阅读说明：本技术 磷酸钽铝锂改性的高镍正极材料、前驱体以及制备方法 (Lithium aluminum tantalum phosphate modified high-nickel cathode material, precursor and preparation method ) 是由 张宝 邓鹏� 林可博 邓梦轩 丁瑶 于 2021-07-13 设计创作，主要内容包括：本发明涉及电池材料技术领域,具体公开了一种磷酸钽铝锂改性的高镍正极材料、前驱体以及制备方法。本发明的正极材料的化学式为LiNi-xCo-yMn-zO-2·nLiAlTa(PO-4)-3,其中x、y、z为摩尔数,0.8≤x<1,0<y≤0.1,0<z≤0.1,0<n≤0.05,x+y+z=1；表面有铝、钽元素掺杂且具有LiAlTa(PO-4)-3的包覆层。在制备高镍正极材料的过程中,首先制备Ni-xCo-yMn-z(OH)-2,然后在前驱体表面包覆LiAlTa(PO-4)-3,最后,与锂源焙烧即得。本发明制备得到的正极材料电化学性能优异,且制备方法简单、生产成本低。(The invention relates to the technical field of battery materials, and particularly discloses a lithium aluminum tantalum phosphate modified high-nickel cathode material, a precursor and a preparation method. The chemical formula of the cathode material is LiNi x Co y Mn z O 2 •nLiAlTa(PO 4 ) 3 Wherein x, y and z are mole numbers, and x is more than or equal to 0.8<1，0<y≤0.1，0<z≤0.1，0<n is less than or equal to 0.05, and x + y + z = 1; the surface is doped with aluminum and tantalum elements and is provided with LiAlTa (P)O 4 ) 3 The coating layer of (2). In the process of preparing the high-nickel cathode material, Ni is firstly prepared x Co y Mn z (OH) 2 Then coating LiAlTa (PO) on the surface of the precursor 4 ) 3 And finally, roasting with a lithium source to obtain the lithium ion battery. The cathode material prepared by the invention has excellent electrochemical performance, and the preparation method is simple and low in production cost.)

1. A precursor of a lithium aluminum tantalum phosphate modified high-nickel anode material is characterized in that the chemical formula is Ni_xCo_yMn_zO₂•nLiAlTa(PO₄)₃Wherein x, y and z are mole numbers, and x is more than or equal to 0.8<1，0<y≤0.1，0<z≤0.1，0<n≤0.05，x+y+z=1。

2. The preparation method of the precursor of the lithium aluminum tantalum phosphate modified high-nickel cathode material as claimed in claim 1, characterized by comprising the following steps:

(1) preparing metal salt solution of Ni, Co and Mn, adding precipitant and complexing agent, and coprecipitating to obtain Ni_xCo_yMn_z(OH)₂；

(2) Sequentially adding a lithium source, an aluminum source, a tantalum source and a phosphorus source into a solvent, and uniformly stirring to obtain a mixed solution; then adding the Ni obtained in the step (1) into the mixed solution_xCo_yMn_z(OH)₂Continuously stirring according to a certain solid-to-liquid ratio, evaporating the solvent and drying in vacuum to obtain a precursor Ni of the lithium aluminum tantalum phosphate modified anode material_xCo_yMn_z(OH)₂•nLiAlTa(PO₄)₃。

3. The method according to claim 2, wherein the metal salts of nickel, cobalt and manganese in step (1) are selected from sulfates, the precipitant is NaOH solution, and the complexing agent is NH₃·H₂And (4) O solution.

4. The preparation method according to claim 3, wherein the concentration of the NaOH solution is 5 to 8 mol/L; the NH₃•H₂The concentration of the O solution is 5-8 mol/L.

5. The preparation method according to claim 2, wherein the stirring speed of the coprecipitation reaction in the step (1) is 400-700 rpm, the pH value of the reaction system is 11-12.5, the concentration of ammonia in the reaction system is 9-12 g/L, and the reaction time is 20-70 h.

6. The preparation method according to claim 2, wherein the aluminum source in the step (2) is one or both of aluminum nitrate and aluminum sulfate; the phosphorus source is one or more of ammonium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate and phosphoric acid; the tantalum source is one or two of tantalum nitrate and tantalum sulfate; the solvent is one or more of water, methanol, absolute ethyl alcohol and propanol; the lithium source is one or more of lithium hydroxide, lithium carbonate and lithium nitrate.

