POSITIVE ELECTRODE PLATE AND LITHIUM-ION BATTERY

Abstract

The present application provides a positive electrode plate and a lithium-ion battery. A first aspect of the present application provides a positive electrode plate, and the positive electrode plate includes a positive-electrode current collector, a functional layer, and a first safety coating; where both an upper surface and a lower surface of the positive-electrode current collector include a first coating area and a second coating area, and the first coating area is provided with the first safety coating; the second coating area is provided with the functional layer, and the functional layer sequentially includes a second safety coating and a positive-electrode active layer in a direction away from the positive-electrode current collector.

Claims

1. A positive electrode plate, wherein the positive electrode plate comprises a positive-electrode current collector, a functional layer, and a first safety coating; wherein both an upper surface and a lower surface of the positive-electrode current collector comprise a first coating area and a second coating area, and the first coating area is provided with the first safety coating; the second coating area is provided with the functional layer, and the functional layer sequentially comprises a second safety coating and a positive-electrode active layer in a direction away from the positive-electrode current collector.

2. The positive electrode plate according to claim 1, wherein the first safety coating comprises an inorganic particle, and the inorganic particle is one or more of CuO, Gd.sub.2O, Lu.sub.2O.sub.3, Sm.sub.2O.sub.3, NiO, SiO.sub.2, Al.sub.2O.sub.3, TiO.sub.2, WO.sub.3, ZnO, Ag.sub.2Se, MoS.sub.2, ZrO.sub.2, Y.sub.2O.sub.3, SiC, CeO.sub.2, SnO.sub.2, Al.sub.2O.sub.3/Ag/ZnO, Al.sub.2O.sub.3/CdS, Al.sub.2O.sub.3/MgO, Al.sub.2O.sub.3/ZnO, Al(OH).sub.3, Mg(OH).sub.2, Ca(OH).sub.2, Ba.sub.2SO.sub.4, and γ-AlOOH.

3. The positive electrode plate according to claim 1, wherein the first safety coating comprises a filler, the filler is one or more of lithium cobaltate, lithium manganate, lithium nickellate, lithium nickel cobalt manganese oxide, ferrous lithium phosphate, lithium ferromanganese phosphate, lithium vanadium phosphate, lithium oxyvanadium phosphate, lithium-rich manganese-based material, lithium nickel cobalt aluminate, lithium titanate, aluminum fiber and aluminum silicate fiber, and a mass of the filler is not greater than 40% of a mass of the first safety coating.

4. The positive electrode plate according to claim 2, wherein the first safety coating comprises a filler, the filler is one or more of lithium cobaltate, lithium manganate, lithium nickellate, lithium nickel cobalt manganese oxide, ferrous lithium phosphate, lithium ferromanganese phosphate, lithium vanadium phosphate, lithium oxyvanadium phosphate, lithium-rich manganese-based material, lithium nickel cobalt aluminate, lithium titanate, aluminum fiber and aluminum silicate fiber, and a mass of the filler is not greater than 40% of a mass of the first safety coating.

5. The positive electrode plate according to claim 3, wherein D10 of lithium cobaltate, lithium manganate, lithium nickelate, lithium nickel cobalt manganese oxide, ferrous lithium phosphate, lithium ferromanganese phosphate, lithium vanadium phosphate, lithium oxyvanadium phosphate, lithium-rich manganese-based material, lithium nickel cobalt aluminate, and lithium titanate is 0.01-0.5 μm, D10 thereof is 0.02-1.5 μm, D90 thereof is 1.6-4.0 μm, and a specific surface area thereof is 0.1-15 m.sup.2/g; and the aluminum fiber and the aluminum silicate fiber have a diameter of 0.1-3 μm and a length of 1-20 μm.

6. The positive electrode plate according to claim 4, wherein D10 of lithium cobaltate, lithium manganate, lithium nickelate, lithium nickel cobalt manganese oxide, ferrous lithium phosphate, lithium ferromanganese phosphate, lithium vanadium phosphate, lithium oxyvanadium phosphate, lithium-rich manganese-based material, lithium nickel cobalt aluminate, and lithium titanate is 0.01-0.5 μm, D10 thereof is 0.02-1.5 μm, D90 thereof is 1.6-4.0 μm, and a specific surface area thereof is 0.1-15 m.sup.2/g; and the aluminum fiber and the aluminum silicate fiber have a diameter of 0.1-3 μm and a length of 1-20 μm.

