Electrochemical apparatus and electrical equipment

Abstract

This application discloses an electrochemical apparatus and an electrical apparatus, the electrochemical apparatus comprising a first housing and a second housing with different polarities, an electrode assembly and a first connecting member. The electrode assembly comprises an electrode sheet assembly, a first tab and a second tab. The first electrode sheet of the electrode sheet assembly is wound inward relative to the second electrode sheet, the first tab is connected to a first region of the first electrode sheet, and the first tab includes a second region connected to the first housing. The second tab is connected to a third region of the second electrode sheet. The first connecting member is connected to the first housing and includes a fourth region for connection to an electrical apparatus. The winding length of the first region beyond the third region is less than one turn, and the angle between the first and third regions with respect to the winding center is θ, satisfying 45° ≤ θ ≤ 135°. The angle between the first and fourth regions with respect to the third region is α, satisfying -60° ≤ α ≤ 45°.

Description

Technical Field

[0001] This application relates to the field of energy storage technologies, and particularly to electrochemical devices and electrical equipment.

Background Art

[0002] In a wound-structure battery, due to the special structure of the spiral involute, a strong axial magnetic field is generated on the end face of the wound structure. This causes significant interference to electrical equipment such as Bluetooth earphones and affects the normal use of the electrical equipment.

Summary of the Invention

[0003] In view of the above circumstances, this application provides an electrochemical device that is advantageous for reducing the axial magnetic field on the end face of the wound structure, thereby reducing the interference caused by the electrochemical device to electrical equipment.

[0004] A first aspect of this application provides an electrochemical apparatus comprising a housing, an electrode assembly, and a first connecting member, wherein the electrode assembly is housed in the housing and the first connecting member is located outside the housing. The housing comprises a first housing portion and a second housing portion having different polarities. The electrode assembly comprises an electrode sheet assembly, a first tab, and a second tab. The electrode sheet assembly comprises a first electrode sheet and a second electrode sheet that are wound and installed, wherein the first electrode sheet comprises a first current collector and a first active layer located on the surface of the first current collector, and the second electrode sheet comprises a second current collector and a second active layer located on the surface of the second current collector, wherein the winding start stage of the first active layer is located inside the winding of the electrode sheet assembly relative to the winding start stage of the second active layer. The first tab includes a first connection portion and a first bend portion, the first connection portion being connected to a first region of the winding tail of the first current collector, the first bend portion being bent toward a first end face of the electrode sheet assembly, the first bend portion being located on one side of the electrode sheet assembly along the width direction of the first electrode sheet, and the first bend portion including a second region connected to a first housing portion. The second tab includes a second connection portion and a second bend portion, the second connection portion being connected to a third region of the winding tail of the second current collector, the second bend portion being bent toward a second end face of the electrode sheet assembly, the second end face being located opposite the first end face along the width direction of the first electrode sheet, and the second bend portion being located on one side away from the first bend portion of the electrode sheet assembly along the width direction of the first electrode sheet. Along the winding direction from the inside to the outside of the electrode sheet assembly, the first region extends beyond the third region, and the winding length of the first region extending beyond the third region is less than one turn. The first connecting member is connected to the first housing and has a fourth region for connecting to an external load. Observing along the width direction of the first electrode sheet and along the winding direction from the inside to the outside of the electrode sheet assembly, the angle of rotation of the ray from the winding center of the electrode sheet assembly to the center of the third region is θ, where 45°≦θ≦135°. Observing along the width direction of the first electrode sheet, the angle between the ray from the center of the second region to the center of the first region and the ray from the center of the second region to the center of the fourth region is α, where -60°≦α≦45°.Of these, the value of angle α, which rotates along the winding direction from the inside to the outside of the electrode sheet assembly from the center of the second region to the center of the first region to the center of the fourth region, is positive, while the value of angle α, which rotates along the direction opposite to the winding direction from the inside to the outside of the electrode sheet assembly from the center of the second region to the center of the first region to the center of the second region to the center of the fourth region, is negative.

[0005] The inventors of this application have discovered through research that, because a wound battery has a special spiral involute structure, the effective current path length of the first electrode sheet on the inside of the winding becomes smaller than the effective current path length of the second electrode sheet on the outside of the winding, thereby generating a strong axial magnetic field at both ends of the winding. At the same time, the current flowing through the bent portion of the tab parallel to the end face of the winding, and through the connecting member provided on the outside of the housing, similarly affects the axial magnetic field. This application, on the one hand, extends the effective length of the first electrode sheet located inside the winding so that the first region exceeds the third region and satisfies θ = 45° ≤ θ ≤ 135°, so that when the electrode assembly discharges and generates current, the magnetic field generated by the portion of the first electrode sheet that exceeds the third region can at least partially cancel out the axial magnetic field generated by the helical involute structure. On the other hand, by controlling the distance between the first tab and the first connecting member so that -60° ≤ α ≤ 45°, the axial magnetic field generated when the current passes through the first tab and the first connecting member further cancels out the axial magnetic field generated by the helical involute structure at the first end face, thereby significantly reducing interference between the electrochemical apparatus and electrical equipment.

