Electrode sheet structure of battery cell, and battery cell and battery

Abstract

An electrode sheet structure of a battery cell, and a battery cell and a battery, which belong to the technical field of batteries. The electrode sheet structure of a battery cell comprises a current collector (1) and an active material layer (2) connected to at least one surface of the current collector (1), wherein the surface of the active material layer (2) in the direction of width is provided with at least one thinned recess (3); the active material layer (2) is further provided with a tab groove (4); the tab groove (4) penetrates in the direction of thickness of the active material layer (2); the tab groove (4) is used for the mounting of a tab (5); and the bottom of the tab groove (4) extends to the surface of the current collector (1). The structure can reduce the occurrence probability of lithium plating in some regions where lithium ions are present, thereby improving the safety and stability of the structure during use, and ensuring the energy density thereof.

Description

An electrode tab structure of an electric core, the electric core and the battery TECHNICAL FIELD

[0001] The utility model belongs to technical field, especially relate to an electrode tab structure of an electric core, the electric core and the battery. BACKGROUND

[0002] Lithium ion battery is a kind of secondary battery, because it has energy density, self-discharge rate is low, potential difference is high, cycle life is long and many advantages, is widely used in consumer electronics, new energy vehicles, energy storage devices and other technical fields. With the continuous iteration of technology, consumer electronics and other lithium batteries cycle life and fast charging ability requirement is higher and higher, to meet customer demand, lithium battery charging and discharging times and charging rate are bigger and bigger.

[0003] However, in the process of high-rate charging, the current density on the surface unit area of the electrode tab is high, that is, the lithium ion concentration is high, which can easily cause lithium precipitation in some areas of the electric core, resulting in performance failure of the electric core and reducing its safety and stability in use.

[0004] Utility model content

[0005] The utility model aims at: in view of the deficiency of prior art, provide an electrode tab structure of an electric core, the electric core and the battery, can solve the technical problem that the safety and stability of prior art in use are low.

[0006] In order to realize the above-mentioned purpose, the utility model adopts the following technical scheme:

[0007] An electrode tab structure of an electric core, comprising a current collector and an active material layer connected to at least one surface of the current collector, the active material layer is provided with at least one thinning recess along the width direction of the surface, the active material layer is further provided with a tab recess, the tab recess is provided through along the thickness direction of the active material layer, the tab recess is used for installing the tab, and the bottom of the tab recess extends to the surface of the current collector.

[0008] Preferably, the thinning recess comprises at least one first recess, the first recess is arranged parallel to the width direction of the active material layer, and the first recess is arranged through the width direction of the active material layer.

[0009] Preferably, when the electrode tab structure is in a winding state, the first recess is arranged at a bending position, and / or at most part of the first recess is arranged at a straight position.

[0010] Preferably, the relationship between the thickness H2 of the first recess and the thickness H1 of the electrode tab structure satisfies H2=H1*A, wherein A=(8%~14%).

[0011] Preferably, the thinning recess further comprises at least one second recess; the second recess is arranged on at least one side of the active material layer in the width direction; and the second recess abuts against the edge of the active material layer in the width direction.

[0012] Preferably, the width L1 of the second recess satisfies: L1 = 5-10 mm.

[0013] And / or, the relationship between the thickness H3 of the second recess and the thickness H1 of the electrode structure of the battery cell satisfies: H3 = H1 * B; wherein B = (8%-14%).

[0014] Preferably, a protective layer is further arranged in the tab groove; the protective layer is connected to the tab; and the projection of the protective layer towards the current collector covers the part of the tab groove where the tab is located.

[0015] The relationship between the length of the protective layer and the length D1 of the tab satisfies: D2-D1≥1 mm.

[0016] The utility model discloses still a kind of battery cell, including polarity opposite first pole piece and second pole piece and diaphragm arranged between the first pole piece and the second pole piece;At least one of the first pole piece and the second pole piece is the above-mentioned battery cell pole structure.

[0017] Preferably, the total thickness T of the bare battery cell and the width K of the corresponding thinning recess of the outermost winding satisfy the relationship: π / 3≤K / T≤2π / 3, wherein T satisfies: 2≤T≤20 mm.

