Pole piece and battery

Abstract

The utility model discloses a pole piece which comprises a current collector, the current collector comprises a coating area, at least one surface of the current collector is provided with an active material layer in the coating area, the pole piece further comprises a plurality of first safety coatings, and the first safety coatings are arranged along the width direction of the current collector. The multiple first safety coatings are arranged between the current collector and the active material layer at intervals, and / or the multiple first safety coatings are arranged on the surface of the side, away from the current collector, of the active material layer at intervals, and the projection area of the first safety coatings on the coating area is 70%-100%. According to the utility model, the risk of short circuit in the battery is reduced, thermal runaway is avoided, and the safety of the battery is improved. The utility model also discloses a battery.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of battery, in particular to a pole piece and battery. BACKGROUND

[0002] With the global new energy electric vehicle sales grow year by year, the demand of electric vehicle for higher energy density, output voltage of secondary battery also increases year by year, so it needs to adopt high nickel positive material, silicon carbon or lithium metal to meet the requirements. But the use of high specific capacity, low stability high nickel material will increase the risk of battery spontaneous combustion. Therefore, the development of lithium ion battery with high energy density and good safety performance is imminent. SUMMARY

[0003] At present, the safety performance of high nickel pole piece is improved by setting safety coating, but the setting mode of safety coating still has loopholes, and the heat spread blocking effect is poor when the burr or lithium dendrite internal short circuit of pole piece occurs. In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the utility model is to provide a kind of pole piece and battery, reduce the risk of internal short circuit of battery, avoid triggering heat runaway, improve the safety of battery.

[0004] The purpose of the utility model is realized by the following technical scheme:

[0005] A pole piece, comprising a current collector, at least one surface of the current collector is provided with a coating area, a coating is arranged in the coating area, and the coating comprises an active material coating and a first safety coating; characterized in that, along the width direction of the current collector, a plurality of the first safety coatings are arranged between the current collector and the active material layer at intervals, and / or a plurality of the first safety coatings are arranged on the active material layer at intervals; the projection area of the first safety coating on the coating area is 70%-100%.

[0006] In an embodiment, the current collector has opposite first and second faces, and the first and second faces of the current collector are both provided with the active material layer; the first and second faces are both provided with a plurality of the first safety coatings along the width direction of the current collector, and the total projection area of the first safety coatings on the coating area of the first and second faces is 70%-100%.

[0007] In an embodiment, the thickness of the first safety coating is D1, the thickness of the active material coating (3) on any surface of the first safety coating (4) is D3, and D1 / D3=0.003-0.35.

[0008] In an embodiment, the thickness of the first safety coating is D1, and D1 is arranged in the range of 1 μm-10 μm.

[0009] In an embodiment, the surface of the coating in the coating area is a concave-convex structure, the maximum thickness of the coating is D2, and the minimum thickness of the coating is D4, wherein 0≤D2-D4≤20μm.

[0010] In an embodiment, the projected area of the first safety coating on one side of the current collector is 20%-100% of the area of the coating area.

[0011] In an embodiment, the heat generation of the first safety coating is Q1, Q1≤-500J / g; and the heat generation of the active material layer is Q3, -500J / g≤Q3≤-1000J / g.

[0012] In an embodiment, the first safety coating is selected from one or more of a carbon-coated LiNi x Co y Mn z O2(wherein x+y+z=1, 0 1.5 Mn 0.5 O4 safety coating, NASCION-type solid-state electrolyte safety coating, LISCION solid-state electrolyte safety coating, garnet-type solid-state electrolyte safety coating, perovskite-type solid-state electrolyte safety coating, sulfide electrolyte safety coating, polymer electrolyte safety coating, Al2O3 safety coating, SiO2 safety coating, ZrO2 safety coating, TiO2 safety coating, γ-AlOOH safety coating, BaTiO3 safety coating, Mg(OH)2 safety coating.

[0013] In an embodiment, the electrode tab further comprises a second safety coating, the second safety coating is arranged around the coating, the maximum thickness of the coating is D2, and the thickness of the second safety coating is greater than or equal to D2.

[0014] In an embodiment, the second safety coating is further arranged at intervals inside the active material layer along the width direction and / or length direction of the current collector.

[0015] In an embodiment, the width of the second safety coating is W1, and the width of the coating area is W2, and the W1 / W2=0.001%-6%.

[0016] In an embodiment, the heat generation of the second safety coating is Q2, Q2≤-500J / g.

