Mechanistic Insight into Next Generation Batteries

Abstract

Current Li-ion batteries dominate the market but face great challenges with respect to safety, cost and the higher energy and power densit requirements of electrical vehicles and stationary energy storage. Relevant for mobile electrical transport, Li-O2 batteries in theory offer the highest specific energy among all the lithium electrochemical energy storage systems. Research efforts have been made to address the challenges that impede the functioning of this battery, which include low round trip efficiency, low specific capacity and poor cycling stability. To understand the origin of these issues, attaining a deeper understanding of the mechanism behind the electrochemical reactions is of vital importance. This also forms the foundation for exploring ideal oxygen cathodes and better electrolytes. The aqueous zinc batteries are another potential candidate for large scale electric energy storage owing to its low-cost, high operational safety, and environmental benignity. However, it is not easy to find a suitable insertion cathode for ZIBs, because the electrostatic interaction between divalent Zn ions. The development of host materials for ZIBs is still in its infancy, and in-depth understanding of the electrochemical processes involved is paramount at this early stage. The focus of this thesis is on attaining mechanistic insight into the electrochemical processes occurring in working Li-O2 and aqueous zinc batteries, which guides the choice/design of proper electrode materials for these next generation battery systems.