Mesoporous Hollow Ge Microspheres Prepared via Molten-Salt Metallothermic Reaction for High-Performance Li-Storage Anode

Generally, Ge-based anodes are prepared by metallothermic reduction of GeO2 with Mg at 650 °C. Herein, a molten-salt system is developed a low-temperature metallothermic reduction of GeO2 to prepare nanostructured Ge based anode materials. Typically, mesoporous hollow Ge microspheres are prepared by reduction of GeO2 with metallic Mg in molten ZnCl2 (mp 292) at 350 °C. Monodispersed Ge particles are synthesized through reduction of GeO2 with Mg in molten AlCl3 (mp 192 °C) at 250 °C. The meso-porous Ge anode delivers the reversible capacity of 1291 mA h g-1 at 0.2 C after 150 cycles with a retention of 97.3%, 1217 mA h g-1 at 0.8 C after 400 cycles with a retention of 91.9%, and superior rate capability with a capacity of 673 mA h g-1 even at 10 C. Then, the reaction mechanism and full-cell performance of as-prepared Ge anodes are studied systemically.