A facile preparation method and proof of cycle-stability of carbon-coated metal oxide and disulfide battery materials

Abstract

Constructing composites of metal oxides and disulfides with carbonaceous materials is considered a useful approach to improve their lithium-ion storage performance. However, complicated synthesis processes and high-cost carbonaceous materials usually used hinder the commercialization of such composites. Here, as an example, carbon-coated tungsten oxides and disulfides are prepared using a facile and simple method on the basis of two kinds of low-cost carbon sources (CTAB and PVP). Following our postulated synthesis route, a variety of carbon-coated WOx, WS2, as well as mixed-phase WOx-WS2 is presented. The CTAB-assisted WOx/C (c-WOx/C), WS2/C (c-WS2/C), and mixed-phase (c-WOx/C-WS2/C) electrodes exhibit outstanding capacity retention of 74%, 99%, and 95%, respectively, which still have 420 mAh g−1, 460 mAh g−1, and 525 mAh g−1 capacity left after 200 cycles at 100 mA g−1. Particularly, the c-WS2/C electrode exhibits superior long-term cycle stability of 97% retention after 500 cycles. Similarly, the PVP-assisted WS2/C (p-WS2/C) electrode displays a capacity retention of 80% after 500 cycles. This work provides an easy and versatile route to fabricate carbon-coated tungsten oxides and disulfides with compelling battery performance and can be easily implemented for other metal oxides and disulfides.