[0006] In some embodiments, 60° ≤ θ ≤ 120°. This allows the magnetic field generated by the portion of the first electrode sheet beyond the third region to better cancel out the axial magnetic field generated by the helical involute structure in the electrode sheet assembly, thereby further reducing interference between the electrochemical apparatus and electrical equipment.

[0007] In some embodiments, -25°≦α≦25°. This allows the axial magnetic field generated by the current passing through the first tab and first connecting member to better cancel out the axial magnetic field generated by the helical involute structure in the electrode sheet assembly, thereby further reducing interference between the electrochemical apparatus and electrical equipment.

[0008] In some embodiments, 30°≦θ+α≦135°. This allows the magnetic field generated by the portion of the first electrode sheet beyond the third region, and the axial magnetic field generated by the current passing through the first tab and first connecting member, to cancel out the axial magnetic field generated by the helical involute structure in the electrode sheet assembly, thereby further reducing interference between the electrochemical apparatus and electrical equipment.

[0009] In some embodiments, the first electrode sheet is a negative electrode sheet, and the second electrode sheet is a positive electrode sheet, and the winding start stage of the first active layer extends beyond the winding start stage of the second active layer along the winding direction opposite to the winding direction from the inside to the outside of the electrode sheet assembly. In some embodiments, the winding tail stage of the first active layer extends beyond the winding tail stage of the second active layer along the winding direction from the inside to the outside of the electrode sheet assembly. This is advantageous in reducing the risk of lithium deposition and improving the safety of the electrochemical apparatus because the end of the negative electrode active layer extends beyond the positive electrode active layer in the winding direction of the electrode sheet assembly.

[0010] In some embodiments, the first housing portion includes a top wall, a bottom wall, and side walls, the first bent portion is connected to the bottom wall, and the second housing portion includes pole columns, the top wall is provided with through holes, and the pole columns are installed in the through holes.

[0011] In some embodiments, along the winding direction from the inside to the outside of the electrode sheet assembly, the winding tail of the first current collector includes a blank section that extends beyond the first region and does not have a first active layer on its surface, and the blank section covers the winding tail of the second current collector. This provides a blank section of the first current collector between the winding tail of the second current collector and the first housing, which is advantageous in enhancing the isolation effect between the second current collector and the first housing, thereby advantageous in reducing the risk of short circuits caused by direct contact between the second current collector and the first housing.

[0012] In some embodiments, the second bend includes a fifth region connected to a second housing, and the electrochemical apparatus further includes a second connecting member, the second connecting member connected to the second housing and having a sixth region for connecting to an external load. Observed along the width direction of the first electrode sheet, β is the angle between the ray from the center of the fifth region to the center of the third region and the ray from the center of the fifth region to the center of the sixth region, satisfying -60° ≤ β ≤ 45°. Of these, the value of the angle β when the ray from the center of the fifth region to the center of the third region rotates to the ray from the center of the fifth region to the ray from the center of the sixth region along the winding direction from the inside to the outside of the electrode sheet assembly is positive, and the value of the angle β when the ray from the center of the fifth region to the center of the third region rotates to the ray from the center of the fifth region to the center of the sixth region along the direction opposite to the winding direction from the inside to the outside of the electrode sheet assembly is negative. As a result, by positioning the second tab and the second connecting member such that the angle between them satisfies -60°≦β≦45°, the axial magnetic field generated by the current passing through the second tab and the second connecting member is further canceled out by the axial magnetic field generated at the second end face by the helical involute structure, thereby further reducing interference with electrical equipment.

[0013] In some embodiments, the electrode sheet assembly further includes a first separator, which is positioned between a first electrode sheet and a second electrode sheet, and along the winding direction from the inside to the outside of the electrode sheet assembly, the winding tail of the first separator extends beyond the first electrode sheet. This is advantageous in reducing the risk of direct contact between the first electrode sheet and the second electrode sheet, as the winding tail of the first electrode sheet is covered by the first separator.

[0014] In some embodiments, the electrode sheet assembly further includes a second separator, which is positioned between the first electrode sheet and the second electrode sheet, and along the winding direction from the inside to the outside of the electrode sheet assembly, the winding tail of the second separator extends beyond the second electrode sheet. This is advantageous in reducing the risk of direct contact between the second electrode sheet and the first electrode sheet or housing, as the winding tail of the second electrode sheet is covered by the second separator.

[0015] In some embodiments, the electrochemical apparatus further includes an insulating member, which is placed between the housing and the electrode sheet assembly. This is advantageous in reducing the risk of direct contact between the electrode sheet assembly and the housing, thereby reducing the risk of internal short circuits occurring in the electrochemical apparatus.

