Pole piece, design method thereof, pole core, battery cell, battery assembly and electric device

Abstract

The application discloses a pole piece, a design method thereof, a pole core, a battery monomer, a battery assembly and a power utilization equipment. The winding track of the pole piece is a spiral line. The pole piece comprises a pole piece body and a pole lug. The pole lug is connected to one side of the pole piece body in the width direction. The starting position of the pole lug in the nth winding is the nth starting position. L xn is the winding length from the winding starting position of the pole piece to the nth starting position. The following relationship is satisfied: L n -k m *L n ≤L xn ≤L n +k l *L n According to the pole piece, the winding length from the winding starting position of the pole piece to the starting position of the pole lug in the nth winding satisfies the above relationship, so that the separation of the pole lugs of the two poles is facilitated, the pole lugs of the two poles do not overlap after being rubbed or flattened, internal short circuit of the battery is avoided, the pole core has a high energy density, the positive and negative poles of the pole core can be led out from the same end, the current flow path can be shortened, and the battery performance is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, in particular to a pole piece, a design method thereof, a pole core, a battery cell, a battery assembly and a power consumption device. BACKGROUND

[0002] In the related art, in order to improve the energy density of the pole core, a tab-free technology is adopted, that is, the shell of the battery cell is used as a conductive part to lead out the negative electrode. However, this method causes the current flow path to be relatively long and the structural resistance to increase. Therefore, improvements are needed. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, one object of the present application is to provide a pole piece, wherein the winding length of the pole piece from the winding start position to the nth start position satisfies: n -k m *L n ≤L xn ≤L n +k l *L n , wherein The pole core formed by winding the pole piece can have different polar tabs located at the same end of the pole core during winding, and the different polar tabs can be arranged apart along the radial direction of the pole core, so that the tabs of the two poles do not overlap after being rubbed or flattened, thereby avoiding internal short circuit of the battery. Since the different polar tabs are located at the same end of the pole core, the pole core can have a high energy density, and the positive and negative poles of the pole core can be easily led out from the same end, without the need to use the shell of the battery cell as a conductive part. This can shorten the current flow path, reduce the structural resistance, and improve the performance of the battery.

[0004] The present application also provides a pole core comprising the pole piece.

[0005] The present application also provides a battery cell comprising the pole core.

[0006] The present application also provides a battery assembly comprising the battery cell.

[0007] The present application also provides a power consumption device comprising the battery assembly.

[0008] The present application also provides a design method of a pole piece.

[0009] According to the pole piece of the first aspect of the present application, the pole piece is used to form a pole core by winding, the winding track of the pole piece is a spiral line, the pole piece comprises a pole piece body and a tab, and the tab is connected to one side of the pole piece body in the width direction.

[0010] The start position of the tab located at the nth turn is the nth start position, and Lxn L is the winding length of the pole piece from the winding start position of the pole piece to the n th winding length n -k m *L n ≤L xn ≤L n +k l *L n wherein k m is a deviation coefficient of the start position of the n th pole tab when the thickness of the pole piece takes a maximum value within a set deviation range, k l is a deviation coefficient of the start position of the n th pole tab when the thickness of the pole piece takes a minimum value within a set deviation range, 0≤k m ≤6%, 0≤k l ≤6%, the formula of the spiral line is: R n =θ*ε n , θ=t0 / 2π, t0 is the thickness of a winding unit in which the pole piece and the separator are stacked, R n is the radius of the pole core at the n th winding, L c is a pre-winding length of the separator in the winding unit before the pole piece is wound.

[0011] According to the pole piece of the embodiment of the present application, by making the winding length from the winding start position of the pole piece to the start position of the n th pole tab satisfy the above relationship, the separation of the two-pole pole tabs is facilitated, the pole tabs of different polarities can be arranged radially apart from each other, so that the pole tabs of the two poles do not overlap after being flattened, avoiding internal short circuit of the battery, since the pole tabs of different polarities are located at the same end of the pole core, the pole core can have a higher energy density, and the positive and negative poles of the pole core can be conveniently led out from the same end, without the need of using the battery core shell as a conductive part, the current flow path can be shortened, the structural resistance is reduced, and the battery performance is improved.

[0012] According to some embodiments of the present application, the winding unit includes a positive pole piece, a negative pole piece, and two layers of the separator stacked together, the diameter D n of the pole core at the n th winding is D0+t3*4+t2*2+t1*2*n, t0=t1+t2+2t3, D0 is the diameter of the center hole of the pole core, t1 is the thickness of the positive pole piece, t2 is the thickness of the negative pole piece, t3 is the thickness of a single layer of the separator, i3 is the pre-winding number of the separator before the positive pole piece is wound, and i2 is the pre-winding number of the negative pole piece before the positive pole piece is wound.

[0013] According to some embodiments of the present application, the height of the tab in the width direction of the tab body is a tab height, the height of the tab of the first circle is h1, and h1 satisfies: 0≤h1≤1 / 2D JR , D JR is the diameter of the core.

[0014] According to some embodiments of the present application, the tab includes a plurality of tabs, the plurality of tabs are connected to the same side of the tab body in the width direction and are arranged at intervals in the length direction of the tab body, and the plurality of tabs of the same polarity are arranged in sequence in the radial direction of the core.

[0015] According to some embodiments of the present application, the distance between the tab of the n+1th circle and the tab of the nth circle in the unwound state of the tab is d n , the distance between the tab of the n+1th circle and the center of the core is greater than the distance between the tab of the nth circle and the center of the core, and the interval d n between adjacent tabs increases in sequence in the direction from the winding start position of the tab to the winding end position of the tab.