7. The production method according to claim 2 or 6, wherein in the step (2), the ratio of the molar amounts of the lithium source, the aluminum source, the tantalum source and the phosphorus source is 1: 1-2: 1-2: 3.

8. the preparation method according to claim 2, wherein in the step (2), the solid-to-liquid ratio is 1g: 5-15 mL; the temperature of the evaporation solvent is 60-120 ℃, and the time is 2-6 h; the temperature of the vacuum drying is 60-120 ℃, and the time is 6-12 h.

9. A lithium aluminum tantalum phosphate modified high nickel anode material is characterized in that the chemical formula is LiNi_xCo_yMn_zO₂•nLiAlTa(PO₄)₃Wherein x, y and z are mole numbers, and x is more than or equal to 0.8<1，0<y≤0.1，0<z≤0.1，0<n is less than or equal to 0.05, and x + y + z = 1; the high nickel anode material is doped with aluminum and tantalum elements, and the surface of the high nickel anode material is provided with LiAlTa (PO)₄)₃The coating layer of (2).

10. The method for preparing the lithium aluminum tantalum phosphate modified high-nickel cathode material according to claim 9, which is obtained by mixing and sintering the precursor of the lithium aluminum tantalum phosphate modified high-nickel cathode material according to claim 1 with a lithium source; the sintering is two-stage sintering: firstly, calcining for 5-10 h at 500-700 ℃, and then heating to 800-950 ℃ for calcining for 10-20 h.

Technical Field

The invention relates to the technical field of battery materials, in particular to a tantalum aluminum lithium phosphate modified high-nickel cathode material, a precursor and a preparation method.

Background

With the development of economy and the rapid consumption of fossil energy, the demand for renewable energy is also increasing. Because renewable energy has the characteristics of dispersibility and indirection, the direct utilization rate of electric energy of renewable energy is low, and therefore an energy storage system is required to store the electric energy. The lithium ion battery has the characteristics of high energy density, high cycle stability and strong safety, and becomes an ideal power supply for large-scale energy storage and electric automobiles. The anode material is one of the key materials of the lithium ion battery, and plays an important role in the energy density and stability of the lithium ion battery. The precursor of the positive electrode material is an important intermediate for preparing the positive electrode material, and the adjustment and control of the physical and chemical properties of the precursor of the positive electrode material have great influence on the electrochemical properties of the positive electrode material and the lithium ion battery.

Recently, high specific discharge capacity, high energy density and low cost of high nickel layered cathode materials have attracted much attention. However, because the layered material can generate continuous phase change of H1 → M → H2 → H3 in the process of lithium ion deintercalation, intergranular cracks are generated by large stress impact, so that the material structure is degraded and the electrochemical performance is degraded. In addition, the high nickel material has high Ni content³⁺/Ni⁴⁺Thereby having stronger surface oxidation and easily generating side reaction with the electrolyte, so that the material is transformed from a lamellar phase (R-3m) to a spinel-like phase (Fd-3m) and a rock salt phase (Fm-3m) to cause electricityThe chemical properties deteriorate. Therefore, there is a need to design and provide a high nickel cathode material with a simple manufacturing process starting from precursors.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention aims to provide a precursor of a lithium aluminum tantalum phosphate modified high-nickel cathode material, a cathode material and a preparation method.

In order to solve the technical problems, the invention mainly adopts the following technical scheme.

Firstly, the invention provides a precursor of a lithium aluminum tantalum phosphate modified high-nickel anode material, wherein the chemical formula of the precursor is Ni_xCo_yMn_zO₂•nLiAlTa(PO₄)₃Wherein x, y and z are mole numbers, and x is more than or equal to 0.8<1，0<y≤0.1，0<z≤0.1，0<n≤0.05，x+y+z=1。

Based on the same inventive concept, the invention provides a preparation method of the precursor of the lithium aluminum tantalum phosphate modified high-nickel cathode material, which comprises the following steps:

(3) preparing metal salt solution of Ni, Co and Mn, adding precipitant and complexing agent, and coprecipitating to obtain Ni_xCo_yMn_z(OH)₂；

(4) Sequentially adding a lithium source, an aluminum source, a tantalum source and a phosphorus source into a solvent, and uniformly stirring to obtain a mixed solution; then adding the Ni obtained in the step (1) into the mixed solution_xCo_yMn_z(OH)₂Continuously stirring according to a certain solid-to-liquid ratio, evaporating the solvent and drying in vacuum to obtain a precursor Ni of the lithium aluminum tantalum phosphate modified anode material_xCo_yMn_z(OH)₂•nLiAlTa(PO₄)₃。

Further, in the above preparation method, the metal salt of nickel, cobalt, manganese described in step (1) is selected from sulfate, the precipitant is NaOH solution, the complexing agent is NH₃·H₂And (4) O solution.

