operation, the electrode assembly may vibrate within the housing, potentially causing a short circuit between the tabs and the housing, thus reducing the reliability and lifespan of the electrochemical device. Summary of the Invention

[0004] In view of this, this application provides an electrochemical device with high reliability and service life.

[0005] Additionally, this application also provides an electronic device having the above-described electrochemical device.

[0006] This application provides an electrochemical device, including a housing and an electrode assembly disposed within the housing. The electrode assembly has a wound structure and includes a first electrode. The first electrode includes a first current collector and a first tab. A first direction is defined as the direction of the winding center axis. The first current collector includes a first side and a second side disposed opposite to each other in the first direction, and the first tab extends from the first side. The first tab includes a first connection region connecting the first side and a second connection region connecting the first connection region, the second connection region being bent relative to the first connection region. The electrode assembly includes a first end face and a second end face disposed opposite to each other in the first direction, the second connection region forming the first end face. The electrochemical device also includes an insulating sleeve. The insulating sleeve includes a first region and a second region integrally connected. The first region covers the first connection region, and the second region is disposed on the second connection region and has a first opening. A portion of the second connection region is exposed through the first opening. The electrode assembly includes a first portion and a second portion connected in the first direction. Viewed from a second direction perpendicular to the first direction, the first portion overlaps with the insulating sleeve, and the second portion is separate from the insulating sleeve. In the second direction, the width of the first portion is smaller than the width of the second portion.

[0007] In this application, the first region of the insulating sleeve can isolate at least a portion of the first connection area with opposite polarities from the housing, reducing the possibility of a short circuit between this portion of the first connection area and the housing. Furthermore, the second region of the insulating sleeve can fill the space between the second connection area and the first wall of the housing, reducing the possibility of damage caused by the electrode assembly's movement along the first direction within the housing during mechanical abuse of the electrochemical device. Therefore, this application improves the reliability and service life of the electrochemical device. In addition, since the first and second regions of the insulating sleeve are integrally connected, compared to the prior art which requires coating the first connection area with adhesive and additionally placing an insulating pad between the second connection area and the housing, this application simplifies the process.

[0008] In some possible implementations, the width of the insulating sleeve is smaller than the width of the second part, thereby reducing the impact of the insulating sleeve on the energy density of the electrochemical device.

[0009] In some possible implementations, the first region includes a first end connecting to the second region and a second end disposed opposite to the first end. The first region extends from the first end along a first direction.

[0010] In some possible implementations, the insulating sleeve further includes a third region. The third region connects the first end and the second region. The third region extends from the first end in a direction offset from the first direction. The presence of the third region reduces the likelihood of a sharp point forming at the junction of the first and second regions, thus reducing the impact of such a sharp point on the housing during mechanical abuse and improving the impact resistance of the electrochemical device.

[0011] In some possible implementations, the first region includes a first end connecting to the second region and a second end disposed opposite to the first end. The first region extends from the first end in a first direction. The second end is further away from the winding center axis than the first end. The increased distance between the inclined first region and the portion of the first connection area located within the insulating sleeve reduces the likelihood of this portion of the first connection area contacting the first region during shaking and thus breaking in the event of mechanical abuse of the electrochemical device, thereby improving impact resistance. Moreover, the diameter of the first region at the second end is larger than the diameter of the first region at the first end, which facilitates the fitting of the insulating sleeve onto the first tab.

[0012] In some possible implementations, the second region includes a third end connected to the first region and a fourth end disposed opposite to the third end. The fourth end surrounds and forms a first opening. The second region extends from the third end along a second direction. Therefore, the space occupied by the second region at the electrode assembly head can be reduced, thereby reducing the impact of the insulating sleeve on the energy density of the electrochemical device.

[0013] In some possible implementations, the second region includes a third end connecting to the first region and a fourth end disposed opposite to the third end. The fourth end forms a first opening. The second region extends from the third end in a second direction. The fourth end is further away from the second connection region than the third end. Therefore, the second region not only fills the space between the second connection region and the housing, but also provides better cushioning in the event of mechanical abuse of the electrochemical device, reducing the possibility of damage to the electrode assembly caused by shaking within the housing.

[0014] In some possible implementations, the insulating sleeve also includes a fourth region extending away from the edge of the first opening. The fourth region also fills the space between the second connection area and the housing, reducing the likelihood of damage to the electrode assembly when it moves within the housing.

[0015] In some possible implementations, the electrode assembly further includes a second electrode and a separator, with the first electrode, separator, and second electrode sequentially stacked and wound to form the electrode assembly. The separator prevents the first and second electrodes from directly contacting each other, thereby reducing the possibility of a short circuit between the first and second electrodes.

[0016] In some possible implementations, a separator is located at least a portion of the outermost layer of the electrode assembly. The separator forms a protective layer, reducing the risk of short circuits caused by wear on the electrodes inside this portion of the separator, thereby increasing the electrode assembly's resistance to mechanical shock.

[0017] In some possible implementations, the outermost insulating membrane includes a first inclined region that overlaps with both the first connection region and the first region in a second direction. The first inclined region is inclined relative to the first direction. The first region includes a first end connecting to the second region and a second end disposed opposite to the first end. Viewed from the first direction, the second end overlaps with the first inclined region. The first inclined region can further isolate at least a portion of the first connection region exhibiting opposite polarities from the housing, reducing the possibility of a short circuit between the first connection region and the housing. Moreover, in the event of mechanical abuse of the electrochemical device, the first inclined region can reduce the possibility of at least a portion of the first connection region directly contacting the first region and thus breaking, thereby improving impact resistance.

[0018] In some possible implementations, the outermost insulating membrane further includes a third connecting region connecting the first inclined region and a second inclined region connecting the third connecting region. Viewed from a second direction, the third connecting region and the second inclined region overlap with the first region. The second inclined region is inclined relative to the first direction. The second inclined region can reduce the possibility of the first current collector directly contacting the insulating sleeve and thus being damaged during mechanical abuse.

[0019] In some possible implementations, the second end contacts the first inclined region. Therefore, the first region can limit the first inclined region, reducing the possibility that the first inclined region will open in a direction away from the winding center axis and fold over during mechanical misuse.

[0020] In some possible implementations, the second electrode includes a second current collector and a second tab. The second current collector includes a third side and a fourth side disposed opposite each other in a first direction, and the second tab is formed by extending from the fourth side. The second tab includes a third connection region connecting the fourth side and a fourth connection region connecting the third connection region. The fourth connection region is bent relative to the third connection region and is located on a second end face. In this case, when the fourth connection region is electrically connected to other components (such as a housing), it is beneficial to increase the contact area between the fourth connection region and other components, thereby improving the reliability of the electrical connection.

[0021] In some possible implementations, the housing includes a first wall facing a first end face, a second wall opposite to the first wall, and a third wall connected to both the first and second walls. The first wall and the second wall are electrically isolated. A second connection region is electrically connected to the first wall, and a fourth connection region is electrically connected to the second wall. Therefore, the first wall and the second wall can exhibit opposite polarities, allowing the electrochemical device to supply power to external components.