[0016] According to some embodiments of the present application, on the core, the line connecting the start positions of the plurality of tabs is a straight line extending in the radial direction of the core.

[0017] According to some embodiments of the present application, on the core, the line connecting the end positions of the plurality of tabs is a straight line extending in the radial direction of the core.

[0018] According to some embodiments of the present application, the height of the tab in the width direction of the tab body is a tab height, the tab height of the tab of the n+1th circle is not greater than the tab height of the tab of the nth circle, and the distance between the tab of the n+1th circle and the center of the core is greater than the distance between the tab of the nth circle and the center of the core.

[0019] According to some embodiments of the present application, the difference between the tab height of the tab of the n+1th circle and the tab height of the tab of the nth circle is hc, and hc satisfies: t0≤h c ≤5t0.

[0020] According to some embodiments of the present application, 1 / 4πD n ≤A n ≤1 / 2πD n , D n is the diameter of the core at the nth circle, and A n is the length of the tab of the nth circle in the length direction of the tab body in the unwound state of the tab.

[0021] According to the second aspect of the present application, the pole core is wound by a winding unit, the winding track of the winding unit is a spiral line, the winding unit comprises a first pole sheet, a second pole sheet and a diaphragm, the first pole sheet and the second pole sheet are opposite in polarity, at least one of the first pole sheet and the second pole sheet is the pole sheet according to the first aspect of the present application, the diaphragm is arranged between the first pole sheet and the second pole sheet, the first pole sheet comprises a first pole sheet body and a first lug connected to one side of the first pole sheet body, the first lug constitutes a first lug part, the second pole sheet comprises a second pole sheet body and a second lug connected to one side of the second pole sheet body, the second lug constitutes a second lug part, the first lug part and the second lug part are located at the same end of the pole core in the axial direction of the pole core, and the first lug part and the second lug part are oppositely and spacedly arranged along the radial direction of the pole core.

[0022] According to the battery cell of the present application, the pole sheet according to the first aspect of the present application is used to form the pole core, and in the winding process, the lugs with different polarities are located at the same end of the pole core, so that the lugs with different polarities are separated, the lugs with different polarities are arranged along the radial direction of the pole core, the lugs of the two poles are not overlapped after being flattened, internal short circuit of the battery is avoided, the pole core has high energy density, the positive and negative poles of the pole core are conveniently led out from the same end, the shell of the pole core is not used as a conductive part, the current flow path is shortened, the structural internal resistance is reduced, and the performance of the battery is improved.

[0023] According to the pole core of the present application, the sum of the number of arcs of the first lug part and the number of arcs of the second lug part ranges from π to 2π.

[0024] According to the third aspect of the present application, the battery cell comprises the pole core according to the second aspect of the present application.

[0025] According to the battery cell of the present application, the pole core according to the second aspect of the present application is used to form the pole core, and in the winding process, the lugs with different polarities are located at the same end of the pole core, so that the lugs with different polarities are separated, the lugs with different polarities are arranged along the radial direction of the pole core, the lugs of the two poles are not overlapped after being flattened, internal short circuit of the battery is avoided, the pole core has high energy density, the positive and negative poles of the pole core are conveniently led out from the same end, the shell of the pole core is not used as a conductive part, the current flow path is shortened, the structural internal resistance is reduced, and the performance of the battery is improved.

[0026] According to the fourth aspect of the present application, the battery assembly comprises the battery cell according to the third aspect of the present application.

[0027] According to the battery assembly of the present invention, by including the battery cell of the third aspect of the present invention, the battery cell has a high energy density and also facilitates the lead-out of the positive and negative electrodes of the core from the same end, without the need to use the cell casing as a conductive component, which can shorten the current flow path, reduce the internal resistance of the structure, and improve the battery performance.

[0028] An electrical appliance according to a fifth aspect of the present invention includes a battery assembly according to a fourth aspect of the present invention.

[0029] According to the embodiments of the present invention, the electrical device includes a battery according to the third aspect of the present invention. The battery core has a high energy density and it is convenient to lead the positive and negative electrodes of the core out from the same end. The battery cell casing does not need to be used as a conductive component. This can shorten the current flow path, reduce the internal resistance of the structure, and improve the battery performance.

[0030] According to a sixth aspect of the present invention, the electrode sheet is used to wind to form an electrode core, the electrode core is wound by a winding unit, the winding trajectory of the electrode sheet or the electrode core is a spiral, the winding unit includes the stacked electrode sheets and a diaphragm, the electrode sheet includes an electrode sheet body and an electrode tab, the electrode tab being connected to one side of the electrode sheet body in the width direction;

[0031] The design method of the electrode includes: based on the thickness t0 of the winding unit and the diameter D of the electrode core at the nth turn... n The pre-wound length L of the diaphragm in the winding unit before the electrode is wound. c The starting position of the tab in the nth turn is determined by the thickness deviation of the electrode sheet.

[0032] According to the electrode design method of the present invention, the electrode is designed based on the thickness t0 of the winding unit and the diameter D of the winding unit at the nth turn. n And the length A of the tab of the nth ring along the length direction of the electrode body when the electrode is in the unfolded state. n Determine d n During the winding process, tabs of different polarities can be located at the same end of the electrode core. Tabs of different polarities can be set separately along the radial direction of the electrode core, so that the tabs of the two poles do not overlap or interfere with each other after being flattened or flattened, thus avoiding short circuits inside the battery. Since tabs of different polarities are located at the same end of the electrode core, the electrode core can have a high energy density, and it is also convenient to lead out the positive and negative poles of the electrode core from the same end. There is no need to use the cell shell as a conductive component, which can shorten the current flow path, reduce the internal resistance of the structure, and improve battery performance.

