Polymer-derived ceramic functionalization of transition metal dichalcogenides for alkali-metal anodes

D.M. Soares, G. Singh
Kansas State University,
United States

Keywords: TMD, PDC, batteries, SIB, LIB

Summary:

Transition metal dichalcogenides (TMDs) are promising layered materials for the several fields due to their variety of species, versatile chemistry and properties. Nevertheless, drawbacks, such as dissolution poly-sulfides and poly-selenides in the electrolyte, require innovative solutions for providing TMDs’ feasibility for electrochemical energy storage applications. Here we report the synthesis of PDC (polymer-derived ceramic) functionalization of MoS2 (MoS2-SiOC) as a composite material for mitigating capacity fading from TMD dissolution. Given the intrinsic resistance to oxidation of ceramic materials, results show that employing a PDC species (SiOC) is as an effective way of safeguarding the TMD. Although SiOC presents negligible capacity towards sodium ions, MoS2 capacity is preserved as well as Na-irreversibility from electrolyte decomposition is mitigated. Furthermore, electrochemical impedance spectroscopy study and Raman spectroscopy show that the electronic conductivity of the composite material was enhanced due to the presence of sp2 carbon. Comparison with another TMD-PDC composite is also presented (MoS2-SiCN). Overall, a facile and effective method is presented for synthesizing MoS2-SiOC, which may contribute for enabling TMDs potential as alkali-metal anodes