Surface and interface properties – nanoscale device – thin film battery

Abstract

Batteries are becoming more widely used as portable and small electronic equipment increases, so does the use of various battery technologies. The increasing demands of a sustainable energy storage system being placed on batteries indicate that the battery technology has developed considerably in the past few years (since 1990), and more development can be expected in the future. Environmental concerns provide extra attention to this field as we have already harmed it enough in the recent past. Li-ion batteries mainly dominate the present battery market because of their long durability, good capacity, and temperature efficiency. But lithium is a very rare material, and that's why Li-ion batteries are not considered as sustainable source for the future demands. This motivates researchers to find new sustainable battery technologies. Al-ion, Na-ion, and K-ion are some examples of new battery technologies. Research for these battery technologies has already started all over the world, but much to do in this field to reach the desired objective. Al-ion batteries are one of the promising solutions because of the availability of raw material and high theoretical specific energy density. To achieve its high theoretical capacity, we need to use aluminum metal as the negative electrode. For the better performance of the Al-ion battery system, we need to work to find suitable electrolyte material and positive electrode material. In this thesis work, the performance of graphitized silicon carbide (EG/SiC) electrode systems, in view of their graphitization induced novel surface and interface properties, for Al-ion battery application has been explored using different techniques. In this work, our main focus is on the analysis of surface properties of positive electrode material by using two techniques, the cyclic voltammetry technique and the galvanostatic charge discharge method. Graphitized SiC has been explored as a working electrode material in Al-ion battery application. It should be noted that previous studies show that such electrode exhibits good Li-ion intake capacity Li-ion battery applications. The cyclic voltammetry technique provides information about the redox reaction mechanism and durability of the battery system. And also, with the help of areas of the voltammograms, we can calculate the specific capacitance of the cell. The galvanostatic charge-discharge method is important for quantitative analysis as we can calculate specific charge 5 capacity, specific energy density, and power density of the system. Analysis of galvanostatic results also provide information about the resistivities faced by the ions due to the electrolyte and electrode-electrolyte interface. By using such relevant data analysis techniques, we can thoroughly study the effect of surface/interface properties in graphitized electrode system in comparison to the bare SiC electrode in determining the performance towards the Al-ion battery application. It should be noted that the complete experimental part of this project work was carried out by the Ph.D. students of my supervisor’s (Dr. Sudeshna Chattopadhyay) research group prior to the Covid 19 situation, and in this thesis work I have focused on the analysis and data interpretation of this project and included it accordingly in my thesis.