[0017] In an embodiment, the second safety coating is selected from one or more of a carbon-coated LiNi x Co y Mn zO2 (where x+y+z=1, x<0.6), LiFePO4 safety coating, LiMn2O4 safety coating, lithium manganese iron phosphate safety coating, LiNi 1.5 Mn 0.5 One or more of the following: O4 safety coating, NASCION type solid electrolyte safety coating, LISCION solid electrolyte safety coating, garnet type solid electrolyte safety coating, perovskite type solid electrolyte safety coating, sulfide electrolyte safety coating, polymer electrolyte safety coating, Al2O3 safety coating, SiO2 safety coating, ZrO2 safety coating, TiO2 safety coating, γ-AlOOH safety coating, BaTiO3 safety coating, and Mg(OH)2 safety coating.

[0018] This utility model also provides a battery comprising the electrodes described above.

[0019] The beneficial effects of this invention are as follows: Multiple first safety coatings are spaced apart between the current collector and the active material layer, and / or multiple first safety coatings are spaced apart on the surface of the active material layer away from the current collector, reducing the energy density loss of the battery caused by the safety coatings. Furthermore, the projected area of ​​the first safety coating on the coating area reaches 70%-100%, which can increase the resistance when burrs / lithium dendrites on adjacent electrodes pierce the separator (not shown) to form an internal short circuit, reducing the current during an internal short circuit in the battery, blocking heat propagation, and suppressing thermal runaway. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the electrode structure according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the electrode structure of another embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the electrode structure of another embodiment of the present invention;

[0024] Figure 4 yes Figure 1 A schematic diagram of two electrodes stacked together;

[0025] Figure 5 yes Figure 3 A schematic diagram of two electrodes stacked together;

[0026] Figure 6 yes Figure 3 Top view;

[0027] Figure 7 This is a schematic diagram of the electrode structure of another embodiment of the present invention;

[0028] Figure 8 yes Figure 7 Top view.

[0029] Figure 9 This is a schematic diagram of the electrode structure of another embodiment of the present invention;

[0030] Figure 10 yes Figure 9 Top view;

[0031] Figure 11 This is a schematic diagram of the electrode structure of another embodiment of the present invention;

[0032] Figure 12 yes Figure 11 Top view;

[0033] Figure 13 This is a top view of the electrode sheet according to another embodiment of the present invention.

[0034] In the figure: 1. Current collector; 11. First surface; 12. Second surface; 2. Coating area; 3. Active material layer; 4. First safety coating; 5. Second safety coating; 6. Positive electrode; 7. Negative electrode. Detailed Implementation

[0035] The specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are merely some, not all, of the embodiments of this utility model. Based on the description of this utility model, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this utility model.

[0036] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0037] The terms “upper,” “lower,” “left,” “right,” “front,” “back,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of description and simplification, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0038] The terms “first,” “second,” “third,” etc., are used merely to distinguish elements with similar properties, not to indicate or imply relative importance or a specific order.

[0039] The terms “include,” “comprising,” or any other variation thereof are intended to cover non-exclusive inclusion, which includes not only the elements listed but also other elements not expressly listed.

[0040] This utility model provides an electrode sheet, such as Figures 1 to 3 and Figure 6 As shown, it includes a current collector 1, at least one surface of the current collector 1 is provided with a coating area 2, the coating area 2 is provided with a coating, the coating includes an active material coating 3 and a first safety coating 4; characterized in that, along the width direction W of the current collector 1, a plurality of first safety coatings 4 are spaced apart between the current collector 1 and the active material layer 3, and / or a plurality of first safety coatings 4 are spaced apart on the active material layer 3; the projected area of ​​the first safety coating 4 on the coating area 2 is 70%-100%.

[0041] In this embodiment, multiple first safety coatings 4 are spaced apart between the current collector 1 and the active material layer 3, and / or multiple first safety coatings 4 are spaced apart on the surface of the active material layer 3 away from the current collector 1. By staggering the first safety coatings 4 in the thickness direction D and spaced apart in the width direction W of the current collector 1, the internal resistance of the electrode can be reduced, and the energy density loss of the battery caused by the safety coating can be reduced. Moreover, the projected area of ​​the first safety coating 4 on the coating area 2 reaches 70%-100%, with a large coverage area and good protection effect. The first safety coating 4 on the electrode effectively reduces the current that forms a short circuit after the burrs / lithium dendrites on the adjacent electrode pierce the separator (not shown) and come into contact with the electrode, which greatly improves the safety of the battery.