[0033] According to some embodiments of the present invention, the starting position of the pole lug of the nth turn is the nth starting position, L xnL n k m L n L xn L n k l L n wherein k m k l k n = θ * ε n , θ = t0 / 2π.

[0034] According to some embodiments of the present application, k m = (L n - L nm ) / (π * D n ), k l = (L nl - L n ) / (π * D n ), L nm is the winding length of the pole piece from the winding start position of the pole piece to the n-th start position when the thickness of the pole piece takes the maximum value within a set deviation range, L nl is the winding length of the pole piece from the winding start position of the pole piece to the n-th start position when the thickness of the pole piece takes the minimum value within a set deviation range.

[0035] According to some embodiments of the present application, 0≤k m ≤6%, 0≤k l ≤6%.

[0036] According to some embodiments of the present application, the winding unit comprises a positive pole piece, a negative pole piece and two layers of the separator which are stacked, the diameter D n of the pole core at the n-th winding is D0+t3*4+t2*2+t1*2*n, t0=t1+t2+2t3, D0 is the diameter of the center hole of the pole core, t1 is the thickness of the positive pole piece, t2 is the thickness of the negative pole piece, t3 is the thickness of a single layer of the separator, i3 is the pre-winding number of the separator before the positive pole piece is wound, i2 is the pre-winding number of the negative pole piece before the positive pole piece is wound.

[0037] Additional aspects and advantages of the present application will be given, partially in the following description, partially will become obvious from the following description, or will be learned by practice of the present application. Attached Figure Description

[0038] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0039] Figure 1 This is a three-dimensional schematic diagram of an electrode core according to some embodiments of the present invention, wherein the first electrode tab and the second electrode tab are separately flattened and respectively form the first electrode tab portion and the second electrode tab portion;

[0040] Figure 2 yes Figure 1 Top view of the intermediate electrode core;

[0041] Figure 3 yes Figure 1 Cross-sectional view of the intermediate electrode core;

[0042] Figure 4 yes Figure 3 Enlarged view of point B in the middle;

[0043] Figure 5 yes Figure 1 A schematic diagram of the first and second tabs of the core before they are kneaded.

[0044] Figure 6 This is a three-dimensional schematic diagram of an electrode core according to other embodiments of the present invention, wherein the first electrode tab and the second electrode tab are flattened separately and respectively form the first electrode tab portion and the second electrode tab portion;

[0045] Figure 7 yes Figure 6 Top view of the intermediate electrode core;

[0046] Figure 8 yes Figure 6 A schematic diagram of the first and second electrodes of the core when they are not in use;

[0047] Figure 9 This is a schematic diagram of the electrode sheet in an unfolded state according to some embodiments of the present invention.

[0048] Figure label:

[0049] 10. Electrode core; 11. Winding unit; 12. First electrode plate; 13. Second electrode plate; 14. Diaphragm; 17. First electrode tab; 18. Second electrode tab;

[0050] 20. Electrode; 21. Electrode body; 22. Electrode tab. Detailed Implementation

[0051] Embodiments of the present application are described below in detail, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only, for the purpose of explanation, and are not to be understood as limiting the present application.

[0052] Reference is made below to Figures 1-9 A pole piece 20 according to an embodiment of the present application is described.

[0053] A pole piece 20 according to an embodiment of the first aspect of the present application, for winding to form a pole core 10, the winding trajectory of the pole piece 20 being a spiral line, the pole piece 20 comprising a pole piece body 21 and a pole tab 22 connected to one side of the pole piece body 21 in the width direction. The winding trajectory of the pole piece 20 refers to the trajectory of the pole piece 20 gradually moving away from the moving point of the winding needle, i.e. the rotation axis.

[0054] The length direction of the body is spaced,

[0055] For example, the spiral line can be an Archimedes spiral line.

[0056] The starting position of the pole tab 22 located in the nth turn is the nth starting position, L xn L is the winding length of the pole piece 20 from the winding starting position of the pole piece 20 to the nth starting position, L n -k m *L n ≤L xn ≤L n +k l *L n , wherein k m k is the deviation coefficient of the starting position of the pole tab 22 of the nth turn when the thickness of the pole piece 20 takes the maximum value within the set deviation range, k l k is the deviation coefficient of the starting position of the pole tab 22 of the nth turn when the thickness of the pole piece 20 takes the minimum value within the set deviation range, 0≤k m ≤6%, 0≤k l ≤6%, the formula of the spiral line is: R n = θ * ε n , θ = t0 / 2π, t0 is the thickness of the winding unit 11 wound to form the pole core 10, the winding unit 11 comprising the stacked pole piece 20 and separator 14, R n L is the radius of the pole core 10 at the nth turn, L c L is the pre-winding length of the separator 14 in the winding unit 11 before the pole piece 20 is wound. Wherein, θ is the arc parameter, and the rotation arc ε nis the total angle of winding rotation of the pole piece 20 at the n th winding turn. By making the winding length L of the pole piece 20 from the winding start position of the pole piece 20 to the start position of the n th winding turn satisfy the relationship xn satisfies L n -k m *L n ≤L xn ≤L n +k l *L n , wherein After winding, the pole tabs 22 of the same pole can be arranged in sequence along the radial direction of the winding unit 11, and the pole tabs 22 of the same pole can be arranged in a concentrated manner in a partial region on one side of the winding unit 11, and sufficient distribution space is reserved for the pole tabs 22 of the other pole, so as to facilitate the separation of the pole tabs 22 of the two poles. When the winding unit 11 includes positive pole pieces 20 and negative pole pieces 20, the positive pole tabs 22 can be arranged in a concentrated manner in a partial region on one side of the winding unit 11, the negative pole tabs 22 can be arranged in a concentrated manner in another partial region on the same side of the winding unit 11, and the regions where the positive pole tabs 22 and the negative pole tabs 22 are arranged do not overlap, so that the regions where the positive pole tabs 22 and the negative pole tabs 22 are arranged are separated, and contact between the positive pole tabs 22 and the negative pole tabs 22 to cause internal short circuit of the battery is avoided.