7. The positive electrode plate according claim 1, wherein the first safety coating further comprises a conductive agent, and a total volume resistance of the first safety coating and the positive-electrode current collector is 10-3500 mΩ.

8. The positive electrode plate according claim 2, wherein the first safety coating further comprises a conductive agent, and a total volume resistance of the first safety coating and the positive-electrode current collector is 10-3500 mΩ.

9. The positive electrode plate according claim 3, wherein the first safety coating further comprises a conductive agent, and a total volume resistance of the first safety coating and the positive-electrode current collector is 10-3500 mΩ.

10. The positive electrode plate according claim 4, wherein the first safety coating further comprises a conductive agent, and a total volume resistance of the first safety coating and the positive-electrode current collector is 10-3500 mΩ.

11. The positive electrode plate according claim 5, wherein the first safety coating further comprises a conductive agent, and a total volume resistance of the first safety coating and the positive-electrode current collector is 10-3500 mΩ.

12. The positive electrode plate according claim 6, wherein the first safety coating further comprises a conductive agent, and a total volume resistance of the first safety coating and the positive-electrode current collector is 10-3500 mΩ.

13. The positive electrode plate according to claim 1, wherein a thickness of the first safety coating is less than or equal to a thickness of the second safety coating.

14. The positive electrode plate according to claim 13, wherein the thickness of the first safety coating is 3-15 μm.

15. A lithium-ion battery, wherein the lithium-ion battery comprises the positive electrode plate according to claim 1.

16. The lithium-ion battery according to claim 15, wherein the first safety coating comprises an inorganic particle, and the inorganic particle is one or more of CuO, Gd.sub.2O, Lu.sub.2O.sub.3, Sm.sub.2O.sub.3, NiO, SiO.sub.2, Al.sub.2O.sub.3, TiO.sub.2, WO.sub.3, ZnO, Ag.sub.2Se, MoS.sub.2, ZrO.sub.2, Y.sub.2O.sub.3, SiC, CeO.sub.2, SnO.sub.2, Al.sub.2O.sub.3/Ag/ZnO, Al.sub.2O.sub.3/CdS, Al.sub.2O.sub.3/MgO, Al.sub.2O.sub.3/ZnO, Al(OH).sub.3, Mg(OH).sub.2, Ca(OH).sub.2, Ba.sub.2SO.sub.4, and γ-AlOOH.

17. The lithium-ion battery according to claim 15, wherein the first safety coating comprises a filler, the filler is one or more of lithium cobaltate, lithium manganate, lithium nickellate, lithium nickel cobalt manganese oxide, ferrous lithium phosphate, lithium ferromanganese phosphate, lithium vanadium phosphate, lithium oxyvanadium phosphate, lithium-rich manganese-based material, lithium nickel cobalt aluminate, lithium titanate, aluminum fiber and aluminum silicate fiber, and a mass of the filler is not greater than 40% of a mass of the first safety coating.

18. The lithium-ion battery according to claim 16, wherein a thickness of the first safety coating is less than or equal to a thickness of the second safety coating.

19. The lithium-ion battery according to claim 15, wherein a length of the first safety coating covering an inner surface of an outermost positive-electrode current collector close to a winding center is less than or equal to ½ of a length of the outermost positive-electrode current collector.

20. The lithium-ion battery according to claim 15, wherein a length of a negative electrode plate is greater than a length of the positive electrode plate, and a length of an overlapping region of a portion of the negative electrode plate beyond the positive electrode plate and a vertical projection of the first safety coating on an outermost positive electrode plate is greater than or equal to 0.5 μm.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0045] FIG. 1 is a schematic structural diagram of a positive electrode plate according to an example of the present application;

[0046] FIG. 2 is a schematic structural diagram of a lithium-ion battery according to an example of the present application;

[0047] FIG. 3 is a schematic structural diagram of a positive electrode plate according to another example of this application;

[0048] FIG. 4 is a schematic structural diagram of a positive electrode plate according to still another example of this application.

