Correlating electrode nano-confinement to interphase chemistry

The electrode/electrolyte interphases in advanced batteries are critical for their performance, influencing the reversibility and rate capability of cell reactions. Although much research has focused on the electrolyte side, our study reveals the significant impact of the electrode’s interlayer distance on interphasial chemistry. We discovered that smaller interlayer distances in graphitic anodes lead to higher sensitivity to co-intercalation of Li⁺ and solvents, resulting in LiF-poor interphases that reduce stability. Conversely, larger interlayer distances allow anion-rich solvation structures, resulting in LiF-rich interphases and facilitating reversible intercalation/deintercalation reactions. This correlation between interlayer distance and interphasial chemistry offers new strategies for designing next-generation battery electrolytes and electrodes, moving beyond electrolyte engineering to include electrode structural considerations. Our findings are universally applicable across diverse electrolyte systems, providing a robust framework for optimizing battery performance.