[0016] A second aspect of this application further provides an electrical device, which includes an electrochemical apparatus as described in any of the above embodiments. The axial magnetic field of the electrochemical apparatus described in the above embodiments is reduced, thereby reducing electromagnetic interference to the electrical device, and thus improving the reliability of the electrical device. [Brief explanation of the drawing]

[0017] [Figure 1] This is a schematic diagram of an electrical device provided in one embodiment of this application. [Figure 2] This is a schematic diagram of the structure of an electrochemical apparatus provided in one embodiment of this application. [Figure 3] Figure 2 is a cross-sectional view of the electrochemical apparatus. [Figure 4] This is a schematic diagram of the structure of an electrode assembly provided in one embodiment of this application. [Figure 5] This is a schematic diagram of the winding of an electrode sheet assembly provided in one embodiment of the present application. [Figure 6] This is a schematic diagram of the structure of an electrode assembly and a first connecting member provided in one embodiment of the present application. [Figure 7] This is a schematic diagram of the winding of an electrode sheet assembly provided in another embodiment of the present application. [Figure 8] This is a schematic diagram of the structure of an electrode assembly and a second connecting member provided in one embodiment of the present application. [Modes for carrying out the invention]

[0018] The following describes the technical solutions in the embodiments of this application with reference to the drawings, but it is clear that the embodiments described are only a selection of embodiments of this application and not all embodiments.

[0019] In this application, the "center of the region" means that when the region is a continuous whole, the center of the region is the centroid of the planar shape of the region. The centroid of the planar shape can be determined by the hanging method. That is, the planar shape is hung with a thin line, a straight line is drawn vertically from the starting point of the thin line, the planar shape is hung again at an end point different from the first one, and another straight line is drawn according to the above method. The intersection of the two straight lines is the centroid of the planar shape. When the region consists of a plurality of discrete regions, the center of the region is the center of the smallest circumscribed circle that encloses the plurality of discrete regions. As can be understood, the smallest circumscribed circle is a circle that contains the plurality of discrete regions and has the smallest radius. When an assembly is considered to be "connected" to another assembly, it may be directly connected to the other assembly or there may be other assemblies in between. When an assembly is considered to be "installed on" another assembly, it may be directly installed on the other assembly or there may be other assemblies in between. The terms "top", "bottom" and similar expressions used in this text are for illustrative purposes only.

[0020] The terms such as "first", "second", etc. are used only to distinguish different objects and are not understood to indicate or imply relative importance, or to implicitly indicate the quantity of the indicated technical features, a specific order or a primary-secondary relationship.

[0021] The term "parallel" is used to describe an ideal state between two members. In the actual production or use state, there may be a generally parallel state between the two members. The two members described as "parallel" do not necessarily have to be absolute straight lines or planes, and may generally be straight lines or planes. Macroscopically, if the overall extension direction is a straight line or a plane, the members can be regarded as "straight lines" or "planes".

[0022] The dimensions and thicknesses of each component shown in the drawings are for better understanding and more convenient explanation. It is necessary to recognize that this application is not limited to the dimensions and thicknesses shown in the drawings. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the technical field of this application. The terms used in the specification of this application are merely for the purpose of explaining specific embodiments and are not intended to limit this application.

[0023] Hereinafter, some embodiments of this application will be described with reference to the drawings. Unless there is a contradiction, the following embodiments and the features in the embodiments can be combined with each other.

[0024] Embodiments of this application provide an electrical device 1000, and the electrical device 1000 includes an electrochemical device 100.

[0025] In some embodiments, referring to FIG. 1, the electrical device 1000 further includes a device body 200, the electrochemical device 100 is attached to the device body 200 and is used to supply power to the device body 200.

[0026] In some embodiments, the electrical device 1000 may be a Bluetooth earphone, a Bluetooth speaker, a mobile phone, a notebook computer, a tablet computer, an e-book reader, an electric toy, a game console, a video recorder, a portable recorder, a radio, a smart watch, a lighting fixture or a calculator, etc., and will not be listed one by one here.

[0027] In some embodiments, referring to FIGS. 2 and 3, the electrochemical device 100 includes a housing 10, an electrode assembly 20 and a first connection member 30. The electrode assembly 20 is housed in the housing 10, and the first connection member 30 is located outside the housing 10 and is connected to the housing 10.

[0028] In some embodiments, referring to Figures 2 and 3, the housing 10 includes a first housing portion 11 and a second housing portion 12, and the first housing portion 11 and the second housing portion 12 are insulated from each other.

[0029] In some embodiments, referring to Figure 3, the first housing portion 11 includes a top wall 111, a bottom wall 112, and a side wall 113, the side wall 113 being located between the top wall 111 and the bottom wall 112, both of which are connected to the side wall 113 and form a housing space 11a for housing the electrode assembly 20. The first housing portion 11 serves to protect the electrode assembly 20 and can reduce the risk of the electrode assembly 20 being subjected to external impact.

[0030] In some embodiments, referring to Figure 3, the second housing portion 12 includes pole columns, and the top wall 111 is provided with through holes 1111, and the pole columns are installed in the through holes 1111 and are insulated from the top wall 111.

