材料期刊网

Surface modification of carbon materials plays an important role in tailoring carbon surface chemistry to specify their electrochemical performance. Here, a surface modification strategy for graphene is proposed to produce LiF-nanoparticle-modified graphene as a high-rate, large-capacity pre-lithiated electrode for high-power and high-energy lithium ion batteries. The LiF nanoparticles covering the active sites of the graphene surface provide an extra Li source and act as an effective solid electrolyte interphase (SEI) inhibiter to suppress LiFP6 electrolyte decomposition reactions, affect SEI components, and reduce their thickness. Consequently, the Li-ion diffusion is greatly sped up and the thermodynamic stability of the electrode is significantly improved. This modified graphene electrode shows excellent rate capability and improved first-cycle coulombic efficiency, cycling stability, and ultrahigh power and energy densities accessible during fast charge/discharge processes.