▎ 摘 要
As anode material for lithium-ion batteries, graphite has the disadvantage of relatively low specific capacity. In this work, a simple yet effective strategy to overcome the disadvantages by using a composite of flake graphite (FG) and small-sized graphene (SG) has been developed. The FG/SG composite prepared by dispersing FG and SG (90:10 w/w) in ethanol and drying delivers much higher specific capacity than that of individual component except for improved rate capability. More surprisingly, FG/SG composite delivers higher reversible capacity than its theoretical value calculated according to the theoretical capacities of graphite and graphene. Therefore, a synergistic effect between FG and SG in lithium storage is clearly discovered. To explain it, we propose a model that abundant nanoscopic cavities were formed due to physical adhesion between FG and SG and could accommodate extra lithium.