[0031] In some embodiments, referring to Figure 3, the pole column includes a mounting portion 121 and a lead portion 122, the mounting portion 121 being located within the housing space 11a and connected to the electrode assembly 20, and the mounting portion 121 being further insulated from the top wall 111. The lead portion 122 is drilled in the through hole 1111 and at least a portion of it is exposed outside the housing space 11a.

[0032] In some embodiments, referring to Figure 3, the electrochemical apparatus 100 further includes a sealing member 50, which is installed between the top wall 111 and the mounting portion 121, and provides an insulating connection and seal between the mounting portion 121 and the top wall 111.

[0033] In some embodiments, the sealing member 50 may be sealing rubber.

[0034] In some embodiments, the pole columns can be made of a conductive metal such as copper, aluminum, nickel, or iron. The shape of the pole columns may be columnar, hemispherical, sheet-like, or a combination of more than one combined shape, and is not specifically limited herein.

[0035] In some embodiments, referring to Figure 3, the electrode assembly 20 includes an electrode sheet assembly 21, a first tab 22 and a second tab 23, both of which are connected to the electrode sheet assembly 21.

[0036] In some embodiments, referring to Figures 4 and 5, the electrode sheet assembly 21 includes a wound-and-installed first electrode sheet 211 and a second electrode sheet 212, and along the width direction X of the first electrode sheet 211, the wound electrode sheet assembly 21 includes opposing first end faces 21a and second end faces 21b. The first electrode sheet 211 has a first polarity, and the second electrode sheet 212 has a second polarity, and the first and second polarities are different. As an exemplary example, the first electrode sheet 211 is a negative electrode sheet and the second electrode sheet 212 is a positive electrode sheet, or the first electrode sheet 211 is a positive electrode sheet and the second electrode sheet 212 is a negative electrode sheet.

[0037] Referring to Figure 5, the first electrode sheet 211 includes a first current collector 2111 and a first active layer 2112 located on the surface of the first current collector 2111, and the second electrode sheet 212 includes a second current collector 2121 and a second active layer 2122 located on the surface of the second current collector 2121. The first current collector 2111 and the second current collector 2121 may be metal layers. As an exemplary example, the first electrode sheet 211 is a negative electrode sheet, the first current collector 2111 is a metal layer containing at least one of the following: copper, nickel, tantalum, titanium, etc., and may be, for example, copper foil, and the first active layer 2112 contains a negative electrode active material, the negative electrode active material may contain at least one of the following: graphite, hard carbon, soft carbon, silicon, silicon oxide material, silicon carbon material, etc. The second electrode sheet 212 is a positive electrode sheet, the second current collector 2121 is a metal layer containing at least one of the following: aluminum, nickel, tantalum, titanium, etc., and may be, for example, aluminum foil, and the first active layer 2112 contains a positive electrode active material, the positive electrode active material may contain at least one of the following: lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminate, lithium iron phosphate, lithium manganese iron phosphate, or lithium manganese oxide.

[0038] In some embodiments, referring to Figures 4 and 5, the first electrode sheet 211 is connected to a first tab 22, which is connected to a first housing portion 11, so that the first tab 22 and the first housing portion 11 have a first polarity. The second electrode sheet 212 is connected to a second tab 23, which is connected to a second housing portion 12, so that the second tab 23 and the second housing portion 12 have a second polarity. The winding start stage of the first active layer 2112 is located inside the winding of the electrode sheet assembly 21 relative to the winding start stage of the second active layer 2122. The first tab 22 includes a first connection portion 221 and a first bend portion 222, the first connection portion 221 being connected to a first region 211a of the winding tail portion of the first current collector 2111. To make it understandable, the first region 211a is the region to which the first current collector 2111 and the first connector 221 are connected. Typically, the first region 211a has a constant planar shape. If the planar shape of the first region 211a is continuous as a whole, the center of the first region 211a is defined as the centroid of the planar shape of the first region 211a. If the first region 211a consists of a plurality of discrete regions (for example, the first current collector 2111 and the first connector 221 are connected via a plurality of discrete point regions), the center of the first region 211a is defined as the center of the smallest circumscribed circle encompassing the plurality of discrete regions. The first bent portion 222 is bent toward the first end face 21a of the electrode sheet assembly 21, and along the width direction X of the first electrode sheet 211, the first bent portion 222 is located on one side of the electrode sheet assembly 21. The first bent portion 222 is connected to the first housing portion 11, and the first bent portion 222 includes a second region 222a connected to the first housing portion 11. As can be understood, the second region 222a is the region to which the first bent portion 222 and the first housing portion 11 are connected, and the method for determining the center of the second region 222a is the same as the method for determining the center of the first region 211a, and will not be explained again here. The second tab 23 includes a second connection portion 231 and a second bent portion 232, and the second connection portion 231 is connected to a third region 212a of the winding tail section of the second current collector 2121.To make it easier to understand, the third region 212a is the region where the second current collector 2121 and the second connection portion 231 are connected. The method for determining the center of the third region 212a is the same as the method for determining the center of the first region 211a, and will not be explained again here. The second bent portion 232 is bent toward the second end face 21b of the electrode sheet assembly 21, and along the width direction X of the first electrode sheet 211, the second bent portion 232 is located on one side away from the first bent portion 222 of the electrode sheet assembly 21.

