High-Yield Room-Temperature Solution Synthesis of Ge Nanoparticles by Alkalide Reduction for High-Performance Li-Ion Anodes

This study reports the room-temperature, one-pot, rapid alkalide reduction synthesis of germanium metal nanoparticles on multilayer graphene nanoshells (MGNSs) at a high yield (97%), as well as their electrochemical performance as a Li-ion battery anode. Ge metal’s theoretical gravimetric capacity is second only, and its volumetric capacity nearly equal, to that of Si which possesses the highest capacities of any lithium alloying metal. An MGNS is a carbon net-negative material composed of nested graphene sheets with high surface area, good electrical conductivity and excellent electrochemical stability. When cycling from 1.5 to 0.02 V vs. Li, a stable capacity of ~750 mAh/g Ge/MGNS composite electrode was obtained with an average capacity fade of 0.014% per cycle, maintaining 85% of the original capacity after 600 cycles.