[0018] The width of the corresponding thinning recess of n-1 winding satisfies K-1*(2S+A+C).

[0019] The width of the corresponding thinning recess of n-2 winding satisfies K-2*(2S+A+C).

[0020] The width of the corresponding thinning recess of n winding satisfies K-n*(2S+A+C).

[0021] Wherein, the total thickness of the bare battery cell is T;The width of the corresponding thinning recess of the outermost winding is K;The total thickness of the first pole piece after winding is C;The total thickness of the second pole piece after winding is A;The total thickness of the diaphragm after winding is S and winding number is n.

[0022] The utility model discloses still a kind of battery, including the battery cell.

[0023] The utility model discloses the beneficial effect lies in, this technical scheme is through adding one or more thinning recess on the surface of active material layer, to form the thinning area of coating area surface, can effectively reduce lithium ion of pole piece partial area and can reduce the probability of occurrence of lithium precipitation of lithium ion partial area, further improve the security and stability of structure use, and guarantee its energy density, in addition, on the basis of the active material layer that is equipped with thinning recess sets up tab groove, can effectively guarantee the installation of tab and reduce the lithium ion of pole piece partial area and realize two functions respectively, reduce the interference of both, thereby improve the security and stability of use, and guarantee its energy density. BRIEF DESCRIPTION OF DRAWINGS

[0024] The features, advantages, and technical effects of the exemplary embodiments of the utility model will be described below with reference to the accompanying drawings 1-6.

[0025] Fig. 1 is a top view of the structure of the cell pole piece of an embodiment of the utility model;

[0026] Fig. 2 is a top view of the structure of the cell pole piece of another embodiment of the utility model;

[0027] Fig. 3 is a front view of the structure of the cell pole piece of another embodiment of the utility model;

[0028] Fig. 4 is a top view of the structure of the cell pole piece of yet another embodiment of the utility model;

[0029] Fig. 5 is a front view of the structure of the cell pole piece of yet another embodiment of the utility model;

[0030] Fig. 6 is a structural schematic view of the cell of an embodiment of the utility model.

[0031] In the drawings: 100 - first pole piece; 200 - second pole piece; 300 - diaphragm; 1 - current collector; 2 - active material layer; 3 - thinning recess; 31 - first recess; 32 - second recess; 4 - tab groove; 5 - tab; 51 - protective layer; 6 - bending position; 7 - straight position. DETAILED DESCRIPTION

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application; the description and the drawings of this application and the above-mentioned drawings in the specification, the terms "comprise" and "have" and any variations thereof, are intended to cover non-exclusive inclusion.

[0033] In the description of the embodiments of the present application, the technical terms "first", "second" and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is more than two, unless otherwise explicitly and specifically limited.

[0034] Reference herein to "embodiments" means that the specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it mutually exclusive or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0035] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can mean: A exists alone, A and B exist together, and multiple cases exist alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0036] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanical connection, or it can be electrical connection; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0037] The utility model will be further described in detail below in combination with the accompanying drawings 1-6, but not as the limitation of the utility model.

[0038] As shown in Figure 1, in an embodiment of the utility model, the cell pole piece structure;Including current collector 1 and the active material layer 2 connected to at least one surface of current collector 1;The surface of active material layer 2 along the width direction is provided with at least one thinning recess 3;Active material layer 2 is also provided with tab groove 4;Tab groove 4 is provided along the thickness direction of active material layer 2;Tab groove 4 is used for installing tab 5;And the bottom of tab groove 4 extends to the surface of current collector 1 setting. As shown in Figure 1, the width direction is Y axis direction, that is, the direction perpendicular to the coated active material layer 2;The thickness direction is Z axis direction.

[0039] The technical scheme of the utility model discloses a technology scheme that adds one or more thinning recesses on the surface of the active material layer to form a thinning area on the surface of the coating area, thereby effectively reducing the lithium ion discharge amount of the partial area of the pole piece and reducing the probability of lithium precipitation in the partial area of the lithium ion, further improving the safety and stability of the structure in use and guaranteeing the energy density thereof; in addition, the thinning recess is further provided on the active material layer to effectively guarantee the installation of the tab and reduce the lithium ion discharge amount of the partial area of the pole piece, thereby reducing the mutual interference of the two functions and improving the safety and stability in use and guaranteeing the energy density thereof.