[0057] For example, the pre-winding turns of the separator 14 in the winding unit 11 before winding of the pole piece 20 are 1-3 turns.

[0058] According to the pole piece 20 of the embodiment of the application, by making the winding length L of the pole piece 20 from the winding start position of the pole piece 20 to the start position of the n th winding turn satisfy the relationship, the separation of the pole tabs 22 of the two poles is facilitated, and the pole tabs 22 of different polarities can be arranged separately along the radial direction of the pole core, so that the pole tabs 22 of the two poles do not overlap after being kneaded or flattened, and internal short circuit of the battery is avoided. Since the pole tabs 22 of different polarities are located at the same end of the pole core 10, the pole core 10 has a high energy density, and the positive and negative poles of the pole core 10 can be easily led out from the same end, without the need of using the battery shell as a conductive part, the current flow path can be shortened, the structural resistance is reduced, and the battery performance is improved.

[0059] According to some embodiments of the application, the winding unit 11 includes stacked positive pole pieces 20, negative pole pieces 20, and two layers of separators 14, and the diameter D of the pole core 10 at the n th winding turn n= D0+ t3*4+ t2*2+ t1*2*n, t0= t1+ t2+ 2t3, D0is the diameter of the central hole of the core 10, t1is the thickness of the positive electrode tab 20, t2is the thickness of the negative electrode tab 20, t3is the thickness of the single layer of the separator 14, i3is the pre-winding number of the separator 14 before the winding of the positive electrode tab 20, i2is the pre-winding number of the negative electrode tab 20 before the winding of the positive electrode tab 20. Generally, the separator 14 is wound more than the positive electrode tab 20 by one or more turns, and the negative electrode tab 20 is wound more than the positive electrode tab 20 by half a turn, thus generally, at the same position of the winding unit 11, the winding length of the winding unit 11 is greater than the winding length of the electrode tab 20. For example, during the winding process of the winding unit to form the core 10, the separator 14 is first wound for 1 to 3 turns, then the negative electrode tab 20 is wound for half a turn, and then the separator 14, the negative electrode tab 20 and the positive electrode tab 20 are wound together. n The winding length of the winding unit 11 at the nth starting position refers to the winding length of the winding unit 11 from the starting winding position of the separator 14 to the nth starting position.

[0060] According to some embodiments of the present application, the height of the tab 22 in the width direction of the tab body 21 is the tab 22 height, the height of the tab 22 of the first turn is h1, and h1 satisfies: 0≤h1≤1 / 2D JR , D JR is the diameter of the core 10. By making the height h of the tab 22 of the first turn not greater than the diameter D JR of the winding unit 11, the height of the tab 22 of the first turn can be prevented from being too large to cause the tab 22 to extend out of the winding unit 11 after being flattened or beaten, and by limiting the upper limit value of the height of the tab 22 of the first turn, the winding unit 11 can be smoothly assembled into the battery case.

[0061] According to some embodiments of the present application, the pole piece 20 comprises a plurality of pole tabs 22, the plurality of pole tabs 22 are connected to the same side of the pole piece body 21 and are arranged at intervals along the length direction of the pole piece body 21, and the plurality of pole tabs 22 of the same polarity are arranged in sequence along the radial direction of the pole core 10. By arranging the plurality of pole tabs 22 of the same polarity in sequence along the radial direction of the pole core 10 on the winding unit 11, the pole tabs 22 of the same polarity can be concentratedly distributed in a partial area on one side of the pole piece body 21, facilitating positioning. Since the plurality of pole tabs 22 of the same polarity of the pole piece 20 are arranged at intervals and the winding length from the winding start position of the pole piece 20 to the start position of the pole tab 22 of the nth winding satisfies the above relationship, in the winding process, the interval between the two adjacent pole tabs 22 of the same polarity of the pole piece 20 can reserve sufficient distribution positions for the pole tabs 22 of the other polarity, facilitating the separation of the two-pole pole tabs 22, and the pole tabs 22 of different polarities can be arranged at intervals along the radial direction of the winding type pole core 10, so that the pole tabs 22 of the two poles do not overlap after being flattened or beaten, avoiding internal short circuit of the battery.

[0062] According to some embodiments of the present application, the distance between the pole tab 22 of the nth+1 winding and the pole tab 22 of the nth winding in the unfolded state of the pole piece 20 is d n , the distance between the pole tab 22 of the nth+1 winding and the center of the pole core 10 is greater than the distance between the pole tab 22 of the nth winding and the center of the pole core 10, and the interval d n between the adjacent pole tabs 22 increases in sequence in the direction from the winding start position of the pole piece 20 (referring to the winding start position g1 in the figure) to the winding end position of the pole piece 20 (referring to the winding end position g2 in the figure). By increasing the interval d n between the adjacent pole tabs 22 in sequence in the direction from the winding start position of the pole piece body 21 to the winding end position of the pole piece body 21, the pole tabs 22 of the same polarity can be concentratedly distributed in a partial area on one side of the pole piece body 21 after winding, facilitating the separation of the distribution positions of the positive pole tabs 22 and the negative pole tabs 22.

