Few-layered WSe2in-situ grown on graphene nanosheets as efficient anode for lithium-ion batteries

Abstract

The hierarchical porous nanoarchitecture of WSe2/reduced graphene oxide (WSe2/RGO) hybrid, constructed by few-layered WSe2 nanosheets in-situ grown on RGO nanosheets, has been synthesized through a facile one-pot solvothermal method. The WSe2/RGO hybrid can be used as an efficient anode for lithium-ion (Li-ion) batteries and exhibits much better electrochemical performance than that of bare WSe2: the WSe2/RGO hybrid delivers a high initial discharge capacity of 744 mA h g−1 at 0.2C and it remains 528 mA h g−1 after 80 cycles, while the bare WSe2 has a lower discharge capacity of 549 mA h g−1 at 0.2C and it remains only 98 mA h g−1 after 80 cycles; the WSe2/RGO hybrid also demonstrates remarkably rate capability under different current rates from 0.2 to 8C. Those outstanding electrochemical performances of WSe2/RGO hybrid can be assigned to its unique nanoarchitecture: the RGO nanosheets with high conductivity work as the skeleton of WSe2/RGO anode facilitating the electron transfer; the RGO nanosheets can effectively prevent WSe2 from the aggregation and promote the in-situ growth of WSe2 layers on graphene, guaranteeing the formation of hierarchical porous nanoarchitecture with abundant electrochemically active sites, which can allow for efficient ionic diffusion and easy electrolyte infiltration. This study presents a rational-designed structure and facile strategy to fabricate transition metal dichalcogenides (TMDs)/graphene hybrid as promising anodes for lithium-ion batteries.