Method for preparing silicon composite cathode material of lithium ion battery

A technology for lithium-ion batteries and negative electrode materials, which is applied in electrode manufacturing, battery electrodes, silicon, etc., can solve the problems of poor material cycle performance, difficult to guarantee reproducibility, complicated processing process, etc., and achieve good cycle stability, heavy duty, etc. Good reproducibility and low preparation cost

Inactive Publication Date: 2009-08-19
SHANGHAI JIAO TONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] Nature Nanotechnology magazine, No. 3, 2008, page 31 reported that the one-dimensional nanowire-arranged silicon thin-film electrode prepared by the gas-liquid-solid (VLS) template-free technology can approach the theoretical value for the first time, and can be greater than 3000mAh/g. It is reversible under the condition of high capacity, but the preparation cost is high, the reproducibility is difficult to guarantee, and it is also difficult to quickly mass-produce; SolidState Ionics magazine 2007, volume 178, page 1297, reported that metal magnesium was used as a reducing agent, and high-e

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  • Method for preparing silicon composite cathode material of lithium ion battery
  • Method for preparing silicon composite cathode material of lithium ion battery
  • Method for preparing silicon composite cathode material of lithium ion battery

Examples

Experimental program
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Embodiment 1

[0030] (1) Under the protection of argon at 20°C, 0.8394g of Li 2 Si powder and 0.4g of carbon black powder are mixed in 2.96g of silicon tetrachloride liquid, are placed in 80ml stainless steel ball mill tank, put into 15 stainless steel balls, keep argon gas in the stainless steel ball mill tank, carry out ball mill, high-energy ball mill The rotating speed is 450 rpm, and the ball milling time is 20 hours to obtain a nano-silicon / carbon black / lithium chloride complex;

[0031] (2) Open the stainless steel ball mill tank under the protection of argon and transfer the nano-silicon / carbon black / lithium chloride complex to the quartz boat, heat treatment at 700°C for 6 hours under the protection of argon, and naturally cool to 20°C; then Transfer to absolute ethanol and stir for 1 hour, and ultrasonic treatment for 10 minutes, centrifuged, and then vacuum-dried at 100 ° C for 4 hours to obtain a nano-silicon / carbon black composite;

[0032] (3) Disperse 0.2g of nano-silicon / ca...

Embodiment 2

[0039] (1) Under the protection of argon at 15°C, 0.8394g of Li 2 Si powder and 0.5g of graphite powder are added to 2g of silicon tetrabromide liquid and mixed, placed in an 80ml stainless steel ball mill tank, 15 stainless steel balls are put into the stainless steel ball mill tank to keep argon gas for ball milling, and the speed of the high energy ball mill is For 400 rev / min, the ball milling time is 10 hours to obtain nano-silicon / graphite / lithium bromide composite;

[0040] (2) Open the stainless steel ball mill tank under the protection of argon and transfer the nano-silicon / graphite / lithium bromide complex to a quartz boat, heat-treat at 200°C for 3 hours under the protection of argon, and cool naturally to 15°C; then transfer to water Stirring for 2 hours, ultrasonic treatment for 30 minutes, centrifugation, and then vacuum drying at 110°C for 10 hours to obtain a nano-silicon / graphite composite;

[0041] (3) Disperse 0.2g of nano-silicon / graphite composite and 0.5g...

Embodiment 3

[0043] (1) Under the protection of argon at 20°C, 0.6233g of Li 13 Si 4 Powder and 0.6g of carbon nanofiber powder are added to 3g of monochloroethylsilane liquid and mixed, placed in an 80ml stainless steel ball mill tank, put 15 stainless steel balls, and keep the stainless steel ball mill tank with argon gas for ball milling, high energy ball mill The rotating speed is 500 rpm, and the ball milling time is 20 hours to obtain nano-silicon / carbon nanofiber / ethyllithium-lithium chloride complex;

[0044] (2) Open the stainless steel ball mill tank under the protection of argon and transfer the nano-silicon / carbon nanofiber / ethyllithium-lithium chloride complex to a quartz boat, heat treat at 500°C for 5 hours under the protection of nitrogen, and cool naturally to 15 °C; then transferred to acetone and stirred for 1 hour, and ultrasonically treated for 20 minutes, centrifuged, and then vacuum-dried at 100°C for 6 hours to obtain a nano-silicon / carbon nanofiber composite;

[...

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Abstract

The invention discloses a preparation method of a silicon composite anode material for lithium ion batteries and the silicon composite anode material is composed of nc-Si/ packing carbon/ cracking carbon. Packing carbon powder is adopted as scattered matrix, Li-Si alloy powder is adopted as a reducing agent and a liquid silicon halide or a liquid silane halide is chemically deoxidized by the high-energy ball milling; afterwards, heat treatment and solvent washing are conducted over the deoxidized silicon halide or silane halide under the shielding gas so as to obtain an nc-Si/ packing carbon complex, wherein the nc-Si is nanometer porous silicon and nanometer silicon fiber. The nc-Si/ packing carbon complex passes through the high-molecular carbon source cladding and heat treatment under the shielding gas to obtain an nc-Si/ packing carbon/ cracking carbon composite anode material. A charge-discharge test of constant current is conducted at a current density of 0.1 mA/mg to 0.3 mA/mg; the coulombic efficiency of the first circulation of the silicon composite anode material reaches up to 70 percent to 80 percent; and after 30 circulations, the reversible capacity reaches 680 mAh/g and the capacity retention rate reaches more than 95 percent.

Description

technical field [0001] The invention relates to a preparation method of a battery electrode material, in particular to a preparation method of a silicon composite negative electrode material for a lithium ion battery. Background technique [0002] Lithium-ion batteries are being used more and more widely, from micro-batteries required for small electronic devices to power sources for large electric vehicles. The improvement of lithium-ion battery performance mainly depends on the performance of lithium intercalation and extraction electrode materials. At present, mesophase carbon microspheres and modified graphite are widely used as negative electrode materials in commercial lithium-ion batteries, but there are disadvantages such as low theoretical lithium storage capacity (graphite is 372mAh / g), and easy occurrence of organic solvent co-intercalation. The research and application of anode materials for ion batteries has become the key to improving battery performance. Amon...

Claims

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Application Information

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IPC IPC(8): H01M4/04C01B33/03B22F9/04B22F9/16H01M4/38C01B33/02
CPCY02E60/12Y02E60/10
Inventor 杨军吕荣冠王久林努丽燕娜
Owner SHANGHAI JIAO TONG UNIV
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