By using a method commonly found in pharmaceutical science to enhance drug solubility, a research team in the Department of Mechanical and Automation Engineering at the Chinese University of Hong Kong (CUHK) has developed eco-friendly electrolytes to create high-performance and long-lasting zinc batteries.
Although lithium-ion batteries have become the preferred power source in cellphones, laptops, and electric cars, their high-performing organic electrolytes are both flammable and toxic. On the other hand, aqueous zinc battery electrolytes are non-flammable and don’t pose any significant risk of explosion. However, zinc batteries have a shorter lifespan due to the accumulation of zinc crystals at the battery’s anode, and existing methods to mitigate this buildup often raise environmental sustainability issues.
Inspired by the hydrotropic solubilization effect used in the pharmaceutical field, the research team led by Professor Lu Yi-chun developed several hydrotropic solubilization agents to increase the solubility of halogen-free zinc acetate. Using a highly concentrated zinc acetate enabled by urea demonstrated a satisfactory battery lifespan of more than 4,000 charging cycles, even when utilizing six-minute fast charging. The former undesirable side effects normally encountered in aqueous zinc batteries, such as hydrogen gas evolution, were virtually eliminated.
Professor Lu stated that this research breaks the solubility limit of salts using a simple method and produces higher-performing and more sustainable batteries which can be manufactured from low-cost eco-friendly materials such as urea. The study was recently published in Nature Sustainability, the sister journal of Nature.
