Manganese-doped Li<2>FeSiO<4>/graphene hollow nanosphere cathode material and preparation method thereof

A cathode material, hollow nanotechnology, which is applied in the fields of material synthesis and electrochemistry, can solve the problems of unfavorable electron transport, large deformation of materials, poor electronic conductivity, etc., and achieves the effect of simple and easy-to-obtain method, good dispersibility, and improved capacity.

Active Publication Date: 2017-11-24
SHANGHAI JIAO TONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But Li 2 FeSiO 4 There are a variety of crystal forms, and the problems of poor electronic conductivity, low ion diffusion coefficient, high second lithium ion extraction / intercalation voltage and large material deformation have always restricted Li 2 FeSiO 4 practical application of
Currently limit Li 2 FeSiO 4 There are two main factors to realize the deintercalation of two lithium ions: one is the low conductivity of the material itself, which is not conducive to the transmission of electrons; the other is that the synthesized material particles are too large, which is not conducive to the migration of lithium ions during charging and discharging.

Method used

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  • Manganese-doped Li&lt;2&gt;FeSiO&lt;4&gt;/graphene hollow nanosphere cathode material and preparation method thereof
  • Manganese-doped Li&lt;2&gt;FeSiO&lt;4&gt;/graphene hollow nanosphere cathode material and preparation method thereof
  • Manganese-doped Li&lt;2&gt;FeSiO&lt;4&gt;/graphene hollow nanosphere cathode material and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] Li in this example 2 FeSiO 4 The preparation steps of @graphene hollow nanosphere cathode material are as follows:

[0044] 1. Use an electronic balance to weigh 0.3g polyvinylpyrrolidone (PVP, Sigma, Mw≈55000) dispersant and ultrasonically dissolve it in 200mL deionized water to form a transparent solution A, during which time N 2 Deoxygenation for half an hour;

[0045] 2. Use an electronic balance to weigh 20g of styrene and slowly drop into solution A to form solution B, and heat up to 70°C;

[0046] 3. Use an electronic balance to weigh 0.4g initiator (V-50) and dissolve it in 2.5mL deionized water, and slowly add it to solution B to form a milky white solution. 2 Emulsion polymerization in air for 24 hours to generate polystyrene microsphere emulsion;

[0047] 4. The polystyrene microsphere emulsion was centrifugally washed 6 times with deionized water, and dried to obtain polystyrene microsphere white powder (PS)D;

[0048] 5. TEOS:CTAB:CH based on Mole rati...

Embodiment 2

[0057] Li in this example 2 Fe 0.8 mn 0.2 SiO 4 The preparation steps of @graphene hollow nanosphere cathode material are as follows:

[0058] 1. Use an electronic balance to weigh 0.3g polyvinylpyrrolidone (PVP, Sigma, Mw≈55000) dispersant and ultrasonically dissolve it in 200mL deionized water to form a transparent solution A, during which time N 2 Deoxygenation for half an hour;

[0059] 2. Use an electronic balance to weigh 20g of styrene and slowly drop into solution A to form solution B, and heat up to 70°C;

[0060] 3. Use an electronic balance to weigh 0.4g initiator (V-50) and dissolve it in 2.5mL deionized water, and slowly add it to solution B to form a milky white solution. 2 Emulsion polymerization in air for 24 hours to generate polystyrene microsphere emulsion;

[0061] 4. The polystyrene microsphere emulsion was centrifugally washed 6 times with deionized water, and dried to obtain polystyrene microsphere white powder (PS)D;

[0062] 5. According to the ...

Embodiment 3

[0068] Li in this example 2 Fe 0.7 mn 0.3 SiO 4 The preparation steps of @graphene hollow nanosphere cathode material are as follows:

[0069] 1. Use an electronic balance to weigh 0.3g polyvinylpyrrolidone (PVP, Sigma, Mw≈55000) dispersant and ultrasonically dissolve it in 200mL deionized water to form a transparent solution A, during which time N 2 Deoxygenation for half an hour;

[0070] 2. Use an electronic balance to weigh 20g of styrene and slowly add it dropwise to solution B, and raise the temperature to 70°C;

[0071] 3. Use an electronic balance to weigh 0.4g initiator (V-50) and dissolve it in 2.5mL deionized water, and slowly add it to solution B to form a milky white solution. 2 Emulsion polymerization in air for 24 hours to generate polystyrene microsphere emulsion;

[0072] 4. The polystyrene microsphere emulsion was centrifugally washed 6 times with deionized water, and dried to obtain polystyrene microsphere white powder (PS)D;

[0073] 5. According to ...

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Abstract

The invention provides a preparation method for a Li<2>Fe<x>Mn<1-x>SiO<4>@graphene hollow nanosphere cathode material. The method comprises the specific steps of taking polystyrene spheres (PS) as templates; coating a layer of uniform mesoporous silica on the surfaces of the templates; ultrasonically dispersing the templates into a certain molar ratio of alcoholic solution of lithium salt, ferric salt and manganese salt; carrying out oil bathing, stirring, absorption, centrifugation, washing and drying to obtain Li<2>FeSiO<4> precursors formed on the surface of the polystyrene spheres, slowing adding the Li<2>FeSiO<4> precursors into graphene water solution, carrying out stirring and freeze drying, and carrying out high-temperature calcination in inert gas, thereby obtaining grey powder and obtaining the prepared Li<2>Fe<x>Mn<1-x>SiO<4>@graphene hollow nanosphere cathode material. According to the method, the raw material content is abundant, the cost is low, the prepared Li<2>Fe<x>Mn<1-x>SiO<4> cathode material hollow nanospheres are distributed uniformly, an excellent microstructure is achieved, and the relatively good electrochemical performance is achieved.

Description

technical field [0001] The invention belongs to the technical field of material synthesis and electrochemistry, and relates to a lithium ion battery positive electrode material and a preparation method thereof, in particular to a manganese-doped lithium iron silicate / graphene hollow nanosphere positive electrode material and a preparation method thereof, more specifically, to A kind of Li 2 Fe x mn 1-x SiO 4 @Graphene hollow nanosphere cathode material and its preparation method. Background technique [0002] Compared with traditional batteries, lithium-ion batteries have the advantages of small size, large capacity, high voltage, and no memory effect, and are recognized as ideal energy storage devices. Lithium-ion batteries are the representative of modern high-performance batteries, and have been widely used in electronic equipment, medical equipment, electric vehicles, aerospace and military industries and other fields. As the cathode material in the key materials of...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/485H01M4/505H01M4/525H01M4/587H01M4/62H01M10/0525
CPCH01M4/362H01M4/485H01M4/505H01M4/525H01M4/587H01M4/625H01M10/0525Y02E60/10
Inventor 章俊良张尧张万森沈水云夏国锋吴爱明殷洁炜
Owner SHANGHAI JIAO TONG UNIV
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