CN118156731A - Battery core and electric equipment - Google Patents

Abstract

The application provides a battery cell and electric equipment, wherein the battery cell comprises an electrode assembly, the electrode assembly is formed by stacking and winding a pole piece and a diaphragm, and the electrode assembly comprises a first straight region, a first bending region, a second straight region and a second bending region which are sequentially connected end to end; the pole piece is provided with the utmost point ear, and along electrode assembly's coiling direction, the utmost point ear includes first portion, second portion and third portion, and first portion is located first flat district, and the second portion is located the second and buckles the district, and the third portion is located the second flat district, and first portion and third portion are connected to the second portion. The width of the electrode lug is larger, so that the current carrying capacity of the electrode lug can be improved, the charge and discharge multiplying power of the battery cell is improved, and the preparation of the high-power battery cell is facilitated; and the number of the electrode lugs can be reduced, so that the preparation efficiency of the battery cell is improved, and the influence on the energy density of the battery cell is small.

Description

Battery core and electric equipment

Technical Field

The application relates to the technical field of batteries, in particular to a battery cell and electric equipment.

Background

With the rapid development of electronic information technology, various electronic devices are developed towards intellectualization and multifunctionality, and the requirement on the charge and discharge multiplying power of the battery is also higher and higher. Therefore, how to increase the charge/discharge rate of the battery is a problem to be solved in the battery field.

Disclosure of Invention

The application provides a battery cell and electric equipment, which can effectively improve the charge and discharge multiplying power of the battery cell.

In a first aspect, the application provides a battery cell, comprising an electrode assembly, wherein the electrode assembly is formed by stacking and winding a pole piece and a diaphragm, and comprises a first straight region, a first bending region, a second straight region and a second bending region which are sequentially connected end to end; the pole piece is provided with the utmost point ear, and along electrode assembly's coiling direction, the utmost point ear includes first portion, second portion and third portion, and first portion is located first flat district, and the second portion is located the second and buckles the district, and the third portion is located the second flat district, and first portion and third portion are connected to the second portion.

In the technical scheme, the first part of the tab is located in the first straight area, the second part of the tab is located in the second bending area, the third part of the tab is located in the second straight area, and the second part of the tab is connected with the first part and the third part of the tab, so that the width of the tab is larger, the current carrying capacity of the tab can be improved, the charge-discharge multiplying power of the battery cell is improved, and the preparation of the high-power battery cell is facilitated; and the first part positioned in the first straight area is connected with the third part positioned in the second straight area through the second part of the second bending area, so that the number of the tabs can be reduced, the preparation efficiency of the battery cell is improved, and the influence on the energy density of the battery cell is small.

In some embodiments of the application, the width of the first portion and the width of the third portion are equal.

In the above technical scheme, the tab can be conveniently connected with other components by making the width of the first portion and the width of the third portion equal, or in the battery cell provided with a plurality of tabs, the plurality of tabs can be conveniently folded and connected.

In some embodiments of the application, the sum of the widths of the first portion and the third portion is W1, 450 mm.ltoreq.W1.ltoreq.10000 mm.

In the technical scheme, when the sum W1 of the widths of the first part and the third part is larger than or equal to 450mm, the width of the electrode lug can be larger, so that the current carrying capacity of the electrode lug can be improved, the charge-discharge multiplying power of the battery cell is improved, and the preparation of the high-power battery cell is facilitated; when the sum W1 of the widths of the first part and the third part is smaller than or equal to 10000mm, the electrode lug does not exceed the width of the active material layer of the electrode plate, so that the energy density of the battery cell is improved; therefore, when the sum W1 of the widths of the first part and the third part is less than or equal to 450mm and less than or equal to W1 and less than or equal to 10000mm, the width of the electrode lug can be enabled to be larger, so that the current carrying capacity of the electrode lug can be improved, the charge-discharge multiplying power of the battery cell is improved, the preparation of a high-power battery cell is facilitated, the electrode lug can be enabled not to exceed the width of the active material layer of the electrode plate, and the energy density of the battery cell is improved.

In some embodiments of the present application, the electrode tab is provided with a plurality of tabs arranged in a thickness direction of the electrode assembly, and the widths of the plurality of tabs sequentially increase from a winding center of the electrode assembly outward.

In the technical scheme, the widths of the plurality of electrode lugs are sequentially increased from the winding center of the electrode assembly outwards, so that the sum of the widths of the electrode lugs is larger, the current carrying capacity of the electrode lugs can be further improved, the charge-discharge multiplying power of the battery cell is improved, and the preparation of the high-power battery cell is facilitated; and the edges of the plurality of tabs are aligned after the electrode assembly is wound, so that the plurality of tabs are conveniently folded and connected.

In some embodiments of the application, the pole pieces comprise a first pole piece and a second pole piece with opposite polarities, the absolute value of the width difference of two pole lugs of two adjacent circles of the first pole piece is delta W1, and 0.9× (H1+H2+2XH2) delta W1 is less than or equal to 1.1× (H1+H2+2XH2); and/or the absolute value of the width difference of two lugs of two adjacent circles of the second pole piece is delta W2, and delta W2 is less than or equal to 0.9× (H1+H2+2XH2) and less than or equal to 1.1× (H1+H2+2XH2); wherein H1 is the thickness of the first pole piece, H2 is the thickness of the second pole piece, and H3 is the thickness of the diaphragm.

