Supersaturated bridge-sulfur and vanadium co-doped M0S2 nanosheet arrays with enhanced sodium storage capability
Yuru Dong, Zhengju Zhu, Yanjie Hu, Guanjie He, Yue Sun, Qilin Cheng, Ivan P. Parkin, Hao Jiang
Abstract
The low specific capacity and sluggish electrochemical reaction kinetics greatly block the development of sodium-ion batteries (SIBs). New high-performance electrode materials will enhance development and are urgently required for SIBs. Herein, we report the preparation of supersaturated bridge-sulfur and vanadium co-doped MoS2 nanosheet arrays on carbon cloth (denoted as V-MoS2+x/CC). The bridge-sulfur in MoS2 has been created as a new active site for greater Na+ storage. The vanadium doping increases the density of carriers and facilitates accelerated electron transfer. The synergistic dual-doping effects endow the V-MoS2+x/CC anodes with high sodium storage performance. The optimized V-MoS2.49/CC gives superhigh capacities of 370 and 214 mAh·g−1 at 0.1 and 10 A·g−1 within 0.4−3.0 V, respectively. After cycling 3,000 times at 2 A·g−1, almost 83% of the reversible capacity is maintained. The findings indicate that the electrochemical performances of metal sulfides can be further improved by edge-engineering and lattice-doping co-modification concept.