Electrode sheet, negative electrode sheet, electrode module, and lithium-ion battery

Abstract

To provide an electrode sheet, a negative electrode sheet, an electrode assembly, and a lithium-ion battery.SOLUTION: The disclosure provides an electrode sheet, a negative electrode sheet, an electrode assembly, and a lithium-ion battery, relating to the technical field of batteries. The electrode sheet comprises a current collector and an active material coating layer; the current collector comprises a coating area, and a tab area and a non-tab area which are respectively provided on two opposite sides of the coating area; the active substance coating layer is provided on the coating area; and the surface of the non-tab area is coated with an insulating coating layer. In addition, also provided are an electrode assembly comprising the electrode sheet and a lithium-ion battery using the electrode assembly.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] This disclosure claims priority to three Chinese patent applications filed on the same date, September 15, 2023, with the China Patent Office, bearing application numbers 202322526600.9, 202311200028.5 and 202322529053.X, respectively, the contents of which are all incorporated herein by reference. The present disclosure relates to the technical field of batteries, and in particular to an electrode sheet, a negative electrode sheet, an electrode assembly, and a lithium ion battery. [Background technology]

[0002] During the operation of the battery, the battery electrode sheet may expand, and in this case, the expansion of the negative electrode is more serious than that of the positive electrode, and the thickness and width of the electrode sheet change due to the expansion of the negative electrode sheet. Such a change leads to the following two possibilities. Possibility 1 is that the volume change of the electrode sheet causes the edge expansion of the electrode sheet to penetrate the separator and contact the positive electrode, causing a short circuit. Possibility 2 is that the negative electrode sheet expands and protrudes from the separator, directly contacting the positive electrode, causing a short circuit, and even leading to fire and explosion. Summary of the Invention

[0003] Therefore, how to prevent the negative electrode sheet from coming into contact with the positive electrode due to expansion and causing a short circuit is a technical problem that needs to be solved in battery technology in order to improve battery safety.

[0004] In a first aspect, the present disclosure provides an electrode sheet, the electrode sheet including a current collector and an active material coating layer, the current collector including a coating region and a tab region and a non-tab region respectively provided on both sides of the coating region, the active material coating layer being provided on the coating region, and an insulating coating layer being coated on a surface of the non-tab region.

[0005] In a second aspect, the present disclosure further provides a negative electrode sheet, the negative electrode sheet including a negative electrode current collector and a negative electrode active material coating layer, the negative electrode current collector including a negative electrode coating region and a negative electrode tab provided on one side of the negative electrode coating region, a negative electrode active material coating layer provided on the negative electrode coating region, and at least one insulating coating layer provided on a surface of the negative electrode active material coating layer remote from the negative electrode current collector, or a non-tab region is further provided on one side of the negative electrode current collector remote from the negative electrode tab, and at least one insulating coating layer is provided on each of the surface of the non-tab region and the surface of the negative electrode active material coating layer remote from the negative electrode current collector.

[0006] In a third aspect, the present disclosure further provides an electrode assembly, the electrode assembly comprising a positive electrode sheet, a separator, and the electrode sheet of the first aspect, the positive electrode sheet and the negative electrode sheet being respectively located on either side of the separator.

[0007] In a fourth aspect, the present disclosure further provides an electrode assembly, the electrode assembly comprising a positive electrode sheet, a separator, and the electrode sheet of the second aspect, the positive electrode sheet and the negative electrode sheet being respectively located on either side of the separator.

[0008] In a fifth aspect, the present disclosure further provides a lithium ion battery comprising the electrode assembly of the third or fourth aspect. Effect of the Invention

[0009] The present disclosure provides an insulating coating layer on the non-tab area of ​​the negative electrode sheet, thereby preventing the negative electrode sheet from expanding and protruding, which may come into contact with the positive electrode sheet and cause a short circuit, thereby improving the safety performance of the battery. [Brief description of the drawings]

[0010] In order to more clearly describe the technical solutions in the embodiments of the present disclosure, the following briefly introduces drawings required for the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present disclosure, and those skilled in the art can also obtain other drawings based on these drawings without any creative efforts. [Figure 1] FIG. 2 is a cross-sectional view of a first structure of a pole sheet in one embodiment of the present disclosure. [Diagram 2] FIG. 2 is a side view of a first structure of a pole sheet in one embodiment of the present disclosure. [Diagram 3] FIG. 2 is a cross-sectional view of a second structure of a pole sheet in one embodiment of the present disclosure. [Figure 4] FIG. 13 is a side view of a second structure of a pole sheet in one embodiment of the present disclosure. [Diagram 5] FIG. 13 is a cross-sectional view of a third structure of a pole sheet in one embodiment of the present disclosure. [Figure 6] FIG. 13 is a side view of a third structure of a pole sheet in one embodiment of the present disclosure. [Figure 7] FIG. 2 is a structural schematic diagram of an electrode assembly in one embodiment of the present disclosure. [Figure 8] FIG. 2 is a cross-sectional view of a first structure of a negative electrode sheet in one embodiment of the present disclosure. [Figure 9] FIG. 2 is a side view of a first structure of a negative electrode sheet in one embodiment of the present disclosure. [Figure 10] FIG. 4 is a cross-sectional view of a second structure of a negative electrode sheet in an embodiment of the present disclosure. [Figure 11] FIG. 2 is a side view of a second structure of a negative electrode sheet in an embodiment of the present disclosure. [Figure 12] FIG. 11 is a cross-sectional view of a third structure of a negative electrode sheet in an embodiment of the present disclosure. [Figure 13] FIG. 11 is a side view of a third structure of a negative electrode sheet in an embodiment of the present disclosure. [Figure 14] FIG. 11 is a schematic diagram of a fourth structure of a negative electrode sheet in an embodiment of the present disclosure. [Figure 15] FIG. 13 is a schematic diagram of a fifth structure of a negative electrode sheet in an embodiment of the present disclosure. [Figure 16]FIG. 11 is a schematic diagram of a sixth structure of a negative electrode sheet in an embodiment of the present disclosure. [Figure 17] FIG. 13 is a schematic diagram of a seventh structure of a negative electrode sheet in an embodiment of the present disclosure. [Figure 18] FIG. 13 is a schematic diagram of an eighth structure of a negative electrode sheet in an embodiment of the present disclosure. [Figure 19] FIG. 2 is a structural schematic diagram of an electrode assembly in one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The embodiment of the present disclosure provides an electrode sheet, and the electrode sheet 100 may be used as a positive electrode sheet in a battery, or may be used as a negative electrode sheet in a battery. Considering that the expansion of the negative electrode sheet during operation is more serious than that of the positive electrode sheet, the electrode sheet 100 is used as the negative electrode sheet in a battery to solve the problem of the expansion protrusion of the negative electrode sheet and the problem of contact with the positive electrode sheet causing a short circuit.

[0012] 1 and 2, in this embodiment, the electrode sheet 100 includes a current collector 110 and an active material coating layer 120 coated on one or more surfaces of the current collector 110, where the current collector 110 includes a coating region 112 located in the center thereof, and a tab region 111 and a non-tab region 113 respectively provided on both sides of the coating region 112.

[0013] Specifically, the active material coating layer 120 is uniformly coated on both sides of the current collector 110 in the first direction X, and the tab region 111 and the non-tab region 113 are respectively located on both sides of the current collector 110 in the second direction Y. The portion of the current collector 110 located in the tab region 111 and the portion of the current collector 110 located in the non-electrode tab region 113 are not coated with the active material coating layer 120, and in this case, one or more tabs of the electrode sheet 100 are formed in the portion of the current collector 110 located in the tab region 111.

