Iodine Vapor Transport-Triggered Preferential Growth of Chevrel Mo₆S₈ Nanosheets for Advanced Multivalent Batteries

Abstract

Owing to its unique structure, Chevrel phase (CP) is a promising candidate for applications in rechargeable multivalent (Mg and Al) batteries. However, its wide applications are severely limited by time-consuming and complex synthesis processes, accompanied by uncontrollable growth and large particle sizes, which will magnify the charge trapping effect and lower the electrochemical performance. Here, an iodine vapor transport reaction (IVT) is proposed to obtain large-scale and highly pure Mo6S8 nanosheets, in which iodine helps to regulate the growth kinetics and induce the preferential growth of Mo6S8, as a typical three-dimensional material, to form nanosheets. When applied in rechargeable multivalent (Mg and Al) batteries, Mo6S8 nanosheets show very fast kinetics owing to the short diffusion distance, thereby exhibiting lower polarization, higher capacities, and better low-temperature performance (up to −40 °C) compared to that of microparticles obtained via the conventional method. It is anticipated that Mo6S8 nanosheets would boost the application of Chevrel phase, especially in areas of energy storage and catalysis, and the IVT reaction would be generalized to a wide range of inorganic compound nanosheets.