In the above technical solution, when the absolute value Δw1 of the width difference between two tabs of two adjacent turns of the first pole piece is greater than or equal to 0.9× (h1+h2+2×h3); and/or the absolute value delta W2 of the width difference of two lugs of two adjacent circles of the second pole piece is more than or equal to 0.9× (H1+H2XH 3), the preparation precision requirement of the electrode lug is lower, and the preparation efficiency of the battery cell is improved; when the absolute value delta W1 of the width difference of two lugs of two adjacent circles of the first pole piece is less than or equal to 1.1× (H1+H2+2×H2); and/or, the absolute value delta W2 of the width difference of two lugs of two adjacent circles of the second pole piece is smaller than or equal to 1.1× (H2+H2XH 3), so that the edge alignment degree of a plurality of lugs is higher after the electrode assembly is wound, and the lugs are convenient to fold and connect; therefore, when the absolute value Δw1 of the width difference of the two tabs of the adjacent two turns of the first pole piece satisfies 0.9× (h1+h2+2×h3) +.Δw1+.1× (h1+h2+2×h3); and/or, the absolute value delta W2 of the width difference of two lugs of two adjacent circles of the second pole piece meets the requirement that delta W2 is less than or equal to 0.9× (H1 + H2+ 2X H3) and less than or equal to 1.1× (H1 + H2+ 2X H3), so that the preparation precision requirement of the lugs is lower, the preparation efficiency of the battery core is improved, and the edge alignment degree of a plurality of lugs is higher after the electrode assembly is wound, thereby facilitating the gathering connection of the lugs.

In some embodiments of the application, the pole piece is provided with a plurality of pole lugs, the sum of the widths of the plurality of pole lugs is S1, and after the pole piece is unfolded, the length of the pole piece is S2, and S1/S2 is more than or equal to 20% and less than or equal to 100%.

In the technical scheme, when the sum of the widths of the plurality of tabs S1 and the length of the developed pole piece S2 is more than or equal to 20%, the sum of the widths of the plurality of tabs is larger, so that the current carrying capacity of the tabs can be improved, the charge and discharge multiplying power of the battery cell is improved, and the preparation of the high-power battery cell is facilitated; when the sum of the widths S1 of the plurality of tabs and the length S2 of the unfolded pole piece are smaller than or equal to 100%, the tab can not exceed the width of the active material layer of the pole piece, so that the energy density of the battery cell is improved; therefore, when the sum of the widths of the plurality of tabs is less than or equal to 20 percent and S1/S2 is less than or equal to 100 percent, the sum of the widths of the plurality of tabs is larger, so that the current carrying capacity of the tabs can be improved, the charge and discharge multiplying power of the battery cell is improved, the preparation of a high-power battery cell is facilitated, the tabs are not more than the width of an active material layer of the pole piece, and the energy density of the battery cell is improved.

In some embodiments of the application, 30% S1/S2% or less than 50%.

In the technical scheme, when the S1/S2 is more than or equal to 30%, the sum of the widths of the plurality of lugs is larger, so that the current carrying capacity of the lugs can be improved, the charge and discharge multiplying power of the battery cell is improved, and the preparation of the high-power battery cell is facilitated; when S1/S2 is less than or equal to 50%, larger spacing space can be reserved among a plurality of lugs, so that the possibility of contact short circuit among lugs with different polarities after the electrode assembly is wound is reduced, and the risk of thermal runaway of the battery core is reduced; therefore, when S1/S2 is more than or equal to 30% and less than or equal to 50%, the sum of the widths of the plurality of lugs is larger, so that the current carrying capacity of the lugs can be improved, the charge-discharge multiplying power of the battery core is improved, the preparation of the high-power battery core is facilitated, larger spacing space can be reserved among the plurality of lugs, the possibility of contact short circuit among the lugs with different polarities after the electrode assembly is wound is reduced, and the risk of thermal runaway of the battery core is reduced.

In some embodiments of the application, the average length of the first portion is L1, the average length of the second portion is L2, and the average length of the third portion is L3, L1 > L2, L3 > L2 along the winding axis of the electrode assembly.

In the above technical solution, by making the average length L1 of the first portion, the average length L2 of the second portion, and the average length L3 of the third portion satisfy L1 > L2, L3 > L2 along the winding axis direction of the electrode assembly, the width of the tab can be made larger, and at the same time, the first portion and the third portion can be conveniently folded and connected, and the preparation material of the tab can be saved.

In some embodiments of the application, 1.ltoreq.L1/L2.ltoreq.4, 1.ltoreq.L3/L2.ltoreq.4.

In the technical scheme, when L1/L2 and L3/L2 are greater than or equal to 1, the width of the tab is larger, the first part and the third part are convenient to fold and connect, and the preparation material of the tab can be saved; when L1/L2 and L3/L2 are smaller than or equal to 4, the length of the second part is enabled to be larger, the current carrying capacity of the electrode lug is improved, the charge and discharge multiplying power of the battery cell is improved, and the preparation of the high-power battery cell is facilitated; therefore, when L1/L2 is less than or equal to 1 and less than or equal to 4, L3/L2 is less than or equal to 1 and less than or equal to 4, the width of the electrode lug is larger, the first part and the third part are convenient to fold and connect, the preparation material of the electrode lug can be saved, the length of the second part is larger, the current carrying capacity of the electrode lug is improved, the charge-discharge multiplying power of the battery cell is improved, and the preparation of the high-power battery cell is facilitated.

