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

Benefiting from the well-dispersed WS 2 nanoparticles, highly conductive 3D porous structure and abundant reaction active sites, hierarchical g-C 3 N 4 @WS 2 composite shows excellent electrochemical performance as lithium-ion battery anode material. • Hierarchical g-C 3 N 4 @WS 2 composite was prepared for lithium-ion battery application. • WS 2 nanoparticles were in situ formed and uniformly distributed on g-C 3 N 4 nanosheets. • The ultrathin g-C 3 N 4 nanosheets can avoid the agglomeration of WS 2 nanoparticles. • Hierarchical g-C 3 N 4 @WS 2 composite displays excellent electrochemical properties. 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-C 3 N 4 @WS 2 composite synthesized by a solvothermal reaction. The as-synthesized g-C 3 N 4 @WS 2 composite provides abundant reaction active sites for lithium storage and sufficient interspace to buffer the volume variation of WS 2 nanoparticles. Moreover, the ultrathin g-C 3 N 4 nanosheets could restraint WS 2 nanoparticles from agglomeration, increase the contact chances with electrolyte and facilitate the charge transport and ion diffusion. In consequence, the optimized g-C 3 N 4 @WS 2 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.