Positive plate, battery and electric equipment

Abstract

The utility model belongs to the technical field of batteries, and particularly relates to a positive plate, a battery and electric equipment, the positive plate comprises a positive current collector and an active material layer, the positive current collector is provided with a protection structure, the protection structure is arranged between the positive current collector and the active material layer, and the active material layer is arranged between the positive current collector and the active material layer. The protection structure comprises a ceramic layer and a gel layer, and the ceramic layer, the gel layer and the active material layer are sequentially arranged on the surface of the positive current collector in the thickness direction of the positive current collector; the ceramic layer and the gel layer can effectively form a dual-protection structure on the surface of the positive current collector, and when the battery is subjected to a needling test, the negative active material firstly contacts with the active material layer, then respectively contacts with the gel layer and the ceramic layer, and finally reaches the surface of the positive current collector, so that the negative active material can be effectively protected. Therefore, the contact area of the negative electrode active material and the positive electrode current collector is effectively reduced, the needling test passing rate of the battery is further improved, and the safety performance of the battery is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of batteries, and in particular relates to a positive electrode sheet, a battery and an electrical device. Background Art

[0002] As a new type of secondary battery, lithium-ion batteries have the advantages of high energy density and power density, high operating voltage, light weight, small size, long cycle life, good safety, and green environmental protection. They have broad application prospects in portable appliances, power tools, large-scale energy storage, electric transportation power supply, etc.

[0003] Currently, the root cause of many safety accidents is that lithium-ion batteries fail due to internal short circuits caused by foreign objects penetrating them. In view of this, in order to ensure the safety and reliability of batteries during use, national standards have listed needle penetration tests and forced internal short circuit tests as mandatory certification test items that must be passed. However, when the battery undergoes a needle penetration test, the needle directly pierces the battery, and the negative electrode active material may come into contact with the positive electrode current collector, causing the battery to short circuit. This short circuit mode has the lowest contact resistance, so the short circuit current is the largest and the temperature rise is the largest. It is the most dangerous short circuit mode and is very likely to trigger thermal runaway of lithium-ion batteries. Utility Model Content

[0004] The purpose of the present invention is to provide a positive electrode sheet, a battery and an electrical device to address the deficiencies of the prior art, thereby solving the technical problem in the prior art that when the battery is punctured from the outside, the negative electrode active material may directly contact and short-circuit the positive electrode current collector.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] In a first aspect, the utility model provides a positive electrode sheet, comprising a positive electrode current collector and an active material layer, wherein a protective structure is arranged on the positive electrode current collector, and the protective structure is arranged between the positive electrode current collector and the active material layer. The protective structure comprises a ceramic layer and a gel layer, and along the thickness direction of the positive electrode current collector, the ceramic layer, the gel layer and the active material layer are sequentially arranged on the surface of the positive electrode current collector.

[0007] Preferably, along the width direction of the positive electrode current collector, the width of the ceramic layer, the width of the gel layer, the width of the active material layer and the width of the positive electrode current collector are the same;

[0008] And / or, along the length direction of the positive electrode current collector, the length of the ceramic layer is D, the length of the gel layer is G, the length of the active material layer is F, and the length of the positive electrode current collector is J, satisfying the relationship: F≤D=G≤J.

[0009] Preferably, the thickness of the ceramic layer is E, which satisfies the relationship: 4 μm≤E≤20 μm.

[0010] Preferably, the thickness of the gel layer is U, which satisfies the relationship: 2 μm≤U≤12 μm.

[0011] Preferably, the ceramic layer is an aluminum oxide layer, a zirconium oxide layer or a chromium oxide layer.

[0012] Preferably, the gel layer is a polyacrylonitrile layer, a polyvinyl alcohol layer, a polyvinylidene fluoride layer, a polymethyl methacrylate layer or a polyimide layer.

[0013] Preferably, along the thickness direction of the positive electrode current collector, the positive electrode current collector has a first surface and a second surface arranged opposite to each other, and the ceramic layer, the gel layer and the active material layer are sequentially arranged on the first surface and the second surface, wherein, along the length direction of the positive electrode current collector, at one end of the positive electrode current collector, the active material layers on the first surface and the second surface are aligned, and at the other end of the positive electrode current collector, the active material layers on the first surface and the second surface are staggered.

[0014] Preferably, along the length direction of the positive electrode current collector, at at least one end of the positive electrode current collector, the active material layer does not completely cover the gel layer.

[0015] In the second aspect, the utility model provides a battery, comprising a shell and a battery cell, the shell having a accommodating cavity, the battery cell being arranged in the accommodating cavity, the battery cell comprising a negative electrode sheet, a diaphragm and the positive electrode sheet of the above embodiment, the positive electrode sheet, the diaphragm and the negative electrode sheet being stacked and wound in sequence to form the battery cell.

