Composite of Two-Dimensional Titanium Carbonitride Mxene and Nano-Sulfur As Cathode for Li-S Batteries

In 2011, a new family of two-dimensional, 2D, transition metal carbides and carbonitrides called MXenes were produced for the first time by etching atomically thin metal layers from ternary layered materials called MAX phases. The latter have a composition of M_n+1AX_n, where M stands for early transition metal, A is a metal that belongs to groups 13 and 14 in the periodic table, X is carbon/nitrogen, and n = 1, 2, or 3. So far, nine different MXenes were reported MXenes were reported, viz., Ti₃C₂, Ti₂C, Nb₂C, V₂C, (Ti_0.5,Nb_0.5)₂C, (V_0.5,Cr_0.5)₃C₂, Ti₃CN, Ta₄C₃, and Nb₄C₃. In addition, many more are predicted to be stable. Since the synthesize process of MXenes is carried in F-contained aqueous systems, the surfaces of the as synthesized material are terminated with a mixture of moieties including O, OH, and F. Bare MXenes are predicted to be metallic conductors while terminated ones are predicted to be semiconductors with relatively small band gaps. Titanium carbonitride is predicted to be an exception since it is predicted to metallic even after termination.   

In this work we used a simple mixing approach to prepare Ti₃CN/nano S composite with a high sulfur content of ~75 wt.%, and high mass loading. Analysis for their performance in Li-S batteries and the effect of mass loading in addition to the composite material characterization will be presented.