BRIEF DESCRIPTION OF THE REFERENCE SIGNS

[0049] 100—positive electrode plate; [0050] 200—negative electrode plate; [0051] 300—positive electrode tab; [0052] 400—negative electrode tab; [0053] 101—positive-electrode current collector; [0054] 102—a first safety coating; [0055] 103—a second safety coating; and [0056] 104—positive-electrode active layer.

DESCRIPTION OF EMBODIMENTS

[0057] In order to make the objects, technical solutions, and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below in conjunction with the examples of the present application. Obviously, the described examples are part of the examples of the present application, rather than all of the examples. All other examples obtained by a person of ordinary skill in the art based on the examples of the present application without creative efforts shall fall within the protection scope of the present application.

[0058] The materials used in the following examples are commercially available.

Example 1

[0059] The positive electrode plate provided by the present example has a structure shown in FIG. 1, and includes an aluminum foil as positive-electrode current collector, a first safety coating, a positive-electrode active layer and a second safety coating, and specifically:

[0060] the first safety coating includes 90 parts by mass of aluminum oxide (Al.sub.2O.sub.3) and 10 parts by mass of polyvinylidene fluoride (PVDF), where D10 of aluminum oxide (Al.sub.2O.sub.3) is 0.15 μm, D50 thereof is 0.32 μm, D90 thereof is 0.65 μm, and a specific surface area thereof is 15.6 m.sup.2/g; a single-sided thickness of the first safety coating is 5 μm;

[0061] the second safety coating includes 65 parts by mass of ferrous lithium phosphate, 30 parts by mass of polyvinylidene fluoride and 5 parts by mass of carbon black, where D50 of ferrous lithium phosphate is 0.75 μm, D90 thereof is 25 μm, and a thickness thereof is 8 μm;

[0062] the positive-electrode active layer includes 97 parts by mass of lithium cobaltate, 1.3 parts by mass of polyvinylidene fluoride and 1.7 parts by mass of carbon black, where D50 of lithium cobaltate is 10 μm, D90 thereof is 25 μm, and a thickness thereof is 95 μm.

[0063] A preparation method of the positive electrode plate provided by the example includes the following steps:

[0064] 1. dissolving 90 parts by mass of aluminum oxide (Al.sub.2O.sub.3) and 10 parts by mass of polyvinylidene fluoride (PVDF) in NMP, and uniformly mixing to obtain a first safety coating slurry (solid content is 32.5%);

[0065] coating the first safety coating slurry on first coating areas of an upper surface and a lower surface of the aluminum foil by a gravure coating machine, and drying at 110° C. to obtain the first safety coating;

[0066] 2. dissolving 65 parts by mass of ferrous lithium phosphate, 30 parts by mass of polyvinylidene fluoride and 5 parts by mass of carbon black in NMP, and uniformly mixing to obtain a second safety coating slurry (solid content is 15%);

[0067] coating the second safety coating slurry on second coating areas of the upper surface and the lower surface of the aluminum foil by a gravure coating machine, and drying at 110° C. to obtain the second safety coating;

[0068] 3. dissolving 97 parts by mass of lithium cobaltate, 1.3 parts by mass of polyvinylidene fluoride and 1.7 parts by mass of carbon black in NMP, and uniformly mixing to form a positive-electrode active layer slurry (solid content being 75%);

[0069] coating the positive-electrode active layer slurry on a surface of the second safety coating by a slit-extrusion coating device, and after drying at 100° C., rolling and cutting to obtain a positive electrode plate of 1000 mm×65 mm.

Example 2

[0070] The positive electrode plate provided in this example may refer to Example 1, except that:

[0071] the first safety coating includes 80 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 10 parts by mass of LiFePO.sub.4 and 10 parts by mass of polyvinylidene fluoride (PVDF); and

[0072] D10 of LiFePO.sub.4 is 0.37 μm, D50 is 0.75 μm, D90 is 2.30 μm, and a specific surface area is 10 m.sup.2/g.

Example 3

[0073] The positive electrode plate provided in this example may refer to Example 2, except that:

[0074] the first safety coating includes 70 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 20 parts by mass of LiFePO.sub.4 and 10 parts by mass of polyvinylidene fluoride (PVDF).

Example 4

[0075] The positive electrode plate provided in this example may refer to Example 2, except that:

[0076] the first safety coating includes 60 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 30 parts by mass of LiFePO.sub.4 and 10 parts by mass of polyvinylidene fluoride (PVDF).