[0040] In some embodiments, the active material of the active material layer 2 is one of lithium cobaltate, lithium iron phosphate, lithium manganate, lithium nickel cobalt manganate and lithium nickel cobalt aluminum.

[0041] Specifically, in some embodiments, as shown in FIGS. 1 and 2, the thinning recess 3 includes at least one first recess 31; the first recess 31 is arranged in parallel to the width direction of the active material layer 2; and the first recess 31 is arranged through the width direction of the active material layer 2. That is, as shown in FIG. 2, the thinning length of the first recess 31 is the width of the pole piece; and a plurality of first recesses 31 are arranged in parallel along the length direction of the active material layer 2 (the length direction is the X-axis direction, i.e., the direction parallel to the coating direction). The structure can effectively reduce the discharge amount of lithium ions in the charging process through the guiding action of the plurality of first recesses 31, thereby improving the lithium precipitation problem of the lithium ion battery in high-rate charging and discharging and achieving the effect of improving the safety of the battery.

[0042] Specifically, in some embodiments, as shown in FIGS. 1 and 2, when the cell pole piece structure is in a wound state, the first recess 31 is arranged at the corner position 6; and / or, at most part of the first recess 31 is arranged at the straight position 7. That is, after the cell pole piece structure is wound into a bare cell, the thinning recess 3 can be exactly arranged in the corner area of the corner position 6 of the bare cell. The thinning recess 3 can also be mostly arranged in the corner area of the bare cell and a small part extends to the straight area of the straight position 7, so as to increase the lithium ion guiding action of the corner, thereby improving the corner lithium precipitation problem of the lithium ion battery in high-rate charging and discharging and achieving the effect of improving the safety of the battery.

[0043] Specifically, in some embodiments, as shown in FIGS. 2 and 3, the relationship between the thickness H2 of the first recess 31 and the thickness H1 of the electrode tab structure satisfies: H2 = H1 * A; wherein A = (8% ~ 14%). After the current collector 1 is completely coated with the active material layer 2, the laser cleaning equipment performs face width thinning on the active material layer 2. The thinning thickness is set in a gradient of 8%, 10%, 12%, 14%, etc. of the roll-pressed thickness of the electrode tab structure, forming a thinning area, and then the electrode tab structure is obtained after slitting. This structure can achieve a CB value of the thinning area that is larger than that of the non-thinning area, thereby better improving the lithium precipitation phenomenon. If the thickness H2 of the first recess 31 is too large, the CB value will be too large, which will lead to an increase in the oxidation state of the tab and thus increase the safety hazard. If the thickness H2 of the first recess 31 is too small, the effect of improving lithium precipitation cannot be achieved.

[0044] Specifically, in some embodiments, as shown in FIGS. 1 and 4, the thinning recess 3 further comprises at least one second recess 32; the second recess 32 is arranged on at least one side of the width direction of the active material layer 2; and the second recess 32 abuts against the edge of the width direction of the active material layer 2. As shown in FIG. 4, the second recess 32 is symmetrically arranged on both sides of the width direction of the active material layer 2 and is arranged through the length direction of the active material layer 2. That is, this structure can increase the lithium ion guiding and aggregation of the corner by arranging the second recess 32 as a thinning area at the edge, effectively reduce the lithium ion release amount of the positive electrode tab partial area, reduce the occurrence of lithium precipitation at the edge of the lithium ion battery, and achieve the effect of improving the safety of the battery; and in combination with the first recess 31, the occurrence of lithium precipitation at the edge and corner of the lithium ion battery can be reduced, and the effect of improving the safety of the battery can be achieved.

