A kind of silicon carbon negative electrode slurry and preparation method thereof

A negative electrode slurry, silicon carbon technology, applied in the direction of battery electrodes, structural parts, electrical components, etc., can solve the problems that the electrochemical performance of active materials cannot be exerted, unfavorable cost control, loss of electrical connection, etc., to achieve improved adhesion effect, improve electrical conductivity, reduce expansion and shrinkage

Active Publication Date: 2021-03-09
HENGDIAN GRP DMEGC MAGNETICS CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For example, during the cycle of the battery, the silicon-carbon negative electrodes of the same layer will expand; the silicon-carbon negative electrodes will gradually generate cracks during the expansion and contraction process, and when the cracks increase to a certain extent, the active materials will become isolated islands shape, loss of electrical connection, and the electrochemical performance of the active material will gradually fail to play, etc.
In addition, most of the existing preparation processes require multiple coatings, and the process is cumbersome, which is not conducive to cost control

Method used

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  • A kind of silicon carbon negative electrode slurry and preparation method thereof
  • A kind of silicon carbon negative electrode slurry and preparation method thereof

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Experimental program
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Effect test

Embodiment 1

[0068] This embodiment provides a silicon-carbon negative electrode slurry, which contains the following components in terms of mass percentage: 94.9% silicon-based / graphite mixture, 2% binder, single-walled carbon nano Tube 1%, carbon black 0.1%, coupling agent 2%;

[0069] Wherein, the binder is a polyacrylic acid-based polymer containing carboxyl functional groups, and the monomer of the polymer contains more than 3 hydroxyl groups, and the molecular weight is greater than 10000; the carbon black is conductive carbon black (Super-p), The particle size is 0.1-2 μm; the diameter of the single-walled carbon nanotube is 0.6-10 nm, and the tube length is 5-30 μm; the silicon base in the silicon-based / graphite mixture is silicon oxide-coated carbon; the graphite is artificial Graphite; the coupling agent is a silane coupling agent.

[0070] Prepare the above silicon carbon negative electrode slurry according to the following method:

[0071](1) Carry out dry mixing with silicon...

Embodiment 2

[0078] This embodiment provides a silicon-carbon negative electrode slurry, which contains the following components in terms of mass percentage: 93.7% silicon-based / graphite mixture, 6% binder, single-walled carbon nano Tube 0.1%, carbon black 0.1%, coupling agent 0.1%;

[0079] Wherein, the binder is a polyacrylic acid-based polymer containing carboxyl functional groups, and the monomer of the polymer contains more than 3 hydroxyl groups, and the molecular weight is greater than 10000; the carbon black is conductive carbon black (Super-p), The particle size is 0.1-2 μm; the diameter of the single-walled carbon nanotube is 0.6-10 nm, and the tube length is 5-30 μm; the silicon base in the silicon base / graphite mixture is silicon alloy coated carbon; the graphite is a natural coating Graphite-coated; the coupling agent is a titanate coupling agent.

[0080] Prepare the above silicon carbon negative electrode slurry according to the following method:

[0081] (1) Carry out dry...

Embodiment 3

[0088] This embodiment provides a silicon-carbon negative electrode slurry, which contains the following components in terms of mass percentage: 96% silicon-based / graphite mixture, 2% binder, single-walled carbon nano Tube 0.1%, carbon black 0.1%, coupling agent 0.8%;

[0089] Wherein, the binder is a polyacrylic acid-based polymer containing carboxyl functional groups, and the monomer of the polymer contains more than 3 hydroxyl groups, and the molecular weight is greater than 10000; the carbon black is conductive carbon black (Super-p), The particle size is 0.1-2 μm; the diameter of the single-walled carbon nanotube is 0.6-10 nm, and the tube length is 5-30 μm; the silicon base in the silicon-based / graphite mixture is nano-silicon-coated carbon; the graphite is a natural coating Graphite-coated; the coupling agent is a titanate coupling agent.

[0090] Prepare the above silicon carbon negative electrode slurry according to the following method:

[0091] (1) Carry out dry m...

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Abstract

The invention relates to a silicon-carbon negative electrode slurry and a preparation method thereof. The silicon-carbon negative electrode slurry contains the following components: a silicon-based / graphite mixture, a binder, a single-walled carbon nanotube, carbon black and a coupling agent; The binder is a polyacrylic acid-based polymer containing carboxyl functional groups. The invention utilizes the polyacrylic acid-based polymer containing carboxyl functional groups and the coupling agent to modify the silicon-carbon negative electrode, reduces the expansion and contraction rate of the silicon-carbon negative electrode, and improves the electrical conductivity of the silicon-carbon negative electrode and the copper foil of the negative electrode current collector. The utilization rate of the negative electrode active material prolongs the cycle life of the battery; at the same time, the addition of single-walled carbon nanotubes plays the role of an "electrical bridge" and eliminates the failure of the active material during the cycle of the battery. The present invention adopts the method of step-by-step addition of binder and dry-wet method to prepare the above-mentioned silicon-carbon negative electrode slurry, which further improves the electrical properties of the material, and the whole preparation process is simple and has good application prospects.

Description

technical field [0001] The invention belongs to the field of high-capacity lithium-ion batteries, and in particular relates to a silicon-carbon negative electrode slurry and a preparation method thereof. Background technique [0002] With the progress of society, electronic products and electric vehicles have higher and higher requirements for battery energy density. At present, the gram capacity of the graphite negative electrode in the full battery has reached 355mAh / g, reaching more than 95% of the theoretical value, and its application is close to the limit. Due to its abundant reserves and ultra-high theoretical specific capacity, silicon-based anode materials are gradually becoming the best choice for battery companies and lithium battery materials to improve anodes, and are one of the most promising anode materials for next-generation lithium-ion batteries. [0003] However, silicon-carbon anode materials also have obvious shortcomings in the actual use process, main...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/36H01M4/38H01M4/62H01M10/0525
CPCH01M4/362H01M4/386H01M4/62H01M4/622H01M4/625H01M4/628H01M10/0525Y02E60/10
Inventor 张章明龚金保黄明
Owner HENGDIAN GRP DMEGC MAGNETICS CO LTD
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