Composite binding agent applicable for silicon-based negative electrode material of lithium ion battery, preparation method of composite binding agent and negative electrode material

Abstract

The invention relates to a composite binding agent applicable for a silicon-based negative electrode material of a lithium ion battery. The composite binding agent comprises a main binding agent and a matched binging agent, wherein the main binding agent is partially neutralized polyacrylic acid. With the partially neutralized polyacrylic acid proposed by the invention, the dispersibility of the composite binding agent is improved, moreover, the mechanical property and the processability of the composite binding agent are improved, and the electrochemical performance of the material is further favorably improved. The binding agent is a mixture of the main binding agent and the matched binding agent, the main binding agent is in an intermediate state of the polyacrylic acid and poly(lithium acrylate) and has performance superior to the polyacrylic acid and the poly(lithium acrylate), and the electrochemical performance of the silicon-based negative electrode material is remarkably improved; the matched agent is styrene-butadiene rubber; moreover, a few amount of lithium-containing raw material is consumed during preparation of the composite binding agent, the composite binding agent is relatively low in cost, is easy for industrialization, has certain lithium ion conductivity, and has relatively high market potential.

Description

Technical field [0001] The invention relates to a binder, in particular to a binder suitable for silicon-based negative electrode materials of lithium ion batteries. The invention also relates to a preparation method of the binder and a lithium ion prepared from the binder. Battery silicon anode material. Background technique [0002] Lithium-ion batteries have attracted people's attention due to their high energy density and good cycle performance. They have developed rapidly in the past 20 years. At present, the negative electrode materials of commercial lithium-ion batteries are mainly various graphite materials, with a theoretical specific capacity of 372mAh / g. However, the current commercial graphite anode materials are close to their theoretical specific capacity. To further improve the energy density of lithium-ion batteries, it is necessary to develop new high-capacity lithium-ion battery anode materials. At present, silicon-based anode materials have attracted more and...

AI Technical Summary

Problems solved by technology

However, the adhesion between lithium polyacrylate and the copper foil current collector in the negative electrode of lithium-ion batteries is poor, and it is easy to cause material drop, which will lead to the attenuation of battery capacity.

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