Ambient-Condition Strategy for Production of Hollow Ga2O3@rGO Crystalline Nanostructures Toward Efficient Lithium Storage

Abstract

Crystalline γ-Ga2O3@rGO core–shell nanostructures are synthesized in gram scale, which are accomplished by a facile sonochemical strategy under ambient condition. They are composed of uniform γ-Ga2O3 nanospheres encapsulated by reduced graphene oxide (rGO) nanolayers, and their formation is mainly attributed to the existed opposite zeta potential between the Ga2O3 and rGO. The as-constructed lithium-ion batteries (LIBs) based on as-fabricated γ-Ga2O3@rGO nanostructures deliver an initial discharge capacity of 1000 mAh g−1 at 100 mA g−1 and reversible capacity of 600 mAh g−1 under 500 mA g−1 after 1000 cycles, respectively, which are remarkably higher than those of pristine γ-Ga2O3 with a much reduced lifetime of 100 cycles and much lower capacity. Ex situ XRD and XPS analyses demonstrate that the reversible LIBs storage is dominant by a conversion reaction and alloying mechanism, where the discharged product of liquid metal Ga exhibits self-healing ability, thus preventing the destroy of electrodes. Additionally, the rGO shell could act robustly as conductive network of the electrode for significantly improved conductivity, endowing the efficient Li storage behaviors. This work might provide some insight on mass production of advanced electrode materials under mild condition for energy storage and conversion applications.