COBALT-FREE HIGH-NICKEL POSITIVE ELECTRODE MATERIAL, PREPARATION METHOD THEREFOR AND USE THEREOF

Abstract

Provided in the present disclosure are a cobalt-free high-nickel positive electrode material, a preparation method therefor and use thereof. The cobalt-free high-nickel positive electrode material comprises a cobalt-free high-nickel matrix material and a coating layer coated on the cobalt-free high-nickel matrix material, wherein a chemical formula of the cobalt-free high-nickel matrix material is Li.sub.mNi.sub.xMn.sub.yO.sub.2, where 0.2?m?0.8, 0.4?x?0.95, and 0.05?y?0.6; and the coating layer is TiB.sub.zO.sub.1-z, where 0.2?z?0.8. The cobalt-free high-nickel positive electrode material obtained by means of modification using the coating layer TiB.sub.zO.sub.1-z has good acid resistance and wear resistance, high mechanical strength and excellent conductivity; and when the cobalt-free high-nickel positive electrode material is used for a lithium ion battery, the high-temperature cycling performance, capacity and initial efficiency of the lithium ion battery are greatly improved.

Claims

1. A cobalt-free high-nickel positive electrode material, comprising: a cobalt-free high-nickel matrix material and a coating layer which is coated on the cobalt-free high-nickel matrix material, wherein a chemical formula of the cobalt-free high-nickel matrix material is Li.sub.mNi.sub.xMn.sub.yO.sub.2, wherein 0.2?m?0.8, 0.4?x?0.95, and 0.05?y?0.6, and the coating layer is TiB.sub.zO.sub.1-z, wherein 0.2?z?0.8.

2. The cobalt-free high-nickel positive electrode material according to claim 1, wherein a mass of the coating layer is from 0.2% to 0.5% of that of the cobalt-free high-nickel matrix material.

3. The cobalt-free high-nickel positive electrode material according to claim 1, wherein the cobalt-free high-nickel positive electrode material has a D50 from 1 m to 5 ?m, and preferably the cobalt-free high-nickel positive electrode material has a specific surface area from 0.3 m.sup.2/g to 1.5 m.sup.2/g.

4. A method for preparing a cobalt-free high-nickel positive electrode material, the method comprising: Step S1, mixing a cobalt-free high-nickel matrix material with a coating agent to obtain a mixture; and Step S2, calcining the mixture to obtain the cobalt-free high-nickel positive electrode material, wherein the coating agent is TiB.sub.zO.sub.1-z solid solution particles, and wherein a chemical formula of the cobalt-free high-nickel matrix material is Li.sub.mNi.sub.xMn.sub.yO.sub.2, wherein 0.2?m?0.8, 0.4?x?0.95, and 0.05?y?0.6.

5. The method according to claim 4, wherein a mass of the coating layer is from 0.2% to 0.5% of that of the cobalt-free high-nickel matrix material.

6. The method according to claim 5, wherein the cobalt-free high-nickel positive electrode material has a D50 from 1 ?m to 5 ?m, and preferably the cobalt-free high-nickel positive electrode material has a specific surface area from 0.3 m.sup.2/g to 1.5 m.sup.2/g.

7. The method according to claim, wherein the TiB.sub.zO.sub.1-z solid solution particles have a D50 from 10 nm to 100 nm.

8. The method according to claim 6, wherein the calcining is performed at a temperature from 300? C. to 900? C., preferably the temperature is increased from 300? C. to 900? C. at an increasing rate from 3? C./min to 5? C./min, and preferably the calcining time is from 6 hours to 12 hours.

9. The method according to claim 6, further comprising a process for preparing the coating agent, wherein the process for preparing the coating agent comprises: reacting a titanium source with a boron source by a high-temperature solid-phase reaction method to obtain TiB.sub.zO.sub.1-z solid solution particles; wherein the titanium source is TiO.sub.2, and the boron source is TiB or H.sub.3BO.sub.3, preferably a molar ratio of the titanium source to the boron source is from 0.5:1 to 1:1; preferably the reaction temperature of the high-temperature solid-phase reaction method is from 1000? C. to 1800? C.; and preferably the reaction time of the high-temperature solid-phase reaction method is from 12 hours to 24 hours.

10. the method according to claim 9, wherein the process for preparing the coating agent further comprises: crushing the TiB.sub.zO.sub.1-z solid solution particles, preferably by grinding.