[0022] In some possible implementations, the electrochemical device further includes a first current collector disposed in a first direction between the second connection region and the second region. The second connection region is electrically connected to the first wall via the first current collector. The first current collector has the function of collecting current.

[0023] In some possible implementations, the first current collector has a second opening. Viewed from the first direction, the second opening overlaps with the first opening. The second opening helps reduce the weight of the first current collector. Moreover, when electrolyte is injected into the housing, the electrolyte can flow in through the first and second openings successively and fully wet the electrode assembly, reducing the impact of the first current collector on the electrolyte wetting efficiency.

[0024] In some possible implementations, the fourth connection area is electrically connected to the second wall via a second current collector. The second current collector serves to collect current.

[0025] In some possible implementations, the housing includes a first wall facing a first end face, a second wall opposite to the first wall, a third wall connected to both the first and second walls, and an electrode post disposed on the first wall. The electrode post is electrically isolated from the first wall. A second connection region is electrically connected to the electrode post, and a fourth connection region is electrically connected to the second wall. Therefore, the first wall and the electrode post can exhibit opposite polarities, allowing the electrochemical device to supply power to external components.

[0026] In some possible implementations, the first electrode further includes a first active material layer and a second active material layer, with the first active material layer, the first current collector, and the second active material layer stacked sequentially. In the first direction, the insulating sleeve is separated from both the first and second active material layers. This reduces the likelihood of an increase in the size of the electrochemical device in the second direction due to the insulating sleeve, thereby reducing the impact of the insulating sleeve on the energy density of the electrochemical device.

[0027] In some possible implementations, viewed from the first direction, the insulating sleeve has a continuous ring structure, which gives it good insulation performance.

[0028] In some possible implementations, the insulating sleeve is made of at least one of rubber, silicone, or plastic, giving it good insulating properties.

[0029] In some possible implementations, the thickness of the insulating sleeve in the first direction is 0.03 mm to 2 mm.

[0030] A second aspect of this application also provides an electronic device including the aforementioned electrochemical device. The electronic device is powered via the electrochemical device. Because the electrochemical device is equipped with an insulating sleeve, the sleeve reduces the possibility of a short circuit between the first electrode tab and the housing, and also reduces the shaking of the electrode assembly within the housing during mechanical abuse, thereby maintaining high reliability and service life. Attached Figure Description

[0031] 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:

[0032] Figure 1 This is a schematic diagram of the structure of an electrochemical device according to one embodiment of this application.

[0033] Figure 2 for Figure 1 An exploded view of the electrochemical device shown.

[0034] Figure 3 for Figure 1 The electrochemical device shown is a cross-sectional view along line III-III.

[0035] Figure 4 for Figure 2 The electrode assembly of the electrochemical device shown is viewed in cross-section along IV-IV.

[0036] Figure 5 for Figure 2 The diagram shows the electrochemical device as viewed from the first direction.

[0037] Figure 6 for Figure 2 The diagram shows the unfolded view of the first electrode of the electrode assembly of the electrochemical device.

[0038] Figure 7 for Figure 2 The diagram shows the unfolded second electrode of the electrode assembly of the electrochemical device.

[0039] Figure 8 for Figure 2 The schematic diagram of the insulating sleeve of the electrochemical device shown is viewed from the second direction.

[0040] Figure 9 for Figure 2 The schematic diagram of the insulating sleeve of the electrochemical device shown is viewed from the first direction.

[0041] Figure 10 This is a structural schematic diagram of the insulating sleeve as viewed from the first direction in some other embodiments.

[0042] Figure 11 for Figure 1 Cross-sectional views of other embodiments of the electrochemical device shown.

[0043] Figure 12 for Figure 1 Cross-sectional views of other embodiments of the electrochemical device shown.

[0044] Figure 13 for Figure 1 Cross-sectional views of other embodiments of the electrochemical device shown.

[0045] Figure 14 for Figure 1 Cross-sectional views of other embodiments of the electrochemical device shown.

[0046] Figure 15 for Figure 1 Cross-sectional views of other embodiments of the electrochemical device shown.

[0047] Figure 16 for Figure 1 Cross-sectional views of other embodiments of the electrochemical device shown.

[0048] Figure 17 for Figure 1 Cross-sectional views of other embodiments of the electrochemical device shown.

[0049] Figure 18 This is a cross-sectional view of an electrochemical device according to another embodiment of this application.

[0050] Figure 19 This is a cross-sectional view of an electrochemical device according to another embodiment of this application.

[0051] Figure 20 This is a cross-sectional view of an electrochemical device according to another embodiment of this application.

[0052] Figure 21 This is a cross-sectional view of an electrochemical device according to another embodiment of this application.

[0053] Figure 22 This is a module architecture diagram of an electronic device according to one embodiment of this application.

[0054] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0055] 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.

[0056] 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.

[0057] 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.

[0058] Furthermore, when describing the implementation of this application, the word "may" refers to "one or more implementations of this application".

[0059] 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.

[0060] 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.

[0061] 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°, parallel can also refer to the dihedral angle between two planes within ±10°, and parallel can also refer to the angle between a straight line and a plane within ±10°. Perpendicular can refer to the angle between two straight lines within 90±10°, perpendicular can also refer to the dihedral angle between two planes within 90±10°, and perpendicular can also refer to 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".

[0062] 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.

[0063] Please see Figures 1 to 3This application provides an electrochemical device 100, including a housing 10, an electrode assembly 20, and an electrolyte such as an electrolyte solution (not shown). The housing 10 includes a first wall 11, a second wall 12, and a third wall 13. The first wall 11 and the second wall 12 are disposed opposite each other in a first direction X. The first wall 11 may be generally circular, and the second wall 12 may also be generally circular. The first wall 11 and the second wall 12 may be disposed parallel to each other and both perpendicular to the first direction X. The first end 131 of the third wall 13 is connected to the first wall 11, and the second end 132 of the third wall 12 is connected to the second wall 12, thereby forming a generally cylindrical receiving cavity S within the housing 10. Viewed from the first direction X, the first wall 11 covers the receiving cavity S. The electrode assembly 20 and the electrolyte solution are housed within the receiving cavity S. In some embodiments, the first wall 11 and the second wall 12 are electrically isolated. The housing 10 may be made entirely of steel. In some embodiments, the steel shell includes elements Fe and C, and the steel shell 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. For example, the first wall 11 is made of steel, and the second wall 12 and the second wall 13 are also made of steel. Moreover, the third wall 13 and the second wall 12 can be integrally formed, and the second wall 12 and the third wall 13 can be bonded and fixed together by a first insulating layer 14. The first insulating layer 14 provides electrical insulation between the first wall 11 and the third wall 13, and also provides electrical insulation between the first wall 11 and the second wall 12. The material of the first insulating layer 14 can be an insulating material resistant to electrolyte corrosion, such as polystyrene (PS), polypropylene (PP), polyethylene (PE), polyester (PET), polyvinyl chloride (PVC), polyimide (PI), acrylonitrile-butadiene-styrene plastic (ABS), polycarbonate (PC), polyamide (PA), etc.

