POSITIVE ELECTRODE MATERIAL, BATTERY, AND ELECTRONIC DEVICE

Abstract

The present disclosure provides a positive electrode material, a battery and an electric device. A first aspect of the present disclosure provides a positive electrode material, the positive electrode material is Li.sub.n-xNa.sub.xCo.sub.1-yMe.sub.yO.sub.2, 0.7≤n≤1, 0<x≤0.15, 0≤y≤0.15, and Me is selected from one or more of Al, Mg, Ti, Zr, Ni, Mn, Y, La, Sr, W, Sc, Ce, P, Nb, V, Ta, and Te; a X-ray diffraction pattern of the positive electrode material includes a peak 002 corresponding to a crystal plane 002, a peak 004 corresponding to a crystal plane 004, a peak 101 corresponding to a crystal plane 101, a peak 102 corresponding to a crystal plane 102, and a peak 103 corresponding to a crystal plane 103; a peak intensity ratio of the peak 101 to the peak 004 is m, wherein m≥1.5.

Claims

1. A positive electrode material, wherein the positive electrode material is Li.sub.n-xNa.sub.xCo.sub.1-yMe.sub.yO.sub.2, 0.7≤n≤1, 0<x≤0.15, 0≤y≤0.15, and Me is selected from one or more of Al, Mg, Ti, Zr, Ni, Mn, Y, La, Sr, W, Sc, Ce, P, Nb, V, Ta, and Te; a X-ray diffraction pattern of the positive electrode material has a peak 002 corresponding to a crystal plane 002, a peak 004 corresponding to a crystal plane 004, a peak 101 corresponding to a crystal plane 101, a peak 102 corresponding to a crystal plane 102, and a peak 103 corresponding to a crystal plane 103; a peak intensity ratio of the peak 101 to the peak 004 is m, wherein m≥1.5.

2. The positive electrode material according to claim 1, wherein a diffraction angle 2θ corresponding to the peak 002 is equal to 18.6°±0.5°, a diffraction angle 2θ corresponding to the peak 102 is equal to 41.7°±0.5°, a diffraction angle 2θ corresponding to the peak 103 is equal to 47.1°±0.5°.

3. The positive electrode material according to claim 1, wherein a particle size of the positive electrode material is 6-18 μm.

4. The positive electrode material according to claim 2, wherein a particle size of the positive electrode material is 6-18 μm.

5. The positive electrode material according to claim 1, wherein a gram capacity of the positive electrode material at a voltage of 3.0-4.5V is ≥196 mAh/g, and a discharge gram capacity at a rate of 0.1 C is C0 mAh/g, a discharge gram capacity from beginning of discharge to 4.4V is C1 mAh/g, and a discharge gram capacity within 3.8V-3.7V is C2 mAh/g, wherein C1/C0≥9%, and C2/C0≥25%.

6. The positive electrode material according to claim 2, wherein a gram capacity of the positive electrode material at a voltage of 3.0-4.5V is ≥196 mAh/g, and a discharge gram capacity at a rate of 0.1 C is C0 mAh/g, a discharge gram capacity from beginning of discharge to 4.4V is C1 mAh/g, and a discharge gram capacity within 3.8V-3.7V is C2 mAh/g, wherein C1/C0≥9%, and C2/C0≥25%.

7. A battery, wherein the battery comprises a positive electrode piece, the positive electrode piece comprises a positive electrode current collector and a positive electrode active layer provided on at least one surface of the positive electrode current collector, and the positive electrode active layer comprises the positive electrode material according to claim 1.

8. The battery according to claim 7, wherein a diffraction angle 2θ corresponding to the peak 002 is equal to 18.6°±0.5°, a diffraction angle 2θ corresponding to the peak 102 is equal to 41.7°±0.5°, a diffraction angle 2θ corresponding to the peak 103 is equal to 47.1°±0.5°.

9. The battery according to claim 7, wherein a particle size of the positive electrode material is 6-18 μm.

10. The battery according to claim 8, wherein a particle size of the positive electrode material is 6-18 μm.

11. The battery according to claim 7, wherein a gram capacity of the positive electrode material at a voltage of 3.0-4.5V is ≥196 mAh/g, and a discharge gram capacity at a rate of 0.1 C is C0 mAh/g, a discharge gram capacity from beginning of discharge to 4.4V is C1 mAh/g, and a discharge gram capacity within 3.8V-3.7V is C2 mAh/g, wherein C1/C0≥9%, and C2/C0≥25%.