11. A lithium ion battery, comprising: a positive electrode and a negative electrode, wherein the positive electrode comprises a positive electrode material, wherein the positive electrode material is a cobalt-free high-nickel positive electrode material comprising a cobalt-free high-nickel matrix material and a coating layer which is coated on the cobalt-free high-nickel matrix material, wherein a chemical formula of the cobalt-free high-nickel matrix material is Li.sub.mNi.sub.xMn.sub.yO.sub.2, wherein 0.2?m?0.8, 0.4?x?0.95, and 0.05?y?0.6, and the coating layer is TiB.sub.zO.sub.1-z, wherein 0.2?z?0.8.

Description

BRIEF DESCRIPTION OF FIGURES

[0017] The accompanying drawings forming a part of the present application are intended to provide a further understanding of the present disclosure, and illustrative examples of the present disclosure and description thereof are intended to illustrate the present disclosure and do not constitute an improper limitation of the present disclosure. In the drawings:

[0018] FIG. 1 shows an X-ray powder diffraction (XRD) pattern of TiB.sub.0.5O.sub.0.5 provided in Example 1;

[0019] FIG. 2 shows a scanning electron microscope (SEM) image of TiB.sub.0.5O.sub.0.5 provided in Example 1;

[0020] FIG. 3 shows a partial elemental analysis diagram of TiB.sub.0.5O.sub.0.5 provided in Example 1;

[0021] FIG. 4 shows an SEM image and a partial elemental analysis diagram of a cobalt-free high-nickel positive electrode material provided in Example 1;

[0022] FIG. 5 shows an SEM image of a cross section of the cobalt-free high-nickel positive electrode material provided in Example 1 and a partial elemental analysis diagram of the cobalt-free high-nickel positive electrode material; and

[0023] FIG. 6 shows a discharge voltage test diagram of Example 1 and Comparative example 1 at 0.1 C.

DETAILED DESCRIPTION

[0024] It should be noted that the examples and the features of the examples in the present application can be combined with each other without conflict. The present disclosure will be described below in detail with reference to the accompanying drawings in conjunction with the examples.

[0025] As analyzed in the background, there is a problem in the prior art that high cycling stability and high capacity of a cobalt-free high-nickel positive electrode material cannot be combined, and to solve the problem, the present disclosure provides a cobalt-free high-nickel positive electrode material and a preparation method therefor, a positive electrode for a lithium ion battery, and a lithium ion battery.

[0026] In one typical embodiment of the present application, provided is a cobalt-free high-nickel positive electrode material, including: a cobalt-free high-nickel matrix material and a coating layer which is coated on the cobalt-free high-nickel matrix material, wherein a chemical formula of the cobalt-free high-nickel matrix material is Li.sub.mNi.sub.xMn.sub.yO.sub.2, wherein 0.2?m?0.8, 0.4?x?0.95, and 0.05?y?0.6, and the coating layer is TiB.sub.zO.sub.1-z, wherein 0.2?z?0.8.

[0027] The present application combines the advantages of high capacity, low cost, high safety, etc., of the cobalt-free high-nickel matrix material, and adopts TiB.sub.xO.sub.1-x which has the advantages of high strength, high wear resistance, high acid resistance, thermal stability, good conductivity, etc., as the coating layer of the cobalt-free high-nickel matrix material. On one hand, oxygen vacancies present in TiB.sub.xO.sub.1-x contribute to the de-intercalation of lithium ions and the effect of reducing oxygen loss during the high-temperature solid-phase reaction; on the other hand, TiB.sub.xO.sub.1-x reduces a contact area of the cobalt-free high-nickel positive electrode material with an electrolyte, relieving the occurrence of side reactions of the cobalt-free high-nickel positive electrode material with the electrolyte. Therefore, the cobalt-free high-nickel positive electrode material obtained by combining the effects of the above two aspects has good acid resistance and wear resistance, high mechanical strength and excellent conductivity, and when the cobalt-free high-nickel positive electrode material is used for a lithium ion battery, the high-temperature cycling performance, capacity and initial efficiency of the lithium ion battery are greatly improved.

[0028] In order to further improve the modification effect of the coating layer on the cobalt-free high-nickel matrix material, preferably a mass of the coating layer is from 0.2% to 0.5% of that of the cobalt-free high-nickel matrix material.