[0064] like Figure 2 and Figure 3 As shown (where, Figure 3 for Figure 1 The electrochemical device 100 shown is a cross-sectional view along section III-III (and section III-III is parallel to the first direction X). The electrode assembly 20 includes a first end face 201 and a second end face 202 disposed opposite to each other in the first direction X. The first end face 201 is disposed toward the first wall 11, and the second end face 202 is disposed toward the second wall 12. Please refer to [the diagram / reference needed]. Figure 4 (in, Figure 4 for Figure 2The electrode assembly 20 shown is a cross-sectional view along IV-IV (with the IV-IV section perpendicular to the first direction X). The electrode assembly 20 has a wound structure and includes a first electrode 21, a second electrode 22, and a separator 23 disposed between the first electrode 21 and the second electrode 22. The separator 23 prevents the first electrode 21 and the second electrode 22 from directly contacting each other, thereby reducing the possibility of a short circuit between the first electrode 21 and the second electrode 22. For simplicity, the separator 23 is shown as a dashed line (composed of a plurality of short lines spaced apart). The electrode assembly 20 has a winding direction C and a winding center axis O disposed along the first direction X. In some embodiments, after winding, the separator 23 is located at least part of the outermost layer of the electrode assembly 20. For example, the separator 23 is located at the outermost layer of the electrode assembly 20. The separator 23 can form a protective layer, reducing the risk of short circuits caused by wear on the electrode inside this portion of the separator 23, thereby increasing the resistance of the electrode assembly 20 to mechanical shock. Here, the winding direction C refers to the direction along the first direction X. Figure 4 The first electrode 21, the separator 23, or the second electrode 22 shown are moved from the inside out around the winding center axis O. The winding direction C can be either clockwise or counterclockwise around the winding center axis O. In some embodiments, the winding direction C is... Figure 4 The direction of the counterclockwise rotation around the central axis O is shown. Figure 5 for Figure 2 The diagram shown illustrates the electrochemical device 100 as viewed from the first direction X. Figure 3 In fact, it is also for Figure 5 The electrochemical device 100 shown is a cross-sectional view along III-III. Figure 5 The outer contour of the electrode assembly 20 shown is Figure 4 The separator 23 shown is located on the outermost layer of the electrode assembly 20. In other embodiments, the first electrode 21 or the second electrode 22 may also be located on the outermost layer of the electrode assembly 20. In some embodiments, the electrochemical device 100 may be a cylindrical power battery. The cross-sectional shape of the electrode assembly 20 along a cross-section perpendicular to the first direction X is approximately circular.

[0065] In some embodiments, the first electrode 21 includes a first active material layer 211, a first current collector 210, and a second active material layer 212 stacked sequentially. The first current collector 210 includes a first surface 2101 facing the winding center axis O and a second surface 2102 facing away from the winding center axis O. The first active material layer 211 is disposed on the first surface 2101, and the second active material layer 212 is disposed on the second surface 2102. The first current collector 210 may contain aluminum or nickel. In some embodiments, when the first electrode 21 is a positive electrode, the first current collector 210 contains aluminum foil, which has relatively weak strength but good conductivity. Both the first active material layer 211 and the second active material layer 212 contain active materials, such as at least one of lithium cobalt oxide, lithium manganese oxide, lithium nickel oxide, lithium nickel cobalt manganese oxide, lithium iron phosphate, lithium manganese iron phosphate, lithium vanadium phosphate, lithium vanadium oxide phosphate, lithium-rich manganese-based materials, or lithium nickel cobalt aluminum oxide.

[0066] The second electrode 22 includes a third active material layer 221, a second current collector 220, and a fourth active material layer 222 stacked together. The second current collector 220 includes a third surface 2201 facing the winding central axis O and a fourth surface 2202 facing away from the winding central axis O. The third active material layer 221 is disposed on the third surface 2201, and the fourth active material layer 222 is disposed on the fourth surface 2202. The second current collector 220 may contain copper, nickel, or a carbon-based conductive material. In some embodiments, when the second electrode 22 is a negative electrode, the second current collector 220 contains copper. Both the third active material layer 221 and the fourth active material layer 222 contain an active material, which may be selected from at least one of graphite-based materials, alloy-based materials, lithium metal, and alloys thereof. Graphite-based materials may be selected from at least one of artificial graphite and natural graphite; alloy-based materials may be selected from at least one of silicon, silicon oxide, tin, and titanium sulfide.

[0067] The separator 23 includes at least one of polyethylene, polypropylene, polyvinylidene fluoride, polyethylene terephthalate, polyimide, or aramid.

[0068] Please see Figure 3 In the first direction X, the first current collector 210 includes a first end 21a and a second end 21b disposed opposite to each other, and the second current collector 220 includes a third end 22a and a fourth end 22b disposed opposite to each other. Viewed from the second direction Y perpendicular to the first direction X (it can be understood that any direction in a two-dimensional plane perpendicular to the first direction X can be considered as the second direction of this application; however, for ease of understanding, in...), Figure 3The first direction X, the second direction Y, and the second direction Y' distinguish two mutually perpendicular directions within the two-dimensional plane. Therefore, the first direction X, the second direction Y, and the second direction Y' can constitute a three-dimensional coordinate system. The first end 21a coincides with one end of the first active material layer 211; the second end 21b coincides with the other end of the first active material layer 211. Viewed from the second direction Y, the third end 22a coincides with one end of the third active material layer 221; the second end 22b coincides with the other end of the third active material layer 221. The separating membrane 23 includes a fifth end 23a and a sixth end 23b disposed opposite to each other. The first end 21a, the third end 22a, and the fifth end 23a are all disposed towards the first wall 11, and the second end 21b, the fourth end 22b, and the sixth end 23b are all disposed towards the second wall 12. When the first electrode 21 is a positive electrode and the second electrode 22 is a negative electrode, to reduce the possibility of lithium plating on the negative electrode, the third end 22a extends beyond the first end 21a in the first direction X, and the fourth end 22b extends beyond the second end 21b in the first direction X. In the first direction X, the third end 22a is closer to the first wall 11 than the first end 21a, and the fourth end 22b is closer to the second wall 12 than the second end 21b. Furthermore, to fully avoid direct contact between the first electrode 21 and the second electrode 22, the fifth end 23a extends beyond the third end 22a in the first direction X, and the sixth end 23b extends beyond the fourth end 22b in the first direction X. In the first direction X, the fifth end 23a is closer to the first wall 11 than the third end 22a, and the sixth end 23b is closer to the second wall 12 than the fourth end 22b.