[0042] Specifically, when multiple electrodes and separators are stacked alternately, when a burr / lithium dendrite from one electrode pierces the separator vertically and falls onto the first safety coating 4 on an adjacent electrode, the first safety coating 4 has the characteristics of high resistance, high stability, and low heat generation. The first safety coating 4 can form a protective layer on the surface of the electrode, increasing the internal resistance generated when the burr / lithium dendrite directly contacts the electrode, reducing the short-circuit current, and preventing thermal runaway. Furthermore, the projections of the first safety coating 4 on the coating area 2 on the same side of the current collector 1 do not overlap, so as to use less material of the first safety coating 4 to achieve the best burr blocking effect and reduce raw material energy consumption.

[0043] As one implementation method, such as Figure 3 As shown, the current collector 1 has a first surface 11 and a second surface 12 facing each other. The active material layer 3 is provided only on the first surface 11 of the current collector 1. The projected area of ​​the plurality of first safety coatings 4 on the first surface 11 on the coating area 2 is 70%-100%. Specifically, on the first surface 11, the projection of the first safety coating 4 between the current collector 1 and the active material layer 3 on the coating area 2 does not overlap with the projection of the first safety coating 4 on the surface of the active material layer 3 (in another embodiment, they may overlap). The second surface 12 does not have the active material layer 3 and the first safety coating 4.

[0044] In one embodiment, the current collector 1 has a first surface 11 and a second surface 12 opposite to each other. Both the first surface 11 and the second surface 12 of the current collector 1 are provided with an active material layer 3. The projected area of ​​the plurality of first safety coatings 4 on the first surface 11 on the coating area 2 is 70%-100% or 80%-90%; and / or the projected area of ​​the plurality of first safety coatings 4 on the second surface 12 on the coating area 2 is 70%-100% or 80%-90%.

[0045] Specifically, such as Figure 2 As shown, the projected area of ​​the multiple first safety coatings 4 on the first surface 11 of the current collector 1 on the coating area 2 is 100%, meaning the blank space between the first safety coating 4 on the coating area 2 between the first surface 11 of the current collector 1 and the active material layer 3 on that side is covered by the projection of the first safety coating 4 on the surface of the active material layer 3 on that side. The second surface 12 of the current collector 1 is not provided with a first safety coating 4; or, the projected area of ​​the multiple first safety coatings 4 on the first surface 11 and the second surface 12 of the current collector 1 on the coating area 2 is 100% each, meaning both sides of the current collector 1 are provided with a first safety coating 4, and the projected area of ​​the first safety coating 4 on each surface is 100%. In this embodiment, after multiple electrodes with the first safety coating 4 provided in the same manner are stacked, the projected area of ​​the first safety coating 4 on the coating area 2 of the two adjacent surfaces of adjacent electrodes is 100%, which improves the protective effect. Figure 2Based on this, the diagram of the latter implementation is easier to conceive of and is not shown here.

[0046] As one implementation method, such as Figure 1 As shown, the current collector 1 has a first surface 11 and a second surface 12 opposite to each other. Both the first surface 11 and the second surface 12 of the current collector 1 are provided with an active material layer 3. Both the first surface 11 and the second surface 12 are provided with a plurality of first safety coatings 4 along the width direction W of the current collector 1. That is, the first safety coatings 4 are provided on both sides of the current collector 1. The total projected area of ​​the first safety coatings 4 on the first surface 11 and the second surface 12 on the coating area 2 is 70%-100% or 80%-90%. The projection of the plurality of first safety coatings 4 on the first surface 11 on the coating area 2 does not overlap with the projection of the plurality of first safety coatings 4 on the second surface 12 on the coating area 2. When the total projected area of ​​the first safety coating 4 on the coating area 2 of the first surface 11 and the second surface 12 is 100%, the blank areas of the projection of the multiple first safety coatings 4 on the coating area 2 on the first surface 11 are covered by the projection of the multiple first safety coatings 4 on the coating area 2 on the second surface 12. This achieves complete coverage of the coating area 2 by the projection of the first safety coating 4, so as to ensure that when the burrs / lithium dendrites on one electrode contact its adjacent electrode in the thickness direction D of the current collector 1, the internal resistance during short circuit is increased, the spread of heat is limited, and thermal runaway is prevented.