[0063] According to some embodiments of the present application, the connecting line of the start positions of the plurality of pole tabs 22 on the pole core 10 is a straight line extending along the radial direction of the pole core 10. By arranging the connecting line of the start positions of the plurality of pole tabs 22 on the pole core 10 as a straight line extending along the radial direction of the pole core 10, the pole tabs 22 of the same polarity can be concentratedly distributed in a partial area on one side of the pole piece body 21, facilitating positioning.

[0064] According to some embodiments of the present application, the connecting line of the end positions of the plurality of pole tabs 22 on the pole core 10 is a straight line extending along the radial direction of the pole core 10. By arranging the connecting line of the end positions of the plurality of pole tabs 22 on the pole core 10 as a straight line extending along the radial direction of the pole core 10, the distribution positions of the pole tabs 22 of different polarities can be avoided from overlapping.

[0065] According to some embodiments of the present application, the height of the tab 22 in the width direction of the tab body 21 is the tab 22 height, the tab 22 height of the tab 22 of the n+1th turn is not greater than the tab 22 height of the tab 22 of the nth turn, and the distance between the tab 22 of the n+1th turn and the center of the core 10 is greater than the distance between the tab 22 of the nth turn and the center of the core 10. By making the tab 22 height of the tab 22 of the n+1th turn not greater than the tab 22 height of the tab 22 of the nth turn, the tab 22 height can be prevented from being too large, and after the tab 22 is flattened or smoothed from the inside to the outside along the radial direction, the tab 22 extends out of the winding unit 11 and interferes with the assembly shell of the core 10, so that the core 10 can be smoothly assembled with other components.

[0066] According to some embodiments of the present application, the difference between the tab 22 height of the tab 22 of the n+1th turn and the tab 22 height of the tab 22 of the nth turn is hc, and hc satisfies: t0≤h c ≤5t0. After the tab 22 is flattened or smoothed, the adjacent tabs 22 can have a larger overlap area and a larger current carrying capacity.

[0067] According to some embodiments of the present application, 1 / 4πD n ≤A n ≤1 / 2πD n , D n is the diameter of the core 10 at the nth turn, and A n is the length of the tab 22 of the nth turn along the length direction of the tab body 21 in the unfolded state of the tab 20. By making the length of the tab 22 of the nth turn along the length direction of the tab body 21 in the unfolded state of the tab 20 not less than / πD n , the length of the tab 22 in the circumferential direction on the winding unit 11 can be prevented from being too short, and the current carrying capacity of the tab 22 can be improved; and by making the length of the tab 22 of the nth turn along the length direction of the tab body 21 in the unfolded state of the tab 20 not greater than / πD n , the distribution position overlap between the positive and negative tabs 22 is prevented from being easily short-circuited, the tabs 22 on a single tab 20 are concentratedly distributed, and sufficient distribution positions are reserved for the tabs 22 on the tab 20 of the other pole, so that the distribution positions of the tabs 22 on the two-pole tabs 20 are separated, and the safety of the battery is ensured.

[0068] According to the second aspect of the present application, the pole core 10 is wound by the winding unit 11, the winding track of the winding unit 11 is a spiral line, the winding unit 11 includes the first pole sheet 12, the second pole sheet 13 and the diaphragm 14, the first pole sheet 12 and the second pole sheet 13 are opposite in polarity, at least one of the first pole sheet 12 and the second pole sheet 13 is the pole sheet 20 according to the first aspect of the present application, the diaphragm 14 is arranged between the first pole sheet 12 and the second pole sheet 13, the first pole sheet 12 includes the first pole sheet body 21 and the first lug 22 connected to one side of the first pole sheet body 21, the first lug 22 constitutes the first lug part 17, the second pole sheet 13 includes the second pole sheet body 21 and the second lug 22 connected to one side of the second pole sheet body 21, the second lug 22 constitutes the second lug part 18, the first lug part 17 and the second lug part 18 are located at the same end of the pole core 10 in the axial direction of the pole core 10, and the first lug part 17 and the second lug part 18 are oppositely and spacedly arranged along the radial direction of the pole core 10.

[0069] According to the pole core 10 of the present application, by including the pole sheet 20 according to the first aspect of the present application, the pole core 10 wound by the pole sheet 20 can make the lugs 22 of different polarities located at the same end of the pole core 10, so that the lugs 22 of different polarities can be arranged apart along the radial direction of the pole core 10 during winding, so that the lugs 22 of the two poles do not overlap after being kneaded or flattened, and internal short circuit of the battery is avoided. Since the lugs 22 of different polarities are located at the same end of the pole core 10, the pole core 10 can have a higher energy density, and the positive and negative poles of the pole core 10 can be conveniently led out from the same end, without needing to use the shell of the pole core 10 as a conductive part, so that the current flow path can be shortened, the structural internal resistance can be reduced, and the battery performance can be improved.

