Novel Graphene Structures: Substantial Capacity Enhancement in Lithium Batteries

摘要

Lithium-ion batteries (LIBs) as high energy- and power-density rechargeable batteries are in high demand for energy storage systems. Novel 3D graphene structures were synthesized by CVD method using commercially available Ni and Cu powders. 3D pristine graphene structures were obtained which consist of up to 93% of incommensurately-stacked graphene. These structures exhibit over four times higher reversible capacity (up to 1540 mAh/g) than the theoretical capacity of graphite applied as an anode material in LIBs coin cells. These high capacities are stable throughout long-term cycling, and the retained capacity remains over 93% throughout hundred cycles by reaching up to 100% Coulombic efficiency for LiC_2 stoichiometry (1116 mAh/g capacity). We consider lithium intercalation model for multilayer graphene where capacity varies with N number of layers resulting Li_N+_1C_(2N) stoichiometry. LIBs based on incommensurate graphene anode promises new development of high capacity, cost-efficient and lightweight secondary batteries.