Hybrid materials based on low-dimensional forms of carbon and MoS₂ and their electrochemical properties

Two-dimensional (2D) materials such as graphene and layered transition metal disulfides (TMD) have a high specific surface and are capable of intercalation with alkali metal ions. The theoretical specific electrochemical capacity of TMD materials is much higher than that of graphite. For low-dimensional 2D structures consisting of one or more monolayers, interaction with alkali metals leads to an even greater effective capacity. In this case, the real surface structure, the presence of vacancy, topological defects, the doping by heteroatoms with electron-donor or electron-acceptor properties into the two-dimensional structure begins to play a significant role Particularly interesting are hybrid materials consisting of layers MoS₂ and graphene. The poor electrical conductivity and high agglomerate risk of pure TMD electrodes can be overcome by interspersing nanocarbon phases within the composite material. The synergetic interactions of TMD and graphene nanohybrid materials for superior electrochemical performance in lithium and sodium ion batteries have been demonstrated in scientific publications in recent years. Using the modern methods of soft X-ray spectroscopy and X-ray photoelectron spectroscopy, NMR spectroscopy and a theoretical quantum chemistry approach, we investigated the process of alkali ions intercalation into composite and hybrid nanomaterials. Based on the results obtained, we determined how the size and morphology of MoS 2 layers and flakes, their imperfection and doping with other metals, as well as the chemical bond with graphene layers will affect the interaction with lithium and sodium atoms and ions and the stability of the electrode material in the processes of electrochemical intercalation/deintercalation. The reported study was funded by RFBR and DFG, project number 21-53-12021.