Example 5

[0077] The positive electrode plate provided in this example may refer to Example 1, except that:

[0078] the first safety coating includes 85 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 5 parts by mass of aluminum fiber and 10 parts by mass of polyvinylidene fluoride (PVDF); and

[0079] a diameter of the aluminum fiber is 2 μm, and a length thereof is 15 μm.

Example 6

[0080] The positive electrode plate provided in this example may refer to Example 1, except that:

[0081] the first safety coating includes 85 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 5 parts by mass of aluminum silicate fiber and 10 parts by mass of polyvinylidene fluoride (PVDF); and

[0082] a diameter of the aluminum silicate fiber is 2 μm, and a length thereof is 15 μm.

Example 7

[0083] The positive electrode plate provided in this example may refer to Example 2, except that:

[0084] the first safety coating includes 80 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 10 parts by mass of LiFePO.sub.4, 1.5 parts by mass of carbon black as conductive agent and 8.5 parts by mass of polyvinylidene fluoride (PVDF).

Example 8

[0085] The positive electrode plate provided in this example may refer to Example 2, except that:

[0086] the first safety coating includes 80 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 10 parts by mass of LiFePO.sub.4, 2.5 parts by mass of carbon black as conductive agent and 7.5 parts by mass of polyvinylidene fluoride (PVDF).

Example 9

[0087] The positive electrode plate provided in this example may refer to Example 1, except that:

[0088] the first safety coating includes 78 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 2.5 parts by mass of carbon black as conductive agent and 19.5 parts by mass of polyvinylidene fluoride (PVDF).

Example 10

[0089] The positive electrode plate provided in this example may refer to Example 1, except that:

[0090] the first safety coating includes 75.5 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 5 parts by mass of carbon black as conductive agent and 19.5 parts by mass of polyvinylidene fluoride (PVDF).

Example 11

[0091] The positive electrode plate provided in this example may refer to Example 1, except that:

[0092] the first safety coating includes 70.5 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 10 parts by mass of carbon black as conductive agent and 19.5 parts by mass of polyvinylidene fluoride (PVDF).

Example 12

[0093] The positive electrode plate provided in this example may refer to Example 1, except that:

[0094] the first safety coating includes 65.5 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 15 parts by mass of carbon black as conductive agent and 19.5 parts by mass of polyvinylidene fluoride (PVDF).

Example 13

[0095] The positive electrode plate provided in this example may refer to Example 1, except that:

[0096] the first safety coating includes 60.5 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 20 parts by mass of carbon black as conductive agent and 19.5 parts by mass of polyvinylidene fluoride (PVDF).

Example 14

[0097] The positive electrode plate provided in this example may refer to Example 1, except that:

[0098] the first safety coating includes 50.5 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 30 parts by mass of carbon black as conductive agent and 19.5 parts by mass of polyvinylidene fluoride (PVDF).

Example 15

[0099] The positive electrode plate provided in this example may refer to Example 1, except that:

[0100] the first safety coating includes 79.5 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 1 part by mass of carbon black as conductive agent and 19.5 parts by mass of polyvinylidene fluoride (PVDF).

Example 16

[0101] The positive electrode plate provided in this example may refer to Example 1, except that:

[0102] the first safety coating includes 79.65 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 0.85 part by mass of carbon black as conductive agent and 19.5 parts by mass of polyvinylidene fluoride (PVDF).

Example 17

[0103] The positive electrode plate provided in this example may refer to Example 1, except that:

[0104] the first safety coating includes 79.85 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 0.65 part by mass of carbon black as conductive agent and 19.5 parts by mass of polyvinylidene fluoride (PVDF).

Example 18

[0105] The positive electrode plate provided in this example may refer to Example 1, except that:

[0106] the first safety coating includes 80 parts by mass of aluminum oxide (Al.sub.2O.sub.3), 0.5 part by mass of carbon black as conductive agent and 19.5 parts by mass of polyvinylidene fluoride (PVDF).

Comparative Example 1

[0107] The positive electrode plate provided by the present comparative example includes a positive-electrode current collector, a second safety coating and a positive-electrode active layer, namely, it does not include a first safety coating.