[0047] Specifically, such as Figure 1 and Figure 4 , Figure 3 and Figure 5 As shown, when two electrodes (positive electrode 6 and negative electrode 7) are stacked, the safety coating on the negative electrode is selected from electrolyte coating and ceramic coating. The positive electrode 6 has a first safety coating 4. When internal burrs / lithium dendrites reach the first safety coating 4, the resistance of the internal short circuit increases, suppressing thermal runaway. At locations on the positive electrode 6 where the first safety coating 4 is not provided, internal burrs / lithium dendrites sequentially pierce the active material layer 3 and the separator (not shown) before contacting the adjacent negative electrode 7. They are then blocked by the first safety coating 4 on the adjacent negative electrode 7, increasing the resistance of the internal short circuit and reducing the current generated when the burrs / lithium dendrites contact the adjacent negative electrode 7, thus suppressing thermal runaway. Therefore, in two adjacent positive electrode 6 and negative electrode 7, the projected area of ​​the first safety coating 4 on the coating region 2 is 100%, improving the protective effect.

[0048] In some embodiments, a safety coating may or may not be provided on the negative electrode 7; not providing a safety coating on the negative electrode 7 can reduce manufacturing costs; providing a safety coating on the negative electrode 7 can improve the battery's ability to prevent thermal runaway.

[0049] As one implementation method, such as Figure 3As shown, the thickness of the first safety coating 4 is D1, and the thickness of the active material layer 3 in the area where the first safety coating 4 is applied is D3. D1 / D3 = 0.003~0.35, or D1 / D3 = 0.01~0.30, or D1 / D3 = 0.05~0.28, or D1 / D3 = 0.1~0.25, or D1 / D3 = 0.13~0.20; wherein, the range of D1 is 1.0μm-10.0μm, or 1.5μm-8.5μm, or 2.0μm-7.0μm, or 2.5μm-6.0μm.

[0050] As one implementation method, such as Figure 1 As shown, the surface of the coating in the coating area has an uneven structure. The maximum thickness of the coating is D2, and the minimum thickness of the coating is D4, where 0≤D2-D4≤20μm. That is, an alternating uneven structure is formed on the surface of the current collector 1. The area where the first safety coating 4 is set is the convex area, and the area where the first safety coating 4 is not set is the concave area. The uneven design solves the problem of needing to design a relatively high NP value to ensure that the negative electrode does not deposit lithium, and facilitates the storage of electrolyte.

[0051] In one embodiment, the projected area of ​​the first safety coating 4 on one side of the current collector 1 is 20%-100% of the area of ​​the coating region 2; thereby, the internal resistance during short circuit in the electrode can be increased.

[0052] In one embodiment, the heat generation of the first safety coating 4 is Q1, where Q1 ≤ -500 J / g; the heat generation of the active material layer 3 is Q3, where -500 J / g ≤ Q3 ≤ -1000 J / g.

[0053] As one implementation method, the first safety coating 4 is selected from carbon-coated LiNi. x Co y Mn z O2 (where x+y+z=1, x<0.6), LiFePO4 safety coating, LiMn2O4 safety coating, lithium manganese iron phosphate safety coating, LiNi 1.5 Mn 0.5 One or more of the following: O4 safety coating, NASCION type solid electrolyte safety coating, LISCION solid electrolyte safety coating, garnet type solid electrolyte safety coating, perovskite type solid electrolyte safety coating, sulfide electrolyte safety coating, polymer electrolyte safety coating, Al2O3 safety coating, SiO2 safety coating, ZrO2 safety coating, TiO2 safety coating, γ-AlOOH safety coating, BaTiO3 safety coating, and Mg(OH)2 safety coating.

[0054] As one implementation method, such as Figure 7 andFigure 8 As shown, the electrode also includes a second safety coating 5, which is disposed around the perimeter of the coating. The second safety coating 5 is located on the outermost side of the active material layer 3 along the width direction W and length direction L of the current collector 1. The maximum thickness of the coating is D2, and the thickness of the second safety coating 5 is greater than or equal to D2, so that the projection of the second safety coating 5 in the thickness direction D of the current collector 1 completely covers the coating on the coating area 2. Therefore, when the electrode is punctured in the horizontal direction, since the second safety coating 5 can completely cover the active material layer 3 in the thickness direction D of the current collector 1, the internal resistance of the battery during a horizontal puncture short circuit is increased, reducing thermal runaway.