[0014] In addition, when the electrode sheet 100 is used as a positive electrode sheet, the material of the current collector 110 may be aluminum, and the material of the active material coating layer 120 may be a ternary or quaternary positive electrode active material formed of lithium cobalt oxide, lithium iron phosphate, lithium manganate, or a lithium metal composite oxide having at least nickel (Ni), cobalt (Co), manganese (Mn) and / or aluminum (Al). When the electrode sheet 100 is used as a negative electrode sheet, the material of the current collector 110 may be copper, and the material of the active material coating layer 120 may be carbon or silicon. Specifically, the material may be flexibly selected as necessary, and there is no specific limitation thereon.

[0015] The first direction X is the thickness direction of the polar sheet 100 , and the second direction Y is perpendicular to the first direction X and is the width direction of the polar sheet 100 .

[0016] In this embodiment, in order to cope with the problem that the positive electrode sheet and the negative electrode sheet are easily brought into contact with each other during use in a battery and cause a short circuit, the electrode sheet 100 is provided with an insulating coating layer 130 on one or more surfaces of the non-tab region 113. When the electrode sheet 100 is expanded and protruded during actual use, the insulating coating layer 130 provides an insulating protection effect for the electrode sheet 100, and prevents the electrode sheet 100 from directly contacting the corresponding positive electrode sheet or negative electrode sheet and causing a short circuit.

[0017] 1 and 2, in one embodiment, the insulating coating layer 130 includes a first insulating layer 131, which is uniformly coated on both sides of the non-tab region 113 along the first direction. In this case, a pre-gap may be provided between the first insulating layer 131 and the active material coating layer 120, so that a small blank area is formed between the first insulating layer 131 and the active material coating layer 120. Here, the pre-gap can prevent the slurry of the first insulating layer 131 from interacting with the slurry of the active material coating layer 120 to prevent the slurry from affecting the battery performance. However, in practical applications, the width of the pre-gap should not be too large to avoid the insulation effect being poor due to the width of the first insulating layer 131 being too small, and the width of the pre-gap should not exceed 100 mm.

[0018] As shown in FIGS. 3 and 4, in other embodiments, there may be no gap between the first insulating layer 131 and the active material coating layer 120, so that the first insulating layer 131 directly abuts the active material coating layer 120.

[0019] In another embodiment, the first insulating layer 131 may be uniformly coated on one side along the first direction of the non-tab region 113. In this case, a preliminary gap may be provided between the first insulating layer 131 and the active material coating layer 120, or no gap may be directly provided, so that the first insulating layer 131 and the active material coating layer 120 abut against each other.

[0020] 5 and 6, in one embodiment, the insulating coating layer 130 further includes a second insulating layer 132, which is disposed on one side of the non-tab region 113 away from the active material coating layer 120. In this case, the second insulating layer 132, together with the first insulating layer 131, covers the edge of the non-tab region 113 on one side away from the active material coating layer 120, while providing a passivation effect on the edge of the non-tab region 113, reducing the risk of the non-tab region expanding and deforming to break through the separator, while even if the non-tab region 113 breaks through the separator and comes into contact with the positive electrode tab, the combination of the first insulating layer 131 and the second insulating layer 132 provides sufficient insulation protection for the edge of the current collector 110 on one side away from the tab region 111, preventing the occurrence of a short circuit.

[0021] In each embodiment, the thickness and width of the first insulating layer 131 are set to H3 and W1, respectively (H3 and W1 are the dimensions of the first insulating layer 131 along the thickness and width directions of the current collector 110, respectively), the dimension of the second insulating layer 132 along the thickness direction of the current collector 110 is H4, and the dimension of the second insulating layer 132 along the width direction of the current collector 110 is W2.

[0022] In order to ensure the insulation protection effect of the insulating coating layer 130, the dimensions should satisfy the following conditions: 0.1 μm≦H3≦H2; 0.1 mm≦W1≦100 mm; H1≦H4≦2*H3+H1; 0.1 μm≦W2≦5000 μm, where H1 is the thickness of the current collector 110 and H2 is the thickness of the active material coating layer 120.

[0023] The specific dimensions of H3, W1, H4 and W2 can be respectively controlled as follows: 5 μm≦H3≦100 um; 1 mm≦W1≦100 mm; 6 um≦H4≦100 um; 1 um≦W2≦100 um. By rationally controlling the thickness H3 of the first insulating layer 131, it is possible to prevent the coating thickness from being too small to provide sufficient insulation, and at the same time, to prevent the coating thickness from being too large to provide poor processing performance, and to avoid the first insulating layer 131 from increasing the loss of electrolyte due to the swelling phenomenon, thereby ensuring the energy density of the battery.

[0024] In addition, in some embodiments, the insulating coating layer 130 only includes the first insulating layer 131, in which case only the thickness H3 and width W1 of the first insulating layer 131 need to satisfy the correlation condition. In order to ensure the insulating protection effect, the thickness H3 of the first insulating layer 131 should always be no greater than the thickness H2 of the active material coating layer 120, so as to prevent the pole sheet from protruding along the thickness direction of the first insulating layer 131 and prevent the pole sheet from being wrinkled when wound, thereby ensuring its processability and manufacturability. The dimension H4 of the second insulating layer 132 along the thickness direction of the current collector 110 should always be greater than or equal to the thickness H1 of the current collector 110, so as to ensure that the second insulating layer 132 can always completely cover one end face of the current collector 110 that is far from the corresponding tab.

[0025] In this embodiment, the first insulating layer 131 and the second insulating layer 132 may adopt the same coating material or different coating materials, specifically, may be determined according to different performance requirements of the first insulating layer 131 and the second insulating layer 132 in use.

[0026] For example, in one embodiment, the first insulating layer 131 and the second insulating layer 132 may be manufactured using the same coating material. Specifically, the material of the insulating coating layer 130 includes inorganic materials, organic materials and solvents.

[0027] The inorganic material may include one or a combination of at least two of the following: boehmite, alumina, silica, hexagonal boron nitride, cubic boron nitride, silicon carbide, silicon nitride.

[0028] The polymerizable monomer of the organic material may include any one or a combination of two or more of vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluoroethylene, alkyl ether, ethylene, propylene, 1,3-butadiene, vinyl chloride, styrene, and vinyl acetate. Alternatively, the polymerizable monomer may include any one or a combination of at least two of acrylic acid, acrylic acid ester, acrylamide, N-vinylpyrrolidone, acrylonitrile, maleic acid, itaconic acid, maleimide, and bismaleimide. Alternatively, the polymerizable monomer may include any one or a combination of at least two of alkyd resin, epoxy resin, polyurethane, silicone resin, polyamide, polyaramid, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polyphenylsulfone, polyethersulfone, polyetheretherketone, polyimide, polyamideimide, polyetherimide, or polyesterimide. Alternatively, it may contain one or a combination of at least two of polyimide, polyamideimide, polyetherimide, polyesterimide, polyvinylidene fluoride, or polytetrafluoroethylene.The weight average molecular weight of the organic material is 20,000 to 1,000,000.

[0029] The solvent may be a water-based deionized water solvent or an oil-based N-methylpyrrolidone (NMP) solvent, but is not particularly limited thereto.

[0030] Taking the technical solution of the present disclosure as an example in which the electrode sheet 100 is used as a negative electrode sheet, if an expansion protrusion occurs on the negative electrode sheet, the negative electrode sheet can contact the positive electrode sheet via the insulating coating layer 130, thereby avoiding direct contact between the positive and negative electrode sheets and causing a short circuit, thereby improving the safety of the battery.

