Adhesive for negative materials for lithium-ion battery and method for preparing electrode containing adhesive

Abstract

The invention discloses an adhesive for negative materials for a lithium-ion battery and a method for preparing an electrode containing the adhesive. The adhesive is a polyether high-molecular polymer, and the method for preparing the electrode containing the adhesive takes the polyether high-molecular polymer as an adhesive precursor, and comprises the following steps of: mixing 1.5-5.5 weight percent of polyether high-molecular polymer, 94-97 weight percent of electrode active material, 0.1-2.5 weight percent of reaction auxiliaries and 0.4-4 weight percent of a conductive agent with deionized water, stirring the mixture for 1-3 hours, enabling the polyether high-molecular polymer to generate cross-linking reaction to prepare electrode slurry, then coating the electrode slurry on the surface of a metal foil and finally drying for 2-4 hours at 120-140 DEG C to obtain the electrode. In an electrode preparation process, the polyether high-molecular polymer can generate cross-linking reaction in the role of the reaction auxiliaries, and therefore the bonding strength and the elastic force of the polyether high-molecular polymer are adjusted. Thus, the battery using the adhesive has good charge and discharge rate performance and cycle performance.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a binder for negative electrode materials of lithium-ion batteries and a method for preparing an electrode containing the binder. Background technique [0002] Due to their high theoretical energy density, alloy materials such as silicon and tin have recently attracted widespread attention as anode materials for lithium-ion secondary batteries. However, because such materials are accompanied by large changes in the intercalation / extraction process of lithium ions, during the charging and discharging cycle of the battery, it is easy to cause detachment between this type of electrode active material and the current collector, resulting in a sharp decline in battery capacity. Adhesives such as SBR, which are widely used in lithium-ion battery anode materials, are limited in their application in such alloy materials due to their low adhesive strength. On th...

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Problems solved by technology

[0003] One of the objectives of the present invention is to provide a binder for lithium-ion battery anode materials in view of the deficiencies in the prior art. The separation of the electrode active material and the current collector caused by the volume change in the battery, and the use of ordinary electrical insulating adhesives cause problems such as the charge-discharge rate and cycle performance of lithium-ion batteries, and poor low-temperature discharge performance.

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