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Preparation method for composite negative electrode material of lithium ion battery

A technology for lithium ion batteries and negative electrode materials, applied in electrode manufacturing, battery electrodes, circuits, etc., can solve the problems of volume effect and pulverization and shedding reducing battery efficiency and cycle performance.

Inactive Publication Date: 2007-02-07
SHANGHAI JIAO TONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the serious volume effect and pulverization of Li-Si or Li-Sn electrodes during the charge and discharge process reduce the efficiency and cycle performance of the battery.

Method used

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  • Preparation method for composite negative electrode material of lithium ion battery
  • Preparation method for composite negative electrode material of lithium ion battery
  • Preparation method for composite negative electrode material of lithium ion battery

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] Embodiment 1. Preparation of nanoporous silicon / copper / graphite composite negative electrode material for lithium ion battery:

[0019] (1) Mix 1 g of silicon oxide powder and 0.6 g of aluminum powder in an argon atmosphere at room temperature at a mass ratio of 1:0.6, place them in a stainless steel ball mill jar equipped with an O-ring, put stainless steel balls, and keep The argon atmosphere in the tank, the rotating speed of the high-energy ball mill is 400 rpm, and the ball milling time is 15 hours, and about 1.4g of highly dispersed nano-silicon / alumina composites are obtained;

[0020] (2) Mix 0.5g of nano-silicon / alumina composite with 0.45g of metal copper powder in an argon atmosphere at room temperature at a mass ratio of 1:0.9, place them in a stainless steel ball mill jar equipped with an O-ring, and put Stainless steel balls to keep the argon atmosphere in the tank, the speed of the high-energy ball mill is 400 rpm, and the ball milling time is 2 hours to ...

Embodiment 2

[0023] Embodiment 2. Preparation of nanoporous silicon / copper / mesophase carbon microsphere composite negative electrode material for lithium ion battery:

[0024] (1) Mix 1 g of silicon oxide powder and 0.6 g of aluminum powder in an argon atmosphere at room temperature at a mass ratio of 1:0.6, place them in a stainless steel ball mill jar equipped with an O-ring, put stainless steel balls, and keep The argon atmosphere in the tank, the rotating speed of the high-energy ball mill is 400 rpm, and the ball milling time is 15 hours, and about 1.4g of highly dispersed nano-silicon / alumina composites are obtained;

[0025] (2) Mix 0.5g of nano-silicon / alumina composite with 0.45g of metal copper powder in an argon atmosphere at room temperature at a mass ratio of 1:0.9, place them in a stainless steel ball mill jar equipped with an O-ring, and put Stainless steel balls to keep the argon atmosphere in the tank, the speed of the high-energy ball mill is 400 rpm, and the ball milling...

Embodiment 3

[0029] In the nanoporous silicon / copper / graphite composite powder material that the lithium ion battery that embodiment 1 obtains, add the acetylene black of 30wt% as conductive agent, the PVDF (polyvinylidene fluoride) of 10wt% (PVDF is the 0.02g / mL of PVDF / NMP solution, NMP is N-methylpyrrolidone) as a binder, after being fully stirred evenly, coated on the copper foil, dried in an oven at 80°C, and then coated with Φ12.5mm The punch is punched into a pole piece, and after being pressed at a pressure of 1MPa, it is placed in a vacuum oven at 120°C for 4 hours to dry. Transfer the pole piece to an argon glove box, and make an experimental button battery with metal lithium as the counter electrode, and the electrolyte is 1mol L -1 LiPF 6 / EC:DMC (1:1 volume ratio, EC: ethylene carbonate, DMC: dimethyl carbonate), the test charge and discharge current density is 0.2mA cm -2 , charge-discharge cut-off voltage relative to Li / Li + It is 0.01~1.4V.

[0030] figure 1 It is the...

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Abstract

The invention relates to a method for preparing the composite cathode of lithium battery, wherein said cathode material is formed by silicon / copper / carbon; said silicon has nanometer porous structure; the nanometer silicon / alumina composite, nanometer silicon / alumina / copper composite, and nanometer silicon / alumina / copper / carbon composite, with high disperse degree, is obtained by high-energy grinding; then adding hydrochloric acid; removing alumina, and over alumina, to obtain said composite cathode. And the inventive method uses hydrochloric acid to remove the inactive alumina and over aluminum, to improve specific capacity of composite; and the treatment of hydrochloric acid makes the silicon with nanometer porous structure, to adsorb the volume change when embedding lithium, to buffer volume effect, improve the structure stability. And the reversible capacity of said cathode material can reach 580mAh .g-1; in the first 35 cycles, the average capacity damage of each cycle is 0.1%.

Description

technical field [0001] The invention relates to a preparation method of a battery electrode material, in particular to a preparation method of a composite negative electrode material for a lithium ion battery. Background technique [0002] At present, lithium-ion batteries in production and use mainly use graphitized carbon as the negative electrode material, but the lithium storage capacity of the material is not high. As far as graphite-based negative electrode materials are concerned, their large layered structure voids not only provide a place for lithium storage, but also determine the low theoretical specific capacity of the material (about 372mAh g -1 ) characteristics. On the other hand, the lithium intercalation potential of the graphite negative electrode is close to the metal lithium potential, and the diffusion rate of lithium in it is not high, which makes lithium may be precipitated on the surface during high-rate charging, which is not conducive to the safety...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/04H01M4/38B22F9/04B22F9/16B82B3/00H01M4/1395
CPCY02E60/10
Inventor 杨军郑颖努丽燕娜
Owner SHANGHAI JIAO TONG UNIV
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