In some embodiments of the application, the pole pieces comprise a first pole piece and a second pole piece with opposite polarities, the pole lugs comprise a first pole lug and a second pole lug, the first pole lug is arranged on the first pole piece, and the second pole lug is arranged on the second pole piece; the first tab and the second tab are located on both sides of the electrode assembly in the winding axis direction thereof, respectively.

In the above technical scheme, through making first utmost point ear and second utmost point ear be located the both sides of electrode assembly in its winding axis direction respectively, can reduce the possibility that first utmost point ear and second utmost point ear contact short circuit, reduce the risk of electric core thermal runaway.

In some embodiments of the application, the pole pieces comprise a first pole piece and a second pole piece with opposite polarities, the pole lugs comprise a first pole lug and a second pole lug, the first pole lug is arranged on the first pole piece, and the second pole lug is arranged on the second pole piece; the first tab and the second tab are positioned on the same side of the electrode assembly in the winding axis direction of the electrode assembly, and the spacing distance between the first tab and the second tab is D, wherein D is more than or equal to 2mm along the first direction; the first direction is the arrangement direction of the first bending region and the second bending region.

In the above technical scheme, the first tab and the second tab are located on the same side of the electrode assembly in the winding axis direction of the electrode assembly, and the distance D between the first tab and the second tab is equal to or greater than 2mm along the first direction, so that the distance between the first tab and the second tab is larger, the possibility of short circuit contact between the first tab and the second tab is smaller, and the risk of thermal runaway of the battery cell can be reduced.

In some embodiments of the present application, the battery cell further includes an electrical connection member, a plurality of tabs are disposed on the electrode sheet, the plurality of tabs are folded and connected in a thickness direction of the electrode assembly, and the electrical connection member is connected to the plurality of tabs.

In the above technical scheme, along the thickness direction of the electrode assembly, the plurality of tabs are folded and connected, and the electric connecting piece is connected to the plurality of tabs, so that the tabs are connected with the load through the electric connecting piece, and the electrode assembly is electrically connected with the load, so that the connection reliability is higher.

In a second aspect, the present application provides an electrical device, including a battery cell as described above, where the battery cell is configured to provide electrical energy.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that other related drawings may be obtained according to these drawings for a person skilled in the art.

Fig. 1 is a schematic cross-sectional structure of a battery cell according to some embodiments of the present application;

Fig. 2 is a schematic cross-sectional structure of a portion of a cell according to some embodiments of the present application;

fig. 3 is a schematic structural diagram of a first pole piece of a battery cell in an unfolded state according to some embodiments of the present application;

Fig. 4 is a schematic view illustrating a view of a portion of a structure of a battery cell according to some embodiments of the present application;

FIG. 5 is a schematic view illustrating a view of a portion of a cell structure according to other embodiments of the present application;

Fig. 6 is a schematic view illustrating a view of a portion of a structure of a battery cell according to another embodiment of the present application;

Fig. 7 is a schematic cross-sectional structure of a battery cell according to other embodiments of the present application.

Icon: 10-an electric core; 100-electrode assembly; 101-a first flat region; 102-a first inflection region; 103-a second straight region; 104-a second inflection region; 110-pole piece; 110 a-a first pole piece; 110 b-a second pole piece; 120-a separator; 130-electrode lugs; 130 a-a first tab; 130 b-a second ear; 131-a first part; 132-a second portion; 133-a third part; 200-a battery cell housing; 310-electrical connection; x-a first direction; the winding axis direction of the Y-electrode assembly; the thickness direction of the Z-electrode assembly.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the technical solutions in the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which are derived by a person skilled in the art based on the embodiments of the application, fall within the scope of protection of the application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion.

The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

In the embodiments of the present application, the same reference numerals denote the same components, and detailed descriptions of the same components are omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width, etc. dimensions of the various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length, width, etc. dimensions of the integrated device, are merely illustrative and should not be construed as limiting the application in any way.

Along with the development of new energy industry, the battery gradually develops towards the directions of high energy density and high power density, and the requirement on the charge and discharge multiplying power of the battery is also higher. However, because the size of the tab of the battery cell is smaller, the tab easily generates higher heat in the process of charging and discharging the battery cell, and potential safety hazards can be caused, so that the improvement of the charging and discharging multiplying power of the battery cell is restricted. The number of the electrode lugs and the number of layers of the electrode assembly are in a positive relation, so that the number of the electrode lugs can be increased by increasing the number of the electrode assemblies, the current carrying capacity of the electrode lugs is improved, but the number of the electrode assemblies is limited. The current carrying capacity of the tab is in a positive relation with the sectional area of the tab on the vertical plane of the extending direction of the tab, the current carrying capacity of the tab can be increased by increasing the thickness of the tab, but the thickness of the tab depends on the thickness of the current collector of the pole piece, and if the thickness of the current collector is too large, the energy density of the battery cell can be influenced.