Further, the concentration of the NaOH solution is 5-8 mol/L; the NH₃•H₂The concentration of the O solution is 5-8 mol/L.

Further, in the preparation method, the stirring speed of the coprecipitation reaction in the step (1) is 400-700 rpm, the pH value of the reaction system is 11-12.5, the concentration of ammonia in the reaction system is 9-12 g/L, and the reaction time is 20-70 h.

Further, in the above preparation method, the aluminum source in step (2) is one or both of aluminum nitrate and aluminum sulfate; the phosphorus source is one or more of ammonium phosphate, ammonium dihydrogen phosphate, diammonium hydrogen phosphate and phosphoric acid; the tantalum source is one or two of tantalum nitrate and tantalum sulfate; the solvent is one or more of water, methanol, absolute ethyl alcohol and propanol; the lithium source is one or more of lithium hydroxide, lithium carbonate and lithium nitrate.

Further, in the above preparation method, in the step (2), the ratio of the molar amounts of the lithium source, the aluminum source, the tantalum source, and the phosphorus source is 1: 1-2: 1-2: 3.

further, in the preparation method, in the step (2), the solid-to-liquid ratio is 1g: 5-15 mL; the temperature of the evaporation solvent is 60-120 ℃, and the time is 2-6 h; the temperature of the vacuum drying is 60-120 ℃, and the time is 6-12 h.

In addition, based on the same inventive concept, the invention provides a lithium aluminum tantalum phosphate modified high-nickel cathode material with a chemical formula of LiNi_xCo_yMn_zO₂•nLiAlTa(PO₄)₃Wherein x, y and z are mole numbers, and x is more than or equal to 0.8<1，0<y≤0.1，0<z≤0.1，0<n is less than or equal to 0.05, and x + y + z = 1; the high nickel anode material is doped with aluminum and tantalum elements, and the surface of the high nickel anode material is provided with LiAlTa (PO)₄)₃The coating layer of (2).

The invention also provides a preparation method of the lithium aluminum tantalum phosphate modified high-nickel cathode material, which is obtained by mixing and sintering the precursor of the lithium aluminum tantalum phosphate modified high-nickel cathode material and a lithium source.

Further, the sintering is two-stage sintering: firstly, calcining for 5-10 h at 500-700 ℃, and then heating to 800-950 ℃ for calcining for 10-20 h.

The invention discloses lithium aluminum tantalum phosphateModified high-nickel cathode material LiNi_xCo_yMn_zO₂•nLiAlTa(PO₄)₃The material particles are uniform; aluminum and tantalum elements are doped on the surface lattice of the anode material, and LiAlTa (PO) is formed on the surface of the anode material₄)₃The coating layer enables the cathode material of the invention to have good electrochemical performance.

The lithium aluminum tantalum phosphate modified high-nickel anode material is prepared by regulating and controlling the preparation of a precursor, and LiAlTa (PO)₄)₃Coating the precursor on the surface of the precursor, mixing the precursor with lithium hydroxide, calcining, doping trace aluminum and tantalum elements on the surface lattice of the anode material at high temperature, and forming LiAlTa (PO) on the surface of the anode material₄)₃The coating layer greatly improves the discharge capacity and the cycle performance of the anode material, and the technical principle is as follows: the crystal lattice on the surface of the anode material is doped with a trace amount of tantalum and aluminum elements, so that the stress impact generated by H2-H3 phase change can be effectively relieved, intergranular cracks are reduced, and the structural stability of the material is enhanced; meanwhile, the doped tantalum and aluminum elements can form bonds with the coating layer, so that the stability of the coating layer is enhanced; LiAlTa (PO) on the surface₄)₃The fast ion conductor coating layer can improve the ion transmission at the interface of the anode/electrolyte on one hand, and can reduce the contact and side reaction of the anode and the electrolyte on the other hand, thereby avoiding the phase transformation of the material from a lamellar phase to a spinel-like phase and a rock salt phase; in conclusion, the rate capability and the cycle performance of the cathode material are improved.