[0039] Referring to Figure 5, along the winding direction C from the inside to the outside of the electrode sheet assembly 21, the first region 211a extends beyond the third region 212a, and the winding length of the first region 211a extending beyond the third region 212a is less than one turn. Observing along the width direction X of the first electrode sheet 211, and along the winding direction C from the inside to the outside of the electrode sheet assembly 21, let θ be the angle of rotation from the winding center D of the electrode sheet assembly 21 to the center of the third region 212a, and satisfy 45° ≤ θ ≤ 135°. Referring to Figures 3 and 6, the first connecting member 30 is connected to the first housing portion 11, and the first connecting member 30 has a fourth region 31 for connecting to an external load. The method for determining the center of the fourth region 31 is the same as the method for determining the center of the first region 211a, and will not be explained again here. In the electrode sheet assembly 21, the first electrode sheet 211 is electrically connected to an external load via the first tab 22, the first housing portion 11, and the first connecting member 30. When observed along the width direction X of the first electrode sheet 211, the angle between the ray from the center of the second region 222a to the center of the first region 211a and the ray from the center of the second region 222a to the center of the fourth region 31 is α, and the condition -60° ≤ α ≤ 45° is satisfied.

[0040] Of these, the value of the angle α at which the ray from the center of the second region 222a to the center of the first region 211a rotates along the winding direction C from the inside to the outside of the electrode sheet assembly 21 to the ray from the center of the second region 222a to the center of the fourth region 31 is positive, and the value of the angle α at which the ray from the center of the second region 222a to the center of the first region 211a rotates along the direction opposite to the winding direction from the inside to the outside of the electrode sheet assembly 21 to the ray from the center of the second region 222a to the center of the fourth region 31 is negative.

[0041] The inventors of this application have discovered through research that, because the wound battery has a special spiral involute structure, the effective current path length of the first electrode sheet 211 on the inside of the winding becomes smaller than the effective current path length of the second electrode sheet 212 on the outside of the winding, thereby generating a strong axial magnetic field at both ends of the winding. At the same time, the current flowing through the first bent portion 222 of the first tab 22 that is parallel to the end face of the winding structure, and the first connecting member 30 installed outside the housing 10, also similarly affect the axial magnetic field. On the one hand, this application extends the effective length of the first electrode sheet 211 located on the inside of the winding so that the first region 211a exceeds the third region 212a and θ satisfies 45°≦θ≦135°, so that when the electrode assembly 20 discharges and generates current, the magnetic field generated by the portion of the first electrode sheet 211 that exceeds the third region 212a can at least partially cancel out the axial magnetic field generated by the helical involute structure. On the other hand, by controlling the distance between the first tab 22 and the first connecting member 30 to satisfy -60°≦α≦45°, the axial magnetic field generated when the current passes through the first tab 22 and the first connecting member 30 further cancels out the axial magnetic field generated at the first end face 21a by the helical involute structure, thereby significantly reducing the interference that the electrochemical apparatus 100 has on the electrical equipment 1000.

[0042] As an example, θ may be a range consisting of 45°, 60°, 75°, 90°, 105°, 120°, 135°, or any two of the above. As an example, α may be a range consisting of -60°, -45°, -30°, -25°, -10°, 0°, 10°, 25°, 35°, 45°, or any two of the above.

[0043] In some embodiments, 60°≦θ≦120°. This allows the magnetic field generated by the portion of the first electrode sheet 211 beyond the third region 212a to better cancel out the axial magnetic field generated by the helical involute structure in the electrode sheet assembly 21, thereby further reducing the interference that the electrochemical apparatus 100 has on the electrical equipment 1000.

[0044] In some embodiments, -25°≦α≦25°. This allows the axial magnetic field generated by the current passing through the first tab 22 and the first connecting member 30 to better cancel out the axial magnetic field generated by the helical involute structure in the electrode sheet assembly 21, thereby further reducing the interference that the electrochemical apparatus 100 has on the electrical equipment 1000.

[0045] In some embodiments, 30°≦θ+α≦135°. This allows the magnetic field generated by the portion of the first electrode sheet 211 beyond the third region 212a, and the axial magnetic field generated by the current passing through the first tab 22 and the first connecting member 30, to cancel out the axial magnetic field generated by the helical involute structure in the electrode sheet assembly 21, thereby further reducing the interference that the electrochemical apparatus 100 has on the electrical equipment 1000. As an exemplary example, θ+α may be in the range of 30°, 45°, 60°, 75°, 90°, 105°, 120°, 135°, or any two of the above.