In order to improve the charge-discharge multiplying power of a battery cell, the application provides a battery cell, which comprises an electrode assembly, wherein the electrode assembly is formed by stacking and winding a pole piece and a diaphragm, and comprises a first straight region, a first bending region, a second straight region and a second bending region which are sequentially connected end to end; the pole piece is provided with the utmost point ear, and along electrode assembly's coiling direction, the utmost point ear includes first portion, second portion and third portion, and first portion is located first flat district, and the second portion is located the second and buckles the district, and the third portion is located the second flat district, and first portion and third portion are connected to the second portion.

In the battery cell with the structure, the first part of the tab is positioned in the first straight area, the second part of the tab is positioned in the second bending area, the third part of the tab is positioned in the second straight area, and the second part is connected with the first part and the third part, so that the width of the tab is larger, the current carrying capacity of the tab can be improved, the charge-discharge multiplying power of the battery cell is improved, and the preparation of a high-power battery cell is facilitated; and the first part positioned in the first straight area is connected with the third part positioned in the second straight area through the second part of the second bending area, so that the number of the tabs can be reduced, the preparation efficiency of the battery cell is improved, and the influence on the energy density of the battery cell is small.

The battery cell provided by the embodiment of the application can be a secondary battery or a primary battery, for example, a lithium ion battery, a sodium ion battery or a magnesium ion battery, and the embodiment of the application is not limited to the above. The battery cell may be a cylinder, a flat body, a cuboid, or other shapes, which is not limited in the embodiment of the present application.

The embodiment of the application provides electric equipment using a battery cell as a power supply, wherein the electric equipment can be, but is not limited to, a mobile phone, a tablet personal computer, an electric toy, an electric tool, a battery car, an electric automobile, a ship, a spacecraft and the like.

Referring to fig. 1 to 4, fig. 1 is a schematic cross-sectional structure of a battery cell according to some embodiments of the present application; fig. 2 is a schematic cross-sectional structure of a portion of a cell according to some embodiments of the present application;

fig. 3 is a schematic structural diagram of a first pole piece of a battery cell in an unfolded state according to some embodiments of the present application.

The embodiment of the application provides a battery cell 10, the battery cell 10 comprises an electrode assembly 100, the electrode assembly 100 is formed by stacking and winding a pole piece 110 and a diaphragm 120, and the electrode assembly 100 comprises a first straight region 101, a first bending region 102, a second straight region 103 and a second bending region 104 which are connected end to end in sequence.

The electrode tab 110 is provided with a tab 130, and the tab 130 includes a first portion 131, a second portion 132, and a third portion 133 along a winding direction of the electrode assembly 100, the first portion 131 being located in the first flat region 101, the second portion 132 being located in the second bending region 104, the third portion 133 being located in the second flat region 103, the second portion 132 connecting the first portion 131 and the third portion 133.

By locating the first portion 131 of the tab 130 in the first flat region 101, locating the second portion 132 in the second bending region 104, locating the third portion 133 in the second flat region 103, and connecting the second portion 132 with the first portion 131 and the third portion 133, the width of the tab 130 can be made larger, so that the current carrying capacity of the tab 130 can be improved, the charge-discharge multiplying power of the battery cell 10 can be improved, and the preparation of the high-power battery cell 10 is facilitated; and the first portion 131 located in the first flat region 101 is connected with the third portion 133 located in the second flat region 103 through the second portion 132 of the second bending region 104, so that the number of the tabs 130 can be reduced, the preparation efficiency of the battery cell 10 is improved, and the influence on the energy density of the battery cell 10 is small.

In some embodiments, pole piece 110 and tab 130 may be integrally formed.

In other embodiments, pole piece 110 and tab 130 may be joined by a welded connection, an adhesive connection, or the like.

In some embodiments, the width W11 of the first portion 131 and the width W12 of the third portion 133 are equal.

By making the width W11 of the first portion 131 and the width W12 of the third portion 133 equal, it is possible to facilitate connection of the tab 130 with other components or to facilitate folding connection of the plurality of tabs 130 in the battery cell 10 provided with the plurality of tabs 130.

In other embodiments, the difference between the width W11 of the first portion 131 and the width W12 of the third portion 133 may be less than a threshold value. For example, the threshold may be 0.2mm, 0.5mm, 1mm, or the like. The tab 130 can be conveniently connected with other components, or in the battery cell 10 provided with a plurality of tabs 130, the plurality of tabs 130 can be conveniently folded and connected.

In some embodiments, the sum of the widths of the first portion 131 and the third portion 133 is W1, 450 mm.ltoreq.W1.ltoreq.10000 mm. For example, W1 may be 450mm, 800mm, 10000mm, etc.

