A world-first - Scientists illuminate the relationship between solid electrolyte interphase structure and performance

Osaka, Japan - A joint international research team has, for the first time, unveiled the crucial link between the structure of the solid electrolyte interphase (SEI) and the efficiency of lithium-mediated nitrogen reduction to ammonia, a promising eco-friendly approach to fertilizer production. Using in situ spectroscopy, the team directly observed the previously poorly understood SEI formation process, revealing that the ethanol-to-water ratio in the electrolyte significantly impacts ammonia conversion efficiency. This discovery opens a new avenue for sustainable fertilizer production by reducing reliance on fossil fuels and lowering greenhouse gas emissions.

Ammonia, a key component of fertilizers, is currently produced globally in large-scale plants using the Haber-Bosch process. This process, however, requires substantial energy input and relies heavily on fossil fuels, contributing significantly to CO2 emissions and global warming. Consequently, there is growing interest in developing smaller-scale, environmentally friendly ammonia production methods. The lithium-mediated nitrogen reduction reaction, the focus of this study, represents one such promising alternative.

This breakthrough developed by researchers from SANNKEN at The University of Osaka and Imperial College London provides a new paradigm for SEI design. By tailoring the electrolyte composition, it becomes possible to engineer SEIs with specific properties, optimizing ammonia production and reducing reliance on fossil fuels. This could revolutionize fertilizer production, significantly decreasing its environmental footprint.

"Clean electrochemical ammonia synthesis is a key process for achieving carbon neutrality," explains Dr. Yu Katayama at The University of Osaka, the lead corresponding author of the study. "Our research demonstrates that even subtle changes in the electrolyte composition significantly affect the SEI structure and reaction efficiency. This is the first step towards designing ideal SEIs as reaction sites. We aim to achieve clean ammonia synthesis by tuning the electrolyte to form SEIs conducive to the reaction."

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The article, “In situ Spectroscopy Reveals How Water-Driven SEI Formation Controls Selectivity in Li-Mediated N₂ Reduction,” was published in Energy & Environmental Science at DOI: https://doi.org/10.1039/D5EE01961C.