12. The battery according to claim 8, wherein a gram capacity of the positive electrode material at a voltage of 3.0-4.5V is ≥196 mAh/g, and a discharge gram capacity at a rate of 0.1 C is C0 mAh/g, a discharge gram capacity from beginning of discharge to 4.4V is C1 mAh/g, and a discharge gram capacity within 3.8V-3.7V is C2 mAh/g, wherein C1/C0≥9%, and C2/C0≥25%.

13. The battery according to claim 7, wherein a mass of the positive electrode material is 70-99% of a total mass of the positive electrode active layer.

14. The battery according to claim 8, wherein a mass of the positive electrode material is 70-99% of a total mass of the positive electrode active layer.

15. The battery according to claim 9, wherein a mass of the positive electrode material is 70-99% of a total mass of the positive electrode active layer.

16. The battery according to claim 7, wherein the positive electrode active layer comprises a binder and a conductive agent.

17. The battery according to claim 13, wherein the positive electrode active layer comprises a binder and a conductive agent.

18. The battery according to claim 16, wherein the binder is selected from one or more of polyvinylidene fluoride, polytetrafluoroethylene and lithium polyacrylate; and/or, the conductive agent is selected from one or more of conductive carbon black, acetylene black, Ketjen black, conductive graphite, conductive carbon fiber, carbon nanotube, single-wall carbon nanotube, multi-wall carbon nanotube, and carbon fiber.

19. The battery according to claim 16, wherein a mass of the binder is 0.5-15% of a total mass of the positive electrode active layer, and a mass of the conductive agent is 0.5-15% of a total mass of the positive electrode active layer.

20. An electronic device, wherein the electronic device comprises the battery according to claim 7.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0038] FIG. 1 is a XRD test data diagram of a positive electrode material provided in Example 1 of the present disclosure; and

[0039] FIG. 2 shows charge and discharge curves of the positive electrode material provided in Example 1 of the present disclosure at 3.0-4.5V (vs.Li) and a rate of 0.1 C.

DESCRIPTION OF EMBODIMENTS

[0040] In order to make the objectives, technical solutions and advantages of the present disclosure more clear, the following will describe the technical solutions in the examples of the present disclosure clearly and completely in combination with the examples of the present disclosure. Obviously, the described examples are part of the examples of the present disclosure, not all of them. Based on the examples of the present disclosure, all other examples obtained by those skilled in the art without creative work belong to the scope of the present disclosure.

[0041] Unless otherwise specified, experimental methods used in the following examples are conventional methods; reagents, materials, and the like used in the following examples can be obtained from commercial sources unless otherwise specified.

Example 1

[0042] A preparation method of a positive electrode material provided in this example includes the following steps: [0043] (1) weigh 3.656 kg of sodium carbonate powder and 29.105 kg of cobalt nitrate hexahydrate powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium carbonate in the mixture, it is considered that the mixture is uniform; [0044] (2) take 30 g of the mixture and put it into a ceramic crucible, conduct high-temperature sintering using a well muffle furnace with device model of VBF-1200X with a temperature rise rate for sintering temperature rise curve being 5° C./min, conduct constant temperature sintering for 10 hours when the temperature rises to 750° C., and after sintering, naturally cool down to room temperature and take out the sample to obtain the sintered Na.sub.0.69CoO.sub.2, a compound containing cobalt and sodium; [0045] (3) add 200 ml of deionized water, 10.49 g of lithium hydroxide monohydrate and 10.59 g of lithium chloride into a reaction vessel, stir for 5 minutes at a water temperature of 78° C. and a rotating speed of 20 rpm, then weigh 10 g of Na.sub.0.69CoO.sub.2, the compound containing cobalt element and sodium element obtained in step 2, and keep them for continuous reaction at 78° C. and a rotating speed of 20 rpm for 8 hours; and [0046] (4) after the reaction, take out reaction product, conduct suction filtration washing with deionized water for three times, then dry it in an air drying oven at 90° C. for 8 hours to obtain the positive electrode material.

Example 2

[0047] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0048] (3) add 200 ml of deionized water, 10.49 g of lithium hydroxide monohydrate and 21.71 g of lithium bromide into a reaction vessel, stir for 5 minutes at a water temperature of 78° C. and at a rotating speed of 20 rpm, weigh 10 g of Na.sub.0.69CoO.sub.2, the compound containing cobalt element and sodium element obtained in step 2, and keep them for continuous reaction at 78° C. and a rotating speed of 20 rpm for 8 hours.

