Engineering Bi2O3-Bi2S3 heterostructure for superior lithium storage.

Bismuth oxide may be a promising battery material due to the high gravimetric (690 mAh g(-1)) and volumetric capacities (6280 mAh cm(-3)). However, this intrinsic merit has been compromised by insufficient Li-storage performance due to poor conductivity and structural integrity. Herein, we engineer a heterostructure composed of bismuth oxide (Bi2O3) and bismuth sulphide (Bi2S3) through sulfurization of Bi2O3 nanosheets. Such a hierarchical Bi2O3-Bi2S3 nanostructure can be employed as efficient electrode material for Li storage, due to the high surface areas, rich porosity, and unique heterogeneous phase. The electrochemical results show that the heterostructure exhibits a high Coulombic efficiency (83.7%), stable capacity delivery (433 mAh g(-1) after 100 cycles at 600 mA g(-1)) and remarkable rate capability (295 mAh g(-1) at 6 A g(-1)), notably outperforming reported bismuth based materials. Such superb performance indicates that constructing heterostructure could be a promising strategy towards high-performance electrodes for rechargeable batteries.