Today’s lithium (Li)-ion batteries play an important role in our society; they are everywhere in our daily life from our smartphones, laptops, and E-bikes to our electric cars. However, the rapidly growing Li-ion battery industry places high pressure on raw materials production such as Li, cobalt, and nickel - needed for electrode preparation. These materials are not only scarcer but also not globally distributed, posing significant geopolitical issues. Furthermore, Li-ion battery accidents have recently become more common, which is closely related to the electrolyte composition. To properly ensure safe batteries, the development of safer and more environmentally-friendly ‘green’ electrolytes is urgently needed. The research aim of this project is to create performant sustainable electrolytes from bio-sourced, abundant, reliable and low-cost materials. This project addressed electrolyte design and development of aqueous Zinc-ion battery (ZIB) – a highly promising battery chemistry for large-scale applications. Indeed ZIBs have the capability to revolutionize the energy storage industry, due to their cost and scalability compared to Li-ion technology. However, a significant challenge facing ZIB technology lies in their limited compatibility of Zn anode with conventional aqueous electrolytes. This issue primarily stems from the undesired water decomposition that occurs during the zinc plating process during battery cycling.
More precisely, the primary innovation of this project lies in the creation of sustainable electrolytes, presented in the form of gel biopolymers and aqueous liquid electrolytes, surpassing the capabilities of existing electrolytes. The gel polymer, derived from a charged chitin polymer, demonstrates significant enhancements of Zn metal stability. Additionally, the developed aqueous eutectic electrolytes not only enhance battery performance but also exhibit compatibility improvement with various battery components. Furthermore, the approach of this electrolyte, based on the Brønsted-Lowry concept, exhibits versatility with different types of salts. This work presents an efficient, simple, and low-cost strategy for the development of aqueous electrolytes for the practical application of zinc batteries.