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Silicon copper lithium ion battery negative electrode preparation method

A lithium-ion battery, negative electrode technology, applied in battery electrodes, negative electrodes, active material electrodes, etc., can solve the problems of low conductivity and actual capacity, insufficient to maintain the stability of the conductive network structure, and aggravate battery capacity attenuation, etc. Battery performance, improving material conductivity, buffering effect of volume change in charge and discharge

Active Publication Date: 2019-04-19
HUNAN NORMAL UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the above method usually adopts the traditional coating process to prepare the medium silicon negative electrode. The electrode slurry contains a conductive agent and a binder, and the non-conductive polymer binder swells in the EC / DMC electrolyte system, which leads to the collapse of the conductive network and aggravates the problem. battery capacity fading
Chinese patent (CN105489839A) coats copper-silicon composites, reducing agents containing C, H, and O elements on the current collector, and reduces them in an inert atmosphere to obtain a copper-silicon negative electrode. However, pyrolytic carbon is generally amorphous carbon, and the electrical conductivity And the actual capacity is low, not enough to maintain the structural stability of the conductive network during the cycle

Method used

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  • Silicon copper lithium ion battery negative electrode preparation method
  • Silicon copper lithium ion battery negative electrode preparation method
  • Silicon copper lithium ion battery negative electrode preparation method

Examples

Experimental program
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Effect test

Embodiment 1

[0036] (1) Ultrasonically disperse 3.75g of copper acetate monohydrate in 300mL of deionized water, add 300mL of ethylene glycol solution during the ultrasonic process, and then add 0.10g of nano-silica powder in batches after obtaining a clear and transparent solution. in a constant temperature water bath of 60°C.

[0037] (2) Separately prepare a precipitating agent: 200 mL of a water / ethylene glycol mixed solution with a volume ratio of 1:1 containing 1.93 g of oxalic acid.

[0038] (3) Slowly add the solution of step (2) to the solution of step (1) dropwise at a rate of 2 mL / min. After the drop is complete, control the reaction temperature to 60°C and the reaction time to 6 hours.

[0039] (4) After the reaction is finished, the product obtained in step (3) is suction filtered, the filter cake is washed twice with water, and washed once with alcohol after the solution is clarified.

[0040] (5) Coat the obtained slurry on the cleaned foamed copper current collector, and ...

Embodiment 2

[0043] (1) Ultrasonically disperse 1.44g of anhydrous copper chloride in 300mL of ethylene glycol, add 100 mL of ethylene glycol during the ultrasonic process, and then add 0.10g of nano silicon powder in batches after obtaining a clear and transparent solution. Stir in an 80°C constant temperature water bath.

[0044] (2) Separately prepare a precipitant: 100mL of ethylene glycol solution containing 1.16g of oxalic acid.

[0045] (3) Slowly add the solution of step (2) to the solution of step (1) dropwise at a rate of 2 mL / min. After the drop is completed, control the reaction temperature to 80°C and the reaction time to 5 hours.

[0046] (4) After the reaction is finished, the product obtained in step (3) is suction filtered, the filter cake is washed twice with water, and washed once with alcohol after the solution is clarified.

[0047] (5) Vacuum-dry the obtained slurry at 90°C for 12 hours to obtain a precursor powder. Without using any current collector, place 0.015g o...

Embodiment 3

[0050] (1) Ultrasonically disperse 1.44g of anhydrous copper chloride in 300mL of ethylene glycol, add 100 mL of ethylene glycol during the ultrasonic process, and then add 0.10g of nano-silica powder in batches to obtain a clear and transparent solution. In an 80°C constant temperature oil bath with stirring.

[0051] (2) Separately prepare a precipitant: 100mL of ethylene glycol solution containing 1.16g of oxalic acid.

[0052] (3) Slowly add the solution of step (2) to the solution of step (1) dropwise at a rate of 2 mL / min. After the drop is completed, control the reaction temperature to 80°C and the reaction time to 3 hours.

[0053] (4) After the reaction is finished, the product obtained in step (3) is suction filtered, the filter cake is washed twice with water, and washed once with alcohol after the solution is clarified.

[0054] (5) The obtained slurry is coated on the cleaned nickel foam current collector, and at 5MPa / cm 2 Press down to form a pole piece with a ...

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Abstract

The invention relates to a silicon copper lithium ion battery negative electrode preparation method. The method comprises the steps of: using nanometer silicon powder as a raw material, performing precipitation in situ of the nanometer silicon powder according to a silicon copper mass ratio of 0.1-60 wt.% to form a copper oxalate-silicon precursor, coating the precursor slurry onto a current collector, and performing pressing, drying and protective atmosphere calcination to obtain an integrated negative electrode of nano copper-nanometer silicon-current collector; and performing subsequent coating by nano-silver or conductive macromolecules to further optimize the silicon copper electrode. The large-size expansion and poor conductivity of the nanometer silicon powder are relieved through adoption of the excellent extension and conductivity of the nano copper grown in situ by the cupric oxalate, and the subsequent coating by nano-silver or conductive macromolecules further optimizes theperformances of the electrode so that the finally obtained electrode is excellent in the cycle stability.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, and in particular relates to a preparation method of a nano-silicon / copper composite battery electrode material and a negative pole piece. Background technique [0002] Lithium-ion batteries are widely used in modern society as high energy density, no memory effect, green and environmentally friendly rechargeable batteries. At present, the promotion and popularization of power vehicles and the development of new energy storage have made the demand for high-energy, high-power, and long-life lithium-ion batteries increasingly urgent. [0003] The specific capacity of graphite, a traditional commercial anode material, is close to the theoretical value (372mAh g -1 ), the space for improvement is limited; in recent years, Li 4 Ti 5 o 12 Negative electrode materials are widely used in battery systems with ternary materials as positive electrodes, but their theoretical specific capacity is low ...

Claims

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Application Information

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IPC IPC(8): H01M4/1395
CPCH01M4/1395H01M2004/027Y02E60/10
Inventor 杨立山周灵邵俐
Owner HUNAN NORMAL UNIVERSITY