Research Projects

The transition to renewable energy sources necessitates efficient, scalable energy storage systems to mitigate supply-demand mismatches. Iron-air batteries (Fe-Air), with their affordability, safety, and scalability, are emerging as strong candidates for large-scale energy storage (LSES). However, challenges such as low round-trip efficiency (50 %), parasitic hydrogen evolution, and limitations in electrode fabrication impede their commercialization. This project addresses these issues by employing two innovative fabrication techniques—Equal Channel Angular Pressing (ECAP) and Cold Spray (CS)—to develop high-performance Fe negative electrodes. The hypothesis is that nanostructured Fe electrodes will enhance cell potential, reduce self-discharge, and extend cycle life by increasing grain boundary area and mitigating side reactions such as hydrogen evolution. This will be tested through a combination of experimental and computational approaches. Key experiments include: • Electrode Fabrication: ECAP will refine Fe grains to nanometer sizes via dynamic recrystallization, while CS will deposit Fe particles onto Ni meshes to form dense, defect-rich layers. Both techniques aim to eliminate binders, improve mechanical integrity, and increase energy density. • Electrode Characterization: Structural and morphological analyses will include XRD, SEM, EBSD, and TEM to evaluate grain refinement and potential fabrication defects. • Electrochemical Testing: Open circuit potential, exchange current densities, Faradaic efficiency, and parasitic reaction kinetics will be studied through cyclic voltammetry, electrochemical impedance spectroscopy (EIS), and XPS. The impact of electrolyte additives on performance metrics will also be investigated. • Durability Assessments: Mechanical tests, such as nano-indentation and residual stress analysis, will validate electrode robustness for prolonged cycling (target: 3,000 cycles). Computational models will complement experiments will be performed at different length scales (Particles to Packs). The significance of this research lies in its potential to advance the fundamental understanding of Fe-Air battery electrochemistry and fabrication. By addressing critical limitations such as hydrogen evolution and scalability, this project could significantly improve the feasibility of Fe-Air batteries for LSES. Achieving more than 50% round-trip efficiency, long cycle life (more than 3,000 cycles), and high discharge rates (1C–3C) will position Fe-Air batteries as cost-effective solutions for renewable energy integration, directly supporting global decarbonization goals. This work is particularly relevant for India's energy ambitions, with a projected need for 63 GW of grid-scale storage by 2030. The outcomes will lay a foundation for deploying sustainable, scalable, and economical Fe-Air battery systems, contributing to energy security and climate change mitigation.