[0031] 7, an embodiment of the present disclosure provides an electrode assembly including a positive electrode sheet 200, a separator 300, and a negative electrode sheet. In the electrode assembly, the negative electrode sheet is used as the electrode sheet 100, and therefore, for ease of explanation and understanding, the electrode sheet 100 will be directly referred to as the "negative electrode sheet" hereinafter.

[0032] The electrode assembly is a component that causes a chemical reaction in a battery, and is mainly formed by winding or stacking a positive electrode sheet 200 and a negative electrode sheet, and usually a separator 300 is provided between the positive electrode sheet 200 and the negative electrode sheet. The positive electrode sheet 200 is provided with a positive electrode coating area 220, and the negative electrode sheet is provided with a negative electrode coating area (corresponding to the coating area 112 in the electrode sheet 100), and the positive electrode coating area 220 and the negative electrode coating area are respectively coated with a positive electrode active material coating layer 230 and a negative electrode active material coating layer (corresponding to the active material coating layer 120 in the electrode sheet 100). The part of the positive electrode sheet 200 where the positive electrode active material coating layer 230 is provided and the part of the negative electrode sheet where the negative electrode active material coating layer is provided constitute the main body of the electrode assembly, and the parts of the positive electrode sheet 200 and the negative electrode sheet where there is no active material coating layer are respectively provided with tabs, which are the positive electrode tab 210 and the negative electrode tab (corresponding to the tab area 111 in the tab 100). Taking the negative electrode sheet as an example, in order to adopt the structural design of the electrode sheet 100 in Example 1, the negative electrode tab thereon constitutes the so-called "tab area 111", and the opposite side of the negative electrode tab constitutes the so-called "non-tab area 113".

[0033] 7, in this embodiment, the electrode assembly includes a plurality of positive electrode sheets 200 and a plurality of negative electrode sheets, the positive electrode sheets 200 and the negative electrode sheets are alternately arranged, and a separator 300 is arranged between any adjacent positive electrode sheets 200 and negative electrode sheets. In this case, taking a pair of adjacent positive electrode sheets 200 and negative electrode sheets as an example, the positive electrode sheets 200 and the negative electrode sheets may be located on both sides of the separator 300, respectively, and the positive electrode tabs 210 and the negative electrode tabs may be located on both sides of the electrode assembly, respectively.

[0034] In this embodiment, to prevent a short circuit between the positive electrode sheet 200 and the negative electrode sheet, the width of the separator 300 is greater than or equal to the width of the negative electrode coating region, which in turn is greater than or equal to the width of the positive electrode coating region 220. Here, "width" refers to the dimension of the corresponding member along the second direction Y.

[0035] In addition, the insulating coating layer 130 is provided on the non-tab area 113 of the negative electrode sheet, and the insulating coating layer 130 includes a first insulating layer 131 and a second insulating layer 132. The specific arrangement of the first insulating layer 131 and the second insulating layer 132 can be referred to the related description above, and the description will be omitted here. In this electrode assembly, one edge of the first insulating layer 131 close to the negative electrode coating area does not exceed the adjacent position of the positive electrode coating area 220 and the positive electrode tab 210, that is, in the second direction Y, one edge of the first insulating layer 131 close to the negative electrode coating area corresponds to the position where the positive electrode tab 210 is located in the positive electrode sheet 200, and does not coat the part where the positive electrode coating area 220 is located, or does not completely coat the part where the positive electrode coating area 220 is located.

[0036] In this way, when an expansion protrusion occurs in the negative electrode sheet and breaks through the separator 300, the non-tab area 113 is ensured to come into contact with the positive electrode tab 210 via the insulating coating layer 130, preventing direct contact between the positive electrode sheet 200 and the negative electrode sheet, avoiding contact short circuits between the positive electrode sheet 200 and the negative electrode sheet, and improving safety.

[0037] Similarly, one edge of the positive electrode coating region 220 away from the positive electrode tab 210 does not extend beyond one edge of the negative electrode coating region closer to the negative electrode tab; that is, in the second direction Y, one edge of the positive electrode coating region 220 away from the positive electrode tab 210 corresponds to the portion of the negative electrode sheet where the negative electrode coating region is located, and is prevented from extending to the portion where the tab region 111 is located.

[0038] In this way, when an expansion protrusion occurs in the negative electrode sheet and breaks through the separator 300, the non-tab area 113 is ensured to come into contact with the positive electrode tab 210 via the insulating coating layer 130, preventing direct contact between the positive electrode sheet 200 and the negative electrode sheet, avoiding contact short circuits between the positive electrode sheet 200 and the negative electrode sheet, and improving safety.

[0039] An embodiment of the present disclosure provides a lithium ion battery including an electrode assembly, and by applying the electrode assembly to the lithium ion battery, direct contact between the positive electrode sheet 200 and the negative electrode sheet during use of the battery is avoided, contact short circuit is avoided, and the safety of the battery is improved.

[0040] In this embodiment, the lithium ion battery is a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery in this embodiment may include a battery module or a battery pack, etc.

[0041] The battery cell includes an electrode assembly and an electrolyte, and the electrode assembly is composed of a positive electrode sheet 200, a negative electrode sheet, and a separator 300. The battery cell operates mainly by metal ions moving between the positive electrode sheet 200 and the negative electrode sheet.

[0042] The positive electrode sheet 200 includes a positive electrode current collector and a positive electrode active material coating layer 230, the positive electrode active material coating layer 230 is coated on the surface of the positive electrode current collector, the positive electrode current collector not coated with the positive electrode active material coating layer 230 protrudes from the positive electrode current collector coated with the positive electrode active material coating layer 230, and the positive electrode current collector not coated with the positive electrode active material coating layer 230 becomes the positive electrode tab 210. The material of the positive electrode current collector may be aluminum, and the material of the positive electrode active material coating layer 230 may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganese oxide, etc.

[0043] The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, the negative electrode active material coating layer is coated on the surface of the negative electrode current collector, the negative electrode current collector not coated with the negative electrode active material coating layer protrudes from the negative electrode current collector coated with the negative electrode active material coating layer, and the negative electrode current collector not coated with the negative electrode active material coating layer becomes a negative electrode tab. Here, the material of the negative electrode current collector may be copper, and the material of the negative electrode active material coating layer may be carbon or silicon, etc.

[0044] In order to ensure that the positive electrode tabs 210 are not melted by a large current, multiple positive electrode tabs 210 may be stacked, and multiple negative electrode tabs may be stacked. The material of the separator 300 may be PP (polypropylene), PE (polyethylene), or the like.

[0045] The battery cell further includes a housing, an electrode terminal, and an adapter plate, the electrode assembly and the electrolyte are provided in the housing, the electrode terminal is provided in the housing, the adapter connects the electrode terminal and the tab of the electrode assembly, and an insulating member is provided between the adapter and the housing to insulate the adapter from the housing. The specific structure of the battery cell is not the main point of the present embodiment and belongs to the prior art, so a description thereof will be omitted here.

[0046] 8 and 9, an embodiment of the present disclosure provides a negative electrode sheet, and the negative electrode sheet 1000 includes a negative electrode current collector 1100 and a negative electrode active material coating layer 1200 coated on the surface of the negative electrode current collector 1100. Here, the negative electrode current collector 1100 includes a negative electrode coating region 1120 located in the center thereof, and a negative electrode tab 1110 and a non-tab region 113 respectively provided on both sides of the negative electrode coating region 1120.

