Computational analysis of 1T-MoS2: Probing the interplay of layer-dependent electronic structure, quantum capacitance, charge density and mechanical properties

To meet the high energy demand of society, a conversion to renewable energy sources has become essential and energy should be appropriately stored for future use. This has led to the development of energy-storing devices such as supercapacitors (SCs). To enhance capacitive behavior, the concept of quantum capacitance ( C Q ) is unveiled, which results from the confinement of electrons in their energy states. In this work, 1T phase of MoS 2 is studied as it has received a lot of attention because of its wide applications in the energy storage devices and electronics. Here, the electronic structure, C Q and surface charge density (σ) of one, two and three-layered structures of 1T phase is studied using Density Functional Theory . No bandgap is obtained in the Density of States (DOS) and the bands plot of 1T structure indicates their metallic character and the DOS is continuous in all three layers. The C Q of three-layered structure dominates over the other two layers throughout the potential window. The larger C Q and σ values are obtained as 1718.06 μF cm −2 and -1299.50 μC cm −2 for three-layered structure at −0.27 V and −1 V respectively. For analyzing the mechanical strength , Young's modulus is evaluated for optimized structure by applying uni-axial strain. The value is obtained as 177.37 GPa, which is a measure of elastic deformation behavior. The results suggest that the capacitive performance of 1T MoS 2 for SC applications is better and it can function as flexible cathode material for asymmetric SC applications.