Researchers at the Institute of Nano Science and Technology in Mohali have developed an electrolyte additive designed to improve the stability and working life of aqueous zinc-ion batteries.
Aqueous zinc-ion batteries are being studied as a lower-cost and safer alternative to lithium-ion systems, particularly for stationary energy storage. Their wider use, however, has been restricted by zinc dendrite growth, corrosion, hydrogen evolution and declining performance over repeated charging cycles.
The INST team developed 1,3-bis (1,3-dicarboxypropyl)-1H-imidazole-3-ium chloride, known as BDIM. The additive contains oxygen and nitrogen donor sites that interact strongly with the zinc surface during battery operation.
According to the research account, BDIM preferentially occupies the Inner Helmholtz Plane at the negatively polarised zinc surface. This displaces water molecules at the interface and reduces water-driven side reactions, including hydrogen evolution and corrosion. The same interfacial control also suppresses the formation of zinc dendrites that can damage battery performance and safety.
The researchers produced BDIM through a process involving glutamic acid, sodium hydroxide, water, glyoxal, formaldehyde and acetic acid. The mixture was heated under nitrogen before extraction and lyophilisation yielded the crystalline additive.
To study zinc deposition, the team combined an ultramicroelectrode with fast-scan cyclic voltammetry. These tools allowed the scientists to examine changes in charge transfer and mass-transfer behaviour when the additive was present, providing a closer view of the mechanism at the electrode-electrolyte interface.
The work was led by Dr Ramendra Sundar Dey of INST Mohali and published in ACS Electrochemistry. The researchers say the approach could support safer and more durable rechargeable zinc batteries for renewable-energy storage, backup systems and grid-scale applications without relying on an expensive redesign of the battery material.