[0047] Specifically, the negative electrode active material coating layer 1200 is uniformly disposed on both sides of the negative electrode current collector 1100 in the first direction X, and the negative electrode tabs 1110 and the non-electrode tabs 113 are located on both sides of the negative electrode current collector 1100 in the second direction Y. Neither the negative electrode tabs 1110 nor the non-tab regions 113 are covered with the negative electrode active material coating layer 1200.

[0048] The material of the negative electrode current collector 1100 may be copper, and the material of the negative electrode active material coating layer 1200 may be carbon or silicon, etc. Specifically, they may be flexibly selected according to need, and there is no specific limitation thereon.

[0049] The first direction X is the thickness direction of the negative electrode sheet 1000 , and the second direction Y is perpendicular to the first direction X and is the width direction of the negative electrode sheet 1000 .

[0050] To address the problem of the positive electrode sheet and the negative electrode sheet coming into contact with each other and causing a short circuit during use of the battery, the negative electrode sheet 1000 is provided with an insulating coating layer 130 on the non-tab region 113 and / or the negative electrode active material coating layer 1200. When an expansion protrusion occurs on the negative electrode sheet 1000 during actual use, the insulating coating layer 130 provides an insulating protection effect for the negative electrode sheet 1000, and can prevent the negative electrode sheet 1000 from directly contacting the corresponding positive electrode sheet and causing a short circuit.

[0051] The insulating coating layer 130 may be provided on the non-tab area 113 and / or the negative active material coating layer 1200, so that in practical applications, the structure of the negative electrode sheet 1000 includes at least the following three types: Type 1: The insulating coating layer 130 is provided only on the non-tab area 113; Type 2: The insulating coating layer 130 is provided only on the negative active material coating layer 1200; Type 3: The insulating coating layer 130 is provided simultaneously on the non-tab area 113 and the negative active material coating layer 1200. The specific structure of the negative electrode sheet 1000 will be described by combining these three types.

[0052] Regarding the type 1 negative electrode sheet 1000 (ie, the case where the insulating coating layer 130 is provided only on the non-tab region 113), the specifics are as follows.

[0053] 8 and 9, in one embodiment, the insulating coating layer 130 includes a first insulating layer 131, which is uniformly coated on both sides of the non-tab region 113 of the negative electrode current collector 1100 along the thickness direction. In this case, a pre-gap may be provided between the first insulating layer 131 and the negative electrode active material coating layer 1200 so that a blank area is formed between the first insulating layer 131 and the negative electrode active material coating layer 1200. Here, the pre-gap can prevent the slurry of the first insulating layer 131 from interacting with the slurry of the negative electrode active material coating layer 1200 to prevent the slurry from affecting the battery performance, but in practical applications, the width of the pre-gap should not be too large to avoid the insulation effect being poor due to the width of the first insulating layer 131 being too small, and the width of the pre-gap should not exceed 100 mm.

[0054] As shown in Figures 10 and 11, in another embodiment, unlike the previous embodiment, there may be no gap between the first insulating layer 131 and the negative active material coating layer 1200, so that the first insulating layer 131 and the negative active material coating layer 1200 may be in direct contact with each other.

[0055] In another embodiment, the first insulating layer 131 may be uniformly coated on one side of the non-tab region 113 along the thickness direction of the negative electrode current collector 1100. In this case, a preliminary gap may be provided between the first insulating layer 131 and the negative electrode active material coating layer 1200, or a gap may not be directly provided, so that the first insulating layer 131 and the negative electrode active material coating layer 1200 abut against each other.

[0056] 12 and 13, in one embodiment, the insulating coating layer 130 further includes a second insulating layer 132, which is provided on one side of the non-tab region 113 away from the negative active material coating layer 1200. In this case, the second insulating layer 132, together with the first insulating layer 131, can cover the edge of the non-tab region 113 on one side away from the negative active material coating layer 1200, while providing a passivation effect on the edge of the non-tab region 113, reducing the risk of the non-tab region expanding and deforming to break through the separator, while even if the non-tab region 113 breaks through the separator and comes into contact with the positive tab, the combination of the first insulating layer 131 and the second insulating layer 132 can provide sufficient insulation protection for the edge of the negative current collector 1100 on one side away from the negative tab 1110, preventing the occurrence of a short circuit.

[0057] In each embodiment relating to the Type 1 negative electrode sheet 1000, the thickness and width of the first insulating layer 131 are set to H3 and W1, respectively (H3 and W1 are the dimensions of the first insulating layer 131 along the thickness and width directions of the negative electrode current collector 1100, respectively), the dimension of the second insulating layer 132 along the thickness direction of the negative electrode current collector 1100 is H4, and the dimension of the second insulating layer 132 along the width direction of the negative electrode current collector 1100 is W2.

[0058] In order to ensure the insulation protection effect of the insulating coating layer 130, the dimensions should satisfy the following conditions: 0.1 μm≦H3≦H2; 0.1 mm≦W1≦100 mm; H1≦H4≦2*H3+H1; 0.1 μm≦W2≦5000 μm, where H1 is the thickness of the negative electrode current collector 1100 and H2 is the thickness of the negative electrode active material coating layer 1200.

[0059] The specific dimensions of H3, W1, H4 and W2 can be respectively controlled as follows: 5 μm≦H3≦100 um; 1 mm≦W1≦100 mm; 6 um≦H4≦100 um; 1 um≦W2≦100 um. By rationally controlling the thickness H3 of the first insulating layer 131, it is possible to prevent the coating thickness from being too small to provide sufficient insulation, and at the same time, to prevent the coating thickness from being too large to provide poor processing performance, and to avoid the first insulating layer 131 from increasing the loss of electrolyte due to the swelling phenomenon, thereby ensuring the energy density of the battery.

[0060] In addition, in some embodiments, the insulating coating layer 130 includes only the first insulating layer 131, in which case only the thickness H3 and width W1 of the first insulating layer 131 need to satisfy the correlation conditions. In order to ensure the insulating protection effect, the thickness H3 of the first insulating layer 131 must not exceed the thickness H2 of the negative active material coating layer 1200, so as to prevent the negative electrode sheet 1000 from protruding in the thickness direction of the first insulating layer 131, prevent the negative electrode sheet 1000 from being wrinkled when wound, and ensure its processability and manufacturing performance. The dimension H4 of the second insulating layer 132 along the thickness direction of the negative electrode current collector 1100 must always be equal to or greater than the thickness H1 of the negative electrode current collector 1100, so as to ensure that the second insulating layer 132 can always completely cover one end face of the negative electrode current collector 1100 away from the corresponding tab.

[0061] Note that each embodiment is merely an example of the present disclosure applied to the type 1 negative electrode sheet 1000, and does not exclude the existence of other combination formats, so a description thereof will be omitted here.

[0062] For the negative electrode sheet 1000 of Type 2 (i.e., when the insulating coating layer 130 is provided only on the negative electrode active material coating layer 1200), specifically, it is as follows.

[0063] Considering that the insulating coating layer 130 is provided only on the negative electrode active material coating layer 1200, since it is difficult for the insulating coating layer 130 to exert a protective effect on the non-tab region 113, in this case, the non-tab region 113 can be eliminated, that is, the entire side of the negative electrode current collector 1100 away from the negative electrode tab 1110 is covered by the negative electrode active material coating layer 1200. Hereinafter, the description of the negative electrode sheet 1000 of Type 2 will be based on the case where the non-tab region 113 is eliminated. However, it should be understood that whether the non-tab region 113 is eliminated or not may not affect the effectiveness of the protective effect of the insulating coating layer 130, and may affect the degree to which the actual protective effect can be achieved.