[0108] Lithium-ion batteries were prepared by a winding process using the positive electrode plates provided by Examples 1-18 and Comparative Example 1 in combination with negative electrode plates and separators, and the lithium-ion batteries were subjected to safety test. The test results are shown in Table 1:

[0109] where a preparation method of the negative electrode plate includes: dissolving 95 parts by mass of graphite, 1.5 parts by mass of CMC, 1.5 parts by mass of SBR and 2 parts by mass of carbon black in deionized water, and uniformly mixing to obtain a negative-electrode active layer slurry; coating the slurry on the upper surface and the lower surface of a copper foil, and after drying at 70-100° C. for 2-5 minutes, rolling and cutting, to obtain a negative electrode plate of 1100 mm×66.5 mm, where a single-sided thickness of the negative-electrode active layer is 120 μm.

[0110] (1) Method for puncture test, including: under an environment of normal temperature, charging a lithium-ion battery at a constant current of 0.5 C until the voltage is 4.35V, and then performing constant voltage charging until the current is 0.025 C; transferring the lithium-ion battery to a nail penetration test device, maintaining the temperature of the test environment to be 25° C., and puncturing a negative-electrode-tab side at a position of 7 mm away from the battery cell with a steel nail of 4 mm in diameter at a constant speed of 30 mm/s; keeping for 300 s, and if the lithium-ion battery does not catch fire or explode, recording it as passing.

[0111] For each example/comparative example, 10 batteries are tested, where puncture test pass rate=the number of batteries passing puncture test/total number of batteries in puncture test.

[0112] (2) Method for testing volume resistance, including: testing a total volume resistance of the first safety coating and the positive-electrode current collector by using a diaphragm resistance test system with device model ACCFILM, where diameter D of the test probe is 14 mm; during the test, placing the positive electrode plate between upper and lower cylindrical probes, adjusting a pressure to be 0.4 MPa, starting a test switch, and recording the test data; testing 10 data points for each group with the testing points spacing being 5 mm, and taking an average value as the value of the volume resistance. The resistance measurement precision of the test system is 0.1 μΩ-100 mΩ, and the resistance measurement range is 0.1 μΩ-3000Ω.

[0113] (3) Method for testing peel strength between first safety coating and fixing adhesive tape, including: cutting the positive electrode plate into small positive electrode plate piece with length of 240 mm and width of 30 mm, using an adhesive tape NITTO No. 5000NS and cutting the adhesive tape into small adhesive tape piece according to specification of length 200 mm and width 24 mm, adhering one side of small adhesive tape piece to a steel plate (260 mm*50 mm), and bonding the other side of the small adhesive tape piece with the small positive electrode plate piece, ensuring that the small positive electrode plate piece completely covers the small adhesive tape piece; rolling a hand-held drum (diameter 95 mm, width 45 mm, and weight 2 kg) back and forth for 3 times to bond the small positive electrode plate piece and the small adhesive tape piece together, then using a tensile machine (the tensile machine model being KJ-1065 series of Dongguan Kejian Instrument) to test (180 degree peeling), and then at a speed of 10 mm/min, the test device automatically recording a tensile force value that changes with the peeling displacement; taking the peeling displacement as the abscissa and the tensile force value as the ordinate to draw a curve of the tensile force value changing with the peeling displacement, and taking the tensile force value when the curve flattens and the peeling displacement is greater than 5 mm as the peel strength.

[0114] (4) Drop Test

[0115] Placing a lithium-ion battery in a clamp to carry out surface drop, edge drop and point drop tests according to the national standard GB/T 18287-2000, where the test distance is 1.2 m, and free drop is conducted for one time in each of six directions in three-dimension.

[0116] For each example/comparative example, 10 batteries are tested, where drop test pass rate=the number of batteries passing drop test/total number of batteries in drop test

[0117] (5) Thermal-Abuse Pass Rate

[0118] Putting fully charged battery cells into a test box, increasing the temperature in the test box at a rate of (5±2°) C/min, and after the temperature reaches 130±2° C., keeping this temperature for 1 hour, and then observing whether the lithium-ion battery has the problems of catching fire and exploding, and if no fire and explosion occur it passes the test.