Example 3

[0049] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0050] (3) add 200 ml of deionized water, 10.49 g of lithium hydroxide monohydrate and 33.46 g of lithium iodide into a reaction vessel, stir for 5 minutes at a water temperature of 78° C. and at a rotating speed of 20 rpm, weigh 10 g of Na.sub.0.69CoO.sub.2, the compound containing cobalt element and sodium element obtained in step 2, and keep them for continuous reaction at 78° C. and at a speed of 20 rpm for 8 hours.

Example 4

[0051] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0052] (3) add 200 ml of deionized water, 10.49 g of lithium hydroxide monohydrate and 6.48 g of lithium fluoride into a reaction vessel, stir for 5 minutes at a water temperature of 78° C. and at a rotating speed of 20 rpm, weigh 10 g of Na.sub.0.69CoO.sub.2, the compound containing cobalt element and sodium element obtained in step 2, and keep them for continuous reaction at 78° C. at a speed of 20 rpm for 8 hours.

Example 5

[0053] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0054] (3) add 200 ml of deionized water, 16.78 g of lithium hydroxide monohydrate and 3.69 g of lithium carbonate into a reaction vessel, stir for 5 minutes at a water temperature of 78° C. and at a rotating speed of 20 rpm, weigh 10 g of Na.sub.0.69CoO.sub.2, the compound containing cobalt element and sodium element obtained in step 2, and keep them for continuous reaction at 78° C. at a speed of 20 rpm for 8 hours.

Example 6

[0055] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0056] (3) add 200 ml of deionized water, 16.78 g of lithium hydroxide monohydrate and 16.96 g of lithium chloride into a reaction vessel, stir for 5 minutes at a water temperature of 78° C. and at a rotating speed of 20 rpm, weigh 10 g of Na.sub.0.69CoO.sub.2, the compound containing cobalt element and sodium element obtained in step 2, and keep them for continuous reaction at 78° C. at a speed of 20 rpm for 8 hours.

Example 7

[0057] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0058] (3) add 200 ml of deionized water, 16.78 g of lithium hydroxide monohydrate and 4.24 g of lithium chloride into a reaction vessel, stir for 5 minutes at a water temperature of 78° C. and at a rotating speed of 20 rpm, weigh 10 g of Na.sub.0.69CoO.sub.2, the compound containing cobalt element and sodium element obtained in step 2, and keep them for continuous reaction at 78° C. at a speed of 20 rpm for 8 hours.

Example 8

[0059] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0060] (3) add 200 ml of deionized water, 10.49 g of lithium hydroxide monohydrate and 10.59 g of lithium chloride into a reaction vessel, stir for 5 minutes at a water temperature of 78° C. and at a rotating speed of 30 rpm, weigh 10 g of Na.sub.0.69CoO.sub.2, the compound containing cobalt element and sodium element obtained in step 2, and keep them for continuous reaction at 78° C. at a speed of 30 rpm for 8 hours.

Example 9

[0061] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0062] (1) weigh 2.138 kg of sodium oxide powder and 29.105 kg of cobalt nitrate hexahydrate powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium oxide in the mixture, it is considered that the mixture is uniform.

Example 10

[0063] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0064] (1) weigh 3.656 kg of sodium carbonate powder and 7.493 kg of cobalt monoxide powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium oxide in the mixture, it is considered that the mixture is uniform.

Example 11

[0065] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0066] (1) weigh 3.656 kg of sodium carbonate powder and 9.293 kg of cobalt hydroxide powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium carbonate in the mixture, it is considered that the mixture is uniform.

Example 12

[0067] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0068] (1) weigh 3.656 kg of sodium carbonate powder and 8.026 kg of tricobalt tetraoxide powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium carbonate in the mixture, it is considered that the mixture is uniform.

Example 13

[0069] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0070] (1) weigh 3.656 kg of sodium carbonate powder, 9.200 kg of cobalt hydroxide powder and 50.98 g of nano aluminium oxide powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium carbonate in the mixture, it is considered that the mixture is uniform.

Example 14

[0071] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0072] (1) weigh 3.656 kg of sodium carbonate powder, 9.014 kg of cobalt hydroxide powder and 152.94 g of nano aluminium oxide powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium carbonate in the mixture, it is considered that the mixture is uniform.

