Preparation method of carbon-lithium titanate double-layer coated silicon negative electrode material

A double-layer coating, lithium titanate technology, used in battery electrodes, electrical components, electrochemical generators, etc., can solve the problems of hindering the insertion and extraction of lithium ions, affecting the performance of batteries, and low electrical conductivity. The effect of uniformity, large specific capacity and long cycle life

Inactive Publication Date: 2014-03-26
SHANGHAI NAT ENG RES CENT FORNANOTECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Silicon and lithium titanate have the same disadvantages, that is, the conductivity is not high, and it is easy to cause electron enrichment during charging and discharging, which hinders the insertion and extraction of lithium ions, and affects the performance of the battery at high rates.

Method used

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  • Preparation method of carbon-lithium titanate double-layer coated silicon negative electrode material

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0021] The soluble compound compounds of Li and Ti were mixed according to the molar ratio of Li:Ti=0.84:1, and 25.52g of tetra-n-butyl titanate (analytical pure), 2.33g of lithium carbonate (analytical pure), 20g were weighed Ethylenediaminetetraacetic acid and 30 g of citric acid were added to 300 ml of absolute ethanol, and stirred by a magnetic heating stirrer to form a sol; then 0.2 g of nano silicon powder was added and heated and stirred at 80°C until the silicon source was fully dispersed. Glue; dried in a blast oven at 240℃ to obtain a black and fluffy lithium titanate coated silicon precursor; then put the precursor into a high-energy ball mill for ball milling for 1-10 hours, where the mass ratio of the ball to the material is 2: 1. Obtain a silicon precursor coated with fine particles of lithium titanate; finally, put the fine particles of the precursor into a tube furnace, pass it through Ar gas, and calcine at 750°C for 5 hours to obtain a finished carbon and lithi...

Embodiment 2

[0023] The soluble compound compounds of Li and Ti are mixed according to the molar ratio of Li:Ti=0.84:1, and 21.31 g of tetraisopropyl titanate (analytical purity), 6.43g of lithium acetate (analytical purity), 20g are weighed Ethylenediaminetetraacetic acid and 40g of citric acid were added to 300ml of absolute ethanol, and stirred by a magnetic heating stirrer to form a sol; then 0.2g of mesoporous silicon nanoparticles were added and heated and stirred at 80°C until the silicon source was fully dispersed. Gel; dried in a blast oven at 240℃ to obtain a black and fluffy lithium titanate coated silicon precursor; then put the precursor into a high-energy ball mill for ball milling for 1-10 hours, where the mass ratio of the ball to the material is 2 :1. Obtain a silicon precursor coated with fine particles of lithium titanate; finally put the fine particles of the precursor into a tube furnace, pass 95%Ar+5%H 2 , Calcined at 750°C for 5 hours to obtain the finished carbon and ...

Embodiment 3

[0025] The soluble compound compounds of Li and Ti were mixed according to the molar ratio of Li:Ti=0.88:1, and 25.52 g of tetra-n-butyl titanate (analytical purity), 4.55g of lithium nitrate (analytical purity), 20g were weighed Ethylenediaminetetraacetic acid and 60g citric acid were added to 300ml of absolute ethanol, and stirred by a magnetic heating stirrer to form a sol; then 0.6g of nano-silica powder was added and heated and stirred at 80°C until a gel with fully dispersed silicon source was obtained ; Dry in a blast oven at 240℃ to obtain a black and fluffy lithium titanate coated silicon precursor; then put the lithium titanate precursor into a high-energy ball mill for ball milling for 1-10 h, where the mass ratio of the ball to the material The ratio is 2:1 to obtain a silicon precursor coated with fine particles of lithium titanate; finally, the fine particles of the precursor are put into a tube furnace, and the precursor is vented with Ar gas and calcined at 750°C...

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Abstract

The invention belongs to the secondary lithium ion battery key material technical field, and provides a method for preparing a carbon-lithium titanate double-layer coated silicon negative electrode material. With chelating agents as carbon sources, a soluble Ti compound as a titanium source, a nano silicon source and various lithium compounds as lithium sources, the carbon-lithium titanate double-layer coated silicon negative electrode material is synthesized by a double-chelating-agent sol-gel method. Through combination of advantages of lithium titanate and the silicon material, a prepared lithium ion battery has high specific capacity, excellent cycling stability and quite high consistency, allows the high specific capacity and the high stability to be organically gathered together, and has wide application prospects.

Description

Technical field [0001] The invention relates to a preparation method of a battery negative electrode material, in particular to a preparation method of a silicon negative electrode material coated with carbon and lithium titanate double layers. Background technique [0002] In the context of today's environmental pollution and energy shortages, lithium-ion batteries have become the first consideration for many manufacturers when they choose power due to their clean, pollution-free, efficient and recyclable characteristics. The development of a new type of lithium-ion battery with larger specific capacity, better cycle performance, faster and safer charge and discharge has also become the goal of many scientific and technological workers. [0003] Silicon has the largest theoretical specific capacity (3572mAh / g) among the known anode materials for lithium-ion batteries, and a lower delithiation potential (<0.5V) at room temperature. It has become a highly anticipated next-generat...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/36H01M4/485
CPCY02E60/122H01M4/366H01M4/485H01M4/625H01M10/0525Y02E60/10
Inventor 张春明黄昭王丹吴晓燕严鹏何丹农
Owner SHANGHAI NAT ENG RES CENT FORNANOTECH
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