The study on advanced electrode materials and structural design for high-energy zinc-air batteries

Abstract

The study on advanced electrode materials and structural design for high-energy zinc-air batteries Sung-Hae Kim Department of Materials Science and Chemical Engineering Graduated School of Hanyang University Modern society has been developed based on the backbone of fossil fuels. However, the environmental issues stemming from this dependency have raised global concerns, propelling the development of eco-friendly alternatives. Foremost among clean energy sources are solar, wind, and geothermal energy. Nevertheless, their intermittent nature, varying with time and location, poses technological challenges, leading to supply-demand fluctuation. This variability necessitates advanced energy storage technologies for efficient retention of sustainable energy. Similarly, the transportation sector, predominantly powered by fossil fuels, is undergoing a transition towards electric energy. Transitioning all transport means to electric energy could reduce petroleum demand by approximately 42%. However, the technological limitations of commercially available lithium-ion batteries, such as shorter driving ranges compared to fossil fuel engines and prolonged charging times, pose inconveniences for customers. Thus, there is an urgent need for the development of high energy-density storage technologies to address the environmental challenges faced by human beings. Zinc-air batteries (ZABs), which operate on the electrochemical energy generated by the redox reaction between oxygen and zinc, are garnering attention as a next-generation energy storage technology. They offer several advantages over lithium-ion technologies, including higher energy density, inherent safety derived from a non-flammable and non-explosive nature, cost-effectiveness due to the utilization of earth-abundant elements, and eco-friendly characteristics. However, compared to lithium-ion batteries, their multi-electron redox kinetics lead to various side reactions and irreversibilities that limit their practical application. Core technologies to overcome these issues are not matured so far, prompting extensive research and comprehensive development in academia. Moreover, due to its own working principle of using oxygen as a reactant, it employs a semi-open system where the positive electrode is exposed to ambient air. This poses significant issues such as electrolyte leakage or evaporation, which are detrimental to the battery's lifespan and practical use. Additionally, the structural limitations provoked by the use of liquid electrolytes necessitate add-ons, hampering battery miniaturization. Therefore, for the successful commercialization and practical application of ZABs, securing a solid-state electrolyte technology that offers high ionic conductivity, water retention, and ensures charge-discharge reversibility is imperative.