Abstract:
Energy crisis is the biggest issue of the modern era. In spite of various renewable energy sources available in abundant quantity we are incapable of utilizing the sources due to low efficiency of already available energy storage devices. Researchers across the globe has been working collectively to overcome this dilemma. Starting from voltaic batteries, alkaline and nickel metal batteries researchers have been improving the technology over the years. The development of Lithium ion batteries has given the world a good hope of improving energy storage technology. Among the batteries lithium ion has the best performance due to its delivered energy density (210 Wh kg-1; 650 Wh l-1). However, the challenges faced by the Lithium ion battery technology is to increase its energy density, to improve its safety, reduction of cost etc. are very unembellished. The thesis presents the first principle understanding of MCo2O4 (M=Co,Cu,Ni,Mn) which can be used for lithium ion batteries as an electrodes. The synthesis and characterization techniques can be expensive and without proper understanding might not give the desired results. Using DFT+U by Kohn-Sham algorithm in the CASTEP module of Material Studio 2017 the calculations are performed. The Band Structure, Density of States (DOS) and partial density of states (PDOS) are calculated which are correlated with the application of lithium ion batteries. It was observed it cobalt is used with Cobalt oxide it shows capacitive like behavior which can increase the electrochemical properties of cobalt due to complete oxidation. However, Co3O4 shows semiconductor like properties because of 0.30 eV band gap. It was evaluated from DFT+U technique that by doping transition metals like Ni and Cu the band gap is reduced and it can enhance the electrochemical properties of the material.