[0046] In some embodiments, referring to Figures 3, 4, and 7, the first bend 222 of the first tab 22 is connected to the bottom wall 112, and the second bend 232 of the second tab 23 is connected to the pole post mounting portion 121. Along the winding direction C from the inside to the outside of the electrode sheet assembly 21, the winding tail of the first current collector 2111 includes a blank section that extends beyond the first region 211a and on which the first active layer 2112 is not installed, and the blank section covers the winding tail of the second current collector 2121. This configuration provides a blank section of the first current collector 2111 between the winding tail of the second current collector 2121 and the first housing portion 11, which is advantageous in enhancing the isolation effect between the second current collector 2121 and the first housing portion 11, thereby reducing the risk of short circuits caused by direct contact between the second current collector 2121 and the first housing portion 11.

[0047] In some embodiments, referring to Figures 5 and 7, the first electrode sheet 211 is a negative electrode sheet, and the second electrode sheet 212 is a positive electrode sheet, and along the direction opposite to the winding direction C from the inside to the outside of the electrode sheet assembly 21, the winding start stage of the first active layer 2112 extends beyond the winding start stage of the second active layer 2122.

[0048] In some embodiments, referring to Figures 5 and 7, along the winding direction C from the inside to the outside of the electrode sheet assembly 21, the winding tail of the first active layer 2112 extends beyond the winding tail of the second active layer 2122. This configuration is advantageous in reducing the risk of lithium deposition and improving the safety of the electrochemical apparatus 100, as the end of the negative electrode active layer extends beyond the positive electrode active layer in the winding direction C of the electrode sheet assembly 21.

[0049] In some embodiments, referring to Figures 5 and 7, the electrode sheet assembly 21 further includes a first separator 213, which is positioned between the first electrode sheet 211 and the second electrode sheet 212, and along the winding direction C from the inside to the outside of the electrode sheet assembly 21, the winding tail of the first separator 213 extends beyond the first electrode sheet 211, so that the winding tail end of the first electrode sheet 211 is covered by the first separator 213, which is advantageous in reducing the risk of direct contact between the first electrode sheet 211 and the second electrode sheet 212.

[0050] In some embodiments, referring to Figures 5 and 7, the electrode sheet assembly 21 further includes a second separator 214, which is positioned between the first electrode sheet 211 and the second electrode sheet 212, and along the winding direction C from the inside to the outside of the electrode sheet assembly 21, the winding tail of the second separator 214 extends beyond the second electrode sheet 212, so that the winding tail of the second electrode sheet 212 is covered by the second separator 214, which is advantageous in reducing the risk of direct contact between the second electrode sheet 212 and the first electrode sheet 211 or the housing 10.

[0051] In some embodiments, the winding tails of the first separator 213 and / or the second separator 214 are attached and secured to the body of the electrode sheet assembly 21 with adhesive tape along the winding direction C from the inside to the outside of the electrode sheet assembly 21, which is advantageous in reducing the risk of the winding tails of the first separator 213 and / or the second separator 214 curling.

[0052] In some embodiments, referring to Figures 5 and 7, the second electrode sheet 212 is located between the first separator 213 and the second separator 214. The first electrode sheet 211 is located between the first separator 213 and the second separator 214.

[0053] In some embodiments, the first separator 213 and the second separator 214 can be made from a material such as polyethylene (PE) or polypropylene (PP), and are used to separate the first electrode sheet 211 and the second electrode sheet 212.

[0054] In some embodiments, referring to Figure 4, the first bent portion 222 extends along a direction parallel to the first end face 21a.

[0055] In some embodiments, the first connecting portion 221 and the first current collector 2111 can be connected by welding, bonding, or crimping, and the first bending portion 222 and the first housing portion 11 can be connected by welding, bonding, or crimping, and are not specifically limited thereto.

[0056] In some embodiments, referring to Figures 3 and 4, the second bent portion 232 is connected to the second housing portion 12, and the second bent portion 232 includes a fifth region 232a connected to the second housing portion 12. As can be understood, the fifth region 232a is the region to which the second bent portion 232 and the second housing portion 12 are connected, and the method for determining the center of the fifth region 232a is the same as the method for determining the center of the first region 211a, and will not be described again here.

[0057] In some embodiments, referring to Figure 4, the second bent portion 232 extends along a direction parallel to the second end face 21b.

[0058] In some embodiments, the second connecting portion 231 and the second current collector 2121 can be connected by welding, bonding, or crimping, and the second bending portion 232 and the second housing portion 12 can be connected by welding, bonding, or crimping, and are not specifically limited thereto.

[0059] In some embodiments, referring to Figures 3 and 8, the electrochemical apparatus 100 further includes a second connecting member 40, which is connected to the second housing 12 and has a sixth region 41 for connecting to an external load. The method for determining the center of the sixth region 41 is the same as the method for determining the center of the first region 211a, and will not be described again here. When observed along the width direction X of the first electrode sheet 211, let β be the angle between the ray from the center of the fifth region 232a to the center of the third region 212a and the ray from the center of the fifth region 232a to the center of the sixth region 41, satisfying -60° ≤ β ≤ 45°. Of these, the value of angle β, which rotates along the winding direction C from the inside to the outside of the electrode sheet assembly 21 from the center of the fifth region 232a to the center of the third region 212a to the center of the sixth region 41, is positive, while the value of angle β, which rotates along the direction opposite to the winding direction C from the inside to the outside of the electrode sheet assembly 21 from the center of the fifth region 232a to the center of the third region 212a to the center of the sixth region 41, is negative.