[0064] As shown in FIG. 14, in one embodiment, the entire insulating coating layer 130 is provided at the edge of the negative electrode active material coating layer 1200 away from the negative electrode tab 1110. The insulating coating layer 130 includes two third insulating layers 133 respectively coated on both sides of the negative electrode active material coating layer 1200, and the two third insulating layers 133 employ the same insulating material.

[0065] At this time, if the length of the third insulating layer 133 is S1, the width is L1, and the thicknesses of the two third insulating layers 133 are d1 and d2 respectively, then S1, L1, d1, and d2 satisfy the conditions of S1≤S; 0.1 mm≤L1≤50; 10 mm≤d1≤500 mm; 10 mm≤d2≤500 mm; 0 < d1:d2≤1. Here, S is the length of the negative electrode sheet 1000 (i.e., the dimension along the winding direction of the negative electrode sheet 1000).

[0066] Here, the length, width, and thickness of the third insulating layer 133 can be flexibly optimized as needed. For example, in actual applications, the width of the third insulating layer 133 may be 1 mm, 5 mm, 10 mm, 20 mm, or 40 mm, or other values, and the thickness of the third insulating layer 133 may be 10 mm, 30 mm, 50 mm, 100 mm, 200 mm, or 300 mm, or other values, without specific limitation in this regard. The third insulating layers 133 on both sides may adopt the same dimensional parameters or different dimensional parameters. However, considering the processing convenience, the third insulating layers 133 on both sides adopt the same dimensional parameters.

[0067] Similarly, in this embodiment, by reasonably controlling the dimensional parameters of the third insulating layer 133, in addition to ensuring the insulation performance of the third insulating layer 133 itself, it is possible to avoid the third insulating layer 133 affecting the processing performance of the electrode sheet, and further avoid the third insulating layer 133 increasing the loss of the electrolyte due to the swelling phenomenon, thereby ensuring the energy density of the battery. Hereinafter, since the purpose of controlling the dimensional parameters of each insulating layer is the same, the description is omitted.

[0068] As shown in FIG. 15, in another embodiment, the insulating coating layer 130 includes a fourth insulating layer 134 and a fifth insulating layer 135. The fourth insulating layer 134 and the fifth insulating layer 135 are respectively provided on both sides of the negative electrode active material coating layer 1200, and the fourth insulating layer 134 and the fifth insulating layer 135 adopt different insulating materials.

[0069] At this time, if the lengths of the fourth insulating layer 134 and the fifth insulating layer 135 are both S1, the widths are both L1, and the thicknesses of the fourth insulating layer 134 and the fifth insulating layer 135 are d1 and d2 respectively, then S1, L1, d1, and d2 satisfy the conditions of S1≤S; 0.1 mm≤L1≤50 mm; 10 mm≤d1≤500 mm; 10 mm≤d2≤500 mm; 0<d1, d2≤1. Here, S is the length of the negative electrode sheet 1000 (i.e., the dimension along the winding direction of the negative electrode sheet 1000).

[0070] Here, the lengths, widths, and thicknesses of the fourth insulating layer 134 and the fifth insulating layer 135 can all be flexibly optimized according to requirements. For example, taking the fourth insulating layer 134 as an example, the width of the fourth insulating layer 134 may be 1 mm, or 5 mm, or 10 mm, or 20 mm, or 40 mm, or other values, and the thickness of the fourth insulating layer 134 may be 10 mm, or 30 mm, or 50 mm, or 100 mm, or 200 mm, or 300 mm, or other values, without specific limitation in this regard. At the same time, the fourth insulating layer 134 and the fifth insulating layer 135 may adopt the same dimensional parameters or different dimensional parameters. Considering the processing convenience, both adopt the same dimensional parameters.

[0071] As shown in FIG. 16, in another embodiment, the insulating coating layer 130 includes a sixth insulating layer 136 and a seventh insulating layer 137 respectively provided on both sides of the negative electrode active material coating layer 1200, and both the sixth insulating layer 136 and the seventh insulating layer 137 include at least two different insulating material layers.

[0072] At this time, if the lengths of the sixth insulating layer 136 and the seventh insulating layer 137 are both S1, the widths are both L1, and the thicknesses of the sixth insulating layer 136 and the seventh insulating layer 137 are d1 and d2 respectively, then S1, L1, d1, and d2 satisfy the conditions of S1 ≤ S; 0.1 mm ≤ L1 ≤ 50 mm; 10 mm ≤ d1 ≤ 500 mm; 10 mm ≤ d2 ≤ 500 mm; 0 < d1, d2 ≤ 1. Here, S is the length of the negative electrode sheet 1000 (i.e., the dimension along the winding direction of the negative electrode sheet 1000).

[0073] It should be noted that at this time, since both the sixth insulating layer 136 and the seventh insulating layer 137 are formed by laminating a plurality of insulating materials, their thicknesses are the sum of the thicknesses of the insulating materials of the laminated layers.

[0074] In this case, the length, width and thickness of the sixth insulating layer 136 and the seventh insulating layer 137 can be flexibly optimized as required, for example, taking the sixth insulating layer 136 as an example, the width of the sixth insulating layer 136 can be 1 mm or 5 mm or 10 mm or 20 mm or 40 mm, or other numerical values, and the thickness of the sixth insulating layer 136 can be 10 mm or 30 mm or 50 mm or 100 mm or 200 mm or 300 mm, or other numerical values, but there is no specific limit thereto. At the same time, the sixth insulating layer 136 and the seventh insulating layer 137 may adopt the same dimensional parameters or different dimensional parameters, but both adopt the same dimensional parameters in consideration of processing convenience.

[0075] In another embodiment, the insulating coating layer 130 includes an eighth insulating layer 138, which is provided on one side of the negative electrode sheet 1000 away from the negative electrode tab 1110. At this time, it should be understood that the eighth insulating layer 138 may be provided based on each embodiment related to the type-2 negative electrode sheet 1000.

[0076] 17, in one of the cases, the insulating coating layer 130 includes an eighth insulating layer 138 and two third insulating layers 133. In this case, the two third insulating layers 133 are provided on both sides of the negative active material coating layer 1200, respectively, and the eighth insulating layer 138 is located on one end face of the negative electrode sheet 1000 away from the negative electrode tab 1110, so that the eighth insulating layer 138, together with the two third insulating layers 133, completely covers one side of the negative electrode sheet 1000 away from the negative electrode tab 1110, thereby ensuring the insulating protection effect.

[0077] In this case, the lengths of the third insulating layer 133 and the eighth insulating layer 138 are both S1, the width of the third insulating layer 133 is L1, the thickness is d, the width of the eighth insulating layer 138 is L2 (i.e., the dimension of the eighth insulating layer 138 along the thickness direction of the negative electrode sheet 1000), and the thickness is n. S1, L1, d, L2, and n satisfy the conditions S1≦S; 0.1 mm≦L1≦50 mm; 10 mm≦d≦500 mm; D≦L2≦700 mm; 10 mm≦n≦500 mm. Here, S is the length of the negative electrode sheet 1000 (i.e., the dimension along the winding direction of the negative electrode sheet 1000), and D is the thickness of the negative electrode sheet 1000.

[0078] Here, the width of the eighth insulating layer 138 can completely cover one end face of the electrode sheet away from the negative electrode tab 1110, and the thickness can be flexibly optimized as necessary, provided that the insulating performance is ensured. For example, the thickness of the eighth insulating layer 138 may be 10 mm, 15 mm, 20 mm, 30 mm, 40 mm, or 50 mm, and there is no specific limitation thereon.