[0070] According to the pole core 10 of the present application, the sum of the number of arcs of the first lug part 17 and the number of arcs of the second lug part 18 is in the range of π-2π. By making the sum of the number of arcs of the first lug part 17 and the number of arcs of the second lug part 18 not less than 2π, it can be avoided that the length of the lugs 22 in the circumferential direction of the winding unit 11 is too short, so that the lugs 22 are too small and have poor current carrying capacity and low performance, and the length of the lugs 22 can be made large enough to improve the performance of the battery; by making the sum of the number of arcs of the first lug part 17 and the number of arcs of the second lug part 18 not more than π, it can be avoided that the first lug part 17 and the second lug part 18 overlap in distribution position, and the first lug part 17 and the second lug part 18 are in contact after being kneaded or flattened, so that short circuit is caused, and the safety of the battery can be ensured.

[0071] According to the third aspect of the present application, the battery monomer includes the pole core 10 according to the second aspect of the present application.

[0072] The battery cell according to the embodiment of the present application comprises the pole core 10 according to the embodiment of the second aspect of the present application, the pole core 10 has a higher energy density, and meanwhile, the positive and negative poles of the pole core 10 are conveniently led out from the same end, the pole core 10 shell does not need to be used as a conductive component, the current flow path can be shortened, the structural internal resistance can be reduced, and the battery performance can be improved.

[0073] The battery assembly according to the embodiment of the fourth aspect of the present application comprises the battery cell according to the embodiment of the third aspect of the present application.

[0074] The battery assembly according to the embodiment of the present application comprises the battery cell according to the embodiment of the third aspect of the present application, the pole core 10 in the battery cell has a higher energy density, and meanwhile, the positive and negative poles of the pole core 10 are conveniently led out from the same end, the pole core 10 shell does not need to be used as a conductive component, the current flow path can be shortened, the structural internal resistance can be reduced, and the battery performance can be improved.

[0075] The electric device according to the embodiment of the fifth aspect of the present application comprises the battery assembly according to the embodiment of the fourth aspect of the present application.

[0076] The electric device according to the embodiment of the present application comprises the battery according to the embodiment of the third aspect of the present application, the pole core 10 of the battery has a higher energy density, and meanwhile, the positive and negative poles of the pole core 10 are conveniently led out from the same end, the pole core 10 shell does not need to be used as a conductive component, the current flow path can be shortened, the structural internal resistance can be reduced, and the battery performance can be improved.

[0077] The design method of the pole sheet 20 according to the embodiment of the sixth aspect of the present application, the pole sheet 20 is used to wind to form a pole core 10, the pole core 10 is wound by a winding unit 11, a winding track of the pole sheet 20 or the pole core 10 is a spiral line, the winding unit 11 comprises the pole sheet 20 and a separator 14 which are stacked, the pole sheet 20 comprises a pole sheet body 21 and a pole lug 22, the pole lug 22 is connected to one side of the pole sheet body 21 in a width direction.

[0078] The design method of the pole sheet 20 comprises: determining a starting position of the pole lug 22 of the n th winding according to a thickness t0 of the winding unit 11, a diameter D n of the pole core 10 at the n th winding, a pre-winding length L c of the separator 14 in the winding unit 11 before the pole sheet 20 is wound, and a thickness deviation of the pole sheet 20.

[0079] The design method of the pole sheet 20 according to the embodiment of the present application, by determining a starting position of the pole lug 22 of the n th winding according to a thickness t0 of the winding unit, a diameter D n of the winding unit 11 at the n th winding, and a length A of the pole lug 22 of the n th winding along a length direction of the pole sheet body 21 in an unfolded state of the pole sheet 20n determined n During winding, the polar tabs 22 of different polarities can be located at the same end of the pole core 10, and the polar tabs 22 of different polarities can be arranged apart in the radial direction of the pole core 10, so that the polar tabs 22 of the two poles do not overlap after being rubbed or flattened, avoiding internal short circuit of the battery. Since the polar tabs 22 of different polarities are located at the same end of the pole core 10, the pole core 10 can have a higher energy density, and the positive and negative poles of the pole core 10 can be conveniently led out from the same end, without the need to use the pole core 10 shell as a conductive part, which can shorten the current flow path, reduce the structural resistance, and improve the battery performance.

[0080] According to some embodiments of the application, the starting position of the polar tab 22 of the nth winding is the nth starting position, L xn L is the winding length of the pole piece 20 from the winding starting position of the pole piece 20 to the nth starting position, L n -k m *L n ≤L xn ≤L n +k l *L n wherein k m k is a deviation coefficient of the starting position of the polar tab 22 of the nth winding when the thickness of the pole piece 20 takes the maximum value within the set deviation range, k l k is a deviation coefficient of the starting position of the polar tab 22 of the nth winding when the thickness of the pole piece 20 takes the minimum value within the set deviation range. For example, the set deviation range is ±2 μm. The formula of the spiral line is: R n = θ * ε n θ = t0 / 2π. By making the winding length of the winding unit 11 at the nth starting position satisfy L n -k m *L n ≤L xn ≤L n +k l *L n wherein The pole piece 20 is arranged in the radial direction of the winding unit 11 after winding, and the tabs 22 of the same pole are arranged in sequence. The tabs 22 of the same pole are concentratedly arranged in a part of the winding unit 11 on one side, and the tabs 22 of the other pole are reserved sufficient distribution space, so as to separate the tabs 22 of the two poles. When the winding unit 11 includes positive pole pieces 20 and negative pole pieces 20, the positive pole tabs 22 are concentratedly arranged in a part of the winding unit 11 on one side, the negative pole tabs 22 are concentratedly arranged in another part of the winding unit 11 on the same side, and the areas where the positive pole tabs 22 and the negative pole tabs 22 are arranged are not overlapped, so as to separate the areas where the positive pole tabs 22 and the negative pole tabs 22 are arranged, and avoid the contact between the positive pole tabs 22 and the negative pole tabs 22 to cause internal short circuit of the battery. Through the design, the starting position of the tabs 22 of the nth turn can be calculated, so that the starting position of the tabs 22 of the nth turn is located at the position designed in advance during the winding process of the pole piece 20, and the winding forming quality of the pole piece 20 in the subsequent winding process is ensured.