Example 15

[0073] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0074] (1) weigh 3.656 kg of sodium carbonate powder, 8.828 kg of cobalt hydroxide powder and 254.9 g of nano aluminium oxide powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium carbonate in the mixture, it is considered that the mixture is uniform.

Example 16

[0075] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0076] (1) weigh 3.656 kg of sodium carbonate powder, 9.200 kg of cobalt hydroxide powder and 40.30 g of nano magnesium oxide powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium carbonate in the mixture, it is considered that the mixture is uniform.

Example 17

[0077] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0078] (1) weigh 3.656 kg of sodium carbonate powder, 9.014 kg of cobalt hydroxide powder and 120.91 g of nano magnesium oxide powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium carbonate in the mixture, it is considered that the mixture is uniform.

Example 18

[0079] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0080] (1) weigh 3.656 kg of sodium carbonate powder, 8.828 kg of cobalt hydroxide powder and 201.52 g of nano magnesium oxide powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium carbonate in the mixture, it is considered that the mixture is uniform.

Example 19

[0081] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0082] (1) weigh 2.138 kg of sodium oxide powder and 9.293 kg of cobalt hydroxide powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium oxide in the mixture, it is considered that the mixture is uniform.

Example 20

[0083] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0084] (1) weigh 2.138 kg of sodium oxide powder, 9.200 kg of cobalt hydroxide powder and 50.98 g of nano aluminium oxide powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium oxide in the mixture, it is considered that the mixture is uniform.

Example 21

[0085] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0086] (1) weigh 2.138 kg of sodium oxide powder, 9.014 kg of cobalt hydroxide powder and 152.94 g of nano aluminium oxide powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium carbonate in the mixture, it is considered that the mixture is uniform.

Example 22

[0087] A preparation method of a positive electrode material provided in this example may refer to Example 1, the difference lies in that: [0088] (1) weigh 2.138 kg of sodium oxide powder, 8.828 kg of cobalt hydroxide powder and 254.9 g of nano aluminium oxide powder, put them into a high-speed mixing device, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture, and after confirming that there is no small white spot of white sodium oxide in the mixture, it is considered that the mixture is uniform.

Comparative Example 1

[0089] A positive electrode material provided by this comparative example is conventional undoped lithium cobaltate with chemical composition of Li.sub.1.003CoO.sub.2, and a preparation method thereof includes the following steps: [0090] (1) weigh lithium carbonate and conventional undoped spherical particles of Co.sub.3O.sub.4 purchased in the market in a molar ratio of Li:Co=100.3:100, mix the two substances at 300 rpm for 3 minutes, at 500 rpm for 5 minutes, and at 1000 rpm for 10 minutes using the same mixing device as the examples, and then take out the mixture, and after confirming that there is no small white spot of white lithium carbonate in the mixture, it is considered that the mixture is uniform; [0091] (2) take 30 g of the mixture and put it into a ceramic crucible, conduct high-temperature sintering using a well muffle furnace with device model of VBF-1200X with a temperature rise rate for sintering temperature rise curve of 5° C./min, conduct constant temperature sintering for 10 hours when the temperature rises to 1050° C., and after sintering, naturally cool down to room temperature and take out the sample, to obtain the sintered Li.sub.1.003CoO.sub.2, a compound containing cobalt and lithium; and [0092] (3) crush and grind the sintered lithium cobaltate, and then put the powder in the muffle furnace again for sintering at 950° C. for 8 hours; crush the sintered product to obtain Li.sub.1.003CoO.sub.2 with D50 being 15.2 m without any doping and coating.

Comparative Example 2

[0093] A positive electrode material provided by this comparative example is doped and coated lithium cobaltate for high voltage, with chemical composition being Li.sub.1.0028Co.sub.0.982 Al.sub.0.014Mg.sub.0.002La.sub.0.002O.sub.2;