[0079] In addition, the eighth insulating layer 138 may be provided in accordance with the fourth insulating layer 134, the fifth insulating layer 135, the sixth insulating layer 136, and the seventh insulating layer 137 to form a negative electrode sheet 1000 of a different structure, but since the combination principle remains the same, a description thereof will be omitted here.

[0080] The type 3 negative electrode sheet 1000 (i.e., when the insulating coating layer 130 is provided on the non-tab region 113 and the negative active material coating layer 1200 at the same time) corresponds to a combination of the type 1 negative electrode sheet 1000 and the type 2 negative electrode sheet 1000. Since the type 1 negative electrode sheet 1000 and the type 2 negative electrode sheet 1000 themselves include multiple cases, after combining the type 1 and type 2 negative electrode sheets 1000 with the type 3 negative electrode sheet 1000, multiple negative electrode sheets 1000 with different structures are formed.

[0081] For example, as shown in FIG. 18 , in one embodiment, the insulating coating layer 130 includes a ninth insulating layer 139 and a tenth insulating layer 1310, where the ninth insulating layer 139 is disposed on the negative electrode active material coating layer 1200 and the tenth insulating layer 1310 is disposed in the non-tube region 113.

[0082] In this case, the ninth insulating layer 139 may include a single insulating layer, or may be formed by stacking multiple insulating layers. Furthermore, if the ninth insulating layer 139 is formed by stacking multiple insulating layers, the multiple insulating layers constituting the ninth insulating layer 139 may be made of the same or different insulating materials.

[0083] Similarly, the tenth insulating layer 1310 may include a single insulating layer, or may be formed by stacking multiple insulating layers. Furthermore, if the tenth insulating layer 1310 is formed by stacking multiple insulating layers, the multiple insulating layers constituting the tenth insulating layer 1310 may use the same or different insulating materials.

[0084] In one embodiment, the insulating coating layer 130 may further include an eleventh insulating layer 1311 provided on one side surface away from the negative electrode tab 1110 of the negative electrode sheet 1000. In this case, the eleventh insulating layer 1311, together with the ninth insulating layer 139 and the tenth insulating layer 1310, may cover the entire one side of the negative electrode sheet 1000 away from the negative electrode tab 1110, thereby ensuring an insulating protection effect.

[0085] The specific structure and dimensional parameters of the ninth insulating layer 139 may refer to the installation form of the insulating coating layer 130 in the Type 1 negative electrode sheet 1000, the specific structure and dimensional parameters of the tenth insulating layer 1310 may refer to the installation form of the insulating coating layer 130 in the Type 2 negative electrode sheet 1000, and the specific structure and dimensional parameters of the eleventh insulating layer 1311 may refer to the installation form of the eighth insulating layer 138, and the description thereof will be omitted here.

[0086] The type 3 negative electrode sheet 1000 may be a combination of the type 1 negative electrode sheet 1000 and the type 2 negative electrode sheet 1000. For the principle of combination, reference may be made to the relevant descriptions of the ninth insulating layer 139, the tenth insulating layer 1310, and the eleventh insulating layer 1311. Therefore, the description of more combination forms is omitted here.

[0087] In this embodiment, no matter what installation form the insulating coating layer 130 adopts, the material of the insulating coating layer 130 can be selected according to the requirements. Specifically, the material of the insulating coating layer 130 can include inorganic materials, organic materials and solvents.

[0088] Here, the inorganic material may include one or a combination of at least two of boehmite, alumina, silica, hexagonal boron nitride, cubic boron nitride, silicon carbide, and silicon nitride.

[0089] Examples of the polymerizable monomer of the organic material include one or a combination of two or more of vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, perfluoroethylene, alkyl ether, ethylene, propylene, 1,3-butadiene, vinyl chloride, styrene, and vinyl acetate. Alternatively, the polymerizable monomer may be a combination of one or at least two of acrylic acid, acrylic acid ester, acrylamide, N-vinylpyrrole, decanone, acrylonitrile, maleic acid, itaconic acid, maleimide, or bismaleimide. Alternatively, the polymerizable monomer may be a combination of one or at least two of alkyd resin, epoxy resin, polyurethane, silicone resin, polyamide, polyaramid, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polyphenylsulfone, polyethersulfone, polyetheretherketone, polyimide, polyamideimide, polyetherimide, or polyesterimide. Alternatively, it may contain one or a combination of at least two of polyimide, polyamideimide, polyetherimide, polyesterimide, polyvinylidene fluoride, or polytetrafluoroethylene. Meanwhile, the weight average molecular weight of the organic material was 20,000 to 1,000,000.

[0090] The solvent may be a water-based deionized water solvent or an oil-based N-methylpyrrolidone (NMP) solvent, but is not particularly limited thereto.

[0091] For different types of negative electrode sheets 1000, the materials of the different insulating layers in the negative electrode sheet 1000 may be the same or different, as long as they satisfy the insulation protection requirements. When the different insulating layers adopt the same insulating material, the specific material may be selected from the combination of the multiple materials described above, and when the different insulating layers adopt different insulating materials, the specific material may be selected from two or more of the combination of the multiple materials described above, and there is no specific limitation thereon.

[0092] According to the technical solution, when the negative electrode sheet 1000 is used as a positive electrode sheet or a negative electrode sheet, taking the case of using it as a negative electrode sheet as an example, if an expansion protrusion occurs on the negative electrode sheet, the negative electrode sheet can contact the positive electrode sheet via the insulating coating layer 130, thereby avoiding direct contact between the positive and negative electrode sheets and causing a short circuit, and improving the safety of the battery.

[0093] Referring to FIG. 19, an embodiment of the present disclosure provides an electrode assembly including a positive electrode sheet 200 , a separator 300 , and a negative electrode sheet 1000 .

[0094] The electrode assembly is a component that causes a chemical reaction in the battery, and is mainly formed by winding or laminating a positive electrode sheet 200 and a negative electrode sheet 1000, and a separator 300 is usually provided between the positive electrode sheet 200 and the negative electrode sheet 1000. A positive electrode coating region 220 is provided on the positive electrode sheet 200, and a negative electrode coating region 1120 is provided on the negative electrode sheet 1000, and the positive electrode coating region 220 and the negative electrode coating region 1120 are coated with a positive electrode active material coating layer 230 and a negative electrode active material coating layer 1200, respectively. The part of the positive electrode sheet 200 where the positive electrode active material coating layer 230 is provided and the part of the negative electrode sheet 1000 where the negative electrode active material coating layer 1200 is provided constitute the main body of the electrode assembly, and tabs are provided on the parts of the positive electrode sheet 200 and the negative electrode sheet 1000 that do not have an active material coating layer, respectively, and are called the positive electrode tab 210 and the negative electrode tab 1110.

[0095] 19, in this embodiment, the electrode assembly includes a plurality of positive electrode sheets 200 and a plurality of negative electrode sheets 1000, and the positive electrode sheets 200 and the negative electrode sheets 1000 may be alternately arranged, and a separator 300 is arranged between any adjacent positive electrode sheets 200 and negative electrode sheets 1000. In this case, taking a pair of adjacent positive electrode sheets 200 and negative electrode sheets 1000 as an example, the positive electrode sheets 200 and the negative electrode sheets 1000 may be located on both sides of the separator 300, respectively, and the positive electrode tabs 210 and the negative electrode tabs 1110 may be located on both sides of the electrode assembly, respectively.