[0081] By making the winding length of the winding unit 11 at the nth starting position satisfy L n -k m *L n ≤L xn ≤L n +k l *L n , the influence of the thickness fluctuation of the positive pole piece 20 or the thickness fluctuation of the negative pole piece 20 on the die-cutting position of the tab 22 can be reduced, so that the die-cutting position of the tab 22 is more accurate.

[0082] According to some embodiments of the present application, k m =(L n -L nm ) / (π*D n ), k l =(L nl -L n ) / (π*D n ), L nm is the maximum value of the thickness of the pole piece 20 within the set deviation range, and the winding length of the pole piece 20 from the winding starting position of the pole piece 20 to the nth starting position, L nl is the minimum value of the thickness of the pole piece 20 within the set deviation range, and the winding length of the pole piece 20 from the winding starting position of the pole piece 20 to the nth starting position. Wherein, L nm can be calculated by the above formula for calculating L n , and t0 in the formula for calculating L nm is the thickness of the winding unit 11 when the thickness of the pole piece 20 is the maximum value within the set deviation range; L nl can be calculated by the above formula for calculating L nThe formula calculation obtains L nl t0 in the formula is the thickness of the pole piece 20 when the thickness of the winding unit 11 is the minimum value within a set deviation range.

[0083] According to some embodiments of the present application, 0≤k m ≤6%, 0≤k l ≤6%. According to different thickness specifications and different incoming pole pieces 20 used in actual production processes, the deviation coefficient of the starting position of the n th pole lug 22 can be calculated to be less than 6%, so that the above formula can be basically applicable to the pole pieces 20 used in the incoming production process.

[0084] According to some embodiments of the present application, the winding unit 11 includes stacked positive pole pieces 20, negative pole pieces 20, and two layers of separators 14, and the diameter F n of the pole core 10 at the n th winding is F = D0 + t3*4 + t2*2 + t1*2*n, t0 = t1 + t2 + 2t3, D0 is the diameter of the center hole of the pole core 10, t1 is the thickness of the positive pole piece 20, t2 is the thickness of the negative pole piece 20, t3 is the thickness of a single layer of the separator 14, i3 is the number of pre-wound layers of the separator 14 before the positive pole piece 20 is wound, and i2 is the number of pre-wound layers of the negative pole piece 20 before the positive pole piece 20 is wound.

[0085] wherein, in actual production, the diameter of the center hole of the pole core 10 cannot be measured before the winding unit 11 is wound, since the winding unit 11 is wound on a winding needle, the diameter of the winding needle is basically the same as the diameter of the center hole of the core, and the diameter of the winding needle can be measured to obtain the diameter D0 of the center hole of the pole core 10.

[0086] In actual production processes, the thickness of the positive pole piece 20, the thickness of the negative pole piece 20, the thickness of the separator 14, and the diameter of the winding needle are all known, and according to the thickness of the positive pole piece 20, the thickness of the negative pole piece 20, the thickness of the separator 14, and the diameter of the winding needle, the thickness t0 of the winding unit 11 can be easily obtained.

Claims

1. An electrode sheet, characterized in that, Used for winding to form an electrode core, the winding trajectory of the electrode sheet is a spiral, the electrode sheet includes an electrode sheet body and an electrode tab, the electrode tab being connected to one side of the electrode sheet body in the width direction; The starting position of the pole piece located in the nth loop is the nth starting position, L xn L is the winding length of the electrode from the starting position of the winding to the nth starting position. n -k m *L n ≤L xn ≤L n +k l *L n ,in k m The starting position of the tab in the nth ring is the deviation coefficient when the thickness of the electrode plate reaches its maximum value within a set deviation range, k. l The starting position of the tab in the nth ring is the deviation coefficient when the thickness of the electrode plate is at its minimum within a set deviation range, 0≤k. m ≤6%, 0≤k l ≤6%, the formula for the spiral is: R n =θ*ε n θ = t0 / 2π, where t0 is the thickness of the winding unit that forms the electrode core, and the winding unit includes the stacked electrode sheets and diaphragm. R n L is the radius of the pole core at the nth revolution. c The pre-wound length of the diaphragm in the winding unit before the electrode is wound.

2. The electrode sheet according to claim 1, characterized in that, The winding unit includes stacked positive electrode plates, negative electrode plates, and two layers of the separator, and the diameter of the electrode core at the nth turn is... t0 = t1 + t2 + 2t3, where D0 is the diameter of the central hole of the electrode core, t1 is the thickness of the positive electrode sheet, t2 is the thickness of the negative electrode sheet, and t3 is the thickness of the single-layer separator. The number of pre-wound turns of the diaphragm before it is wound onto the positive electrode sheet. The negative electrode sheet is pre-wound by the number of turns before being wound around the positive electrode sheet.

3. The electrode sheet according to claim 1, characterized in that, The height of the electrode tab in the width direction of the electrode body is the electrode tab height. The height of the electrode tab in the first ring is h1, and h1 satisfies: 0 ≤ h1 ≤ 1 / 2D JR D JR The diameter of the electrode core is given.