When the sum W1 of the widths of the first portion 131 and the third portion 133 is greater than or equal to 450mm, the width of the tab 130 can be made larger, so that the current carrying capacity of the tab 130 can be improved, the charge-discharge multiplying power of the battery cell 10 is improved, and the preparation of the high-power battery cell 10 is facilitated; when the sum W1 of the widths of the first portion 131 and the third portion 133 is less than or equal to 10000mm, the tab 130 can be made not to exceed the width of the active material layer of the pole piece, thereby being beneficial to improving the energy density of the battery cell 10; therefore, when the sum W1 of the widths of the first portion 131 and the third portion 133 satisfies that W1 is less than or equal to 450mm and less than or equal to 10000mm, the width of the tab 130 can be made larger, so that the current carrying capacity of the tab 130 can be improved, the charge-discharge multiplying power of the battery cell 10 can be improved, the preparation of the high-power battery cell 10 is facilitated, and the tab 130 can be made to not exceed the width of the active material layer of the pole piece, so that the energy density of the battery cell 10 is improved.

In some embodiments, the electrode tab 110 is provided with a plurality of tabs 130, the plurality of tabs 130 being arranged in the thickness direction Z of the electrode assembly, and the widths of the plurality of tabs 130 sequentially increasing from the winding center of the electrode assembly 100 outward.

By sequentially increasing the widths of the plurality of tabs 130 from the winding center of the electrode assembly 100 to the outside, the sum of the widths of the tabs 130 can be made larger, so that the current carrying capacity of the tabs 130 can be further improved, the charge-discharge rate of the battery cell 10 is improved, and the preparation of the high-power battery cell 10 is facilitated; and facilitates the alignment of the edges of the plurality of tabs 130 after the electrode assembly 100 is wound, thereby facilitating the folding connection of the plurality of tabs 130.

In other embodiments, the widths of the plurality of tabs 130 of the pole piece 110 may be equal, so that the manufacturing difficulty of the battery cell 10 is lower and the manufacturing efficiency is higher.

In some embodiments, pole piece 110 comprises a first pole piece 110a and a second pole piece 110b of opposite polarity, the absolute value of the width difference between two tabs 130 of two adjacent turns of first pole piece 110a is ΔW1,0.9× (H1+H2+2XH2 3) +.ΔW1+.1× (H1+H2+2XH2 3); and/or the absolute value of the width difference of two lugs of two adjacent circles of the second pole piece is delta W2, and delta W2 is less than or equal to 0.9× (H1+H2+2XH2) and less than or equal to 1.1× (H1+H2+2XH2). For example, Δw1 may be 0.9× (h1+h2+2×h3), or 1.1× (h1+h2+2×h3), or the like. Δw2 may be 0.9× (h1+h2+2×h3), 1.05× (h1+h2+2×h3), 1.1× (h1+h2+2×h3), or the like.

Where H1 is the thickness of the first pole piece 110a, H2 is the thickness of the second pole piece 110b, and H3 is the thickness of the diaphragm 120.

When the absolute value Δw1 of the width difference between two tabs 130 of two adjacent turns of the first pole piece 110a is greater than or equal to 0.9× (h1+h2+2×h3); and/or, the absolute value Δw2 of the width difference between two tabs 130 of two adjacent circles of the second tab 110b is greater than or equal to 0.9× (h1+h2+2×h3), so that the requirements on the preparation precision of the tabs 130 are lower, and the preparation efficiency of the battery cell 10 is improved; when the absolute value Δw1 of the width difference between two tabs 130 of two adjacent turns of the first pole piece 110a is less than or equal to 1.1× (h1+h2+2×h3); and/or, the absolute value Δw2 of the width difference between two tabs 130 of two adjacent turns of the second tab 110b is less than or equal to 1.1× (h1+h2+2×h3), so that the edge alignment degree of the plurality of tabs 130 is higher after the electrode assembly 100 is wound, thereby facilitating the folding connection of the plurality of tabs 130; therefore, when the absolute value Δw1 of the width difference of the two tabs 130 on the adjacent two turns of the first pole piece 110a satisfies 0.9× (h1+h2+2×h3) +.Δw1+.1× (h1+h2+2×h3); and/or, the absolute value Δw2 of the width difference between two tabs 130 of two adjacent circles of the second tab 110b satisfies 0.9× (h1+h2+2×h3) +.Δw2+.1× (h1+h2+2×h3), which not only can make the preparation precision requirement of the tab 130 lower, and is beneficial to improving the preparation efficiency of the battery cell 10, but also can make the edge alignment degree of the tabs 130 higher after the electrode assembly 100 is wound, thereby facilitating the folding connection of the tabs 130.

In some embodiments, the pole piece 110 is provided with a plurality of pole lugs 130, the sum of the widths of the plurality of pole lugs 130 is S1, and after the pole piece is unfolded, the length of the pole piece 110 is S2, and S1/S2 is more than or equal to 20% and less than or equal to 100%. For example, S1/S2 may be 20%, 60%, 100%, or the like.

When the sum of the widths of the plurality of tabs 130S 1 and the length of the expanded pole piece 110S 2 is greater than or equal to 20%, the sum of the widths of the plurality of tabs 130 can be made larger, so that the current carrying capacity of the tabs 130 can be improved, the charge-discharge multiplying power of the battery cell 10 is improved, and the preparation of the high-power battery cell 10 is facilitated; when the sum of the widths S1 of the plurality of tabs 130 and the length S2 of the expanded electrode sheet 110 are less than or equal to 100%, the tab 130 can not exceed the width of the active material layer of the electrode sheet 110, thereby being beneficial to improving the energy density of the battery cell 10; therefore, when the sum of the widths of the plurality of tabs 130S 1 and the expanded length of the pole piece 110S 2 satisfy 20% S1/S2% or less than 100%, the sum of the widths of the plurality of tabs 130 can be made larger, so that the current carrying capacity of the tabs 130 can be improved, the charge-discharge multiplying power of the battery cell 10 is improved, the preparation of the high-power battery cell 10 is facilitated, the tab 130 does not exceed the width of the active material layer of the pole piece 110, and the energy density of the battery cell 10 is improved.