[0096] In this embodiment, to address the problem of short circuit contact between the positive electrode sheet 200 and the negative electrode sheet 1000, the width of the separator 300 is greater than or equal to the width of the negative electrode coating region 1120, which in turn is greater than or equal to the width of the positive electrode coating region 220. Here, "width" refers to the dimension of the corresponding member along the second direction Y.

[0097] In addition, an insulating coating layer 130 is provided in the non-tab region 113 of the negative electrode sheet 1000, and the insulating coating layer 130 includes a first insulating layer 131 and a second insulating layer 132. The specific arrangement of the first insulating layer 131 and the second insulating layer 132 can be referred to the related explanation above, and the explanation will be omitted here.

[0098] In this electrode assembly, one edge of the first insulating layer 131 close to the negative electrode coating region 1120 does not exceed one edge of the positive electrode coating region 220 close to the positive electrode tab 210, i.e., in the second direction Y, one edge of the first insulating layer 131 close to the negative electrode coating region 1120 corresponds to the portion of the positive electrode sheet 200 where the positive electrode tab 210 is located, and does not coat the portion where the positive electrode coating region 220 is located, or does not completely coat the portion where the positive electrode coating region 220 is located.

[0099] Similarly, one edge of the positive electrode coating region 220 away from the positive electrode tab 210 does not exceed one edge of the negative electrode coating region 122 closer to the negative electrode tab 1110; that is, in the second direction Y, one edge of the positive electrode coating region 220 away from the positive electrode tab 210 corresponds to the portion of the negative electrode sheet 1000 where the negative electrode coating region 1120 is located, and does not cover the portion where the negative electrode tab 1110 is located, or does not completely cover the portion where the negative electrode tab 1110 is located.

[0100] In this way, when an expansion protrusion occurs in the negative electrode sheet 1000 and breaks through the separator 300, the non-tab area 113 is ensured to come into contact with the positive electrode tab 210 via the insulating coating layer 130, and direct contact between the positive electrode sheet 200 and the negative electrode sheet is prevented, thereby avoiding a short circuit between the positive electrode sheet 200 and the negative electrode sheet 1000 and improving safety.

[0101] In addition, in this embodiment, the negative electrode sheet 1000 includes a number of different structural forms. For the negative electrode sheets 1000 of different structural forms, it is necessary to ensure that the width of the separator 300 is greater than or equal to the width of the negative electrode coating region 1120, and the width of the negative electrode coating region 1120 is greater than or equal to the width of the positive electrode coating region 220. The projection of the negative electrode coating region 1120 on the separator 300 overlaps with the separator 300 or is located within the range of the separator 300, and the projection of the negative electrode coating region 1120 on the separator 300 overlaps with the separator 300 or is located within the range of the separator 300. It should be understood that the projection on the negative electrode coating region 1120 overlaps with or is located within the negative electrode coating region 1120, and at the same time, one edge of the insulating coating layer 130 closer to the negative electrode tab 1110 does not extend beyond one edge of the positive electrode coating region 220 closer to the positive electrode tab 210, and one edge of the positive electrode coating region 220 away from the positive electrode tab 210 does not extend beyond one edge of the negative electrode coating region 1120 closer to the negative electrode tab 1110.

[0102] An embodiment of the present disclosure provides a lithium ion battery including an electrode assembly, and applying the electrode assembly to the lithium ion battery avoids direct contact between the positive electrode plate 200 and the negative electrode sheet 1000 during use of the battery, thereby avoiding contact short circuits and improving the safety of the battery.

[0103] In this embodiment, the lithium ion battery is a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery in this embodiment may include a battery module or a battery pack, etc.

[0104] The battery cell includes an electrode assembly and an electrolyte, and the electrode assembly is composed of a positive electrode sheet 200, a negative electrode sheet 1000, and a separator 300. The battery cell operates mainly by metal ions moving between the positive electrode sheet 200 and the negative electrode sheet 1000.

[0105] The positive electrode sheet 200 includes a positive electrode current collector and a positive electrode active material coating layer 230, the positive electrode active material coating layer 230 is coated on the surface of the positive electrode current collector, the positive electrode current collector not coated with the positive electrode active material coating layer 230 protrudes from the positive electrode current collector coated with the positive electrode active material coating layer 230, and the positive electrode current collector not coated with the positive electrode active material coating layer 230 is called a positive electrode tab 210. Here, the material of the positive electrode current collector may be aluminum, and the material of the positive electrode active material coating layer 230 may be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganate, etc.

[0106] The negative electrode sheet 1000 includes a negative electrode current collector 1100 and a negative electrode active material coating layer 1200, the negative electrode active material coating layer 1200 being coated on the surface of the negative electrode current collector 1100, the negative electrode current collector 1100 not coated with the negative electrode active material coating layer 1200 protruding from the negative electrode current collector 1100 coated with the negative electrode active material coating layer 1200, and the negative electrode current collector 1100 not coated with the negative electrode active material coating layer 1200 is referred to as a negative electrode tab 1110. Here, the material of the negative electrode current collector 1100 may be copper, and the material of the negative electrode active material coating layer 1200 may be carbon or silicon, etc.

[0107] In order to ensure that the positive electrode tabs 210 are not melted by a large current, multiple positive electrode tabs 210 may be stacked, and multiple negative electrode tabs 1110 may be stacked. The material of the separator 300 may be PP (polypropylene), PE (polyethylene), or the like.

[0108] The battery cell further includes a housing, an electrode terminal, and an adapter plate, the electrode assembly and the electrolyte are provided within the housing, the electrode terminal is provided on the housing, the adapter connects the electrode terminal and the tab of the electrode assembly, and an insulating member is provided between the adapter and the housing to insulate the adapter from the housing. The specific structure of the battery cell is not described in this embodiment, but belongs to the prior art, so a description thereof will be omitted here. [Explanation of symbols]

[0109] 100: Extreme Sheet 110: Current collector 111: Tab area 112: Coating area 113: Non-tab area 120: Active material coating layer 130: Insulating coating layer 131: First insulating layer 132: Second insulating layer 200: Positive electrode sheet 210: Positive electrode tab 220: Positive electrode coating area 230: Positive electrode active material coating layer 300: Separator 1000: Negative electrode sheet 1100: Negative electrode current collector 1110: Negative electrode tab 1120: Anode coating area 1200: Negative electrode active material coating layer 133: Third insulating layer 134: Fourth insulating layer 135: 5th insulating layer 136: 6th insulating layer 137: 7th insulating layer 138: 8th insulating layer 139: 9th insulating layer 1310: 10th insulating layer 1311: 11th insulating layer

Claims

1. A polar sheet, a current collector and an active material coating layer; the current collector includes a coating region, and a tab region and a non-tab region provided on either side of the coating region, the active material coating layer is provided on the coating area; An insulating coating layer is coated on the surface of the non-tube region. A polar sheet characterized by the above.

2. A pre-gap is provided between the insulating coating layer and the active material coating layer, or the insulating coating layer and the active material coating layer abut against each other; 2. The pole sheet according to claim 1 .

3. The insulating coating layer includes one or more first insulating layers, and the first insulating layers are provided on one or both sides of the current collector in a thickness direction.

2. The pole sheet according to claim 1 .

4. The insulating coating layer further includes a second insulating layer, the second insulating layer being provided on one side of the non-tube region away from the active material coating layer and covering the one side of the non-tube region away from the active material coating layer together with the first insulating layer.

4. The pole sheet according to claim 3.

5. The dimension of the first insulating layer along the thickness direction of the current collector is H3, and H3 satisfies the condition of 0.1 μm≦H3≦H2, and H2 is the thickness of the active material coating layer; 5. The electrode sheet according to claim 3 or 4.

