Graphene-based lithium-ion battery cathode and preparation method thereof

Abstract

The invention relates to a graphene-based lithium-ion battery cathode and a preparation technology thereof. According to the technology, cathode slurry taking graphite doped graphene as an active substance is prepared and applied to copper foil, and the lithium-ion battery cathode is prepared. A novel polystyrene-polyisoprene-polystyrene block polymer binder is adopted in the technology, has higher binding force for graphene and can provide high elasticity and improve performance of the graphene-based lithium-ion battery cathode, the obtained high-energy density type cathode has 410 mAh / g of energy density during 0.2 C charging and discharging, and the power type cathode has 310 mAh / g of energy density during 5 C charging and discharging. Raw materials are economical and easy to obtain, and the technology is simple and environment-friendly.

Description

technical field [0001] The invention relates to a lithium ion battery, in particular to a graphene-based lithium ion battery negative electrode and a preparation method thereof. Background technique [0002] In recent years, due to the energy crisis and the aggravation of environmental pollution and other reasons, electric vehicle technology has begun to receive extensive attention from governments of various countries. For a long period of time in the future, only lithium-ion batteries will have the appropriate energy density and cycle life to meet the needs of electric vehicles. 2014 is called by many people the "first year" of the development of new energy vehicles in China, because in this year, the development of new energy vehicles in the Chinese market has achieved a "quantity" breakthrough, becoming the second largest in the world after the United States. electric vehicle market. Preliminary statistics show that sales in the U.S. market are close to 120,000 vehicle...

AI Technical Summary

Problems solved by technology

However, as a power battery used in electric vehicles, there are still two key issues that have not been well resolved: (1) The energy density of the battery cannot meet the requirements of the cruising range of electric vehicles

(2) Large current discharge will cause great damage to the battery, resulting in poor acceleration performance of electric vehicles

Due to the existence of polybutadiene block in SBR, it is an adhesive with excellent viscoelasticity. Although SBR shows excellent performance in traditional lithium-ion batteries, it still lacks performance in negative electrodes with graphene. We think it is mainly because the adhesion of graphite and graphene to graphite and graphene is greatly affected after SBR swells the electrolyte.

Images