Rational Design of Pillared SnS/Ti₃C₂T_<i>x</i> MXene for Superior Lithium-Ion Storage

Abstract

MXenes have been widely explored in energy storage because of their extraordinary properties; however, the majority of research on their application was staged at multilayered MXenes or assisted by carbon materials. Scientifically speaking, the two most distinctive properties of MXenes are usually neglected, composed of large interlayer spacing and abundant surface chemistry, which distinguish MXenes from other two-dimensional materials. Herein, few-layered MXene (f-MXene) nanosheet powders can be easily prepared according to the modified solution-phase flocculation method, completely avoiding the restacking phenomenon of f-MXene nanosheets in preparation and oxidation issues during the storage process. <i>Via</i> further employing the solvothermal reaction and annealing treatment, we successfully constructed pillared SnS/Ti₃C₂T_<i>x</i> composites decorated with <i>in situ</i> formed TiO₂ nanoparticles. In the composites, MXenes can play the role of a conductive network, a buffer matrix for volume expansion of SnS, while the active SnS nanoplates can fully deliver the advantage of high capacity and further induce interlayer engineering of Ti₃C₂T_<i>x</i> during cycling. As a result, the pillared SnS/Ti₃C₂T_<i>x</i> MXene composites exhibit obvious improvement in electrochemical performance. Interestingly, there is an apparent enhancement of capacity at succedent cycling, which can be ascribed to the "pillar effect" of Ti₃C₂T_<i>x</i> MXenes. The efforts and attempts made in this work can further broaden the development of pillared MXene composites.