4. The electrode sheet according to claim 1, characterized in that, The electrode includes a plurality of tabs, which are connected to the same side in the width direction of the electrode body and are spaced apart along the length direction of the electrode body. The plurality of tabs of the same polarity are arranged sequentially along the radial direction of the electrode core.

5. The electrode sheet according to claim 4, characterized in that, The distance between the electrode tab of the (n+1)th ring and the electrode tab of the nth ring in the unfolded state of the electrode sheet is d. n The distance between the center of the electrode tab and the center of the electrode core in the (n+1)th turn is greater than the distance between the center of the electrode tab and the center of the electrode core in the nth turn. The spacing d between adjacent electrode tabs is greater in the direction from the starting position of the electrode winding to the ending position of the electrode winding. n Increase sequentially.

6. The electrode sheet according to claim 4, characterized in that, On the pole core, the line connecting the starting positions of the plurality of pole tabs is a straight line extending radially along the pole core.

7. The electrode sheet according to claim 6, characterized in that, On the pole core, the line connecting the end positions of the plurality of pole tabs is a straight line extending radially along the pole core.

8. The electrode sheet according to claim 1, characterized in that, The height of the tab in the width direction of the electrode body is the tab height. The tab height of the (n+1)th turn is not greater than the tab height of the nth turn. The distance between the tab in the (n+1)th turn and the center of the electrode core is greater than the distance between the tab in the nth turn and the center of the electrode core.

9. The electrode sheet according to claim 8, characterized in that, The difference between the electrode height of the (n+1)th loop and the electrode height of the nth loop is hc, where hc satisfies: t0 ≤ h c ≤5t0.

10. The electrode sheet according to claim 1, characterized in that, 1 / 4πD n ≤A n ≤1 / 2πD n D n Let A be the diameter of the pole core at the nth revolution. n The length of the nth loop of the electrode tab along the length direction of the electrode body when the electrode is in the unfolded state.

11. An electrode core, characterized in that, The electrode core is formed by winding a spiral unit. The winding unit includes a stacked first electrode, a second electrode, and a diaphragm. The first and second electrode have opposite polarities, and at least one of the first and second electrode is... According to any one of claims 1-10, the electrode sheet is provided with the diaphragm between the first electrode sheet and the second electrode sheet. The first electrode sheet includes a first electrode sheet body and a first electrode tab connected to one side of the first electrode sheet body, the first electrode tab forming a first electrode tab portion. The second electrode sheet includes a second electrode sheet body and a second electrode tab connected to one side of the second electrode sheet body, the second electrode tab forming a second electrode tab portion. The first electrode tab portion and the second electrode tab portion are located at the same end of the electrode core in the axial direction of the electrode core. The first electrode tab portion and the second electrode tab portion are arranged opposite to each other and spaced apart along the radial direction of the electrode core.

12. The electrode core according to claim 11, characterized in that, The sum of the arc value of the first electrode ear and the arc value of the second electrode ear ranges from π to 2π.

13. A single battery cell, characterized in that, include: The electrode core according to claim 11 or 12.

14. A battery assembly, characterized in that, include: The battery cell according to claim 13.

15. An electrical appliance, characterized in that, include: The battery assembly according to claim 14.

16. A method for designing an electrode, characterized in that, The electrode sheet is used to wind to form an electrode core, the electrode core is wound by a winding unit, the winding trajectory of the electrode sheet or the electrode core is a spiral, the winding unit includes stacked electrode sheets and diaphragms, the electrode sheet includes an electrode sheet body and an electrode tab, the electrode tab is connected to one side of the electrode sheet body in the width direction; The design method of the electrode includes: based on the thickness t0 of the winding unit and the diameter D of the electrode core at the nth turn... n The pre-wound length L of the diaphragm in the winding unit before the electrode is wound. c The starting position of the tab in the nth turn is determined by the thickness deviation of the electrode sheet. The starting position of the pole piece in the nth rotation is the nth starting position, L xn L is the winding length of the electrode from the starting position of the winding to the nth starting position. n -k m *L n ≤L xn ≤L n +k l *L n ,in k m The starting position of the tab in the nth ring is the deviation coefficient when the thickness of the electrode plate reaches its maximum value within a set deviation range, k. l The starting position of the tab in the nth turn is the deviation coefficient when the thickness of the electrode sheet is at its minimum within a set deviation range. The formula for the spiral is: R n =θ*ε n θ = t0 / 2π; k m =( L n -L nm ) / (π*D n ), k l =( L nl -L n ) / (π*D n ), L nm When the thickness of the electrode sheet reaches its maximum value within a set deviation range, the winding length L of the electrode sheet from the winding start position to the nth starting position is... nl When the thickness of the electrode sheet is at its minimum within a set deviation range, the winding length of the electrode sheet from the winding start position to the nth starting position, 0≤k m ≤6%, 0≤k l ≤6%.

17. The electrode design method according to claim 16, characterized in that, The winding unit includes stacked positive electrode plates, negative electrode plates, and two layers of the separator, and the diameter of the electrode core at the nth turn is... t0 = t1 + t2 + 2t3, where D0 is the diameter of the central hole of the electrode core, t1 is the thickness of the positive electrode sheet, t2 is the thickness of the negative electrode sheet, and t3 is the thickness of the single-layer separator. The number of pre-wound turns of the diaphragm before it is wound onto the positive electrode sheet. The negative electrode sheet is pre-wound by the number of turns before being wound around the positive electrode sheet.

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