[0029] In one example of the present application, the cobalt-free high-nickel positive electrode material has a D50 from 1 m to 5 ?m, and preferably the cobalt-free high-nickel positive electrode material has a specific surface area from 0.3 m.sup.2/g to 1.5 m.sup.2/g.

[0030] The cobalt-free high-nickel positive electrode material having the above particle size and specific surface area carries more TiB.sub.zO.sub.1-z particles, and thus it is easier to exert the modification effect of the TiB.sub.zO.sub.1-z particles on the cobalt-free high-nickel positive electrode material. Wherein the D50 and specific surface area of the cobalt-free high-nickel positive electrode material fluctuate within the above ranges with the different particle sizes of the cobalt-free high-nickel matrix material.

[0031] In another typical embodiment of the present application, provided is a method for preparing the cobalt-free high-nickel positive electrode material, including: Step S1, mixing the cobalt-free high-nickel matrix material with a coating agent to obtain a mixture; and Step S2, calcining the mixture to obtain the cobalt-free high-nickel positive electrode material, wherein the coating agent is TiB.sub.zO.sub.1-z solid solution particles.

[0032] First, mixing with the coating agent is performed to obtain a uniform mixture, and then the mixture is calcined so that the TiB.sub.zO.sub.1-z solid solution particles coat the cobalt-free high-nickel matrix material after a process of melting-cooling. The preparation method is simple and easy to perform. The obtained cobalt-free high-nickel positive electrode material combines the advantages of high capacity, low cost, high safety, etc., of the cobalt-free high-nickel matrix material, and adopts TiB.sub.xO.sub.1-x which has the advantages of high strength, high wear resistance, high acid resistance, thermal stability, good conductivity, etc., as the coating layer of the cobalt-free high-nickel matrix material. On one hand, oxygen vacancies present in TiB.sub.xO.sub.1-x contribute to the de-intercalation of lithium ions and the effect of reducing oxygen loss during the high-temperature solid-phase reaction; on the other hand, TiB.sub.xO.sub.1-x reduces a contact area of the cobalt-free high-nickel positive electrode material with an electrolyte, relieving the occurrence of side reactions of the cobalt-free high-nickel positive electrode material with the electrolyte. Therefore, the cobalt-free high-nickel positive electrode material obtained by combining the effects of the above two aspects has good acid resistance and wear resistance, high mechanical strength and excellent conductivity, and when the cobalt-free high-nickel positive electrode material is used for a lithium ion battery, the high-temperature cycling performance, capacity and initial efficiency of the lithium ion battery are greatly improved.

[0033] The TiB.sub.zO.sub.1-z solid solution particles have oxygen vacancies, and preferably the above TiB.sub.zO.sub.1-z solid solution particles have a D50 from 10 nm to 100 nm, so that the TiB.sub.zO.sub.1-z solid solution particles have a larger specific surface area and more oxygen vacancies, thus more fully exerting the effects of the TiB.sub.zO.sub.1-z solid solution in de-intercalation of ions and reducing oxygen loss during the high-temperature solid-phase reaction.

[0034] In order to further improve sufficient contact of a melt formed after calcining the TiB.sub.zO.sub.1-z solid solution particles with the cobalt-free high-nickel matrix material, thereby facilitating more full coating of the cobalt-free high-nickel matrix material, preferably the calcining is performed at a temperature from 300? C. to 900? C., preferably the temperature is increased from 300? C. to 900? C. at an increasing rate from 3? C./min to 5? C./min, and preferably the calcining time is from 6 hours to 12 hours.

[0035] In one example of the present application, the preparation method further includes a process for preparing the coating agent, wherein the process for preparing the coating agent includes: reacting a titanium source with a boron source by a high-temperature solid-phase reaction method to obtain TiB.sub.zO.sub.1-z solid solution particles; wherein the titanium source is TiO.sub.2, and the boron source is TiB or H.sub.3BO.sub.3, preferably a molar ratio of the titanium source to the boron source is from 0.5:1 to 1:1; preferably the reaction temperature of the high-temperature solid-phase reaction method is from 1000? C. to 1800? C.; and preferably the reaction time of the high-temperature solid-phase reaction method is from 12 hours to 24 hours.