[0069] Please refer to Figure 6 ,in Figure 6 The diagram shows the unfolded view of the first electrode 21. The first current collector 210 includes a first side 210a and a second side 210b disposed opposite each other in the first direction X. Please refer to the diagram for further details. Figure 3 and Figure 6 After winding, when viewed from the second direction Y, the first side 210a coincides with the first end 21a, and the second side 210b coincides with the second end 21b. For example... Figure 6As shown, after the first electrode 21 is unfolded, a three-dimensional coordinate system is established based on the mutually perpendicular first direction X, third direction Y”, and fourth direction Z. The third direction Y” is defined as the stacking direction of the first active material layer 211, the first current collector 210, and the second active material layer 212 after the first electrode 21 is unfolded. The fourth direction Z is the extension direction of the first electrode 21 before the electrode assembly 20 is wound. The first side 210a and the second side 210b of the first current collector 210 can both extend along the fourth direction Z. The first electrode 21 also includes a first tab 24, which is formed by extending the first side 210a (e.g., the first tab 24 is integrally formed with the first current collector 210). In the fourth direction Z, the width of the first tab 24 can be equal to the width of the first current collector 210. This can prevent the current distribution of the first electrode 21 from being too concentrated, reduce the internal resistance of the first electrode 21, and thus improve the charge and discharge rate of the first electrode 21. The first electrode tab 24 includes a first connecting region 241 connecting to the first side 210a and a second connecting region 242 connecting to the first connecting region 241. The first connecting region 241 includes a first connecting end 2401 connected to the first current collector 210 (viewed from the second direction Y, the first connecting end 2401 coincides with the first end 21a, and the first connecting end 2401 and the second electrode 22 overlap), and the first connecting region 241 extends substantially from the first connecting end 2401 along the first direction X. The second connecting region 242 is bent relative to the first connecting region 241 and extends away from the first direction X. The second connecting region 242 forms a first end face 201. (Referring to a reference...) Figure 3 and Figure 6 It can be understood that, when viewed from the second direction Y, the first electrode 24 is formed into a multi-layered first electrode 24 after being wound. Therefore, when viewed from the second direction Y, the first connection area 241 of the first electrode 24 is also a multi-layered structure.

[0070] Please refer to the above as well. Figure 3 and Figure 7The second current collector 220 includes a third side 220a and a fourth side 220b disposed opposite to each other in the first direction X. Viewed from the second direction Y, the third side 220a coincides with the third end 22a, and the fourth side 220b coincides with the fourth end 22b. The first side 210a and the third side 220a are located on the same side of the electrode assembly 20, and the second side 210b and the fourth side 220b are located on the other side of the electrode assembly 20. The second electrode 22 also includes a second tab 25, which is formed by extending from the fourth side 220b (e.g., the second tab 25 is integrally formed with the second current collector 220). In the fourth direction Z, the width of the second tab 25 can be equal to the width of the second current collector 220, which can prevent the current distribution of the second electrode 22 from being too concentrated, reduce the internal resistance of the second electrode 22, and thus improve the charge and discharge rate of the second electrode 22. The second electrode tab 25 includes a third connecting region 251 connecting to the fourth side 220b and a fourth connecting region 252 connecting the third connecting region 251. The third connecting region 251 includes a second connecting end 2511 connected to the second current collector 220 (viewed from the second direction Y, the second connecting end 2511 coincides with the third end 22a, and the second connecting end 2511 is separate from the first electrode 21), and the third connecting region 251 can extend from the second connecting end 2511 generally along the first direction X. The fourth connecting region 252 is bent relative to the third connecting region 251, and the fourth connecting region 252 is located on the second end face 202. (Refer to reference...) Figure 3 and Figure 7 It can be understood that, when viewed from the second direction Y, the second electrode 25 is formed into a multi-layered second electrode 25 after being wound. Therefore, when viewed from the second direction Y, the third connection area 251 of the second electrode 25 is also a multi-layered structure.

[0071] During fabrication, active materials are coated on both surfaces of the first current collector 210 to form a first electrode 21, and a first tab 24 is provided at one end of the first current collector 210 along the first direction X. The first tab 24 is separate from both the first active material layer 211 and the second active material layer 212. Active materials are coated on both surfaces of the second current collector 220 to form a second electrode 22, and a second tab 25 is provided at one end of the second current collector 220 along the first direction X. The second tab 25 is separate from both the third active material layer 221 and the fourth active material layer 222. After the first electrode 21, the separator 23, and the second electrode 22 are sequentially stacked and wound, a portion of the first tab 24 is flattened using a flattening device (not shown) to form a first flattened surface (the second connecting area 242 forms the first flattened surface). Similarly, a portion of the second tab 25 is flattened using a flattening device to form a second flattened surface (the fourth connecting area 252 forms the second flattened surface). Thus, an electrode assembly 20 with a full tab structure is obtained.

[0072] like Figure 3As shown, the second connection region 242 is electrically connected to the first wall 11, and the fourth connection region 252 is electrically connected to the second wall 12. At this time, the first wall 11 and the second wall 12 exhibit opposite polarities, allowing 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 first wall 11 is positive, and the second wall 12 and the third wall 13 are negative.

[0073] Please refer to the following: Figure 2 , Figure 3 , Figure 5 and Figure 8 The electrochemical device 100 also includes an insulating sleeve 30. The insulating sleeve 30 is made of at least one of rubber, silicone, or plastic. In some embodiments, the insulating sleeve 30 is made of an insulating material resistant to electrolyte corrosion, such as polystyrene (PS), polypropylene (PP), polyethylene (PE), polyester (PET), polyvinyl chloride (PVC), polyimide (PI), acrylonitrile-butadiene-styrene plastic (ABS), polycarbonate (PC), polyamide (PA), etc. Figure 3 As shown, an insulating sleeve 30 covers the first tab 24. In some embodiments, in the first direction X, the insulating sleeve 30 is separate from the first active material layer 211 and the second active material layer 212, respectively. Viewed from the second direction Y, the insulating sleeve 30 does not overlap with the first active material layer 211, and the insulating sleeve 30 does not overlap with the second active material layer 212. This reduces the possibility of an increase in the size of the electrochemical device 100 in the second direction Y' due to the installation of the insulating sleeve 30, thereby reducing the impact of the insulating sleeve 30 on the energy density of the electrochemical device 100. In some embodiments, in the first direction X, the insulating sleeve 30 is separate from the third active material layer 221 and the fourth active material layer 222, respectively. Viewed from the second direction Y, the insulating sleeve 30 does not overlap with the third active material layer 221, and the insulating sleeve 30 does not overlap with the fourth active material layer 222. This also reduces the impact of the insulating sleeve 30 on the energy density of the electrochemical device 100.