[0055] As one implementation method, such as Figures 9 to 13 As shown, along the width direction W and / or length direction L of the current collector 1, the second safety coating 5 is also spaced within the active material layer 3 to enhance the protection of the current collector 1 in the thickness direction D. Simultaneously, it can act as a "partition wall" within the electrode, preventing heat spread within the electrode and suppressing thermal runaway. Specifically, as... Figure 10 and Figure 12 As shown, along the width direction W of the current collector 1, the second safety coating 5 is spaced apart inside the active material layer 3; as Figure 13 As shown, along the width direction W and length direction L of the current collector 1, the second safety coating 5 is spaced apart inside the active material layer 3.

[0056] In one implementation, the thickness of the second safety coating 5 is greater than the thickness of the active material layer 3 at its adjacent position. That is, the projection of the second safety coating 5 in the thickness direction D of the current collector 1 can completely cover the active material layer 3 at its adjacent position, so that the "partition wall" can provide sufficient barrier and achieve the best effect.

[0057] As one implementation method, such as Figure 10As shown, the width of the second safety coating 5 is W1, and the width of the coating area 2 is W2. W1 / W2 = 0.001%–6%, or W1 / W2 = 0.005%–5.5%, or W1 / W2 = 0.01%–5.3%, or W1 / W2 = 0.03%–5.0%, or W1 / W2 = 0.05%–4.8%, or W1 / W2 = 0.1%–4.5%, or W1 / W2 = 0.5%–4.0%, or W1 / W2 = 1.0%– 3.5%; In some embodiments, W1 is set in the range of 1μm-50mm, or 5μm-45mm, or 10μm-40mm, or 50μm-35mm, or 100μm-30mm, or 300μm-25mm, or 500μm-20mm, or 1mm-15mm; In some embodiments, W2 is set in the range of 90mm-900mm, or 150mm-800mm, or 200mm-700mm.

[0058] As one implementation, the heat generation of the second safety coating 5 is Q2, where Q2 ≤ -500 J / g.

[0059] In one embodiment, the first safety coating 4 and the second safety coating 5 are safety coatings made of the same or different materials, and are independently selected from one or more of high-resistivity material safety coatings, high-stability material safety coatings, and low-heat-generating material safety coatings.

[0060] In one implementation, the second safety coating 5 is selected from carbon-coated LiNi. x Co y Mn z O2 (where x+y+z=1, x<0.6), LiFePO4 safety coating, LiMn2O4 safety coating, lithium manganese iron phosphate safety coating, LiNi 1.5 Mn 0.5 One or more of the following: O4 safety coating, NASCION type solid electrolyte safety coating, LISCION solid electrolyte safety coating, garnet type solid electrolyte safety coating, perovskite type solid electrolyte safety coating, sulfide electrolyte safety coating, polymer electrolyte safety coating, Al2O3 safety coating, SiO2 safety coating, ZrO2 safety coating, TiO2 safety coating, γ-AlOOH safety coating, BaTiO3 safety coating, and Mg(OH)2 safety coating.

[0061] As one implementation method, the active material layer 3 is selected from one or more combinations of high nickel coatings such as Ni6, Ni7, Ni8, Ni9 and above, and lithium-rich manganese-based coatings.

[0062] In one embodiment, the electrode sheet also includes a tab region (not shown) disposed adjacent to the coating region 2, and the tab region is not provided with an active material layer.

[0063] This utility model also provides a battery comprising the electrodes described above.

[0064] This invention provides multiple first safety coatings 4 spaced apart between the current collector 1 and the active material layer 3, and / or multiple first safety coatings 4 spaced apart on the surface of the active material layer 3 away from the current collector 1. While increasing the projected area of ​​the first safety coatings 4 on the coating area 2 to 70%-100%, the first safety coatings 4 are staggered in the thickness direction D and spaced apart in the width direction W of the current collector 1, reducing the energy density loss caused by the safety coatings. Furthermore, the first safety coatings 4 on the electrode can prevent burrs on adjacent electrodes from piercing the separator and contacting the electrode, effectively reducing the risk of internal short circuits and greatly improving battery safety. Simultaneously, the large coverage area of ​​the first safety coatings 4 on the coating area 2 (70%-100%) provides better protection. Moreover, when the electrode is punctured horizontally, the second safety coatings 5 ​​located around the coating can completely cover the active material layer 3 in the thickness direction D of the current collector 1, increasing the internal resistance during horizontal puncture and short circuit and reducing the short circuit current. Meanwhile, the second safety coating 5 is also spaced inside the active material layer 3 to enhance the protection of the current collector 1 in the thickness direction D. It can act as a "partition wall" inside the electrode to prevent heat spread inside the electrode and suppress thermal runaway.