[0016] In a third aspect, the present invention provides an electrical device comprising the battery of the above embodiment.

[0017] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0018] The positive electrode sheet of the present invention is provided with a protective structure on the positive electrode current collector, the protective structure including a ceramic layer and a gel layer. Along the thickness direction of the positive electrode current collector, the ceramic layer, the gel layer and the active material layer are sequentially provided on the surface of the positive electrode current collector, effectively enabling the ceramic layer and the gel layer to form a double protective structure on the surface of the positive electrode current collector. When the battery is subjected to a needle penetration test, the negative electrode active material first contacts the active material layer, then contacts the gel layer and the ceramic layer respectively, and finally reaches the surface of the positive electrode current collector, thereby effectively reducing the contact area between the negative electrode active material and the positive electrode current collector, thereby improving the pass rate of the battery's needle penetration test and improving the safety performance of the battery.

[0019] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] Figure 1 This is one of the structural schematic diagrams of the positive electrode sheet of the utility model.

[0022] Figure 2 This is one of the top views of the positive electrode sheet of the present invention.

[0023] Figure 3 This is the second structural diagram of the positive electrode sheet of the present utility model.

[0024] Figure 4 This is the second top view of the positive electrode sheet of the present invention.

[0025] Figure 5 This is the third structural diagram of the positive electrode sheet of the present utility model.

[0026] Figure 6 This is the third top view of the positive electrode sheet of the present invention.

[0027] The description of the accompanying drawings is as follows:

[0028] 100. Positive electrode;

[0029] 10. positive electrode current collector; 11. first surface; 12. second surface;

[0030] 20. Active material layer;

[0031] 30. Protective structure; 31. Ceramic layer; 32. Gel layer;

[0032] 40. Positive electrode tab;

[0033] a, thickness direction of the positive electrode current collector; b, width direction of the positive electrode current collector; c, length direction of the positive electrode current collector. DETAILED DESCRIPTION

[0034] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of the components as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.

[0035] Furthermore, the terms “first,” “second,” etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

[0036] In this utility model, unless otherwise expressly specified or limited, terms such as "installed," "connected," "connect," and "fixed" should be interpreted broadly. For example, they may refer to fixed connection, detachable connection, or integral connection; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in this utility model based on specific circumstances.

[0037] The following will be combined with the Figures 1 to 6 The technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] The electrical equipment of the embodiment of the present utility model includes a battery. The electrical equipment can be a car, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The car can be a fuel car, a gas car, or a new energy car. The new energy car can be a pure electric car, a hybrid car, or an extended-range car, and the like; the spacecraft includes airplanes, rockets, space shuttles, and spacecraft, and the like; the electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like; the electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, and the like. The embodiment of the present application does not impose any special restrictions on the above-mentioned electrical equipment.

[0039] The battery of an embodiment of the present invention includes a shell and a battery cell. The shell has a receiving cavity. The battery cell is arranged in the receiving cavity. The battery cell includes a positive electrode sheet 100, a negative electrode sheet and a separator. The positive electrode sheet 100, the separator and the negative electrode sheet are stacked and wound in sequence to form the battery cell.

[0040] See also Figures 1 to 6 The positive electrode sheet 100 of an embodiment of the present invention includes a positive electrode current collector 10 and an active material layer 20. A protective structure 30 is provided on the positive electrode current collector 10. The protective structure 30 is arranged between the positive electrode current collector 10 and the active material layer 20. The protective structure 30 includes a ceramic layer 31 and a gel layer 32. Along the thickness direction a of the positive electrode current collector 10, the ceramic layer 31, the gel layer 32 and the active material layer 20 are sequentially arranged on the surface of the positive electrode current collector 10.

[0041] Compared with the prior art, the positive electrode sheet 100 of the embodiment of the present invention is provided with a protective structure 30 on the positive electrode current collector 10. The protective structure 30 includes a ceramic layer 31 and a gel layer 32. Along the thickness direction a of the positive electrode current collector 10, the ceramic layer 31, the gel layer 32 and the active material layer 20 are sequentially arranged on the surface of the positive electrode current collector 10, effectively enabling the ceramic layer 31 and the gel layer 32 to form a double protective structure 30 on the surface of the positive electrode current collector 10. When the battery is subjected to a needle penetration test, the negative electrode active material first contacts the active material layer 20, then contacts the gel layer 32 and the ceramic layer 31 respectively, and finally reaches the surface of the positive electrode current collector 10, thereby effectively reducing the contact area between the negative electrode active material and the positive electrode current collector 10, thereby improving the battery's needle penetration test pass rate and improving the battery's safety performance.