[0036] The above molar ratio of the titanium source to the boron source is more conducive to obtaining the TiB.sub.zO.sub.1-z solid solution particles, wherein both the temperature and time of the high-temperature solid-phase reaction method contribute to increasing the efficiency of the high-temperature solid-phase reaction.

[0037] In one example of the present application, the process for preparing the coating agent further includes: crushing the TiB.sub.zO.sub.1-z solid solution particles, preferably by grinding.

[0038] A TiB.sub.zO.sub.1-z solid solution with a more suitable particle size can be obtained by crushing the TiB.sub.zO.sub.1-z solid solution particles to more fully coat the cobalt-free high-nickel matrix material. Wherein the grinding is more cost-effective.

[0039] In yet another typical embodiment of the present application, provided is a positive electrode for a lithium ion battery, including a positive electrode material, wherein the positive electrode material is the cobalt-free high-nickel positive electrode material described above.

[0040] When the positive electrode for a lithium ion battery including the cobalt-free high-nickel positive electrode material of the present application is applied to a battery, the battery has excellent cycling stability and higher capacity.

[0041] In yet another typical embodiment of the present application, provided is a lithium ion battery, including a positive electrode and a negative electrode, wherein the positive electrode is the positive electrode for a lithium ion battery described above.

[0042] The lithium ion battery including the positive electrode of the present application has more excellent cycling stability and higher capacity.

[0043] The beneficial effects of the present application will be described below with reference to specific examples and comparative examples.

Example 1

[0044] Synthesis of a cobalt-free high-nickel matrix material: a lithium salt (LiOH) and a cobalt-free precursor Ni.sub.0.82Mn.sub.0.18(OH).sub.2 were mixed in a molar ratio of Li to Mn being 1.05:1 at 2000 rpm/min for 10 min to obtain a mixed material; the mixed material was calcined in an oxygen atmosphere (a concentration of greater than 99.99%, and an oxygen flow rate of 10 L/min), and heated in a box atmosphere furnace at 5? C./min to a high temperature of 1000? C. for a reaction for 20 h, and then cooling was performed at 5? C./min to room temperature to obtain a matrix material, the matrix material was crushed by using a crusher, and the obtained powder material was sieved (a sieve was from 300-mesh to 400-mesh) to obtain the cobalt-free high-nickel matrix material having a chemical formula of Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2.

[0045] Synthesis of a TiB.sub.zO.sub.1-z solid solution: TiB.sub.2 and TiO.sub.2 were uniformly mixed in a molar ratio of 0.5:1, dried and ground, the mixed material was heated at 8? C./min in a nitrogen atmosphere (a concentration of greater than 99.99%, and a nitrogen flow rate of 10 L/min) and in a box atmosphere furnace to 1000? C. for a high-temperature solid-phase reaction for 12 h to obtain TiB.sub.0.5O.sub.0.5 solid solution particles, and the TiB.sub.0.5O.sub.0.5 solid solution particles were ground for standby application, an XRD pattern of the TiB.sub.0.5O.sub.0.5 solid solution particles is shown in FIG. 1, an SEM image of the TiB.sub.0.5O.sub.0.5 solid solution particles is shown in FIG. 2, and FIG. 3 is a partial elemental analysis diagram of the TiB.sub.0.5O.sub.0.5 solid solution.

[0046] Coating: 0.5 g of the TiB.sub.0.5O.sub.0.5 solid solution particles were mixed with Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 to obtain a mixture. Wherein the TiB.sub.0.5O.sub.0.5 solid solution particles have a D50 of 50 nm, a mass of the TiB.sub.0.5O.sub.0.5 solid solution particles is 0.3% of that of Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2, and the mixing was performed with a hand-held mixer for 20 min, the mixed material was heated in an oxygen atmosphere (a concentration of greater than 99.99%, and an oxygen flow rate of 10 L/min) and in a box atmosphere furnace at 5? C./min to 900? C. for calcining for 12 h to obtain a cobalt-free high-nickel positive electrode material, and the cobalt-free high-nickel positive electrode material was ground for standby application, an SEM image and a partial elemental analysis diagram of the cobalt-free high-nickel positive electrode material are shown in FIG. 4, and an SEM image of a cross section of the cobalt-free high-nickel positive electrode material and a partial elemental analysis diagram of the cobalt-free high-nickel positive electrode material are shown in FIG. 5.