Compared with the prior art, the anode material provided by the invention has good rate performance and cycle performance, and the preparation method is simple and easy to implement, has little environmental pollution and excellent economic benefit and has good value.

Drawings

FIG. 1 shows LiNi, a tantalum aluminum lithium phosphate modified high-nickel cathode material prepared in example 1 of the present invention_0.8Co_0.1Mn_0.1O₂•0.03LiAlTa(PO₄)₃SEM image of (d).

FIG. 2 shows LiNi, a Ni-Co-Mn positive electrode material prepared by a comparative example of the present invention_0.8Co_0.1Mn_0.1O₂SEM image of (d).

FIG. 3 shows LiNi, a tantalum aluminum lithium phosphate modified high-nickel cathode material prepared in example 3 of the present invention_0.88Co_0.09Mn_0.03O₂•0.04LiAlTa(PO₄)₃LiNi of nickel-cobalt-manganese cathode material prepared by comparison example_0.88Co_0.09Mn_0.03O₂Graph of the cycle performance of (a).

Detailed Description

The present invention will be further described with reference to the accompanying drawings and specific embodiments, wherein the following description is only a partial, rather than a complete, example of the present invention, and the examples are not intended to limit the scope of the claims of the present application. All other changes and modifications which can be made by one skilled in the art based on the embodiments of the present invention without inventive faculty are within the scope of the claims of the present application.

Example 1

This example prepares a compound of formula LiNi_0.8Co_0.1Mn_0.1O₂•0.03LiAlTa(PO₄)₃The preparation method of the lithium aluminum tantalum phosphate modified high-nickel cathode material comprises the following steps:

(1) 80 mol of NiSO₄·6H₂O、10 mol CoSO₄·7H₂O and 10 mol MnSO₄·H₂O (Ni: Co: Mn =8:1:1) is put into a reaction kettle and mixed evenly, and then 4L of 6 mol/L NaOH solution and 4L of 6 mol/L NH are added₃•H₂Feeding the O solution into a reaction kettle, uniformly stirring at a stirring speed of 500 rpm, and carrying out coprecipitation reaction; the pH value of the reaction system is 10.5, the concentration value of ammonia in the reaction system is 11 g/L, and the reaction time is 50 h, so that a solid-liquid mixture is obtained; collecting, washing and drying the solid to obtain Ni_0.8Co_0.1Mn_0.1(OH)₂。

(2) Sequentially adding 3 mol of lithium nitrate, 3 mol of aluminum nitrate, 3 mol of tantalum nitrate and 9 mol of ammonium phosphate into an ethanol solvent, and uniformly stirring to obtain a mixed solution; then adding step into the mixed solution(1) Obtained Ni_0.8Co_0.1Mn_0.1(OH)₂Adjusting the solid-to-liquid ratio to be 1g:10ml, continuously stirring, evaporating at 80 ℃ for 6h, and then vacuum drying at 120 ℃ for 12h to obtain the lithium aluminum tantalum phosphate modified anode precursor material Ni_0.8Co_0.1Mn_0.1(OH)₂•0.03LiAlTa(PO₄)₃。

(3) Ni is taken as 1mol of precursor material obtained in the step (2)_0.8Co_0.1Mn_0.1(OH)₂•0.03LiAlTa(PO₄)₃Uniformly mixing with 1.05 mol of lithium hydroxide to obtain a mixture; then calcining the mixture at 750 ℃ for 6h, heating to 900 ℃ for calcining for 12h, and cooling to room temperature to obtain the lithium aluminum tantalum phosphate modified high-nickel cathode material LiNi_0.8Co_0.1Mn_0.1O₂•0.03LiAlTa(PO₄)₃。

The chemical formula of the lithium aluminum tantalum phosphate modified high-nickel cathode material prepared in this embodiment is LiNi_0.8Co_0.1Mn_0.1O₂•0.03LiAlTa(PO₄)₃And FIG. 1 is a topography under an electron microscope. As can be seen from FIG. 1, the particles of the high nickel cathode material are uniform and have a particle size of 6-10 μm. The lithium ion button cell is assembled, and the first ring has 203 mAh g under the test condition of 0.1C and the voltage range of 2.7-4.3V at room temperature^-1The first 1C ring had a specific capacity of 191.8 mAh g^-1Has a specific capacity of 163 mAh g after 200 cycles^-1The capacity retention ratio of (2) was 85%.