[0045] Specifically, in some embodiments, as shown in FIG. 4, the width L1 of the second recess 32 satisfies: L1 = 5 ~ 10 mm. Wherein L1 can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm and 10 mm, etc. This structure can effectively reduce the lithium ion release amount of the positive electrode tab partial area, reduce the occurrence of lithium precipitation at the edge of the lithium ion battery, and achieve the effect of improving the safety of the battery by the second recess 32 with a reasonable width value.

[0046] Specifically, in some embodiments, as shown in FIG. 5, the relationship between the thickness H3 of the second recess 32 and the thickness H1 of the electrode tab structure satisfies: H3 = H1 * B; wherein B = (8%~14%). After the current collector 1 is completely coated with the active material layer 2, the laser cleaning equipment performs face width thinning on the active material layer 2. The thinning thickness is set in a gradient of 8%, 10%, 12%, 14%, etc. of the roll-pressed thickness of the electrode tab structure to form a thinning area, and then the electrode tab structure is obtained after slitting. The CB value of the thinning area is larger than that of the non-thinning area, so as to better improve the lithium precipitation phenomenon. When the thickness H3 of the second recess 32 is too large, the CB value will be too large; thus, the oxidation state of the tab will be increased, which will increase the safety hazard. When the thickness H3 of the second recess 32 is too small, the effect of improving lithium precipitation cannot be achieved.

[0047] Wherein, as shown in FIGS. 1 and 2, the tab 5 is welded to the current collector 1; and the tab recess 4 is further provided with a protective layer 51; the protective layer 51 is connected to the tab 5; and the projection of the protective layer 51 towards the current collector 1 covers the part of the tab 5 located in the tab recess 4. Wherein, the protective layer 51 is an adhesive. That is to say, in order to ensure the assembly stability and overall packaging of the tab 5, the protective layer 51 with a larger coverage area is used to package and protect the tab 5, so as to improve the safety and stability in use. As shown in FIG. 4, the relationship between the length D2 of the protective layer 51 and the length D1 of the tab 5 satisfies: D2-D1≥1mm.

[0048] The utility model discloses still propose a kind of electric core, as shown in Figure 6, the electric core includes polarity opposite first tab 100 and second tab 200 and diaphragm 300 between first tab 100 and second tab 200;At least one of first tab 100 and second tab 200 is electric core tab structure;The specific structure of the electric core tab structure refers to the above embodiment, since at least one of the first tab 100 and the second tab 200 adopts all technical solutions of the above all embodiments, at least has all beneficial effects brought by the technical solutions of the above embodiment, which will not be repeated here. Wherein, first tab 100 is cathode sheet, and second tab 200 is anode sheet;Or, first tab 100 is anode sheet, and second tab 200 is cathode sheet.

[0049] Specifically, in some embodiments, as shown in FIG. 6, the total thickness T of the bare electric core and the width K of the corresponding thinning recess of the outermost winding satisfy the relationship: π / 3≤K / T≤2π / 3, wherein T satisfies: 2≤T≤20mm;

[0050] The width of the corresponding thinning recess of n-1 winding satisfies K-1*(2S+A+C);

[0051] The width of the thinning recess corresponding to the n-2th circle satisfies K-2*(2S+A+C);

[0052] The width of the thinning recess corresponding to the n-2th circle satisfies K-2*(2S+A+C);

[0053] Wherein, the total thickness of the bare cell is T; the width of the thinning recess corresponding to the outermost winding is K; the total thickness of the first tab after winding is C; the total thickness of the second tab after winding is A; the total thickness of the separator after winding is S; and the winding number is n.

[0054] That is, when the finished cell has tab corner lithium precipitation, specifically edge lithium precipitation or corner and edge lithium precipitation, laser cleaning equipment can be used to clean the lithium precipitation of the tab according to the corresponding parameters, so as to improve the lithium precipitation problem of the cell and improve the safety of the battery.

[0055] Example 1

[0056] The laser cleaning equipment is used to thin the surface of the cathode sheet to form a thinning recess 3. The thinning thickness of the thinning recess 3 is set according to 8% of the rolling thickness of the cell tab structure, and then the corresponding cathode sheet is obtained after slitting.