[0074] The insulating sleeve 30 includes an integrally connected first region 31 and a second region 32, the second region 32 being bent relative to the first region 31. The first region 31 covers at least a portion of the first connection area 241, thus isolating at least a portion of the first connection area 241 with opposite polarities from the third wall 13, reducing the possibility of a short circuit between this portion of the first connection area 241 and the third wall 13. The first region 31 includes a first end 311 connecting to the second region 32 and a second end 312 disposed opposite to the first end 311. Viewed from the second direction Y, the second end 312 overlaps with the first connection area 241, and the second end 312 may be located in the first direction X between the first connection end 2401 of the first connection area 241 and the second connection area 242. The second region 32 is disposed on the second connection area 242, and the second connection area 242 is closer to the second region 32 than the first connection area 241. The second region 32 may fill the space between the second connection area 242 and the first wall 11. Viewed from the second direction Y, the second connection region 242 may be located between the first end 311 and the second end 312 in the first direction X. The second region 32 includes a third end 321 connecting the first region 31 and a fourth end 322 disposed opposite to the third end 321. Viewed from the first direction X, the third end 321 is separate from the second connection region 242, while the fourth end 322 overlaps with the second connection region 242. In some embodiments, such as... Figure 9 and Figure 10 As shown, viewed from the first direction X, the insulating sleeve 30 has a continuous ring structure. For example, Figure 9 As shown when viewed from the first direction X, the insulating sleeve 30 is a continuous circular structure; Figure 10 Viewed from the first direction X, the insulating sleeve 30 is a continuous rectangular ring structure. The specific shape of the insulating sleeve 30 when viewed from the first direction X can be varied according to the shape of the planar shape formed by the second connection area 242. Therefore, the first end 311 and the second end 312 are both sealed rings when viewed from the first direction X, and the third end 321 and the fourth end 322 are also sealed rings when viewed from the first direction X. In this application, "continuous" means that along the circumferential direction of the insulating sleeve 30, there are no interrupted areas or interfaces. Therefore, the insulating sleeve 30 of this application differs from the insulating structure formed by coating the head of the electrode assembly 20.

[0075] like Figure 3 and Figure 8 As shown, in some embodiments, a first region 31 extends from a first end 311 along a first direction X. A second region 32 extends from a third end 321 along a second direction Y', such that when viewed from the second direction Y, the first region 31 is perpendicular to the second region 32. Because the second region 32 extends along the second direction Y', the space occupied by the second region 32 at the head of the electrode assembly 20 can be reduced, thereby reducing the impact of the insulating sleeve 30 on the energy density of the electrochemical device 100.

[0076] like Figure 3 and Figure 5 As shown, the second region 32 has a first opening 320, and the fourth end 322 surrounds and forms the first opening 320. Viewed from the first direction X, a portion of the second connection region 242 is exposed through the first opening 320. The second connection region 242 and the first wall 11 can be electrically connected through the first opening 320. Furthermore, when electrolyte is injected into the receiving cavity S of the housing 10, the electrolyte can flow through the first opening 320 and fully wet the electrode assembly 20, reducing the impact of the insulating sleeve 30 on the electrolyte wetting efficiency. Moreover, the second connection region 242 can be electrically connected to the first wall 11 through the first opening 320. It is understood that the first wall 11 may have an injection port (not shown), which is sealed with a sealing pin after injection.

[0077] In some embodiments, the thickness T of the insulating sleeve 30 in the first direction X is 0.03 mm to 2 mm. For example... Figure 8 As shown, the thickness T is the height of the insulating sleeve 30 from the first end 311 to the second end 312.

[0078] like Figure 2 and Figure 3As shown, in some embodiments, the electrochemical device 100 further includes a first current collector 40 disposed in the first direction X between the second connection region 242 and the second region 32, and the first current collector 40 is made entirely of conductive material. For example, the first current collector 40 is made of metal, such as aluminum, copper, steel, nickel, or their alloys. The second connection region 242 is electrically connected to the first wall 11 through the first current collector 40. The first current collector 40 has the function of collecting current. At this time, the insulating sleeve 30 can also limit the first current collector 40, reducing the possibility of short circuit when the first current collector 40 comes into contact with the second wall 12 or the third wall 13 of the housing 10 when it is detached from the second connection region 242. In some embodiments, the first current collector 40 is provided with a bendable section 42, which can be bent under external force, so that the bendable section 42 can extend from the first opening 320 and connect to the first wall 11. In some embodiments, the first current collector 40 is provided with a second opening 41. Viewed from the first direction X, the second opening 41 overlaps with the first opening 320. The second opening 41 helps reduce the weight of the first current collector 40. Furthermore, when electrolyte is injected into the receiving cavity S of the housing 10, the electrolyte can flow in sequentially through the first opening 320 and the second opening 41, fully wetting the electrode assembly 20, reducing the impact of the first current collector 40 on the electrolyte wetting efficiency. The first current collector 40 can be welded (e.g., by resistance welding or laser welding) to the second connection area 242. Since the second connection area 242 is formed into a flat surface through a flattening process, this helps increase the contact area between the second connection area 242 and the first current collector 40, facilitating welding between them and improving the reliability of the electrical connection.

[0079] Please see Figures 11 to 13 The structure or position of the first current collector 40 can also be changed. For example... Figure 11 As shown, in some embodiments, the bendable segment 42 may be omitted. The first current collector 40a is approximately inverted T-shaped when viewed from the second direction Y. The first current collector 40a includes a first current collecting region 401 and a second current collecting region 402 connected in the first direction X. The first current collecting region 401 is located in the first direction X between the second connecting region 242 and the second region 32, and the first current collecting region 401 connects to the second connecting region 242. The second current collecting region 402 is located within the first opening 320 of the second region 32. The second opening 41 can penetrate the first current collecting region 401 and the second current collecting region 402 in the first direction X. In this way, the second connecting region 242 can also be electrically connected to the first wall 11.

[0080] like Figure 12 As shown, in some other embodiments, the first current collector 40b is at least partially disposed within the first opening 320, and the first current collector 40b directly electrically connects the second connection area 242 to the first wall 11. Figure 12The diagram shows that in the first direction X, the thickness of the first current collector 40b is greater than the thickness of the second region 32. It is understood that the thickness of the first current collector 40b can also be approximately equal to the thickness of the second region 32, and this application does not impose any limitation on this.

[0081] like Figure 13 As shown, in some embodiments, the first current collector 40c may also be located between the first wall 11 and the second region 32 in the second direction Y. The first current collector 40 is generally T-shaped when viewed from the second direction Y. The first current collector 40c includes a third current collector region 403 and a fourth current collector region 404 connected in the first direction X. The third current collector region 403 is at least partially disposed within the first opening 320 of the second region 32, and the third current collector region 403 connects to the second connection region 242. The fourth current collector region 404 is disposed between the first wall 11 and the second region 32 in the first direction X. The second opening 41 may penetrate the third current collector region 403 and the fourth current collector region 404 in the first direction X. In this way, the second connection region 242 can also be electrically connected to the first wall 11.

[0082] like Figure 2 and Figure 3 As shown, in some embodiments, when viewed from the first direction X, the first opening 320 and the second opening 41 can both be circular. In other embodiments, the shapes of the first opening 320 and the second opening 41 can also be changed, such as elliptical, square, hexagonal, etc.

[0083] like Figure 3 As shown, in some embodiments, the electrochemical device 100 further includes a second current collector 50 disposed in the first direction X between the fourth connection region 252 and the second wall 12, and the second current collector 50 is entirely made of a conductive material. For example, the second current collector 50 is made of a metal, such as aluminum, copper, steel, nickel, or their alloys. The fourth connection region 252 is electrically connected to the second wall 12 through the second current collector 50. The second current collector 50 has the function of collecting current. The second current collector 50 can be welded to the fourth connection region 252. Since the fourth connection region 252 is formed into a flat surface through a flattening process, this helps to increase the contact area between the fourth connection region 252 and the second current collector 50, facilitating welding between the fourth connection region 252 and the second current collector 50, and improving the reliability of the electrical connection. In other embodiments, the fourth connection region 252 can also be directly welded to the second wall 12.