[0094] a preparation method of the positive electrode material includes the following steps: [0095] (1) weigh lithium carbonate, conventional spherical Co.sub.3O.sub.4 particles doped with Al and La and purchased in the market, and magnesium oxide particles in a molar ratio of Li:Co:Mg=100.28:98.2:0.2, with stoichiometric ratio of the Co.sub.3O.sub.4 particles is Co:Al:La=98.2:1.4:0.2, mix the two substances at 300 rpm for 3 minutes, at 500 rpm for 5 minutes, and at 1000 rpm for 10 minutes using the same mixing device as the examples, and then take out the mixture, and after confirming that there is no small white spot of white lithium carbonate in the mixture, it is considered that the mixture is uniform; [0096] (2) take 30 g of the mixture and put it into a ceramic crucible, conduct high-temperature sintering using a well muffle furnace with device model of VBF-1200X with a temperature rise rate for sintering temperature rise curve of 5° C./min, conduct constant temperature sintering for 10 hours when the temperature rises to 1030° C., and after sintering naturally cool down to room temperature and take out the sample, to obtain the sintered Li.sub.1.0028Co.sub.0.982 Al.sub.0.014Mg.sub.0.002La.sub.0.002O.sub.2, a compound containing cobalt and lithium; and [0097] (3) crush and grind the sintered lithium cobaltate, weigh it and titanium dioxide in a molar ratio of Co:Ti=98.2:0.2, then put the two substances into a high-speed mixing device, set a mixing procedure, mix them at 300 rpm for 3 minutes, mix them at 500 rpm for 5 minutes, mix them at 1000 rpm for 10 minutes, and then take out the mixture; put the powder in the muffle furnace again for sintering at 950° C. for 8 hours, and then crush the sintered product to obtain Li.sub.1.0028Co.sub.0.982 Al.sub.0.014Mg.sub.0.002La.sub.0.002Ti.sub.0.002O.sub.2, a doped and coated lithium cobaltate material for high voltage, with D50 of 14.8 μm.

Comparative Example 3

[0098] A preparation method of a positive electrode material provided in this comparative example may refer to Example 1, the difference lies in that: [0099] (3) weigh 10.49 g of lithium hydroxide monohydrate, 10.59 g of lithium chloride and 10 g of Na.sub.0.69CoO.sub.2, the compound containing cobalt and sodium obtained in step 2, add them into a mixer, mix them evenly and sinter them at high temperature of 300° C. for 5 hours.

Comparative Example 4

[0100] A preparation method of a positive electrode material provided in this comparative example may refer to Example 1, the difference lies in that: [0101] (3) weigh 10.49 g of lithium hydroxide monohydrate, 10.59 g of lithium chloride and 10 g of Na.sub.0.69CoO.sub.2, the compound containing cobalt and sodium obtained in step 2, add them into a mixer, mix them evenly and sinter them at high temperature of 250° C. for 5 hours.

[0102] XRD tests are carried out on the positive electrode materials provided by Examples 1-22 and Comparative examples 1-4. FIG. 1 is a XRD test data diagram of the positive electrode material provided by Example 1 of the present disclosure. According to FIG. 1, the XRD diagram for the positive electrode material provided by Example 1 includes a peak 002 corresponding to a crystal plane 002, a peak 102 corresponding to a crystal plane 102, a peak 103 corresponding to a crystal plane 103, a peak 101 corresponding to a crystal plane 101 and a peak 004 corresponding to a crystal plane 004, and corresponding diffraction angles and peak intensities are listed, as shown in Table 1:

TABLE-US-00001 TABLE 1 Test results of the positive electrode materials provided by Examples 1-22 and Comparative Examples 1-4 Peak intensity ratio of Peak Peak crystal plane 2θ value of 2θ value of 2θ value of intensity intensity 101/crystal crystal plane crystal plane crystal plane of crystal of crystal plane 004 002 (°) 102 (°) 103 (°) plane 004 plane 101 (m) Example 1 18.5937 41.7818 47.139 1799.23 3236.43 1.799 Example 2 18.62 41.7687 47.0864 1542.01 3111.83 2.018 Example 3 18.6069 41.703 47.0733 1393.6 4775.51 3.427 Example 4 18.5675 41.6768 47.0208 1305.81 5078.15 3.889 Example 5 18.5675 41.6768 47.0208 1241.2 5071.88 4.086 Example 6 18.5806 41.6899 47.047 1259.84 3540.2 2.81 Example 7 18.5675 41.703 47.0339 856.25 3942.59 4.604 Example 8 18.5675 41.6899 47.047 1652.05 3029.03 1.833 Example 9 18.5675 41.6899 47.047 1499.32 4205.86 2.805 Example 10 18.5543 41.6768 47.0208 1556.6 2638.51 1.695 Example 11 18.5543 41.6636 47.0208 1602.74 4142.8 2.585 Example 12 18.5806 41.6899 47.0339 1257.34 2717.86 2.162 Example 13 18.5806 41.703 47.047 1284.85 3809.11 2.965 Example 14 18.5806 41.6899 47.0339 1603.14 5367.07 3.348 Example 15 18.5675 41.703 47.0339 1047.47 4753.9 4.538 Example 16 18.5806 41.703 47.047 1043.66 2195.1 2.103 Example 17 18.5675 41.703 47.0208 1029.42 4484.2 4.356 Example 18 18.5675 41.6899 47.0208 546.35 2922.41 5.349 Example 19 18.5675 41.6899 47.047 1438.28 3646.54 2.535 Example 20 18.5675 41.6768 47.0339 1174.97 4204.03 3.578 Example 21 18.5543 41.6899 47.0339 681.77 3926.77 5.76 Example 22 18.5543 41.6899 47.0208 469.15 3219.22 6.862 Comparative No No No / / / Example 1 characteristic characteristic characteristic peak peak peak Comparative No No No / / / Example 2 characteristic characteristic characteristic peak peak peak Comparative 18.5825 41.6885 47.0338 428.32 624.92 1.459 Example 3 Comparative 18.5782 41.6977 47.0309 478.20 651.78 1.363 Example 4