[0047] As can be seen from the comparison between FIG. 4 and FIG. 5, TiB.sub.0.5O.sub.0.5 has successfully coated the surface of Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2, and based on this and in combination with the above coating conditions, applicants hypothesized that TiB.sub.0.5O.sub.0.5 should have retained its original crystal structure.

Example 2

[0048] Example 2 differs from Example 1 in that: [0049] a mass of the TiB.sub.0.5O.sub.0.5 solid solution particles is 0.2% of that of Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2, finally obtaining a cobalt-free high-nickel positive electrode material.

Example 3

[0050] Example 3 differs from Example 1 in that: [0051] a mass of the TiB.sub.0.5O.sub.0.5 solid solution particles is 0.5% of that of Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2, finally obtaining a cobalt-free high-nickel positive electrode material.

Example 4

[0052] Example 4 differs from Example 1 in that: [0053] a mass of the TiB.sub.0.5O.sub.0.5 solid solution particles is 0.1% of that of Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2, finally obtaining a cobalt-free high-nickel positive electrode material.

Example 5

[0054] Example 5 differs from Example 1 in that: [0055] a mass of the TiB.sub.0.5O.sub.0.5 solid solution particles is 0.8% of that of Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2, finally obtaining a cobalt-free high-nickel positive electrode material.

Example 6

[0056] Example 6 differs from Example 1 in that: [0057] the TiB.sub.0.5O.sub.0.5 solid solution particles have a D50 of 10 nm, finally obtaining a cobalt-free high-nickel positive electrode material.

Example 7

[0058] Example 7 differs from Example 1 in that: [0059] the TiB.sub.0.5O.sub.0.5 solid solution particles have a D50 of 100 nm, finally obtaining a cobalt-free high-nickel positive electrode material.

Example 8

[0060] Example 8 differs from Example 1 in that: [0061] the TiB.sub.0.5O.sub.0.5 solid solution particles have a D50 of 200 nm, finally obtaining a cobalt-free high-nickel positive electrode material.

Example 9

[0062] Example 9 differs from Example 1 in that: [0063] the TiB.sub.0.5O.sub.0.5 solid solution particles have a D50 of 5 nm, finally obtaining a cobalt-free high-nickel positive electrode material.

Example 10

[0064] Example 10 differs from Example 1 in that: [0065] the calcining during coating was performed at 500? C., finally obtaining a cobalt-free high-nickel positive electrode material.

Example 11

[0066] Example 11 differs from Example 1 in that: [0067] the calcining during coating was performed at 300? C., finally obtaining a cobalt-free high-nickel positive electrode material.

Example 12

[0068] Example 12 differs from Example 1 in that: [0069] the calcining during coating was performed at 200? C., finally obtaining a cobalt-free high-nickel positive electrode material.

Example 13

[0070] Example 13 differs from Example 1 in that: [0071] the calcining during coating was performed at 1000? C., finally obtaining a cobalt-free high-nickel positive electrode material.

Example 14

[0072] Example 14 differs from Example 1 in that: [0073] a heating rate for the calcining was 3? C./min, finally obtaining a cobalt-free high-nickel positive electrode material.

Example 15

[0074] Example 15 differs from Example 1 in that: [0075] a molar ratio of TiB.sub.2 to TiO.sub.2 was 1:1, obtaining TiB.sub.0.75O.sub.0.25, and finally obtaining a cobalt-free high-nickel positive electrode material.

Example 16

[0076] Example 16 differs from Example 1 in that: [0077] a high-temperature solid-phase reaction was carried out at 1800? C. for 24 h to obtain TiB.sub.0.5O.sub.0.5, finally obtaining a cobalt-free high-nickel positive electrode material.

Example 17

[0078] Example 17 differs from Example 1 in that: [0079] a lithium salt (LiOH) and a cobalt-free precursor Ni.sub.0.95Mn.sub.0.05(OH).sub.2 were mixed in a molar ratio of Li to Mn being 1.05:1, and the resulting cobalt-free high-nickel matrix material was Li.sub.1.05Ni.sub.0.95Mn.sub.0.05O.sub.2, finally obtaining a cobalt-free high-nickel positive electrode material.

Example 18

[0080] Example 18 differs from Example 1 in that: [0081] a lithium salt (LiOH) and a cobalt-free precursor Ni.sub.0.4Mn.sub.0.6(OH).sub.2 were mixed in a molar ratio of Li to Mn being 1.1:1, and the resulting cobalt-free high-nickel matrix material was Li.sub.1.1Ni.sub.0.4Mn.sub.0.6O.sub.2, finally obtaining a cobalt-free high-nickel positive electrode material.