Example 2

This example prepares a compound of formula LiNi_0.92Co_0.04Mn_0.04O₂•0.05LiAlTa(PO₄)₃The preparation method of the lithium aluminum tantalum phosphate modified high-nickel cathode material comprises the following steps:

(1) mixing 92 mol of NiSO₄·6H₂O、4 mol CoSO₄·7H₂O and 4 mol MnSO₄·H₂O (Ni: Co: Mn =92:4:4) is put into a reaction kettle and mixed evenly, and then 5L of 6 mol/L NaOH solution and 5L of 6 mol/L NH are added₃•H₂Feeding the O solution into a reaction kettle, uniformly stirring at the stirring speed of 600 rpm, and carrying out coprecipitation reaction; the pH value of the reaction system is 11.3, the concentration value of ammonia in the reaction system is 11.3 g/L, and the reaction time is 55 h, so that a solid-liquid mixture is obtained; collecting, washing and drying the solid to obtain Ni_0.92Co_0.04Mn_0.04 (OH)₂。

(2) Sequentially adding 5 mol of lithium carbonate, 5 mol of aluminum nitrate, 5 mol of tantalum sulfate and 15 mol of diammonium phosphate into methanol, and uniformly stirring to obtain a mixed solution; then adding Ni obtained in the step (1) into the mixed solution_0.92Co_0.04Mn_0.04(OH)₂Adjusting the solid-to-liquid ratio to be 1g:10ml, continuously stirring, evaporating at 80 ℃ for 10h, and then drying at 100 ℃ for 6h in vacuum to obtain the lithium aluminum tantalum phosphate modified anode precursor material Ni_0.92Co_0.04Mn_0.04(OH)₂•0.05LiAlTa(PO₄)₃。

(3) Ni is taken as 1mol of precursor material obtained in the step (2)_0.92Co_0.04Mn_0.04•0.05LiAlTa(PO₄)₃Uniformly mixing with 1.06 mol of lithium hydroxide to obtain a mixture; then calcining the mixture at 700 ℃ for 8h, heating to 880 ℃ for 15h, and cooling to room temperature to obtain the lithium aluminum tantalum phosphate modified high-nickel cathode material LiNi_0.92Co_0.04Mn_0.04O₂•0.05LiAlTa(PO₄)₃.

The chemical formula of the lithium aluminum tantalum phosphate modified high-nickel cathode material prepared in this embodiment is LiNi_0.92Co_0.04Mn_0.04O₂•0.05LiAlTa(PO₄)₃. The lithium ion button cell is assembled, and the first ring has 225.2 mAh g under the test conditions of room temperature in a voltage range of 2.7-4.3V and 0.1C^-1Specific capacity of 1C first turn 210 mAh g^-1The specific capacity of the resin is 180.5 mAh g after 200 cycles of circulation^-1The capacity retention ratio of (2) was 86%.

Example 3

This example prepares a compound of formula LiNi_0.88Co_0.09Mn_0.03O₂•0.04LiAlTa(PO₄)₃The preparation method of the lithium aluminum tantalum phosphate modified high-nickel cathode material comprises the following steps:

(1) mixing 88 mol of NiSO₄·6H₂O、9 mol CoSO₄·7H₂O and 3 mol MnSO₄·H₂O (Ni: Co: Mn =88:9:3) is put into a reaction kettle and mixed evenly, and then 4L of 7 mol/L NaOH solution and 4L of 7 mol/L NH are added₃•H₂Feeding the O solution into a reaction kettle, uniformly stirring at a stirring speed of 500 rpm, and carrying out coprecipitation reaction; the pH value of the reaction system is 10.8, the ammonia concentration value in the reaction system is 10.8 g/L, and the reaction time is 60 hours, so that a solid-liquid mixture is obtained; collecting, washing and drying the solid to obtain Ni_0.88Co_0.09Mn_0.03(OH)₂。