6. The dimension of the first insulating layer along the width direction of the current collector is W1, and W1 satisfies the condition of 0.1 mm≦W1≦100 mm.

5. The electrode sheet according to claim 3 or 4.

7. The dimension of the second insulating layer along the thickness direction of the current collector is H4, and the H4 satisfies the condition H1≦H4≦2*H3+H1, H1 is the thickness of the current collector, and H3 is the thickness of the first insulating layer.

5. The pole sheet according to claim 4.

8. The dimension of the second insulating layer along the width direction of the current collector is W2, and W2 satisfies the condition of 0.1 μm≦W2≦5000 μm.

5. The pole sheet according to claim 4.

9. A negative electrode sheet, a negative electrode current collector; and a negative electrode active material coating layer; the negative electrode current collector includes a negative electrode coating region and a negative electrode tab provided on one side of the negative electrode coating region, One or more of the negative electrode active material coating layers are provided in the negative electrode coating region; At least one insulating coating layer is provided on a surface of the negative electrode active material coating layer away from the negative electrode current collector; Alternatively, a non-tab region is further provided on one side of the negative electrode current collector away from the negative electrode tab, and an insulating coating layer is provided on at least one of a surface of the non-tab region and a surface of the negative electrode active material coating layer away from the negative electrode current collector. A negative electrode sheet comprising:

10. In the non-tab region, a preliminary gap is provided between the insulating coating layer and the negative electrode active material coating layer, or the insulating coating layer and one side of the negative electrode active material coating layer away from the negative electrode tab abut against each other. The negative electrode sheet according to claim 9 .

11. In the non-tab region, the insulating coating layer includes a first insulating layer, and the first insulating layer is provided on one side or both sides in a thickness direction of the negative electrode current collector. The negative electrode sheet according to claim 10 .

12. In the non-tube region, the insulating coating layer further includes a second insulating layer, and the second insulating layer is provided on one end surface of the non-tube region away from the negative electrode active material coating layer; The negative electrode sheet according to claim 11 .

13. The dimensions of the first insulating layer along the thickness direction and width direction of the negative electrode current collector are H3 and W1, respectively, and the H3 and W1 satisfy the conditions of 0.1 μm≦H3≦H2; 0.1 mm≦W1≦100 mm, and H2 is the thickness of the negative electrode active material coating layer; The negative electrode sheet according to claim 11 or 12.

14. a dimension of the second insulating layer along a thickness direction of the negative electrode current collector is H4, a dimension of the second insulating layer along a width direction of the negative electrode current collector is W2, the H4 and the W2 satisfy the conditions H1≦H4≦2*H3+H1; 0.1 μm≦W2≦5000 μm, H1 is a thickness of the negative electrode current collector, and H3 is a thickness of the first insulating layer; The negative electrode sheet according to claim 12 .

15. On the surface of the negative electrode active material coating layer, the insulating coating layer is located at an edge of the negative electrode active material coating layer away from the negative electrode tab; The negative electrode sheet according to claim 9 .

16. On the surface of the negative electrode active material coating layer, the insulating coating layer includes two third insulating layers respectively coated on both sides of the negative electrode active material coating layer, and the two third insulating layers adopt the same insulating material; The negative electrode sheet according to claim 15 .

17. On the surface of the negative electrode active material coating layer, the insulating coating layer includes a fourth insulating layer and a fifth insulating layer; the fourth insulating layer is provided on one side of the negative electrode active material coating layer; the fifth insulating layer faces the fourth insulating layer, The fourth insulating layer and the fifth insulating layer employ different insulating materials. The negative electrode sheet according to claim 15 .

18. On the surface of the negative electrode active material coating layer, the insulating coating layer includes a sixth insulating layer and a seventh insulating layer respectively provided on both sides of the negative electrode active material coating layer, and each of the sixth insulating layer and the seventh insulating layer includes at least two different insulating material layers; The negative electrode sheet according to claim 15 .

19. The insulating coating layer further includes an eighth insulating layer provided on one end surface of the negative electrode sheet away from the negative electrode tab, on the surface of the negative electrode active material coating layer.

19. The negative electrode sheet according to claim 15, wherein the negative electrode sheet is a sheet having a thickness of 100 nm or less.

20. the insulating coating layer includes a ninth insulating layer and a tenth insulating layer; the ninth insulating layer is provided on the negative electrode active material coating layer; the tenth insulating layer is provided on a surface of the non-tub region; When the ninth insulating layer and / or the tenth insulating layer include a single layer or multiple insulating layers, and the ninth insulating layer and / or the tenth insulating layer adopt multiple insulating layers, each insulating layer adopts the same or different insulating materials; The negative electrode sheet according to claim 17 .

21. the insulating coating layer further includes an eleventh insulating layer provided on one end surface of the negative electrode sheet away from the negative electrode tab, and the eleventh insulating layer, together with the tenth insulating layer, covers the one side of the negative electrode sheet away from the negative electrode tab; The negative electrode sheet according to claim 20 .

22. 1. An electrode assembly comprising: A battery comprising a positive electrode sheet, a separator, and a negative electrode sheet, the negative electrode sheet being the electrode sheet according to any one of claims 1 to 4, 7, and 8, the positive electrode sheet and the negative electrode sheet being located on both sides of the separator, respectively.

13. An electrode assembly comprising:

23. a positive electrode coating area and a positive electrode tab are provided on the positive electrode sheet, a negative electrode coating area and a negative electrode tab are provided on the negative electrode sheet, the negative electrode coating area and the negative electrode tab respectively constitute the coating area and the tab area, a projection of the negative electrode coating area on the separator overlaps with the separator or is located within a range of the separator, and a projection of the positive electrode coating area on the negative electrode coating area overlaps with the negative electrode coating area or is located within the range of the negative electrode coating area; 23. The electrode assembly of claim 22.

24. the positive electrode tab and the negative electrode tab are located on both sides of the electrode assembly, respectively, and one edge of the first insulating layer close to the negative electrode coating region does not exceed one edge of the positive electrode coating region close to the positive electrode tab, and one edge of the positive electrode coating region away from the positive electrode tab does not exceed one edge of the negative electrode coating region close to the tab region; 24. The electrode assembly of claim 23.

25. 1. An electrode assembly comprising: The battery includes a positive electrode sheet, a separator, and the negative electrode sheet according to any one of claims 9 to 12, 14 to 18, 20, and 21, and the positive electrode sheet and the negative electrode sheet are located on both sides of the separator, respectively.

13. An electrode assembly comprising:

26. The positive electrode sheet is provided with a positive electrode coating area and a positive electrode tab, a projection of the negative electrode coating area on the separator overlaps with the separator or is located within the range of the separator, and a projection of the positive electrode coating area on the negative electrode coating area overlaps with the negative electrode coating area or is located within the range of the negative electrode coating area.

26. The electrode assembly of claim 25.

27. the positive electrode tab and the negative electrode tab are located on both sides of the electrode assembly, respectively, and one edge of the insulating coating layer close to the negative electrode tab does not exceed one edge of the positive electrode coating region close to the positive electrode tab, and one edge of the positive electrode coating region away from the positive electrode tab does not exceed one edge of the negative electrode coating region close to the negative electrode tab; 27. The electrode assembly of claim 26.

28. 1. A lithium ion battery, 23. The electrode assembly of claim 22, A lithium-ion battery characterized by:

29. 1. A lithium ion battery, 26. The electrode assembly of claim 25, A lithium-ion battery characterized by:

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