Example 19

[0082] Example 19 differs from Example 1 in that: [0083] the TiB.sub.zO.sub.1-z solid solution particles were TiB.sub.0.2O.sub.0.8, finally obtaining a cobalt-free high-nickel positive electrode material.

Example 20

[0084] Example 20 differs from Example 1 in that: [0085] the TiB.sub.zO.sub.1-z solid solution particles were TiB.sub.0.8O.sub.0.2, finally obtaining a cobalt-free high-nickel positive electrode material.

Comparative Example 1

[0086] Comparative example 1 differs from Example 1 in that: [0087] the cobalt-free high-nickel matrix material Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 was used directly as a cobalt-free high-nickel positive electrode material.

[0088] A discharge voltage test diagram of Example 1 and Comparative example 1 at 0.1 C is shown in FIG. 6, and it can be seen from FIG. 6 that a discharge voltage of the cobalt-free high-nickel positive electrode material coated with the TiB.sub.zO.sub.1-z solid solution was slightly higher than that of the cobalt-free high-nickel matrix material not coated with the TiB.sub.zO.sub.1-z solid solution.

[0089] The chemical formulas of the cobalt-free high-nickel positive electrode materials obtained in the above Examples 1-20 and Comparative example 1, the mass percentage of the coating layer in the cobalt-free high-nickel matrix material, D50, and the specific surface area are listed in Table 1.

TABLE-US-00001 TABLE 1 Mass percentage of the coating Chemical formula of layer in the a cobalt-free high- cobalt-free high- Specific nickel positive nickel matrix D50/ surface electrode material material/% ?m area/m.sup.2/g Example 1 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.54 0.34 Example 2 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.2 3.52 0.35 Example 3 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.5 3.56 0.33 Example 4 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.1 3.51 0.35 Example 5 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.8 3.58 0.32 Example 6 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.55 0.32 Example 7 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.51 0.35 Example 8 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.53 0.36 Example 9 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.52 0.46 Example 10 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.50 0.33 Example 11 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.53 0.32 Example 12 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.54 0.35 Example 13 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.80 0.25 Example 14 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.56 0.31 Example 15 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.52 0.32 Example 16 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.53 0.34 Example 17 Li.sub.1.05Ni.sub.0.95Mn.sub.0.05O.sub.2 0.3 3.53 0.33 Example 18 Li.sub.1.1Ni.sub.0.4Mn.sub.0.6O.sub.2 0.3 3.57 0.33 Example 19 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.53 0.31 Example 20 Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0.3 3.56 0.33 Comparative Li.sub.1.05Ni.sub.0.82Mn.sub.0.18O.sub.2 0 3.50 0.37 example 1

[0090] The cobalt-free high-nickel positive electrode materials obtained in the above Examples 1-20 and Comparative example 1 were separately subjected to button cell assembly: coating was performed according to a ratio of the cobalt-free high-nickel positive electrode material to Sp to a PVDF glue solution being 92:4:4, and the solid content of the PVDF glue solution being 6.05%, and button cell assembly was performed by using a BR2032 shell to obtain button cells.

[0091] The cycling performance of the button cells was tested, and the differences in capacity, initial efficiency, cycling performance and voltage of the button cells were mainly examined: testing was performed at a voltage from 3.0 V to 4.3 V at 25? C. to obtain data in Table 2.