[0060] By positioning the second tab 23 and the second connecting member 40 such that the angle between them satisfies -60°≦β≦45°, the axial magnetic field generated by the current passing through the second tab 23 and the second connecting member 40 further cancels out the axial magnetic field generated at the second end face 21b by the helical involute structure, thereby further reducing interference with the electrical equipment 1000.

[0061] In some embodiments, the electrochemical apparatus 100 further includes an insulating member (not shown) which is placed between the housing 10 and the electrode sheet assembly 21. This is advantageous in reducing the risk of direct contact between the electrode sheet assembly 21 and the housing 10, thereby reducing the risk of internal short circuits occurring in the electrochemical apparatus 100.

[0062] To verify the cancellation effect of the magnetic field generated in the axial direction by the electrochemical apparatus 100 of this application, the following comparative tests were conducted.

[0063] Taking a Bluetooth earphone equipped with a cylindrical steel case battery with a wound structure as an example, the voice coil radius of the Bluetooth earphone is 3.5 mm, and the negative pole (bottom wall 112 of the housing 10) is close to the speaker position of the Bluetooth earphone. When the values ​​of α and θ are different, the current sound level of the Bluetooth earphone is tested, and the test results are shown in Table 1 below.

[0064] In this process, the angle θ between the first tab 22 and the second tab 23 is changed by changing the welding position of the first tab 22 and the second tab 23, and the angle α between the first connecting member 30 and the first tab 22 on the outside of the housing 10 is changed by changing the connection direction of the first connecting member 30.

[0065] [Table 1] It's important to explain that the quieter the sound, the lower the decibel value, with 0 dB being the lowest sound audible to the human ear.

[0066] Referring to Table 1 and Figure 5, when the angle θ satisfies 45°≦θ≦135° and the angle α satisfies -60°≦α≦45°, the Bluetooth earphones have a significantly reduced current sound level. The reason for this is that, on the one hand, by extending the effective length of the negative electrode sheet located inside the winding, the first region exceeds the third region and θ satisfies 45°≦θ≦135°, so that when the electrode assembly discharges and generates current, the magnetic field generated by the portion of the negative electrode sheet that exceeds the third region can at least partially cancel out the axial magnetic field generated by the helical involute structure. On the other hand, by controlling the distance between the first tab and the first connecting member to satisfy -60°≦α≦45°, the axial magnetic field generated when the current passes through the first tab and the first connecting member further cancels out the axial magnetic field generated by the helical involute structure at the negative electrode end face, thereby significantly reducing the interference that the battery has on the Bluetooth earphones.

[0067] Furthermore, when angle θ satisfies 60° ≤ θ ≤ 120° and angle α satisfies -25° ≤ α ≤ 25°, the current sound level of the Bluetooth earphones becomes even lower. At this time, the magnetic field generated by the portion of the negative electrode sheet that exceeds the third region, and the axial magnetic field generated by the current passing through the first tab and the first connecting member, have a better canceling effect against the axial magnetic field generated by the helical involute structure in the electrode sheet assembly, thereby further reducing the interference that the battery has on the Bluetooth earphones.

[0068] Furthermore, those skilled in the art should recognize that the above embodiments are merely illustrative of this application and do not limit it, and that any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should all be included within the scope of protection of this application. [Explanation of Symbols]

[0069] 100 Electrochemical apparatus 10 cabinets 11. First enclosure section 111 Summit Wall 1111 Through hole 112 Bottom wall 113 Side wall 11a Containment space 12. Second enclosure section 121 Mounting part 122 Drawer section 20 Electrode Assembly 21 Electrode Sheet Assembly 21a First end surface 21b 2nd end face 211 First electrode sheet 2111 First current collector 211a 1st area 2112 1st active layer 212 Second electrode sheet 2121 Second current collector 212a Third area 2122 2nd active layer 213 First Separator 214 Second Separator 22 Tab 1 221 First connection section 222 First folding section 222a 2nd area 23 Second Tab 231 Second connection section 232 Second folding section 232a 5th area 30 First connecting member 31 4th area 40 Second connecting member 41 Area 6 50 Sealing member D Winding center X Width direction of the first electrode sheet Winding direction of electrode sheet assembly from inside to outside 200 Main unit 1000 Electrical equipment

