Synthesis of graphene/Ca2Ge7O16 nanofibers composite as anode materials for lithium-ion batteries

Graphene/Ca2Ge7O16 nanofibers composite (GCNF) was synthesized by a facile in situ hydrothermal process. In the composite, Ca2Ge7O16 nanofibers (CNF) were enwrapped by the highly conductive graphene sheets. As anode material for lithium ion batteries, at the current density of 0.6 mA cm−2, the GCNF electrode delivered a reversible charge capacity of 602 mA h g−1, with a capacity retention of 99% after 100 cycles. When the current density was increased to 3, 6 and 15 mA cm−2, the electrode still delivered 517, 414 and 354 mA h g−1, respectively. The excellent electrochemical performance can be attributed to synergistic effect between graphene and CNF, which improve the structural stability and the electronic conductivity of the composite.