Electrochemically exfoliated WS <sub>2</sub> in molten salt for sodium‐ion battery anode
Beilei Zhang, Xiang Chen, Haijia Zhao, Hongwei Xie, Huayi Yin
Abstract
Abstract The poor crystallinity and unstable crystal structure of tungsten disulfide (WS 2 ) limit its application in practice. In this paper, a molten salt electrolysis method is proposed to intercalate metal ions into the interlayers of layered WS 2 to obtain few‐layer sheetlike structures. The effect of the molten salt system, applied constant current and electrolysis duration on the exfoliation degree of WS 2 bulk has been investigated. The results show that the products electrolyzed in molten LiCl‐NaCl‐KCl and NaCl‐KCl salts under 25 mA were more transparent and thinner flakes sheets due to the uniform intercalation of Li + and Na + with smaller size. The exfoliated WS 2 was used as an anode material for sodium‐ion batteries with a potential of 0.01–2.50 V. In comparison, the WS 2 ‐NaCl‐25 mA electrode displays a high reversible capacity of 373 mAh·g –1 at 0.1 A·g –1 after cycling for 100 cycles at the same time showing great rate and cycle performance. It also presents a high capacitive ratio of 90.65% at 1.0 mV·s –1 . The molten salt electrolysis provides a new perspective on the exfoliation of layered material, while demonstrating the great potential of WS 2 as an anode material for sodium‐ion battery.