[0103] According to the XRD data provided by Examples 1-12 in Table 1, different raw materials and their ratios have a certain impact on phase peak position and the peak intensity of the positive electrode material; it can be seen according to the XRD data provided by Examples 13-22 that with an increase of doping element content, the peak intensity ratio of crystal plane 101 to crystal plane 004 in the positive electrode materials increases significantly; it can be seen according to the Comparative Examples 3-4 that the peak intensity ratio m of the crystal plane 101 and the crystal plane 004 in the positive electrode materials prepared according to the solution method provided by the present disclosure is significantly increased compared with an ion exchange reaction by the means of sintering.

[0104] Button cell capacity tests are carried out for the positive electrode materials prepared from Examples 1-22 and Comparative Examples 1-4. A preparation method of a button cell is as follows: mix each of the positive electrode materials prepared from Examples 1-22 and Comparative Examples 1-2 with conductive carbon black (SP) and PVDF in a weight ratio of 80:10:10, disperse them in a solvent to obtain positive electrode slurry, coat the slurry on an aluminum foil current collector, and roll to prepare a positive electrode piece; then, punch the positive electrode piece with a die to obtain small round pieces with a diameter of 12 mm, conduct drying treatment and weighing treatment, then assemble the button cell using a button cell shell of type 2025, a Li metal round piece as negative electrode, and conventional high voltage lithium cobaltate electrolyte in a glove box under Ar protective atmosphere. After the button cell is made, it is left to stand for 4 hours in a normal environment, and then a first charge and discharge capacity test is carried out, with the test conditions as below: charging to 4.5V at 0.1 C, charging to 0.025 C at constant voltage, and cutting off to stand for 3 minutes, then discharging to 3.0V at 0.1 C. Charge and discharge curves of the positive electrode material provided in Example 1 are shown in FIG. 2. The first charge gram capacity, and the first discharge gram capacity C0 mAh/g are recorded, and at the same time, a discharge gram capacity within the range from beginning of discharge to the cut-off voltage 4.4V is defined as C1 mAh/g, the gram capacity discharged within the discharge voltage range of 3.8V-3.7V in discharge capacity is defined as C2 mAh/g, and first time efficiency, C1/C0 and C2/C0 are calculated. The results are shown in Table 2.

[0105] The positive electrode materials provided according to Examples 1-22 and Comparative Examples 1-4 are mixed, after a certain amount of amplification, with conductive carbon black and PVDF in a weight ratio of 96:2:2, dispersed in a solvent to prepare a positive electrode active layer slurry, the slurry is coated on a surface of a positive electrode aluminum current collector to obtain a positive electrode piece, which is subsequently assembled with a negative electrode piece, a separator and electrolyte to obtain a lithium ion battery. A specific preparation method is as follows:

[0106] artificial graphite (with charging cut-off voltage being 4.5V), styrene butadiene rubber (SBR), sodium carboxymethylcellulose and conductive carbon black are mixed in a weight ratio of 94:3:2:1, dispersed in water and mixed by revolution-rotation mixing equipment, to obtain a negative electrode active layer slurry, which is coated on a negative electrode copper current collector to obtain the negative electrode piece.