[0042] See also Figures 1 to 6 In some embodiments, along the width direction b of the positive electrode current collector 10, the width of the ceramic layer 31, the width of the gel layer 32, the width of the active material layer 20, and the width of the positive electrode current collector 10 are the same. By setting the width of the ceramic layer 31, the width of the gel layer 32, the width of the active material layer 20, and the width of the positive electrode current collector 10, the width of the ceramic layer 31, the width of the gel layer 32, the width of the active material layer 20, and the width of the positive electrode current collector 10 are made the same, effectively allowing the ceramic layer 31 and the gel layer 32 to cover the positive electrode current collector 10 in the width direction b of the positive electrode current collector 10, thereby effectively reducing the contact area between the negative electrode active material and the positive electrode current collector 10 when the battery is subjected to a needle penetration test, thereby improving the battery's needle penetration test pass rate and improving the battery's safety performance.

[0043] And / or, along the length direction c of the positive electrode current collector 10, the length of the ceramic layer 31 is D, the length of the gel layer 32 is G, the length of the active material layer 20 is F, and the length of the positive electrode current collector 10 is J, satisfying the relationship: F≤D=G≤J. By setting the length D of the ceramic layer 31, the length G of the gel layer 32, the length F of the active material layer 20, and the length J of the positive electrode current collector 10 so that F≤D=G≤J, the ceramic layer 31 and the gel layer 32 effectively form a dual protective structure 30 on the surface of the positive electrode current collector 10, thereby effectively reducing the contact area between the negative electrode active material and the positive electrode current collector 10 during a battery penetration test, thereby improving the battery's penetration test pass rate and enhancing the battery's safety performance.

[0044] Preferably, when the length J of the positive current collector 10, the length D of the ceramic layer 31 and the length G of the gel layer 32 are all equal, and the width of the positive current collector 10, the width of the ceramic layer 31 and the width of the gel layer 32 are all equal, the ceramic layer 31 and the gel layer 32 can cover the surface of the positive current collector 10, effectively enabling the ceramic layer 31 and the gel layer 32 to form a double protection structure 30 on the surface of the positive current collector 10, thereby effectively reducing the contact area between the negative electrode active material and the positive current collector 10 when the battery is subjected to a needle penetration test, thereby improving the battery's needle penetration test pass rate and improving the battery's safety performance.

[0045] See also Figure 1 、 Figure 3 and Figure 5 In some embodiments, the thickness of the ceramic layer 31 is E, satisfying the relationship: 4μm≤E≤20μm. By setting the thickness E of the ceramic layer 31, the thickness of the ceramic layer 31 cannot be too thick or too thin. When the thickness E of the ceramic layer 31 is too thin, that is, E<4μm, the ceramic layer 31 may not provide effective protection for the positive electrode current collector 10. When the thickness E of the ceramic layer 31 is too thick, that is, E>20μm, although the ceramic layer 31 can enhance the strength and hardness of the structure to a certain extent, the excessively thick ceramic layer 31 may increase the weight and volume of the battery, affecting the energy density of the battery.

[0046] Therefore, to ensure the performance of ceramic layer 31 while also taking into account the battery's energy density, the present embodiment sets the thickness E of ceramic layer 31 to satisfy the relationship: 4μm ≤ E ≤ 20μm. This thickness range ensures that ceramic layer 31 can effectively perform its functions while avoiding the negative effects of being too thick or too thin.

[0047] Furthermore, the thickness E of the ceramic layer 31 is 4 μm, 5 μm, 5.5 μm, 7 μm, 7.1 μm, 9 μm, 10 μm, 11 μm, 12.8 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, or 20 μm, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0048] See also Figure 1 、 Figure 3 and Figure 5 In some embodiments, the thickness of the gel layer 32 is U, satisfying the relationship: 2μm≤U≤12μm. By setting the thickness U of the gel layer 32, the thickness U of the gel layer 32 cannot be too thick or too thin. When the thickness U of the gel layer 32 is too thin, that is, U<2μm, the gel layer 32 may not provide effective protection for the positive electrode current collector 10. When the thickness U of the gel layer 32 is too thick, that is, U>12μm, although the gel layer 32 can protect the positive electrode current collector 10 to a certain extent, the excessively thick ceramic layer 31 may increase the weight and volume of the battery, affecting the energy density of the battery.