In some embodiments, 30% S1/S2% or less than 50%. For example, S1/S2 may be 30%, 40% or 50%, etc.

When S1/S2 is larger than or equal to 30%, the sum of the widths of the plurality of lugs 130 is larger, so that the current carrying capacity of the lugs 130 can be improved, the charge-discharge multiplying power of the battery cell 10 is improved, and the preparation of the high-power battery cell 10 is facilitated; when S1/S2 is less than or equal to 50%, a large space can be reserved between the plurality of tabs 130, so that the possibility of contact short circuit between the tabs 130 with different polarities after the electrode assembly 100 is wound is reduced, and the risk of thermal runaway of the battery cell 10 is reduced; therefore, when the S1/S2 is more than or equal to 30% and less than or equal to 50%, the sum of the widths of the plurality of lugs 130 is larger, so that the current carrying capacity of the lugs 130 can be improved, the charge-discharge multiplying power of the battery cell 10 is improved, the preparation of the high-power battery cell 10 is facilitated, larger spacing spaces can be reserved among the plurality of lugs 130, the possibility of contact short circuit among the lugs 130 with different polarities after the electrode assembly 100 is wound is reduced, and the risk of thermal runaway of the battery cell 10 is reduced.

Referring to fig. 3, in some embodiments, the tab 130 is arranged in a trapezoid, and the width of the tab 130 gradually decreases in a direction away from the pole piece 110. The tab 130 of such a shape is simple to manufacture, has high manufacturing efficiency, and facilitates the folding and connection of the plurality of tabs 130 after the electrode assembly 100 is wound.

Referring to fig. 4, fig. 4 is a schematic view illustrating a portion of a structure of a battery cell according to some embodiments of the present application.

In other embodiments, the tab 130 may also be rectangular, so as to facilitate the preparation of the tab 130.

In some embodiments, the pole piece 110 includes a first pole piece 110a and a second pole piece 110b with opposite polarities, the tab 130 includes a first tab 130a and a second tab 130b, the first tab 130a is disposed on the first pole piece 110a, and the second tab 130b is disposed on the second pole piece 110b.

The first tab 130a and the second tab 130b are located on the same side of the electrode assembly 100 in the winding axis direction Y thereof, and the first tab 130a and the second tab 130b are spaced apart from each other by a distance D of not less than 2mm in the first direction X. For example, D may be 2mm, 3mm, 5mm, or the like.

The first direction X is the arrangement direction of the first inflection region 102 and the second inflection region 104.

The first tab 130a and the second tab 130b are located on the same side of the electrode assembly 100 in the winding axis direction Y thereof, and by making the spacing distance D between the first tab 130a and the second tab 130b in the first direction X satisfy d+.2mm, the spacing distance between the first tab 130a and the second tab 130b can be made larger, the possibility of contact short-circuiting between the first tab 130a and the second tab 130b is smaller, and thus the risk of thermal runaway of the battery cell 10 can be reduced.

Referring to fig. 5, fig. 5 is a schematic view illustrating a view of a portion of a cell structure according to other embodiments of the present application.

In other embodiments, the pole piece 110 includes a first pole piece 110a and a second pole piece 110b with opposite polarities, the tab 130 includes a first tab 130a and a second tab 130b, the first tab 130a is disposed on the first pole piece 110a, and the second tab 130b is disposed on the second pole piece 110b.

The first tab 130a and the second tab 130b are located at both sides of the electrode assembly 100 in the winding axis direction Y thereof, respectively.

By having the first tab 130a and the second tab 130b respectively located at both sides of the electrode assembly 100 in the winding axis direction Y thereof, the possibility of contact short-circuiting of the first tab 130a and the second tab 130b can be reduced, reducing the risk of thermal runaway of the battery cell 10. In addition, the ratio of the sum of the widths of the plurality of first tabs 130a to the width of the first pole piece 110a can reach 100%, that is, the plurality of first tabs 130a are connected into a whole, and the width of the first tab 130a is equal to the width of the first pole piece 110 a. The ratio of the sum of the widths of the plurality of second tabs 130b to the width of the second tab 110b can be up to 100%, i.e., the plurality of second tabs 130b are connected as a unit, and the width of the second tab 130b is equal to the width of the second tab 110 b.

In some embodiments, the average lengths of the first portion 131, the second portion 132, and the third portion 133 are all equal. The preparation of the tab 130 can be facilitated, and the preparation efficiency of the battery cell 10 can be improved.

Referring to fig. 6, fig. 6 is a schematic view illustrating a view of a portion of a cell structure according to other embodiments of the present application.