[0084] like Figure 3As shown, the electrode assembly 20 includes a first portion 203 and a second portion 204 connected in the first direction X. Viewed from the second direction Y, the first portion 203 overlaps with the insulating sleeve 30, and the first portion 203 is disposed within the insulating sleeve 30; the second portion 204 is separate from the insulating sleeve 30. Viewed from the second direction Y, a virtual line L1 is defined passing through the second end 312 of the first region 31 and perpendicular to the first direction X. The virtual line L1 divides the electrode assembly 20 into the first portion 203 and the second portion 204. The virtual line L1 intersects the outermost layer of the electrode assembly 20 at a first intersection point P1 and a second intersection point P2, respectively. The distance between the first intersection point P1 and the second intersection point P2 is the width W1 of the first portion 203 in the second direction Y'. The width W2 of the second portion 204 in the second direction Y' is the maximum width of the electrode assembly 20. The width W of the insulating sleeve 30 in the second direction Y should be the outer diameter of the insulating sleeve 30 at the second end 312. In this application, in the second direction Y', the width W1 of the first portion 203 is smaller than the width W2 of the second portion 204. In some embodiments, the width W of the insulating sleeve 30 is smaller than the width W2 of the second portion 204. Since the width W of the insulating sleeve 30 is smaller than the width of the electrode assembly 20, the influence of the insulating sleeve 30 on the energy density of the electrochemical device 100 can be reduced.

[0085] like Figure 14 As shown, in some other embodiments, the width W of the insulating sleeve 30 may also be greater than the width W2 of the second portion 204. For example, as Figure 14 As shown, the thickness of the first region 31 in the second direction Y' can be increased, making the width W of the insulating sleeve 30 greater than the width W2 of the second part 204. On the one hand, this helps to improve the mechanical strength of the insulating sleeve 30, thereby improving the impact resistance of the electrode assembly 20 during mechanical abuse and reducing the possibility of damage to the electrode assembly 20 due to shaking. On the other hand, the width of the first current collector 40 in the second direction Y' can be appropriately increased, which helps to increase the contact area between the second connection area 242 and the first current collector 40, facilitating welding between the second connection area 242 and the first current collector 40, and improving the reliability of the electrical connection. Viewed from the first direction X and the second direction Y, W1 is located within W2, and W2 is located within W.

[0086] The measurement steps for W1, W2, and W can be as follows: (1) Using X-rays to perform two-dimensional projection and scanning tests on the electrochemical device 100 from the second direction Y. The instrument can be an instrument or device known to those skilled in the art (e.g., GEPhoenix vtomex S device) to obtain a CT image; (2) Using calipers or other suitable measuring tools to directly measure the values ​​of W2 and W; then marking the positions of the first intersection point P1 and the second intersection point P2 to directly measure the value of W1.

[0087] The measurement steps for W1, W2, and W can also be: (1) Discharge the electrochemical device 100 to 2.75V at 0.2C; (2) Prepare a resin composition, which is made of a crystal resin matrix (such as epoxy resin), a catalyst, and a curing agent in a certain proportion; (3) Pour the resin composition into a mold, and cut open the first wall 11 of the electrochemical device 100 and place it in the mold at an angle to reduce the air bubbles that may remain at the bottom of the electrochemical device 100, and then continue to slowly pour in the resin composition so that the electrochemical device 100 is completely immersed in the resin. In the resin composition, the resin composition is allowed to slowly flow into the housing 10 through the cut in the housing 10; (4) the electrochemical device 100 is brought to a horizontal position, excess air bubbles are expelled, and then it is allowed to stand until the resin composition solidifies; (5) the electrochemical device 100 is cut along a section parallel to the first direction X and the cut surface is polished to obtain a cross section of the electrochemical device 100; (6) the values ​​of W2 and W are directly measured using calipers or other suitable measuring tools; then the positions of the first intersection point P1 and the second intersection point P2 are marked to directly measure the value of W1.

[0088] This application provides an insulating sleeve 30 within the housing 10 and positions the insulating sleeve 30 on the first electrode tab 24. The first region 31 of the insulating sleeve 30 can isolate at least a portion of the first connection area 241, which exhibits opposite polarity, from the third wall 13, reducing the possibility of a short circuit between the first connection area 241 and the third wall 13. Furthermore, the second region 32 of the insulating sleeve 30 can fill the space between the second connection area 242 and the housing 10, reducing damage caused by the swaying of the electrode assembly 20 within the housing 10 along the first direction X during mechanical abuse (such as drops, collisions, vibrations, etc.) of the electrochemical device 100, thus improving its impact resistance. Therefore, this application improves the reliability and service life of the electrochemical device 100. In addition, since the first region 31 and the second region 32 of the insulating sleeve 30 are integrally connected, compared to the prior art which requires coating the first connection area 241 with adhesive and additionally providing an insulating pad between the second connection area 242 and the first wall 11, this application simplifies the process. Moreover, the insulating sleeve 30 of this application has higher mechanical strength than other insulating structures formed by insulating tape or rubber coating, thus further improving the impact resistance of the electrode assembly 20 during mechanical abuse and reducing the possibility of damage to the electrode assembly 20 due to shaking.

[0089] Please see Figure 15In some embodiments of the insulating sleeve 30a, the first region 31 extends from the first end 311 away from the first direction X, such that the first region 31 is inclined relative to the first direction X. Furthermore, the second end 312 is further away from the winding center axis O than the first end 311. In this case, the width W of the insulating sleeve 30a is the outer diameter of the first region 31 at the second end 312. Thus, viewed from the second direction Y, the distance between the inclined first region 31 and the portion of the first connection area 241 located within the insulating sleeve 30a is increased. This helps reduce the possibility of the portion of the first connection area 242 contacting the first region 31 during shaking and thus breaking when the electrochemical device 100 is subjected to mechanical abuse, thereby improving impact resistance. Moreover, the outer diameter W of the first region 31 at the second end 312 is larger than the diameter W3 of the first region 31 at the first end 311, which facilitates the fitting of the insulating sleeve 30a onto the first tab 24.

[0090] Please see Figure 16 In some embodiments of the insulating sleeve 30b, the first region 31 extends from the first end 311 along or deviates from the first direction X. Furthermore, the second region 32 extends from the third end 321 deviating from the second direction Y', such that the second region 32 is inclined relative to the second direction Y'. In the first direction X, the fourth end 322 is further away from the second end 312 than the third end 321. Thus, the inclined second region 32 not only fills the space between the second connection area 242 and the first wall 11, but also provides better cushioning in the event of mechanical abuse of the electrochemical device 100, reducing the possibility of damage to the electrode assembly 20 when it shakes within the housing 10.

[0091] Please see Figure 17 Furthermore, the insulating sleeve 30c may also include a fourth region 33. The fourth region 33 connects to the fourth end 322 of the second region 22, and the fourth region 33 is formed by extending away from the first region 31 from the edge of the first opening 320. The fourth region 33 extends along the first direction X. The arrangement of the fourth region 33 can also fill the space between the second connection area 242 and the first wall 11, reducing the possibility of damage to the electrode assembly 20 when it shakes within the housing 10.

