Tuning Pseudocapacitance via C-S Bonding in WS2 Nanorods Anchored on N,S Codoped Graphene for High-Power Lithium Batteries.

Abstract

Pseudocapacitance plays an important role in high-power lithium-ion batteries (LIBs). However, it is still lack of effective methods to tailor the pseudocapacitance contribution in electrode materials for LIBs. Herein, pseudocapacitance tuned by the strength of C-S bonding has been rendered in WS2 nanorods anchored on the N,S codoped three-dimensional graphene hybrid (WS2@N,S-3DG) for the first time. The pseudocapacitive contributions in the charge storage can be enhanced effectively with the increased strength of C-S bonding. As expected, the enhanced extrinsic pseudocapacitance makes WS2@N,S-3DG a fascinating electrode material for high-power LIBs, with a high reversible capacity of 509 mA h g-1 over 500 cycles at a current density as high as 2 A g-1. These encouraging results of pseudocapacitance tailored by chemical bonding provide new opportunities for designing advanced electrode materials.