In some embodiments, the average length of the first portion 131 is L1, the average length of the second portion 132 is L2, and the average length of the third portion 133 is L3, L1 > L2, L3 > L2 along the winding axis direction Y of the electrode assembly. For example, L1 may be 1.1XL2, 1.2XL2, 1.3XL2, or the like. For example, L3 may be 1.1XL2, 1.2XL2, 1.3XL2, or the like.

By making the average length L1 of the first portion 131, the average length L2 of the second portion 132, and the average length L3 of the third portion 133 satisfy L1 > L2, L3 > L2 along the winding axis direction Y of the electrode assembly, it is possible to make the width of the tab 130 large while facilitating the folding connection of the first portion 131 and the third portion 133, and to save the manufacturing material of the tab 130.

In some embodiments, 1.ltoreq.L1/L2.ltoreq.4, 1.ltoreq.L3/L2.ltoreq.4. For example, L1/L2 may be 1, 2, 4, or the like. For example, L3/L2 may be 1, 3, 4, or the like.

When L1/L2 and L3/L2 are greater than or equal to 1, the width of the tab 130 can be made larger, the first part 131 and the third part 133 can be conveniently folded and connected, and the preparation material of the tab 130 can be saved; when L1/L2 and L3/L2 are smaller than or equal to 4, the length of the second part 132 can be made larger, the current carrying capacity of the tab 130 is improved, the charge-discharge multiplying power of the battery cell 10 is improved, and the preparation of the high-power battery cell 10 is facilitated; therefore, when 1 is less than or equal to L1/L2 is less than or equal to 4,1 is less than or equal to L3/L2 is less than or equal to 4, the width of the tab 130 can be enabled to be larger, the first part 131 and the third part 133 can be conveniently folded and connected, the preparation material of the tab 130 can be saved, the length of the second part 132 can be enabled to be larger, the current carrying capacity of the tab 130 is improved, the charge-discharge multiplying power of the battery cell 10 is improved, and the preparation of the high-power battery cell 10 is facilitated.

In some embodiments, the second portion 132 is connected to the pole piece 110, i.e., the portion of the tab 130 connected to the pole piece 110 has a larger width, and the portion distal from the pole piece 110 has a smaller width, such that the wider portion of the tab 130 can directly carry current on the pole piece 110, thereby making the current carrying capacity of the tab 130 stronger.

In some embodiments, the first portion 131, the second portion 132, and the third portion 133 are respectively rectangular, which can facilitate the preparation of the tab 130.

In other embodiments, the first portion 131, the second portion 132, and the third portion 133 may also be configured in a trapezoid, a semicircle, or the like.

In some embodiments, the battery cell 10 further includes an electrical connector 310, the pole piece 110 is provided with a plurality of tabs 130, and the plurality of tabs 130 are folded and connected along the thickness direction Z of the electrode assembly, and the electrical connector 310 is connected to the plurality of tabs 130.

By causing the plurality of tabs 130 to be folded and connected in the thickness direction Z of the electrode assembly, the electrical connection member 310 is connected to the plurality of tabs 130, so that the tabs 130 can be connected to a load through the electrical connection member 310 to realize electrical connection of the electrode assembly 100 and the load, and connection reliability is high.

Referring to fig. 1, in some embodiments, a plurality of tabs 130 are folded and connected, and an electrical connector 310 is connected between the plurality of tabs 130.

Through making electric connector 310 connect between a plurality of tabs 130, can make the connection area between electric connector 310 and the tab 130 great, electric connector is difficult for breaking away from with tab 130, and the connection reliability is higher.

Referring to fig. 7, fig. 7 is a schematic cross-sectional structure of a battery cell according to other embodiments of the present application.

In other embodiments, the plurality of tabs 130 are folded and connected, and the electrical connector 310 is connected to one side of the plurality of tabs 130.

Through making the electric connector connect in the one side of a plurality of utmost point ear 130, can be convenient for a plurality of utmost point ears 130 draw in and the electric connector 310 with the connection of utmost point ear 130 for electric core 10 preparation is simpler.

In some embodiments, the battery cell 10 further includes a battery cell housing 200, and the electrode assembly 100 is housed within the battery cell housing 200. The electrical connector 310 is disposed through the battery case 200, and the electrical connector 310 is electrically connected with the first tab 130a, so that an external device can be electrically connected with the first pole piece 110a through the first electrical connector 310.

In some embodiments, the battery cell 10 further includes a second electrical connector (not shown) disposed through the battery cell housing 200, the second electrical connector being electrically connected to the second tab 130b such that an external device can be electrically connected to the second tab 110b through the second electrical connector.

In other embodiments, the second electrical connector may be connected to the second pole piece 110b and the cell housing 200, respectively, such that an external device can be electrically connected to the second pole piece 110b through the cell housing 200.

In some embodiments, the electrical connector 310 and the first tab 130a may be a welded connection, and the second electrical connector and the second tab 130b may be a welded connection.

In other embodiments, the electrical connector 310 and the first tab 130a may be integrally formed, and the second electrical connector and the second tab 130b may be integrally formed.

In some embodiments, the electrical connector 310 and the second electrical connector may be made of a material with better electrical conductivity, such as a metal material, for example, lead or copper.

