Researchers from the Institute of Nano Science and Technology (INST), an autonomous institute of the Department of Science and Technology, have developed a novel electrolyte additive called 1,3-bis(1,3-dicarboxypropyl)-1H-imidazole-3-ium chloride (BDIM) that addresses critical challenges in aqueous zinc ion batteries (AZIBs). The additive selectively adsorbs on zinc metal surfaces and regulates the Inner Helmholtz Plane where electrochemical reactions occur, suppressing water-induced side reactions including hydrogen evolution reaction, corrosion, and dendrite formation that hinder commercialization of these batteries.
The BDIM additive contains multiple oxygen and nitrogen donor sites that strongly interact with zinc metal. During battery operation, it preferentially adsorbs on the negatively polarized zinc surface and occupies the Inner Helmholtz Plane, displacing water molecules from the interface. This displacement reduces water-induced side reactions and improves battery stability and cycling performance.
The research team employed advanced characterization techniques including a lab-made ultramicroelectrode (UME) with dimensions below 50 micrometers combined with fast-scan cyclic voltammetry (FSCV) to probe zinc-deposition mechanisms. This approach enabled direct investigation of interfacial charge-transfer and mass-transfer kinetics, providing new insights into the fundamental processes occurring at the electrode-electrolyte interface.
The technology development represents a practical and scalable strategy for extending battery life while maintaining safety and low cost, which is essential for large-scale renewable energy storage applications. Improved zinc-ion batteries can be used for renewable energy storage, backup power systems, and grid-scale energy storage, potentially lowering maintenance costs and improving the reliability of sustainable energy infrastructure. The research was led by Dr. Ramendra Sundar Dey, Scientist E at INST Mohali, and published in ACS Electrochemistry journal (DOI: 10.1021/acselectrochem.5c00322).