Germanium Oxide/germanium/ reduced Graphene (GeO2/Ge/r-GO) Hybrid Composite Anodes for Lithium-ion Batteries: Effect of Ge loading on Electrochemical Performance

Abstract

Hybrid composites between Germanium (Ge) and carbonaceous materials are promising anode materials for Li-ion batteries (LIBs). The mitigation of reduced cycling ability and rate capability allows for the unhindered benefit of higher capacities in Ge-based anodes. Here, the effect of Ge mass loading on the electrochemical performance of GeO2/Ge/r-GO composites was evaluated as LIBs anode. GeO2/Ge/r-GO composites were synthesized by controlled microwave radiation of ball-milled Ge and sonicated dispersion of graphene oxide (GO). The composite anode at Ge 25% showed greatest cycling retention with 91% after 100 cycles and an average specific capacity of 300 mAh/g (1600 mAh/g Ge). At 75% Ge mass loading the anode suffered with limited cycling retention of 57.5% at the cost of greater specific capacities. The composite at 50% Ge attained advantageous characteristics of both composites with a stable cycling performance of 71.4% after 50 cycles and an average specific capacity of 400 mAh/g (1067 mAh/g Ge). These findings can be used to shape high-energy Ge-based anodes and guide future development in energy storage.