In some embodiments, the cell 10 further includes an electrolyte, and the cell housing 200 is configured to contain the electrode assembly 100 and the electrolyte. The electrode assembly 100 is composed of a positive electrode tab, a negative electrode tab, and a separator. The cell 10 operates primarily by means of metal ions moving between the positive and negative pole pieces. The positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is coated on the surface of the positive electrode current collector, and the part of the positive electrode current collector which is not coated with the positive electrode active material layer is used as a positive electrode lug so as to realize electric energy input or output of the positive electrode plate through the positive electrode lug. Taking a lithium ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary material, lithium manganate or the like. The negative electrode plate comprises a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer is coated on the surface of the negative electrode current collector, and the part of the negative electrode current collector which is not coated with the negative electrode active material layer is used as a negative electrode tab so as to realize electric energy input or output of the negative electrode plate through the negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be a carbon material, a silicon material, or the like. The material of the isolation film can be polypropylene (PP) or Polyethylene (PE). The electrolyte may include an organic solvent, an electrolyte lithium salt, and the like.

In some embodiments, the cell housing 200 may be made of a material with higher strength, such as a metal material like steel or aluminum alloy, so that the cell housing 200 has higher acceptance performance, and thus the cell housing 200 is not easy to deform or break due to stress or environmental change, and further the reliability of the cell 10 is higher.

In other embodiments, the cell housing 200 may be made of a non-metallic material with high strength, such as carbon fiber, hard plastic, etc.

The embodiment of the application provides electric equipment, which comprises the electric core 10 in any scheme, wherein the electric core 10 is used for providing electric energy for the electric equipment.

The powered device may be any of the devices or systems described above that employ the battery cell 10.

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other.

The above is only a preferred embodiment of the present application, and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (13)

1. The battery cell comprises an electrode assembly, wherein the electrode assembly is formed by stacking and winding a pole piece and a diaphragm, and comprises a first straight area, a first bending area, a second straight area and a second bending area which are connected end to end in sequence;

The electrode assembly is characterized in that the electrode plate is provided with a tab, the tab comprises a first part, a second part and a third part along the winding direction of the electrode assembly, the first part is positioned in the first straight area, the second part is positioned in the second bending area, the third part is positioned in the second straight area, and the second part is connected with the first part and the third part.

2. The cell of claim 1, wherein the width of the first portion and the width of the third portion are equal.

3. The cell of claim 1, wherein the sum of the widths of the first portion and the third portion is W1, 450mm ∈w1 ∈10000mm.

4. The cell of claim 1, wherein the pole piece is provided with a plurality of the tabs, the plurality of the tabs being arranged in a thickness direction of the electrode assembly, a winding center of the electrode assembly being outward, and a width of the plurality of the tabs being sequentially increased.

5. The cell of claim 4, wherein the pole pieces comprise a first pole piece and a second pole piece with opposite polarities, and the absolute value of the width difference of two pole ears of two adjacent circles of the first pole piece is Δw1,0.9× (h1+h2+2×h3) +.Δw1+.1× (h1+h2+2×h3); and/or the absolute value of the width difference of two lugs of two adjacent circles of the second pole piece is delta W2, and delta W2 is more than or equal to 0.9× (H1+H2+2XH2) and less than or equal to 1.1× (H1+H2+2XH2);

Wherein H1 is the thickness of the first pole piece, H2 is the thickness of the second pole piece, and H3 is the thickness of the diaphragm.

6. The cell of claim 1, wherein a plurality of tabs are provided on the pole piece, the sum of the widths of the tabs is S1, and the length of the pole piece after the pole piece is unfolded is S2, and S1/S2 is 20% or more and 100% or less.

7. The cell of claim 6, wherein 30% to 50% S1/S2.

8. The cell of claim 1, wherein the average length of the first portion is L1, the average length of the second portion is L2, and the average length of the third portion is L3, L1 > L2, L3 > L2 along the winding axis of the electrode assembly.

9. The cell of claim 8, wherein 1.ltoreq.l1/l2.ltoreq.4, 1.ltoreq.l3/l2.ltoreq.4.

10. The cell of claim 1, wherein the pole pieces comprise a first pole piece and a second pole piece of opposite polarity, the tab comprises a first tab and a second tab, the first tab is disposed on the first pole piece, and the second tab is disposed on the second pole piece;

the first tab and the second tab are located on both sides of the electrode assembly in a winding axis direction thereof, respectively.

11. The cell of claim 1, wherein the pole pieces comprise a first pole piece and a second pole piece of opposite polarity, the tab comprises a first tab and a second tab, the first tab is disposed on the first pole piece, and the second tab is disposed on the second pole piece;

The first tab and the second tab are positioned on the same side of the electrode assembly in the winding axis direction of the electrode assembly, and the distance between the first tab and the second tab is D, wherein D is more than or equal to 2mm along the first direction;

The first direction is the arrangement direction of the first bending region and the second bending region.

12. The cell of claim 1, further comprising an electrical connector, wherein the pole piece is provided with a plurality of tabs, and wherein the plurality of tabs are folded and connected in a thickness direction of the electrode assembly, and wherein the electrical connector is connected to the plurality of tabs.

13. A powered device comprising a battery cell according to any of claims 1-12, said battery cell being configured to provide electrical energy.