[0092] Please see Figure 3In some embodiments, when the separator 23 is located at least part of the outermost layer of the electrode assembly 20, the outermost separator 23 includes a first inclined region 2300 that overlaps with both the first connection region 241 and the first region 31 in the second direction Y. The first inclined region 2300 is inclined relative to the first direction X. In this case, the first intersection point P1 and the second intersection point P2 are actually the intersection points of the virtual line L1 and the first inclined region 2300. The first inclined region 2300 can further isolate at least part of the first connection region 241 with opposite polarities from the third wall 13, reducing the possibility of short circuit between the first connection region 241 and the third wall 13. Moreover, since the separator 23 itself is relatively soft, in the event of mechanical abuse of the electrochemical device 100, the first inclined region 2300 can reduce the possibility of at least part of the first connection region 241 directly contacting the first region 31 and thus breaking, improving the impact resistance. The first inclined region 2300 includes a fifth end 23a and a seventh end 23c disposed opposite to the fifth end 23a. The fifth end 23a is closer to the winding center axis O than the seventh end 23c. The separator 23 can extend along the first direction X from the sixth end 23b to the seventh end 23c. Viewed from the first direction X, the second end 312 of the first region 31 overlaps with the first inclined region 2300. Viewed from the second direction Y, the second end 312 contacts the first inclined region 2300. Since the second end 312 contacts the first inclined region 2300, the first region 31 can limit the first inclined region 2300, reducing the possibility that the first inclined region 2300 will open in a direction away from the winding center axis O and fold over during mechanical abuse. Here, the first inclined region 2300 being inclined relative to the first direction X means that the overall extension direction of the first inclined region 2300 is inclined relative to the first direction X. Since the separator 23 itself is relatively soft, the position where the first inclined region 2300 contacts the second end 312 can be formed as follows. Figure 3 The stepped portion is shown. Among them, the portion of the insulating membrane 23 near the fifth end 23a is inclined toward the winding center axis O during the flattening process of the first electrode tab 24, and the first region 31 plays a limiting role on the first inclined region 2300, thereby forming the first inclined region 2300.

[0093] Please see Figure 18Another embodiment of this application provides an electrochemical device 200. Unlike the electrochemical device 100 described above, the first wall 11 of the housing 10 has a through hole 110 communicating with the receiving cavity S. The housing 10 may also include an electrode post 16 disposed within the through hole 110. The electrode post 16 is electrically isolated from the first wall 11. For example, a second insulating layer 15 may be provided between the electrode post 16 and the first wall 11, the second insulating layer 15 serving to electrically isolate the electrode post 16 from the first wall 11. In this case, the third wall 13 and the second wall 12 can be integrally formed, and the first wall 11 and the third wall 13 can be fixed together by welding or snap-fit.

[0094] Furthermore, the second connection region 242 is electrically connected to the electrode post 16 via the first current collector 40, and the fourth connection region 252 is electrically connected to the second wall 12 via the second current collector 50. Therefore, the first wall 11 and the electrode post 16 exhibit opposite polarities, allowing the electrochemical device 200 to supply power to external components (not shown). Specifically, when the first electrode 21 is the positive electrode and the second electrode 22 is the negative electrode, the electrode post 16 is positive, and the first wall 11, second wall 12, and third wall 13 are negative.

[0095] In some embodiments, the bendable section 42 of the first current collector 40 may be omitted. The electrode post 16 includes a first electrode post plate 161, a second electrode post plate 162, and an electrode post body 160 connected to the first electrode post plate 161 and the second electrode post plate 162. The electrode post body 160 is disposed within the through hole 110. The first electrode post plate 161 and the second electrode post plate 162 are respectively disposed on opposite surfaces of the first wall 11, and the second electrode post plate 162 is located within the receiving cavity S. The second electrode post plate 162 also extends into the first opening 320 and contacts the first current collector 40, thereby achieving an electrical connection between the electrode post 16 and the first current collector 40.

[0096] In this embodiment, the first region 31 of the insulating sleeve 30 can isolate at least a portion of the first connection region 241 with opposite polarity from the third wall 13, reducing the possibility of a short circuit between at least a portion of the first connection region 241 and the third wall 13. Furthermore, the second region 32 of the insulating sleeve 30 not only fills the gap between the first tab 24 and the first wall 11 of the housing 10, reducing the shaking of the electrode assembly 20 within the housing 10 during mechanical abuse of the electrochemical device 200, but also isolates the second connection region 242 with opposite polarity from the first wall 11, reducing the possibility of a short circuit between the second connection region 242 and the first wall 11, further improving the reliability and service life of the electrochemical device 200. Additionally, when the housing 10 is entirely made of steel, the insulating sleeve 30 isolates the positively polarized first tab 24 from the housing 10, reducing the possibility of the steel housing being corroded by the electrolyte.

[0097] Please see Figure 19Another embodiment of this application also provides an electrochemical device 300. Unlike the electrochemical device 100 described above, the fourth connection region 252 of the second electrode tab 25 is electrically connected to the first wall 11, and the second connection region 242 of the first electrode tab 24 is electrically connected to the second wall 12. When the first electrode 21 is a positive electrode and the second electrode 22 is a negative electrode, the first wall 11 is negatively polarized, while the second wall 12 and the third wall 13 are positively polarized.

[0098] Please see Figure 20 Another embodiment of this application also provides an electrochemical device 400. Unlike the electrochemical device 300 described above, after winding, the second electrode 22 is located at least part of the outermost layer of the electrode assembly 20. For example, the second electrode 22 is located on the outermost layer of the electrode assembly 20. The second connection region 252 of the second tab 25 of the second electrode 22 located on the outermost layer forms a second inclined region 2520, which is inclined relative to the first direction X. Viewed from the second direction Y, the second end 312 is in contact with the second inclined region 2520.

[0099] Please see Figure 21 Another embodiment of this application provides an electrochemical device 500. Unlike the electrochemical device 100 described above, the insulating sleeve 30d further includes a third region 34, which connects the first end 311 of the first region 31 and the third end 321 of the second region 32. The third region 34 extends from the first end 311 away from the first direction X. The provision of the third region 34 reduces the possibility of a sharp point forming at the connection between the first region 31 and the second region 32, thus reducing the impact of such a sharp point on the housing 10 during mechanical abuse and improving the impact resistance of the electrochemical device 500.

