Facile synthesis of hierarchical g-C3N4@WS2 composite as Lithium-ion battery anode

Abstract

Transition metal sulfides (TMSs), as highly promising candidate anode materials, are gradually attracting the attention for lithium-ion batteries (LIBs) recently on account of its multiple valence states as well as considerable capacity. Nevertheless, TMSs have relatively low inherent electronic conductivity and large volume variation, which stands in the way of their practical applications. Herein, to ameliorate the drawbacks of TMSs, we report a hierarchical g-C3N4@WS2 composite synthesized by a solvothermal reaction. The as-synthesized g-C3N4@WS2 composite provides abundant reaction active sites for lithium storage and sufficient interspace to buffer the volume variation of WS2 nanoparticles. Moreover, the ultrathin g-C3N4 nanosheets could restraint WS2 nanoparticles from agglomeration, increase the contact chances with electrolyte and facilitate the charge transport and ion diffusion. In consequence, the optimized g-C3N4@WS2 electrode delivers a large discharge capacity (1136.1 mAh g−1 at 0.1C) and superior cycling stability (433.8 mAh g−1 after 1000 cycles). In summary, a simple method for constructing hierarchical transition metal sulfides as anode materials for LIBs is proposed.