Spherical compound lithium-rich multielement cathode material with core shell structure and preparation method thereof

A technology of core-shell structure and positive electrode material, which is applied in the field of spherical core-shell structure composite lithium-rich multi-element positive electrode material and its preparation, can solve the problems of affecting the specific discharge capacity of the material, affecting the cycle performance of the material, and poor rate performance, etc., to achieve Cost-friendly and environmentally friendly, suitable for large-scale industrialization, and high energy density

Inactive Publication Date: 2012-03-28
XIANGTAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

xLi in current literature reports 2 MnO 3 ·(1-x)Li[Ni 0.5 mn 0.5 ]O 2 The material exhibits a discharge specific capacity greater than 250mAh/g and good cycle performance, but its rate performance is not good; and xLi doped with some Co 2 MnO 3 ·(1-x)Li[Ni x co y mn 1-x-y ]O 2 Due to the high ion and electronic conductivity of Co, the rate performance of the material can be significantly

Method used

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  • Spherical compound lithium-rich multielement cathode material with core shell structure and preparation method thereof
  • Spherical compound lithium-rich multielement cathode material with core shell structure and preparation method thereof
  • Spherical compound lithium-rich multielement cathode material with core shell structure and preparation method thereof

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Experimental program
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Effect test

Embodiment 1

[0025] (1) Nickel sulfate, manganese sulfate, and cobalt sulfate are mixed according to the ratio of Ni:Mn:Co (molar ratio)=1:1:1, dissolved in deionized water, and mixed with a total metal ion concentration of 2.0mol / L. Salt solution A; Nickel sulfate, manganese sulfate are mixed by Ni:Mn (molar ratio)=1:3 ratio, dissolve in deionized water, be mixed with the mixed salt solution B that total metal ion concentration is 2.0mol / L; Prepare respectively Na at a concentration of 2.0 mol / l 2 CO 3 Alkaline solution and ammonia water with a concentration of 0.8mol / L.

[0026] (2) the mixed salt solution A, Na prepared in step (1) 2 CO 3 Alkali solution and ammonia water are fed into the reaction kettle in parallel through a constant flow pump, the stirring speed is controlled at 1000rpm, the reaction temperature is 55°C, the pH value is 8.0, and the reaction time is 12h. The spherical core [Ni 1 / 3 mn 1 / 3 co 1 / 3 ]CO 3 .

[0027] (3) The mixed salt solution B, Na 2 CO 3 Alkali...

Embodiment 2

[0032] (1)-(3) are the same as in Example 1.

[0033] (4) The precursor obtained in step (3) is filtered, washed, dried, and Li 2 CO 3 After the ratio of the moles of lithium to the total moles of Ni, Mn and Co is 1.37:1, after uniform mixing, it is pre-fired at 500°C for 8 hours in an air atmosphere, and then heated to 850°C for 12 hours to obtain a core-shell structure composite type. Lithium-rich multi-element cathode material Li 1.15 [(Ni 1 / 3 mn 1 / 3 co 1 / 3 ) 0.6 (Ni 0.25 mn 0.75 ) 0.4 ] 0.85 o 2 .

[0034] Electrochemical tests show that the first discharge specific capacity is 258mAh / g in the voltage range of 0.1C and 2.0-4.8V; the capacity retention rate after 100 cycles at 0.2C and 2.0-4.6V is 96.7%; at 0.5C , 1C, and 2C rates, the reversible capacities are 215mAh / g, 180mAh / g, and 168mAh / g, respectively, showing good electrochemical performance.

Embodiment 3

[0036] (1) Nickel sulfate, manganese sulfate, and cobalt sulfate are mixed according to the ratio of Ni: Mn: Co (molar ratio) = 4: 4: 2, dissolved in deionized water, and mixed with a total metal ion concentration of 2.0mol / L. Salt solution A; Nickel sulfate, manganese sulfate are mixed by Ni: Mn (molar ratio)=1: 3 ratio, dissolve in deionized water, be prepared into the mixed salt solution B that total metal ion concentration is 2.0mol / L; Prepare respectively Concentration is 4.0mol / l NaOH alkaline solution and concentration is 4.0mol / L ammonia water.

[0037] (2) Add the mixed salt solution A, NaOH alkali solution and ammonia water prepared in step (1) into the reactor filled with nitrogen protection in parallel through a constant flow pump, control the stirring speed to 1000rpm, and the reaction temperature to be 55°C and The value is 11.0, the reaction time is 24h, and the spherical inner core [Ni 0.4 mn 0.4 co 0.2 ](OH) 2 .

[0038] (3) Add the mixed salt solution B,...

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Abstract

The invention discloses a preparation method of a spherical compound lithium-rich multielement cathode material with a core shell structure. The cathode material has a general formula of Li1+m[(NixCoyMn1-x-y)1-n(Ni0.25Mn0.75)n]1-mO2. The spherical compound lithium-rich multielement cathode material breaks through traditional idea of cladding or doping to improve material performance, and acquires better integrated performance through material structure design by realizing nuclear casing functional composition and complementation. The material combines advantages of nuclear and casing, has high energy density and good rate capability and excellent cyclical stability, and is simply prepared, at low cost and easy for industrialized production; therefore, the material has promising development prospect.

Description

technical field [0001] The invention relates to a spherical core-shell structure composite lithium-rich multi-element positive electrode material and a preparation method thereof, which belong to the field of lithium ion battery positive electrode materials and electrochemistry. Background technique [0002] At present, with the shortage of global oil resources and the continuous deterioration of the climate environment, the development of human society is facing severe challenges. The development of clean and energy-saving new energy vehicles is highly valued by countries all over the world. The key to the development of new energy vehicles lies in their power sources. Lithium-ion batteries have the advantages of high energy density, small self-discharge, no memory effect, wide operating voltage range, long service life, and no environmental pollution. They are currently the main power source for new energy vehicles. The key electrode material of lithium-ion battery is th...

Claims

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Application Information

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IPC IPC(8): H01M4/525H01M4/505
CPCY02E60/122Y02E60/10
Inventor 王先友杨秀康刘黎白艳松舒洪波魏启亮杨顺毅
Owner XIANGTAN UNIV
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