[0057] Then the lithium ion cell (battery) containing the above-mentioned cathode sheet is placed in a 25℃ constant temperature room, and is placed for 10 minutes. It is charged to 4.50V at 2.8C constant current, and then charged to 0.05C at 4.50V constant voltage. Then it is discharged to 3.0V at 1.0C constant current. This is one charge and discharge cycle. Repeat the charging and discharging, and observe the lithium precipitation window interface of the lithium ion cell (battery) after 20 cycles.

[0058] Example 2

[0059] Different from example 1: the thinning thickness of the thinning recess 3 is set according to 10% of the rolling thickness of the cell tab structure.

[0060] Example 3

[0061] Different from example 1: the thinning thickness of the thinning recess 3 is set according to 12% of the rolling thickness of the cell tab structure.

[0062] Example 4

[0063] Different from example 1: the thinning thickness of the thinning recess 3 is set according to 14% of the rolling thickness of the cell tab structure.

[0064] Example 5

[0065] Different from example 2: the total thickness T of the bare cell is 5mm, and the width K of the outermost winding corresponding to the thinning recess is 3.33πmm; that is, K / T = 2 / 3π.

[0066] Example 6

[0067] Different from example 2: the total thickness T of the bare cell is 5mm, and the width K of the outermost winding corresponding to the thinning recess is 1.67πmm; that is, K / T = π / 3.

[0068] Comparative example 1

[0069] Different from example 1: the thinning thickness of the thinning recess 3 is set according to 4% of the rolling thickness of the cell pole piece structure.

[0070] Comparative example 2

[0071] Different from example 1: the thinning thickness of the thinning recess 3 is set according to 6% of the rolling thickness of the cell pole piece structure.

[0072] Comparative example 3

[0073] Different from example 1: the thinning thickness of the thinning recess 3 is set according to 16% of the rolling thickness of the cell pole piece structure.

[0074] Comparative example 4

[0075] Different from example 1: the thinning thickness of the thinning recess 3 is set according to 16% of the rolling thickness of the cell pole piece structure.

[0076] Comparative example 5

[0077] Different from example 1: the thinning thickness of the thinning recess 3 is set according to 18% of the rolling thickness of the cell pole piece structure.

[0078] Table 1-Performance parameters of all examples and comparative examples

[0079] Among them, the lithium precipitation level is marked as A < B < C in turn from slight to severe.

[0080] As can be seen from the table:

[0081] 1. When the thinning thickness of the thinning recess 3 is controlled according to 10% of the rolling thickness of the cell pole piece structure, the pole piece corner can be effectively improved for lithium precipitation. In addition, the thinning recess width and the cell thickness are controlled within a reasonable range:

[0082] When K / T=2 / 3pi, as in Example 5, the core thickness is uniform, the outermost coil is wound corresponding to the width K of the thinning recess T*2pi / 3, the overall corner area is wound relatively loose, more electrolyte is stored, but the lithium ion transmission path is lengthened, and thus the lithium precipitation improvement effect is poorer than that of Example K=pi / 2*T;

[0083] When K / T=pi / 3, as in Example 6, when the outermost coil is wound corresponding to the width K of the thinning recess T*1pi / 3, the overall corner area is wound relatively tight, although the lithium ion transmission path is shortened, but the local area electrolyte storage is less, and as the cycle proceeds, the electrolyte consumption increases, and thus causes the lithium precipitation to be aggravated;

[0084] Therefore, it is preferred that K / T=pi / 2, as in Example 2, at this time the bare core winding yield is optimal, and the lithium precipitation improvement effect is optimal.

[0085] 2. When the cathode sheet edge or corner is not thinned, at 2.8C charge rate, lithium ions are completely removed, causing serious local lithium precipitation of the sheet, and further affecting the performance.

[0086] 3. When the thinning value is too high, the CB value is too large, the local positive electrode oxidation state is increased, causing the interface to appear purple spots, and thus the lithium precipitation is aggravated;

[0087] 4. According to the corresponding parameters (as shown in Example 5, T=5mm, K=2.5pi mm, at this time K / T=pi / 2), a laser cleaning device is used to clean the lithium precipitation of the sheet, so as to improve the lithium precipitation of the cell and improve the safety of the battery.

