Modifying critical components in Zn-based batteries for extending their cycle life

Abstract

Zn-based batteries have been studied for a long time due to their cost-effectiveness and environment-friendliness. Recently, they are also adopted in secondary battery systems and the representative systems are Zn-ion batteries (ZIBs) and Zn-Br batteries (ZBBs). Due to their low cost and decent energy density, they are considered one of the most promising next-generation batteries. However, these batteries have problems with low cycling stability which originate from the severe dissolution of cathode material and uneven redox reaction of Zn metal anode for ZIBs, and from the irreversible gas-generating side reactions for ZBBs. In this thesis, works for solving failures of each system’s components are provided. Specifically, the cathode material is coated with an orbital-modifying material which can trigger a competitive reaction of the reaction that causes the dissolution, and a polymer with a microporosity is introduced on the Zn metal electrode to uniformize the redox reaction for ZIBs. For ZBBs, specifically designed ionic liquid is used as the electrolyte to minimize the gas-generating side reaction.