High-rate long-cycle performance multi-element composite positive electrode material and preparation method thereof

A cathode material and multi-component composite technology, which is applied in the field of high-rate and long-cycle performance multi-component composite cathode materials and their preparation, and can solve the problems of deterioration, fragile cycle performance, and shortening of lithium ion transmission paths.

Active Publication Date: 2019-06-14
HENAN KELONG NEW ENERGY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In order to meet the rate and cycle requirements of the 48V micro-mixing system, a multi-component composite positive electrode material with high rate and long cycle performance and its preparation method are specially provided; The path of lithium ion transmission provides effective structural support for high-current and high-rate charge and discharge; on the other hand, although the hollow structure can improve the rate performance, the hollow structure is easily broken during the rolling process and the hollow structure is in contact with the electrolyte. Too much is likely to cause more side reactions and lead to poor cycle performance. Therefore, the present invention proposes to use niobium or tantalum doping with hard characteristics to increase the hardness of the hollow sphere structure and stabilize the lattice junction. At the same time, the surface coating Further suppress the side reaction with the electrolyte, and greatly improve the cycle performance of the material

Method used

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  • High-rate long-cycle performance multi-element composite positive electrode material and preparation method thereof
  • High-rate long-cycle performance multi-element composite positive electrode material and preparation method thereof
  • High-rate long-cycle performance multi-element composite positive electrode material and preparation method thereof

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Embodiment 1

[0035] Select spherical graphite with a D50 of 0.5 microns and add it to the reactor for high-speed dispersion for 20 minutes, then make a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate according to the Ni:Co:Mn molar ratio of 0.6:0.2:0.2 and mix evenly. Ni, The total number of moles of the three transition metal ions of Co and Mn is 2mol / L, and then 6mol / L of NaOH solution and transition metal ion solution and 6mol / L of ammonia are added to the reaction vessel at the same time, and the pH of the reaction system is controlled to be 11.5, the reaction temperature is 60°C. Then the obtained precipitate was filtered, washed, and dried at 110°C for 10 hours to obtain a C core Ni0.6Co0.2Mn0.2(OH)2 precursor. Lithium hydroxide and C core Ni0.6Co0.2Mn0.2(OH)2 are added with 0.1wt% Nb2O5 (as Nb Mix with the mass ratio of the precursor), mix evenly in a high-speed mixer, raise the temperature to 650°C at a heating rate of 3°C / min, keep it for 2h, then heat up t...

Embodiment 2

[0038] Based on the LiNi0.6Co0.2Mn0.2O2 matrix material with 0.1% Nb-doped hollow prepared in Example 1, 1000mL H2O was added to the stirring tank, 2000g of the above-mentioned sieved material was added, and after 30°C constant temperature for 10min, 56g of nano The alumina dispersion was stirred at a constant temperature of 30°C for 1 hour, and then vacuum-dried with a rotary evaporator. The dried material was put into a high-temperature furnace, sintered at 700°C for 10 hours, and then passed through a 325-mesh sieve. Finally, the Al coating amount was 0.15% uniformly coated LiNi0.6Co0.2Mn0.2O2 multi-element composite cathode material of the hollow doped Nb, other is the same as embodiment 1

Embodiment 3

[0040] Except replacing Nb2O5 with Ta2O5, others are the same as in Example 1, and a tantalum-doped LiNi0.6Co0.2Mn0.2O2 composite cathode material with a uniform hollow structure is obtained.

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Abstract

The invention relates to a high-rate long-cycle performance multi-element composite positive electrode material and a preparation method thereof, wherein the positive electrode material is a hollow structural sphere with D50 of 2-7 microns, and the chemical formula of the positive electrode material is LixNiyCozMn1-y-zO2; the positive electrode material is internally doped with 0.02-1mass% of a Zcompound, wherein Z is at least one of Nb or Ta; an aluminum compound accounting for 0.01-1mass% of a matrix is coated on the surface of the positive electrode material; and in the chemical formula, x, y and z are the values of the molar ratio of the related elements, wherein x is greater than 0.9 and less than 1.3, y is greater than or equal to 0.2 and less than 1, z is greater than 0 and less than 0.5, and y+z is less than or equal to 1. By virtue of the hollow structure of the invention, the infiltration and liquid retention capability of the non-aqueous electrolyte can be enhanced, the path of lithium ion transmission can be effectively shortened, and an effective structure support is provided for high-current high-rate charge and discharge; and the hardness of the hollow sphere structure can be increased, the crystal lattice junction also can be stabilized, and meanwhile, the cycling performance of the material is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of cathode materials for lithium ion batteries, and in particular relates to a multi-component composite cathode material with high rate and long cycle performance and a preparation method thereof. Background technique [0002] Lithium-ion batteries are widely used in various mobile terminal devices such as mobile phones and notebooks at home and abroad because of their high specific capacity, long cycle life, good safety performance, and environmental friendliness. Due to the aggravation of environmental pollution and the raging smog in recent years, the national and local governments are imminent in reducing motor vehicle emission pollution and improving ambient air quality. The 48V micro-hybrid system came into being, and the lithium battery it needs is also in a state of emergency development. , and has a vast market. [0003] The difficulties in the development of the 48V micro-hybrid system are: 1) wi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/48H01M4/505H01M4/525H01M4/58H01M10/0525
CPCY02E60/10
Inventor 李金锁文万超徐云军栗晓静
Owner HENAN KELONG NEW ENERGY CO LTD
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