Advanced Electrodes from 2D Layered Materials for Li- and Na- Storage

Abstract

Layered structure 2D materials with large surface areas, high charge carrier mobility, and unique chemical and electronic properties provide multiple advantages as electrode materials for rechargeable lithium/ sodium-ion batteries (SIBs). Among these materials, transition metal chalcogenides (TMDs) with an MX2-type of structure (where M=Mo and X=S, Se, Te) are now of interest in research as electrode materials in the field of LIBs/SIBs. As a part of this objective, this thesis studies a new class of bulk semiconducting TMDs, specifically, the 2D layered structure molybdenum ditelluride (MoTe2). The relatively high interlayer spacing of MoTe2 about 0.70 nm (graphite (0.335 nm) and MoS2 (0.615 nm)) and the higher electronic conductivity of MoTe2 make it an efficient anode material for both LIBs/SIBs. The lithium and sodium storage mechanism in both semiconducting (2H) phase and semi metallic (1T') phase of MoTe2 during the Li+/Na+ insertion and desertion process using different Synchrotron-based in situ/ex situ experimental techniques alongside theoretical studies have been investigated. The present study opens up a new direction for the development of anode materials for rechargeable LIBs/SIBs applications.