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

Crystalline gamma-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 gamma-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 gamma-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 gamma-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.

Automated summary

Crystalline gamma-Ga2O3@rGO core-shell nanostructures were synthesized in gram scale using a facile sonochemical strategy under ambient conditions. The structures consisted of uniform gamma-Ga2O3 nanospheres encapsulated by reduced graphene oxide (rGO) nanolayers, with their formation attributed to the opposite zeta potential between Ga2O3 and rGO. The as-fabricated gamma-Ga2O3@rGO nanostructures exhibited improved reversible capacity and longer lifetime in lithium-ion batteries compared to pristine gamma-Ga2O3, largely due to a conversion reaction and alloying mechanism, as well as the self-healing ability of the discharged product of liquid metal Ga. The rGO shell also acted as a robust conductive network, enhancing the conductivity and contributing to efficient Li storage behaviors. This work provides insights for mass production of advanced electrode materials for energy storage and conversion applications under mild conditions.