Vacancy engineering in transition metal sulfide and oxide composite material for thermal batteries of high specific capacity

Abstract

As a thermal battery cathode material, WS2 has high decomposition temperature and large specific capacity, but its low voltage problem has been rarely reported. In this work, we first prepared WS2 containing sulfur vacancies and then used it as a precursor to prepare a mixture of sulfur-vacancy and oxygen-vacancy double-doped WO3 with WS2 (WS2-x-WO3-x). WO3 was attached to the surface of WS2, which made the samples easier to be pressed into tablets. The presence of vacancies was confirmed by x-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance spectroscopy (EPR). The discharge results show that the discharge time of WS2-x-WO3-x is 52% higher than that of WS2. This work provides a beginning for further applying transition metal sulfide and oxide composite material for high capacity thermal batteries.