[0100] Furthermore, in some embodiments, the outermost insulating membrane 23 further includes a third connecting region 2301 connecting the first inclined region 2300 and a second inclined region 2302 connecting the third connecting region 2301. The third connecting region 2301 is located between the first inclined region 2300 and the second inclined region 2302. Viewed from the second direction Y, the third connecting region 2301 and the second inclined region 2302 overlap with the first region 31, respectively. The third connecting region 2301 may extend approximately along the first direction Y. The second inclined region 2302 is inclined relative to the first direction X. It can be understood that, since the insulating membrane 23 itself is relatively soft, if the insulating membrane 23 is larger in size in the first direction X before the flattening step, after the insulating sleeve 30d is fitted onto the first tab 24, the insulating membrane 23 will form a second inclined region 2302 at the position corresponding to the third region 34. The inclination angle of the second inclined region 2302 may be approximately equal to the inclination angle of the third region 34. Since the separator 23 itself is relatively soft, when the first current collector 40 shakes inside the insulating sleeve 30d due to mechanical abuse, the second inclined area 2302 can play a certain buffering role, reducing the possibility of the first current collector 40 directly contacting the insulating sleeve 30d and thus being damaged, thereby improving the impact resistance.

[0101] The electrochemical device 100 (or electrochemical devices 200, 300, 400, 500) 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.

[0102] Please see Figure 22One embodiment of this application also provides an electronic device 1, including the aforementioned electrochemical device 100 (or electrochemical devices 200, 300, 400, 500). The electronic device 1 is powered by the aforementioned electrochemical device 100. Because the electrochemical device 100 is provided with an insulating sleeve 30, the insulating sleeve 30 can reduce the possibility of a short circuit between the first electrode tab 24 and the housing 10, and can also reduce the shaking of the electrode assembly 20 within the housing 10 when the electrochemical device 100 is subjected to mechanical abuse, thereby maintaining high reliability and service life. In one embodiment, the electronic device 1 of this application may be, but is not limited to, a laptop computer, a pen input computer, a mobile computer, an e-book player, a portable telephone, a portable fax machine, a portable copier, a portable printer, a stereo headset, a video recorder, an LCD TV, a portable cleaner, a portable CD player, a mini CD, a transceiver, an electronic notebook, a calculator, a memory card, a portable recorder, a radio, a backup power supply, a motor, an automobile, 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.

[0103] 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, wherein, include: case; and An electrode assembly is disposed within the housing. The electrode assembly is a wound structure and includes a first electrode, a second electrode, and a separator. The first electrode, the separator, and the second electrode are sequentially stacked and wound to form the electrode assembly. The first electrode includes a first current collector and a first tab. The direction of the winding center axis is defined as a first direction. The first current collector includes a first side and a second side disposed opposite to each other in the first direction. The first tab is formed by extending from the first side. The first electrode includes a first connecting region connecting the first side and a second connecting region connecting the first connecting region, the second connecting region being bent relative to the first connecting region, and the electrode assembly including a first end face and a second end face disposed opposite to each other in the first direction, the second connecting region forming the first end face; The electrochemical device further includes an insulating sleeve and a first current collector. The insulating sleeve includes an integrally connected first region and a second region. The first region covers the first connection region, and the second region is disposed on the second connection region and has a first opening, with a portion of the second connection region exposed through the first opening. The electrode assembly includes a first part and a second part connected in the first direction. When viewed from a second direction perpendicular to the first direction, the first part overlaps with the insulating sleeve, and the second part is separate from the insulating sleeve. In the second direction, the width of the first part is smaller than the width of the second part. The first current collector is disposed between the second connection area and the second region in the first direction, and the second connection area is electrically connected to the housing through the first current collector; The isolation membrane is located at least part of the outermost layer of the electrode assembly. The outermost isolation membrane includes a first inclined region that overlaps with both the first connection region and the first region in the second direction. The first inclined region is inclined relative to the first direction. The first region includes a first end connecting the second region and a second end disposed opposite to the first end. When viewed from the first direction, the second end overlaps with the first inclined region.

2. The electrochemical device as claimed in claim 1, wherein, The width of the insulating sleeve is smaller than the width of the second part.

3. The electrochemical device as described in claim 1, wherein, The first region extends from the first end along the first direction.

4. The electrochemical device as described in claim 3, wherein, The insulating sleeve further includes a third region connected between the first end and the second region, the third region extending from the first end away from the first direction.

5. The electrochemical device as claimed in claim 1, wherein, The first region extends from the first end away from the first direction, and the second end is further away from the winding center axis than the first end.

6. The electrochemical device as claimed in claim 1, wherein, The second region includes a third end connected to the first region and a fourth end disposed opposite to the third end, the fourth end forming the first opening, and the second region extending from the third end along the second direction.

7. The electrochemical device as claimed in claim 1, wherein, The second region includes a third end connecting the first region and a fourth end disposed opposite to the third end. The fourth end surrounds and forms the first opening. The second region extends from the third end away from the second direction, and the fourth end is farther away from the second connection area than the third end.

8. The electrochemical device as claimed in claim 1, wherein, The insulating sleeve further includes a fourth region, which is formed by the edge of the first opening extending away from the first region.

9. The electrochemical device as claimed in claim 1, wherein, The outermost layer of the isolation membrane also includes a third connecting region connecting the first inclined region and a second inclined region connecting the third connecting region. When viewed from the second direction, the third connecting region and the second inclined region overlap with the first region, and the second inclined region is inclined relative to the first direction.

10. The electrochemical device as claimed in claim 1, wherein, The second end contacts the first inclined region.

11. The electrochemical device as claimed in claim 1, wherein, The second electrode includes a second current collector and a second tab. The second current collector includes a third side and a fourth side disposed opposite to each other in the first direction, and the second tab is formed by extending from the fourth side. The second electrode includes a third connecting region connecting the fourth side and a fourth connecting region connecting the third connecting region. The fourth connecting region is bent relative to the third connecting region and is located on the second end face.

12. The electrochemical device of claim 11, wherein, The housing includes a first wall facing the first end face, a second wall opposite to the first wall, and a third wall connected to both the first wall and the second wall; the first wall and the second wall are electrically isolated; the second connection area is electrically connected to the first wall through the first current collector, and the fourth connection area is electrically connected to the second wall.

13. The electrochemical device of claim 12, wherein, The first current collector has a second opening, and when viewed from the first direction, the second opening overlaps with the first opening.

14. The electrochemical device of claim 12, wherein, The fourth connection area is electrically connected to the second wall via the second current collector.

15. The electrochemical device of claim 11, wherein, The housing includes a first wall facing the first end face, a second wall opposite to the first wall, a third wall connected to both the first wall and the second wall, and a pole provided on the first wall; the pole is electrically isolated from the first wall; the second connection area is electrically connected to the pole through the first current collector, and the fourth connection area is electrically connected to the second wall.

16. The electrochemical device as claimed in claim 1, wherein, The first electrode further includes a first active material layer and a second active material layer, wherein the first active material layer, the first current collector and the second active material layer are stacked sequentially, and in the first direction, the insulating sleeve is separated from the first active material layer and the second active material layer respectively.

17. The electrochemical device of claim 1, wherein, Viewed from the first direction, the insulating sleeve has a continuous ring structure.

18. The electrochemical device of claim 1, wherein, The insulating sleeve is made of at least one of rubber, silicone, or plastic.

19. The electrochemical device of claim 1, wherein, The thickness of the insulating sleeve in the first direction is 0.03 mm to 2 mm.

20. An electronic device, wherein, Includes the electrochemical device as described in any one of claims 1 to 19.

Images