TABLE-US-00001 TABLE 1 Test results of lithium-ion batteries provided according to Examples 1-18 and Comparative Example 1 Peel strength between first safety coating (current collector) and Puncture Volume Drop adhesive tape test pass resistance test pass Thermal- Component of first safety coating (N/m) rate (%) (mΩ) rate (%) abuse test Example 1 Al.sub.2O.sub.3:PVDF = 90:10 15.62 100 Infinity 70 Failed Example 2 Al.sub.2O.sub.3:LiFePO.sub.4:PVDF = 80:10:10 19.59 100 305 90 Failed Example 3 Al.sub.2O.sub.3:LiFePO.sub.4:PVDF = 70:20:10 26.24 70 582 95 Failed Example 4 Al.sub.2O.sub.3:LiFePO.sub.4:PVDF = 60:30:10 28.91 65 60 100 Failed Example 5 Al.sub.2O.sub.3:Al fiber:PVDF = 85:5:10 28.92 70 126 100 Failed Example 6 Al.sub.2O.sub.3:Aluminosilicate fiber:PVDF = 85:5:10 28.97 100 8365 100 Failed Example 7 Al.sub.2O.sub.3:LiFePO.sub.4:SP:PVDF = 80:10:1.5:8.5 28.21 100 684 100 Passing Example 8 Al.sub.2O.sub.3:LiFePO.sub.4:SP:PVDF = 80:10:2.5:7.5 28.53 80 539 100 Passing Example 9 AL.sub.2O.sub.3:SP:PVDF = 78:2.5:19.5 28.69 100 731 100 Passing Example 10 AL.sub.2O.sub.3:SP:PVDF = 75.5:5:19.5 28.32 100 510 100 Passing Example 11 AL.sub.2O.sub.3:SP:PVDF = 70.5:10:19.5 28.16 100 204 100 Passing Example 12 AL.sub.2O.sub.3:SP:PVDF = 65.5:15:19.5 27.91 68 85.1 100 Passing Example 13 AL.sub.2O.sub.3:SP:PVDF = 60.5:20:19.5 27.29 46 18.2 100 Passing Example 14 AL.sub.2O.sub.3:SP:PVDF = 50.5:30:19.5 26.82 35 10.6 97 Passing Example 15 AL.sub.2O.sub.3:SP:PVDF = 79.5:1.0:19.5 28.33 100 1560 100 Passing Example 16 AL.sub.2O.sub.3:SP:PVDF = 79.65:0.85:19.5 28.81 100 2104 100 Passing Example 17 AL.sub.2O.sub.3:SP:PVDF = 79.85:0.65:19.5 28.69 100 2261 100 Passing Example 18 AL.sub.2O.sub.3:SP:PVDF = 80:0.5:19.5 28.69 100 3164 100 Passing Comparative / 29.13 50 3 100 Failed Example 1

[0119] According to the data provided in Table 1, it can be seen that the volume resistance and puncture test pass rate of the lithium-ion batteries provided in Examples 1-8 are greater than those of Comparative Example 1. Therefore, providing the first safety coating is beneficial to improve the puncture test pass rate of the lithium-ion battery. According to Example 1 and Example 2-4, it can be known that the inclusion of a particulate filler in the first safety coating is beneficial to improve the peel force between the first safety coating and the adhesive tape, thereby improving the drop test pass rate of the lithium-ion battery; however, as the mass fraction of the particulate filler increases, the puncture test pass rate of the lithium-ion battery decreases, and therefore, when the mass fraction of the particulate filler is 10%, the comprehensive safety of the lithium-ion battery is good. According to the Examples 5-6, it can be known that the peel force between the first safety coating and the adhesive tape is improved after a fiber filler is used, but the puncture test pass rate of the lithium-ion battery is reduced due to that the aluminum fiber is pure conductive; whereas an aluminum silicate fiber has relatively good puncture test pass rate due to its good electrical insulation property and large volume resistance. According to Examples 7-8, it can be known that adding an appropriate amount of conductive agent to the first safety coating is also beneficial to prevent the accumulation of the internal temperature of the lithium-ion battery, improving the safety of the lithium-ion battery. According to Examples 9-18, it can be known that when a conductive agent is included in the first safety coating, the content of the conductive agent should be controlled, and the total volume resistance of the current collector and the first safety coating should be controlled at 20-3500 mΩ.

[0120] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing examples, it should be understood by those of ordinary skill in the art that they may still modify the technical solutions described in the foregoing examples, or equivalently substitute some or all of the technical features therein; however, these modifications or substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the examples in the present application.