[0049] Therefore, to ensure the performance of gel layer 32 while also taking into account the battery's energy density, the present embodiment sets the thickness U of gel layer 32 to satisfy the relationship: 2μm ≤ U ≤ 12μm. This thickness range ensures that gel layer 32 can effectively perform its functions while avoiding the negative effects of being too thick or too thin.

[0050] Furthermore, the thickness U of the gel layer 32 is 2 μm, 2.5 μm, 3 μm, 4 μm, 4.7 μm, 5 μm, 6 μm, 6.9 μm, 7 μm, 7.1 μm, 8 μm, 9 μm, 9.5 μm, 10 μm, 11 μm, or 12 μm, but is not limited to the listed values, and other values ​​within the numerical range are also applicable.

[0051] In some embodiments, the ceramic layer 31 is an aluminum oxide layer, a zirconium oxide layer, or a chromium oxide layer. Since aluminum oxide layers, zirconium oxide layers, and chromium oxide layers all have high hardness and corrosion resistance, using an aluminum oxide layer, a zirconium oxide layer, or a chromium oxide layer as the ceramic layer 31 can provide effective protection for the positive electrode current collector 10.

[0052] In some embodiments, the gel layer 32 is a polyacrylonitrile layer, a polyvinyl alcohol layer, a polyvinylidene fluoride layer, a polymethyl methacrylate layer, or a polyimide layer. Since polyacrylonitrile (PAN), polyvinyl alcohol (PVA), polyvinylidene fluoride (PVDF), polymethyl methacrylate (PMMA), or polyimide (PI) layers all have good mechanical properties, such as tensile strength and flexural strength, the gel layer 32 is a polyacrylonitrile layer, a polyvinyl alcohol layer, polyvinylidene fluoride layer, polymethyl methacrylate layer, or a polyimide layer, which can provide effective protection for the positive electrode current collector 10.

[0053] See also Figures 1 to 6 In some embodiments, along the thickness direction a of the positive electrode current collector 10, the positive electrode current collector 10 has a first surface 11 and a second surface 12 disposed opposite each other. The ceramic layer 31, the gel layer 32, and the active material layer 20 are sequentially disposed on each of the first and second surfaces 11, 12. Along the length direction c of the positive electrode current collector 10, at one end of the positive electrode current collector 10, the active material layers 20 on the first and second surfaces 11, 12 are aligned, while at the other end of the positive electrode current collector 10, the active material layers 20 on the first and second surfaces 11, 12 are staggered. By providing the ceramic layer 31 and the gel layer 32 on both the first and second surfaces 11, 12, a dual protective structure 30 is effectively formed on each of the first and second surfaces 11, 12. This effectively reduces the contact area between the negative electrode active material and the positive electrode current collector 10 during a battery penetration test, thereby improving the battery's penetration test pass rate and enhancing the battery's safety performance.

[0054] In some embodiments, along the length direction c of the positive electrode current collector 10, at least one end of the positive electrode current collector 10, the active material layer 20 does not completely cover the gel layer 32. Through the above-mentioned structural arrangement, the gel layer 32 can effectively cover the positive electrode current collector 10, and the gel layer 32 is still provided in the area of ​​the positive electrode current collector 10 not coated with the positive electrode active material. Therefore, when the battery is subjected to a needle penetration test, the contact area between the negative electrode active material and the positive electrode current collector 10 can be effectively reduced, thereby improving the battery's needle penetration test pass rate and improving the battery's safety performance.

[0055] See also Figures 1 to 6 The positive electrode sheet 100 of the embodiment of the present invention further includes a positive electrode tab 40, which is integrally formed with the positive electrode current collector 10, that is, the positive electrode tab 40 and the positive electrode current collector 10 are one component; or, the positive electrode tab 40 and the positive electrode current collector 10 are separate structures, that is, the positive electrode is positive and the positive electrode current collector 10 are two separate components.

[0056] When the positive electrode tab 40 is integrally formed with the positive electrode current collector 10 , the positive electrode tab 40 extends outward from one side of the positive electrode current collector 10 along the width direction b of the positive electrode current collector 10 ;

[0057] When the positive electrode tab 40 and the positive electrode current collector 10 are separate structures, a tab welding area is provided in the middle or end of the positive electrode current collector 10 along the length direction c of the positive electrode current collector 10 , and the positive electrode tab 40 is welded to the tab welding area.

[0058] In summary, the acupuncture test of the battery cell according to the embodiment of the present invention includes:

[0059] In cell A, the positive electrode current collector 10 is coated with a ceramic layer 31 and an active material layer 20 in sequence;

[0060] In cell B, the positive electrode current collector 10 is coated with a ceramic layer 31, a gel layer 32, and an active material layer 20 in sequence;

[0061] Among them, the voltage of battery cell A and the voltage of battery cell B are both 4.50V.

