A graphene/carbon black hybrid material: a novel binary conductive additive for lithium-ion batteries

A novel graphene(GN)/carbon black(CB) binary conductive additive has been developed, which is characterized by a unique microstructure and excellent performance for lithium ion batteries (LIBs). It was fabricated using a hydrothermal process, followed by heat treatment. The introduction of CB particles prevents GN from agglomerating and hence improves the electronic conductivity of the resulting additive. CB particles can also enhance the Li⁺ ion diffusion, owing to a reduction of the GN fraction and an increase in electrolyte adsorption. Therefore, the rate performance of the LIB is improved to some extent. Experimental data shows that the specific capacity of LiFePO₄ containing 5% of this binary conductive additive (after 900 ℃ treatment) is 73 mAh/g at 10 C, which is superior to that of LiFePO₄ with 10% of CB (62 mAh/g). Compared with the latter, the former has a specific capacity increase of 25% based on the mass of the whole electrode and shows superior cycle stability.