Claims

1. The casing and The electrode assembly housed in the aforementioned housing, The first connecting member located outside the housing is included, The housing includes a first housing section and a second housing section having different polarities. The electrode assembly includes an electrode sheet assembly, a first tab and a second tab, the electrode sheet assembly includes a first electrode sheet and a second electrode sheet that are wound and installed, the first electrode sheet includes a first current collector and a first active layer located on the surface of the first current collector, and the second electrode sheet includes a second current collector and a second active layer located on the surface of the second current collector. The winding start stage of the first active layer is located on the winding side of the electrode sheet assembly relative to the winding start stage of the second active layer, the first tab includes a first connecting portion and a first bent portion, the first connecting portion is connected to a first region of the winding tail stage of the first current collector, the first bent portion is bent toward the first end face of the electrode sheet assembly, the first bent portion is located on one side of the electrode sheet assembly along the width direction of the first electrode sheet, the first bent portion includes a second region connected to the first housing portion, and the second tab includes a second connecting portion and a second bent portion. The second connection portion is connected to the third region of the winding tail section of the second current collector, the second bent portion is bent toward the second end face of the electrode sheet assembly, the second end face is positioned opposite the first end face along the width direction of the first electrode sheet, the second bent portion is located on one side away from the first bent portion of the electrode sheet assembly along the width direction of the first electrode sheet, the first region extends beyond the third region along the winding direction from the inside to the outside of the electrode sheet assembly, and the winding length of the first region extending beyond the third region is less than one turn. The first connecting member is connected to the first housing portion and has a fourth region for connecting to an external load. Observing along the width direction of the first electrode sheet, along the winding direction from the inside to the outside of the electrode sheet assembly, the angle of rotation of the ray from the winding center of the electrode sheet assembly to the center of the third region is θ, satisfying 45° ≤ θ ≤ 135°, and observing along the width direction of the first electrode sheet, the angle between the ray from the center of the second region to the center of the first region and the ray from the center of the second region to the center of the fourth region is α, satisfying -60° ≤ α ≤ 45°, An electrochemical apparatus characterized in that, along the winding direction from the inside to the outside of the electrode sheet assembly, the angle α of rotation from the center of the second region to the center of the first region to the angle α of rotation from the center of the second region to the center of the fourth region is positive, and along the direction opposite to the winding direction from the inside to the outside of the electrode sheet assembly, the angle α of rotation from the center of the second region to the center of the first region to the angle α of rotation from the center of the second region to the center of the fourth region is negative.

2. (1) 60° ≤ θ ≤ 120°, （２）－２５°≦α≦２５°、 The electrochemical apparatus according to claim 1, characterized in that it satisfies at least one of the above conditions.

3. The electrochemical apparatus according to claim 1, characterized in that 30° ≤ θ + α ≤ 135°.

4. The first electrode sheet is a negative electrode sheet, and the second electrode sheet is a positive electrode sheet, satisfying at least one of the following conditions: (1) Along the direction opposite to the winding direction from the inside to the outside of the electrode sheet assembly, the winding start stage of the first active layer extends beyond the winding start stage of the second active layer. (2) The electrochemical apparatus according to claim 1, characterized in that, along the winding direction from the inside to the outside of the electrode sheet assembly, the winding tail of the first active layer extends beyond the winding tail of the second active layer.

5. The electrochemical apparatus according to 1, characterized in that the first housing portion includes a top wall, a bottom wall, and side walls, the first bent portion is connected to the bottom wall, the second housing portion includes an pole column, a through hole is provided in the top wall, and the pole column is installed in the through hole.

6. The electrochemical apparatus according to 5, wherein, along the winding direction from the inside to the outside of the electrode sheet assembly, the winding tail of the first current collector includes a blank section that extends beyond the first region and on which the first active layer is not installed, and the blank section covers the winding tail of the second current collector.

7. The electrochemical apparatus according to claim 1, wherein the second bent portion includes a fifth region connected to the second housing portion, the electrochemical apparatus further includes a second connecting member, the second connecting member is connected to the second housing portion and has a sixth region for connecting to an external load, and when observed along the width direction of the first electrode sheet, the angle between the ray from the center of the fifth region to the center of the third region and the ray from the center of the fifth region to the center of the sixth region is β, satisfying -60° ≤ β ≤ 45°, the value of the angle β in which the ray from the center of the fifth region to the center of the third region rotates along the winding direction from the inside to the outside of the electrode sheet assembly to the ray from the center of the fifth region to the ray from the center of the sixth region is a positive value, and the value of the angle β in which the ray from the center of the fifth region to the center of the third region rotates along the direction opposite to the winding direction from the inside to the outside of the electrode sheet assembly to the ray from the center of the fifth region to the ray from the center of the sixth region is a negative value.

8. Satisfying at least one of the following conditions: (1) The electrode sheet assembly further includes a first separator, the first separator being positioned between the first electrode sheet and the second electrode sheet, and the tail of the first separator extending beyond the first electrode sheet along the winding direction from the inside to the outside of the electrode sheet assembly; and (2) The electrode sheet assembly further includes a second separator, the second separator being positioned between the first electrode sheet and the second electrode sheet, and the tail of the second separator extending beyond the second electrode sheet along the winding direction from the inside to the outside of the electrode sheet assembly, as described in any one of claims 1 to 7.

9. The electrochemical apparatus according to any one of claims 1 to 7, further comprising an insulating member, wherein the insulating member is installed between the housing and the electrode sheet assembly.

10. An electrical apparatus characterized by including an electrochemical apparatus as described in any one of claims 1 to 9.

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