[0088] Therefore, the utility model discloses a kind of sheet with optimal components designed in combination with the thinning thickness of thinning area and its coating width, to improve the local lithium precipitation of lithium ion battery, to improve the effect of battery safety.

[0089] The utility model also proposes a kind of battery, the battery includes cell, and the specific structure of the cell refers to the above embodiment, since the battery uses all the technical solutions of the above all embodiments, at least has all the beneficial effects brought by the technical solutions of the above embodiment, and here is not repeated.

[0090] In addition, it should be understood that, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the specification is described only for clarity, and those skilled in the art should understand the specification as a whole, and the technical solutions in each embodiment can be combined appropriately to form other embodiments that can be understood by those skilled in the art.

[0091] According to the disclosure and teaching of the above description, the person skilled in the art of the present application can also change and modify the above embodiments. Therefore, the present application is not limited to the above specific embodiments, and any obvious improvement, replacement or modification made by the person skilled in the art on the basis of the present application belongs to the protection scope of the present application. In addition, although some specific terms are used in the specification, these terms are only for convenience of description and do not constitute any limitation on the present application.

Claims

1. An electrode tab structure of a battery cell, characterized by: The electrode core structure comprises a current collector and an active material layer connected to at least one surface of the current collector; the active material layer is provided with at least one thinned recess along the width direction; the active material layer is further provided with a tab groove; the tab groove is arranged through the thickness direction of the active material layer; the tab groove is used for mounting a tab; and the bottom of the tab groove extends to the surface of the current collector.

2. The electrode structure of claim 1, wherein: The thinned recess comprises at least one first recess; the first recess is arranged parallel to the width direction of the active material layer; and the first recess is arranged through the width direction of the active material layer.

3. The electrode structure of claim 2, wherein: When the electrode core structure is in a wound state, the first recess is arranged at a bending position; and / or, at most part of the first recess is arranged at a flat position.

4. The electrode tab structure of claim 2 or 3, wherein: The relationship between the thickness H2 of the first recess and the thickness H1 of the electrode core structure satisfies: H2=H1*A; wherein A=8% to 14%.

5. The electrode tab structure of claim 1 or 2, wherein: The thinned recess further comprises at least one second recess; the second recess is arranged on at least one side of the width direction of the active material layer; and the second recess abuts against the edge of the width direction of the active material layer.

6. The electrode structure of claim 5, wherein: The width L1 of the second recess satisfies: L1=5 to 10 mm; And / or, the relationship between the thickness H3 of the second recess and the thickness H1 of the electrode core structure satisfies: H3=H1*B; wherein B=8% to 14%.

7. The electrode structure of claim 1, wherein: The tab groove is further provided with a protective layer; the protective layer is connected to the tab; and the projection of the protective layer towards the current collector covers the part of the tab groove where the tab is located; The relationship between the length of the protective layer and the length D1 of the tab satisfies: D2-D1≥1 mm.

8. An electric cell characterized by: The electrode core structure comprises first and second polar plates with opposite polarities and a separator arranged between the first and second polar plates; at least one of the first and second polar plates is the electrode core structure according to any one of claims 1 to 7.

9. The cell of claim 8, wherein: The total thickness T of the bare electrode core and the width K of the thinned recess corresponding to the outermost winding satisfy the relationship: π / 3≤K / T≤2π / 3, wherein T satisfies: 2≤T≤20 mm; The width of the thinned recess corresponding to n-1 winding satisfies: K-1*(2S+A+C); The width of the thinned recess corresponding to n-2 winding satisfies: K-2*(2S+A+C); The width of the thinned recess corresponding to n winding satisfies: K-n*(2S+A+C); The total thickness of the bare electrode core is T; the width of the thinned recess corresponding to the outermost winding is K; the total thickness of the first polar plate after winding is C; the total thickness of the second polar plate after winding is A; the total thickness of the separator after winding is S; and the winding number is n.

10. A battery, characterized by: The electrode core comprises the electrode core according to claim 8 or 9.

Images