(2) Sequentially adding 4 mol of lithium carbonate, 4 mol of aluminum nitrate, 4 mol of tantalum sulfate and 12 mol of diammonium phosphate into ethanol, and uniformly stirring to obtain a mixed solution; then adding Ni obtained in the step (1) into the mixed solution_0.88Co_0.09Mn_0.03(OH)₂Adjusting the solid-to-liquid ratio to be 1g:8ml, continuously stirring, evaporating at 80 ℃ for 6h, and then drying at 110 ℃ for 8h in vacuum to obtain the lithium aluminum tantalum phosphate modified anode precursor material Ni_0.88Co_0.09Mn_0.03(OH)₂•0.04LiAlTa(PO₄)₃。

(3) Ni is taken as 1mol of precursor material obtained in the step (2)_0.8Co_0.1Mn_0.1(OH)₂•0.03LiAlTa(PO₄)₃Uniformly mixing with 1.05 mol of lithium hydroxide to obtain a mixture; then calcining the mixture at 750 ℃ for 6h, heating to 900 ℃ for calcining for 12h, and cooling to room temperature to obtain the lithium aluminum tantalum phosphate modified high-nickel cathode material LiNi_0.88Co_0.09Mn_0.03O₂•0.04LiAlTa(PO₄)₃。

The chemical formula of the lithium aluminum tantalum phosphate modified high-nickel cathode material prepared in this embodiment is LiNi_0.88Co_0.09Mn_0.03O₂•0.04LiAlTa(PO₄)₃。

Comparative example

This comparative example was prepared to have the chemical formula LiNi_0.88Co_0.09Mn_0.03O₂The preparation method of the high nickel anode material comprises the following steps:

(1) mixing 88 mol of NiSO₄·6H₂O、9 mol CoSO₄·7H₂O and 3 mol MnSO₄·H₂O (Ni: Co: Mn =88:9:3) is put into a reaction kettle and mixed evenly, and then 4L of 7 mol/L NaOH solution and 4L of 7 mol/L NH are added₃•H₂Feeding the O solution into a reaction kettle, uniformly stirring at a stirring speed of 500 rpm, and carrying out coprecipitation reaction; the pH value of the reaction system is 10.8, the ammonia concentration value in the reaction system is 10.8 g/L, and the reaction time is 60 hours, so that a solid-liquid mixture is obtained; collecting, washing and drying the solid to obtain Ni_0.88Co_0.09Mn_0.03(OH)₂。

(2) 1mol of precursor Ni obtained in the step (1)_0.8Co_0.1Mn_0.1(OH)₂Uniformly mixing with 1.05 mol of lithium hydroxide to obtain a mixture; then calcining the mixture at 750 ℃ for 6h, heating to 900 ℃ for calcining for 12h, and cooling to room temperature to obtain the high-nickel cathode material LiNi_0.88Co_0.09Mn_0.03O₂。

The chemical formula of the high-nickel cathode material prepared by the comparative example is LiNi_0.88Co_0.09Mn_0.03O₂The morphology structure of the material was observed by an electron microscope, and the results are shown in FIG. 2. As can be seen from FIG. 2, the material particles are uniform and have a particle size of 6-10 μm.

Further comparative analysis was made on the electrochemical properties of the positive electrode material prepared in example 3 and the positive electrode material prepared in comparative example, and the results are shown in fig. 3. As can be seen from fig. 3, the lithium aluminum tantalum phosphate modified high-nickel cathode material prepared in example 3 of the present invention has more excellent electrochemical properties.

Specifically, the lithium aluminum tantalum phosphate modified cathode material prepared in example 3 is assembled into a lithium ion button battery, and the first ring of the lithium aluminum tantalum phosphate modified cathode material has 208 mAh under the test conditions of room temperature in a voltage range of 2.7-4.3V and 0.1Cg^-1Specific capacity of (1C) first turn 195.4 mAh g^-1The specific capacity of the resin is 170 mAh g after 200 cycles of circulation^-1The specific capacity and the capacity retention rate are 87%; the high-nickel cathode material prepared by the comparative example is assembled into a lithium ion button battery, and the first circle of the lithium ion button battery has 204 mAh g under the test condition of 0.1C and the voltage range of 2.7-4.3V at room temperature^-1The first 1C ring had a specific capacity of 189.6 mAh g^-1The specific capacity of the resin is 140.3 mAh g after 200 cycles of circulation^-1The capacity retention ratio of (2) was 74%.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.