Silicon anode material and preparation method thereof and lithium battery using silicon anode material

A negative electrode material, lithium ion battery technology, applied in battery electrodes, secondary batteries, electrode manufacturing, etc., can solve the problem of inability to mass-produce cyclic performance silicon negative electrode materials, improve the problem of pulverization and shedding, high specific capacity, and improved The effect of cycle performance

Active Publication Date: 2010-07-14
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0007] The technical problem to be solved by the present invention is: in the prior art, silicon negative electrode materials with good cycle performance cannot be produced in batches

Method used

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  • Silicon anode material and preparation method thereof and lithium battery using silicon anode material
  • Silicon anode material and preparation method thereof and lithium battery using silicon anode material
  • Silicon anode material and preparation method thereof and lithium battery using silicon anode material

Examples

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preparation example Construction

[0020] A method for preparing the above negative electrode material, comprising: sintering pretreated silicon dioxide powder and carbon reducing agent powder at high temperature in vacuum; taking the total weight of silicon dioxide and carbon reducing agent as a basis, the carbon reducing agent The weight accounts for 16.67%-35.8%.

[0021] The raw material for the preparation of silica refers to natural quartz sand with a purity of more than 99%, which may contain Al 3 o 2 , CaO, Fe 2 o 3 and P 2 o 5 and other impurities.

[0022] The pretreatment refers to pulverizing and grinding the silicon dioxide into ultrafine silicon dioxide with a particle size of 5-20 μm, and then chemically pickling and drying the ultrafine silicon dioxide.

[0023] The crushing and grinding is mechanical high-energy ball milling under a protective gas atmosphere, wherein the protective gas is an inert gas.

[0024] Described chemical pickling can be well-known to those skilled in the art, al...

Embodiment 1

[0044] The quartz sand with a purity of more than 99% is mechanically milled to 10 μm by a high-energy ball in an argon atmosphere to obtain ultrafine silica powder.

[0045] Then put the superfine silicon dioxide powder into aqua regia and stir for 3 hours, and then rinse repeatedly with pure water after filtering; then put it into hydrofluoric acid with a mass percentage concentration of 0.96wt% and stir for 3 hours, and then rinse repeatedly with pure water after filtering; Put it into a centrifuge for dehydration, and dry it in an oven at 100°C for 5 hours to make the water content <1%. Made into pretreated silica powder.

[0046] Coke powder with an average particle size of <50 μm is mechanically milled with high-energy balls in an argon atmosphere, crushed and classified to prepare a carbon reducing agent with a particle size of 0.5 μm.

[0047] Mix 360 grams of pretreated silica powder and 120 grams of carbon reducing agent, and stir thoroughly for 12 hours to make the...

Embodiment 2

[0051] The difference from Example 1 is that 420 grams of pretreated silica powder and 120 grams of carbon reducing agent were mixed. Negative electrode material A2 was prepared.

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Abstract

The invention provides an anode material of a lithium battery, which comprises an active substance and a volume buffering agent. The active substance is coated or partly coated on the surfaces of the particles of the volume buffering agent. The active substance is silicon. The volume buffering agent is silicon dioxide. The invention also provides a preparation method for the anode material, wherein silicon dioxide of powder and powder of a carbon reducing agent which are subjected to pretreatment are subjected to vacuum high temperature sintering; and based on the total weight of the silicon dioxide and the carbon reducing agent, the weight of the carbon reducing agent occupies 16.67 to 35.8 percent of the total weight. The anode material provided by the invention has good cycle performance and high capacity.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries. The invention specifically relates to a silicon-based negative electrode material, a preparation method thereof and a lithium battery using the material. Background technique [0002] Lithium-ion batteries have attracted widespread attention due to a series of remarkable advantages such as high working voltage, high specific energy, light weight, small size, long cycle life, no memory effect, fast charging and discharging, and no environmental pollution. With the continuous development of lithium-ion batteries, people have put forward higher requirements on the performance of lithium-ion batteries. In this case, it is of great strategic significance to develop lithium-ion battery materials with higher specific capacity and better cycle performance. [0003] Silicon-based materials are currently the most promising anode materials that can meet the requirements of the new generation of lithiu...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/38H01M4/62H01M4/04H01M10/38H01M10/40
CPCY02E60/12Y02E60/10Y02P70/50
Inventor 张路吴振悦姜占锋
Owner BYD CO LTD
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