[0062] Example 1:

[0063] In the needle penetration test of a screw with a length of 3mm and a diameter of 1.5mm, battery cell A and battery cell B were compared and tested. The pass rate of the needle penetration test for battery cell A was 30%, while the pass rate of the needle penetration test for battery cell B was 100%.

[0064] Example 2:

[0065] In the needle penetration test with a steel needle with a diameter of 5 mm, comparative experiments were conducted on battery cell A and battery cell B respectively. Among them, the pass rate of the needle penetration test of battery cell A was 30%, and the pass rate of the needle penetration test of battery cell B was 100%.

[0066] In summary, through Examples 1 and 2, it can be seen that the pass rate of the pinhole test of cell B is higher than that of cell A. This is because, compared to cell A in which only the ceramic layer 31 is coated on the positive electrode current collector 10, the positive electrode current collector 10 of cell B is coated with a ceramic layer 31 and a gel layer 32. The ceramic layer 31 and the gel layer 32 can form a double protection on the positive electrode current collector 10. When the battery is subjected to a pinhole test, the negative electrode active material first contacts the active material layer 20, then contacts the gel layer 32 and the ceramic layer 31 respectively, and finally reaches the surface of the positive electrode current collector 10, thereby effectively reducing the contact area between the negative electrode active material and the positive electrode current collector 10, thereby improving the pass rate of the pinhole test of the battery and improving the safety performance of the battery.

[0067] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced within the present invention.

Claims

1. A positive electrode sheet, characterized in that: The invention comprises a positive electrode current collector (10) and an active material layer (20), wherein a protective structure (30) is provided on the positive electrode current collector (10), wherein the protective structure (30) is provided between the positive electrode current collector (10) and the active material layer (20), and wherein the protective structure (30) comprises a ceramic layer (31) and a gel layer (32), and wherein along the thickness direction (a) of the positive electrode current collector (10), the ceramic layer (31), the gel layer (32) and the active material layer (20) are sequentially provided on the surface of the positive electrode current collector (10).

2. The positive electrode sheet according to claim 1, wherein: Along the width direction (b) of the positive electrode current collector (10), the width of the ceramic layer (31), the width of the gel layer (32), the width of the active material layer (20), and the width of the positive electrode current collector (10) are the same; And / or, along the length direction (c) of the positive electrode current collector (10), the length of the ceramic layer (31) is D, the length of the gel layer (32) is G, the length of the active material layer (20) is F, and the length of the positive electrode current collector (10) is J, satisfying the relationship: F≤D=G≤J.

3. The positive electrode sheet according to claim 1, wherein: The thickness of the ceramic layer (31) is E, which satisfies the relationship: 4 μm≤E≤20 μm.

4. The positive electrode sheet according to claim 1, wherein: The thickness of the gel layer (32) is U, which satisfies the relationship: 2 μm≤U≤12 μm.

5. The positive electrode sheet according to claim 1, wherein: The ceramic layer (31) is an aluminum oxide layer, a zirconium oxide layer or a chromium oxide layer.

6. The positive electrode sheet according to claim 1, wherein: The gel layer (32) is a polyacrylonitrile layer, a polyvinyl alcohol layer, a polyvinylidene fluoride layer, a polymethyl methacrylate layer or a polyimide layer.

7. The positive electrode sheet according to claim 1, wherein: Along the thickness direction (a) of the positive electrode current collector (10), the positive electrode current collector (10) has a first surface (11) and a second surface (12) that are arranged opposite to each other, and the ceramic layer (31), the gel layer (32) and the active material layer (20) are sequentially arranged on the first surface (11) and the second surface (12), wherein, along the length direction (c) of the positive electrode current collector (10), at one end of the positive electrode current collector (10), the active material layers (20) on the first surface (11) and the second surface (12) are aligned, and at the other end of the positive electrode current collector (10), the active material layers (20) on the first surface (11) and the second surface (12) are staggered.

8. The positive electrode sheet according to claim 7, wherein: Along the length direction (c) of the positive electrode current collector (10), at at least one end of the positive electrode current collector (10), the active material layer (20) does not completely cover the gel layer (32).

9. A battery, characterized in that: The battery cell comprises a shell and a battery cell, wherein the shell has a receiving cavity, the battery cell is arranged in the receiving cavity, the battery cell comprises a negative electrode sheet, a separator and a positive electrode sheet according to any one of claims 1 to 8, and the positive electrode sheet (100), the separator and the negative electrode sheet are stacked and wound in sequence to form the battery cell.

10. An electrical device, characterized in that: A battery comprising the battery of claim 9.

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