Positive electrode material as well as preparation method and application thereof

A positive electrode material and crystal technology, applied in the field of chemical power sources, can solve the problems of reduced structural stability, unreachable, and reduced cycle life of high-nickel materials, and achieve the effects of improving structural stability, stabilizing the positive electrode structure, and improving safety performance

Inactive Publication Date: 2020-07-03
CHINA AVIATION LITHIUM BATTERY RES INST CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

During the charging and discharging process, the high-nickel material reacts with the electrolyte to generate a large amount of oxygen, which affects the safety performance of the high-nickel material; at the same time, the increase in the nickel content will also increase the degree of Li / Ni mixing, and the lithium ion deintercalation The crystal structure is easily destroyed during the process, and the structural stability is reduced, which in turn leads to a decrease in the cycle life of high-nickel materials.
These two main defects limit the further application of high-nickel materials
[0003] At present, high-nickel materials mainly rely on tetravalent Mn ions to stabilize them. However, with the increase of nickel content, the skeleton support effect of tetravalent Mn ions alone cannot achieve the stability of high-voltage high-nickel materials in current battery systems. Require

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  • Positive electrode material as well as preparation method and application thereof
  • Positive electrode material as well as preparation method and application thereof
  • Positive electrode material as well as preparation method and application thereof

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preparation example Construction

[0019] The preparation of the above positive electrode material may include the following steps: a step of preparing a precursor and a step of sintering. First, a precursor containing Ni, Co and Mn is formed, and then the precursor is mixed and sintered with a lithium source compound to obtain a positive electrode material. Specifically, the preparation method of the positive electrode material includes: adjusting the pH value of the solution containing nickel ions, manganese ions and cobalt ions to 10-12 under stirring conditions, and aging at 50-90°C for 5-12h after the reaction is completed , to obtain the precursor after separation, washing and drying. Then a sintering step is performed, mixing the lithium source compound and the obtained precursor uniformly, and sintering at 600° C.-1000° C. for 6-15 hours.

[0020] In a preferred embodiment, the precursor may be a carbonate or a hydroxide.

[0021] In a preferred embodiment, the lithium source compound can be LiOH·H 2...

Embodiment 1

[0028] Pass a certain volume of nickel sulfate, cobalt, manganese solution and excess 2% molar sodium hydroxide solution through a peristaltic pump at 580 μL min -1 The feed rate is added dropwise to the mother liquor. The molar ratio of nickel, cobalt and manganese is listed as 72:9:19, the reaction temperature of the material is 50°C, the pH is controlled at 10, and at the same time the top stirring rod is set at 400rmp·min -1 Stir vigorously at a rotating speed of 100°C, and nitrogen protection is added during the reaction. After aging for 10 hours, the obtained hydroxide precursor was suction-filtered, washed twice with a certain volume of distilled water, and finally dried in vacuum at 100° C. for 6 hours to obtain a dry precursor. The precursor was thoroughly ground and mixed with a certain molar ratio of LiOH, and then heated in a muffle furnace at 5 °C min -1 The heating rate was pre-calcined at 500°C for 5h, and then calcined at 800°C for 12h to obtain the lithium-r...

Embodiment 2

[0033]Pass a certain volume of nickel acetate, cobalt, manganese solution and excess 3% mole sodium carbonate solution through a peristaltic pump at 1000 μL min -1 The feed rate is added dropwise to the mother liquor containing sodium carbonate. The molar ratio of nickel, cobalt, and manganese is listed as 76:9.5:14.5, the reaction temperature of the material is 55°C, pH=11, and the top stirring rod is set at 500rmp·min -1 Stir vigorously at a rotating speed of 100°C, and add argon protection during the reaction. The carbonate precursor obtained after aging for 5 h was first filtered with suction, then washed twice in 800 mL of distilled water, and finally dried in vacuum at 120° C. for 8 h to obtain a dry precursor. The obtained precursor was fully ground and mixed with a certain molar ratio of LiOH, and then heated in a muffle furnace at 5 °C min -1 The heating rate was first pre-calcined at 500°C for 5h, and then calcined at 600°C for 10h to obtain a lithium-rich nickel-b...

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Abstract

The invention discloses a positive electrode material, which contains a crystal with a superlattice structure, the chemical formula of the crystal is xLi2MO3. (1-x) LiNiaCobMn (1-a-b) O2, 0< x <= 0.1,0.8 <= a < 1, b < = 0.1, and M is selected from one or more of Mn, Co and Ni. The invention also discloses a preparation method of the positive electrode material and a battery or a capacitor containing the positive electrode material. The positive electrode material disclosed by the invention comprises crystals with a layered-layered superlattice structure, another layered structure is crossed on the basis of a conventional high-nickel ternary material with a layered structure, and the structural stability of a product is improved by utilizing mutual meshing between two different layered structures. According to the positive electrode material disclosed by the invention, due to the addition of the manganese-based lithium-rich phase (Li2MnO3), the content of nickel in the product is diluted to a certain extent, and the gas production of the battery can be effectively improved by reducing the content of nickel. Therefore, the safety performance of the battery can be improved from two aspects of reducing gas production and stabilizing the positive electrode structure.

Description

technical field [0001] The invention belongs to the field of chemical power sources, and in particular relates to a positive electrode material, its preparation method and application. Background technique [0002] The surface state of the high-nickel ternary cathode material is extremely active as the nickel content increases. During the charging and discharging process, the high-nickel material reacts with the electrolyte to generate a large amount of oxygen, which affects the safety performance of the high-nickel material; at the same time, the increase in the nickel content will also increase the degree of Li / Ni mixing, and the lithium ion deintercalation During the process, the crystal structure is easily destroyed, and the structural stability is reduced, which in turn leads to a decrease in the cycle life of high-nickel materials. These two main defects limit the further application of high-nickel materials. [0003] At present, high-nickel materials mainly rely on ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/505H01M4/525H01M10/0525
CPCH01M4/364H01M4/505H01M4/525H01M4/366H01M10/0525H01M2004/028Y02E60/10C01G53/50C01P2002/72C01P2004/03C01P2006/40C01P2002/52C01P2002/88C01P2004/80H01G11/46H01G11/50H01G11/86H01M4/62H01B1/08
Inventor 曹凯王志敏王宁单旭意
Owner CHINA AVIATION LITHIUM BATTERY RES INST CO LTD
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