[0065] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content without departing from the scope of the technical solution of the present utility model. These are equivalent embodiments with equivalent changes. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the technical solution of the present utility model shall still fall within the protection scope of the technical solution of the present utility model.

Claims

1. An electrode comprising a current collector (1), at least one surface of the current collector (1) having a coating region (2), the coating region (2) having a coating comprising an active material layer (3) and a first safety coating (4); characterized in that, Along the width direction (W) of the current collector (1), a plurality of first safety coatings (4) are spaced apart between the current collector (1) and the active material layer (3), and / or a plurality of first safety coatings (4) are spaced apart on the active material layer (3); the projected area of ​​the first safety coating (4) on the coating area (2) is 70%-100%.

2. The electrode sheet as described in claim 1, characterized in that, The current collector (1) has a first surface (11) and a second surface (12) opposite to each other. The first surface (11) and the second surface (12) are both provided with the active material layer (3). The first surface (11) and the second surface (12) are both provided with a plurality of first safety coatings (4) along the width direction (W) of the current collector (1). The total projected area of ​​the first safety coatings (4) on the first surface (11) and the second surface (12) on the coating area (2) is 70%-100%.

3. The electrode sheet as described in claim 1, characterized in that, The thickness of the first safety coating (4) is D1, and the thickness of the active substance coating (3) located on any surface of the first safety coating (4) is D3, wherein D1 / D3 = 0.003 to 0.

35.

4. The electrode sheet as described in claim 1, characterized in that, The thickness of the first safety coating (4) is D1, and the range of D1 is 1μm-10μm.

5. The electrode sheet as described in claim 1, characterized in that, The surface of the coating has an uneven structure. The maximum thickness of the coating is D2, and the minimum thickness of the coating is D4, where 0≤D2-D4≤20μm.

6. The electrode sheet as described in claim 1, characterized in that, The projected area of ​​the first safety coating (4) located on the single surface of the current collector is 20%-100% of the area of ​​the coating area (2).

7. The electrode sheet according to any one of claims 1-6, characterized in that, The first safety coating (4) is selected from carbon-coated LiNi. x Co y Mn z O2 (where x+y+z=1, 0<x<0.6, 0<y, 0<z), LiFePO4 safety coating, LiMn2O4 safety coating, lithium manganese iron phosphate safety coating, LiNi 1.5 Mn 0.5 One or more of the following: O4 safety coating, NASCION type solid electrolyte safety coating, LISCION solid electrolyte safety coating, garnet type solid electrolyte safety coating, perovskite type solid electrolyte safety coating, sulfide electrolyte safety coating, polymer electrolyte safety coating, Al2O3 safety coating, SiO2 safety coating, ZrO2 safety coating, TiO2 safety coating, γ-AlOOH safety coating, BaTiO3 safety coating, and Mg(OH)2 safety coating.

8. The electrode sheet as described in claim 1, characterized in that, At least one surface of the current collector (1) is further provided with a second safety coating (5), the second safety coating (5) is provided around the coating, the maximum thickness of the coating is D2, and the thickness of the second safety coating (5) is greater than or equal to D2.

9. The electrode sheet as described in claim 8, characterized in that, Along the width direction (W) and / or length direction (L) of the current collector (1), the second safety coating (5) is also spaced inside the active material layer (3).

10. The electrode sheet as described in claim 8, characterized in that, The width of the second safety coating (5) is W1, and the width of the coating area (2) is W2, wherein W1 / W2 = 0.001% to 6%.

11. The electrode sheet as described in claim 8, characterized in that, The second safety coating (5) is selected from carbon-coated LiNi x Co y Mn z O2 (where x+y+z=1, 0<x<0.6, 0<y, 0<z), LiFePO4 safety coating, LiMn2O4 safety coating, lithium manganese iron phosphate safety coating, LiNi 1.5 Mn 0.5 One or more of the following: O4 safety coating, NASCION type solid electrolyte safety coating, LISCION solid electrolyte safety coating, garnet type solid electrolyte safety coating, perovskite type solid electrolyte safety coating, sulfide electrolyte safety coating, polymer electrolyte safety coating, Al2O3 safety coating, SiO2 safety coating, ZrO2 safety coating, TiO2 safety coating, γ-AlOOH safety coating, BaTiO3 safety coating, and Mg(OH)2 safety coating.

12. A battery, characterized in that, It includes the electrode as described in any one of claims 1-11.

Images