TABLE-US-00002 TABLE 2 Charge Discharge 50-cycle capacity capacity Initial Discharge capacity at 0.1 at 0.1 efficien- capacity at retention C/mAh/g C/mAh/g cy/% 1 C/mAh/g rate/% Example 1 216.5 193.7 89.47 175.0 97.1 Example 2 220.1 196.2 89.14 178.2 96.1 Example 3 216.4 194.1 89.70 174.3 96.8 Example 4 217.3 188.4 86.69 172.6 93.0 Example 5 216.2 185.7 85.87 172.6 92.8 Example 6 218.3 195.6 89.60 176.2 97.1 Example 7 219.4 196.3 89.47 178.1 96.2 Example 8 215.3 181.2 84.15 172.1 93.5 Example 9 216.1 181.6 84.05 173.3 93.3 Example 10 217.2 195.2 89.87 174.6 96.7 Example 11 218.7 196.6 89.89 175.2 96.8 Example 12 218.6 184.0 84.17 171.4 92.8 Example 13 219.3 187.6 85.56 172.1 93.4 Example 14 219.5 197.1 89.79 176.2 96.1 Example 15 218.6 196.2 89.75 176.3 97.2 Example 16 217.1 193.6 89.19 174.2 97.1 Example 17 216.9 194.3 89.58 174.3 97.3 Example 18 220.6 198.1 89.80 178.6 97.5 Example 19 215.9 192.2 89.04 174.3 97.3 Example 20 218.2 195.2 89.46 175.6 97.2 Comparative 209.0 168.6 80.68 165.4 90.2 example 1

[0092] The button cells corresponding to Examples 1, 4, 8, 12, 17, and 18, and Comparative example 1 were tested for the capacity, initial efficiency, and cycling performance at 25? C., 45? C., and 60? C., respectively, and the test results are listed in Table 3.

TABLE-US-00003 TABLE 3 Charge Discharge Discharge 50-cycle capacity capacity Initial capacity capacity Temperature/ at 0.1 at 0.1 efficiency/ at 1 retention ? C. C/mAh/g C/mAh/g % C/mAh/g rate/% Example 1 25 216.5 193.7 89.47 175.0 97.1 45 220.1 193.1 87.74 178.2 98.1 60 216.4 189.5 87.57 174.3 96.8 Example 4 25 217.3 188.4 86.69 172.6 93.0 45 219.2 185.9 84.82 173.5 93.2 60 218.6 185.0 84.64 172.1 93.8 Example 8 25 215.3 181.2 84.15 172.1 93.5 45 218.2 187.5 85.91 174.0 93.8 60 217.3 187.0 86.05 173.5 93.0 Example 12 25 218.6 184.0 84.17 171.4 92.8 45 217.3 185.3 85.27 174.2 90.8 60 216.3 184.5 85.30 174.9 89.3 Example 17 25 216.9 194.3 89.58 174.3 97.3 45 216.3 192.5 89.01 174.2 96.8 60 215.2 191.6 89.05 173.6 96.5 Example 18 25 220.6 198.1 89.80 178.6 97.5 45 222.3 198.2 89.15 177.6 96.1 60 219.3 196.5 89.60 177.8 97.2 Comparative 25 209.0 168.6 80.68 165.4 90.2 example 1 45 206.0 172.2 83.58 160.3 88.2 60 205.4 164.5 80.08 159.3 82.3

[0093] As can be seen from Table 3, compared with Comparative example 1, the cobalt-free high-nickel positive electrode material provided in the present application has little difference in capacity and cycling performance at different temperatures, and has good high temperature resistance.

[0094] From the above description, it can be seen that the above examples of the present disclosure achieve the following technical effects: [0095] the present application combines the advantages of high capacity, low cost, high safety, etc., of the cobalt-free high-nickel matrix material, and adopts TiB.sub.xO.sub.1-x which has the advantages of high strength, high wear resistance, high acid resistance, thermal stability, good conductivity, etc., as the coating layer of the cobalt-free high-nickel matrix material. On one hand, oxygen vacancies present in TiB.sub.xO.sub.1-x contribute to the de-intercalation of lithium ions and the effect of reducing oxygen loss during the high-temperature solid-phase reaction; on the other hand, TiB.sub.xO.sub.1-x reduces a contact area of the cobalt-free high-nickel positive electrode material with an electrolyte, relieving the occurrence of side reactions of the cobalt-free high-nickel positive electrode material with the electrolyte. Therefore, the cobalt-free high-nickel positive electrode material obtained by combining the effects of the above two aspects has good acid resistance and wear resistance, high mechanical strength and excellent conductivity, and when the cobalt-free high-nickel positive electrode material is used for a lithium ion battery, the high-temperature cycling performance, capacity and initial efficiency of the lithium ion battery are greatly improved.

[0096] The above are only the preferred examples of the present disclosure, and are not intended to limit the present disclosure, and various modifications and variations of the present disclosure may be made for those skilled in the art. Any modifications, equivalent replacements, improvements, and the like, made within the spirit and principle of the present disclosure should be included within the scope of protection of the present disclosure.