[0107] The electrolyte includes an organic solvent and an additive, and the organic solvent includes ethylene carbonate (EC), diethyl carbonate (DEC), propylene carbonate (PC) and fluoroethylene carbonate (FEC), and the additive has the following structure:

##STR00002##

then cycle performance of the lithium ion battery is tested. The cycle performance test process is as follows: at 25° C., charge to 4.50V at a constant current with a charge rate of 1 C, then charge to 4.50V at a constant voltage with a charge rate of 0.05 C, and then discharge to 3.0V at a discharge rate of 1 C. This charge and discharge cycle are repeated for 500 times. A discharge capacity at the first cycle and a discharge capacity at the 500.sup.th cycle are determined, to calculate capacity retention rate after cycles as follows: capacity retention rate after cycles=(discharge capacity at the 500.sup.th cycle)/(discharge capacity at the first cycle)*100%. The results are shown in Table 2.

TABLE-US-00002 TABLE 2 Test results of gram capacity and battery performance of the positive electrode materials provided in Examples 1-22 and Comparative Examples 1-4 First First Capacity charge discharge retention gram gram First rate capacity capacity effi- after for for ciency 500 button button for cycles cell cell button for full (mAh/g) (mAh/g) cell C1/C0 C2/C0 battery Example 1 210.5 201.2 95.60% 11.30% 29.60% 85.30% Example 2 209.8 200.7 95.70% 10.90% 29.90% 85.83% Example 3 208.3 200.3 96.20% 10.30% 30.20% 84.97% Example 4 209.2 201.4 96.30% 11.10% 29.70% 86.56% Example 5 211.3 202.5 95.80% 11.90% 29.60% 86.02% Example 6 209.7 202 96.30% 12.20% 30.10% 84.83% Example 7 210.8 199.8 94.80% 12.60% 31.50% 86.39% Example 8 208.9 201.3 96.40% 11.50% 28.90% 83.98% Example 9 209.7 201 95.90% 11.30% 29.80% 85.76% Example 10 211 200.8 95.20% 12.10% 30.05% 86.13% Example 11 212.4 202.3 95.20% 10.85% 31.06% 85.93% Example 12 210.6 201.4 95.60% 12.30% 29.45% 86.77% Example 13 211.2 199.5 94.50% 11.70% 30.64% 87.81% Example 14 208.5 198.4 95.20% 12.34% 31.47% 88.34% Example 15 208.1 197.4 94.90% 12.98% 32.05% 88.76% Example 16 210.9 200 94.80% 11.87% 29.86% 86.98% Example 17 211.3 198.7 94.00% 12.48% 30.96% 87.44% Example 18 208.6 198 94.90% 13.13% 31.07% 88.65% Example 19 210.6 201.4 95.60% 11.59% 29.64% 84.86% Example 20 209.5 199.9 95.40% 11.78% 29.63% 86.76% Example 21 208.9 199.1 95.30% 12.18% 30.32% 87.95% Example 22 207.8 198.4 95.50% 13.04% 31.05% 88.35% Comparative 205.2 195.4 95.20%  6.54%  0.46% 56.32% Example 1 Comparative 199 187.8 94.40%  5.87%  0.52% 78.42% Example 2 Comparative 206.5 189.6 91.8%  9.08% 24.89% 79.45% Example 3 Comparative 207.3 190.4 91.8%  8.17% 24.68% 78.87% Example 4

[0108] It can be found from Table 2 that the positive electrode materials provided in Examples 1-22 of the present disclosure are helpful to improve the capacity and cycle performance of a lithium ion battery compared with Comparative Examples 1-4, and the capacity retention rate after 500 cycles is at least 8000. It can be known according to Examples 13-22 and Comparative Examples 3-4, that the cycle performance of a lithium ion battery is also improved with the increase of the peak intensity ratio m. To sum up, the positive electrode materials provided by the present disclosure can enable the lithium ion battery to achieve high discharge gram capacity and excellent cycle performance at high voltage, and meet people's demand for thin lithium-ion batteries.

[0109] Finally, it should be noted that the above examples are only used to illustrate the technical solution of the present disclosure, not to limit it; although the present disclosure has been described in detail with reference to the above-mentioned examples, those skilled in the art should understand that they can still modify the technical solutions recited in the above-mentioned examples, or replace equivalently some or all of the technical features therein; however, these modifications or replacements do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the examples of the present disclosure.