Influence of Battery Electrode Chemistry on Electrolyte Decomposition

Abstract In rechargeable batteries a stable electrode‐electrolyte interface is the key for achieving high coulombic efficiency, rate capability, and cycle lifetime. Numerous studies are published on how the electrolyte influences the interface and whether it leads to the formation of a stable solid‐electrolyte‐interphase (SEI) on the anode surface. However, the influence of the electrode material upon formation of the SEI has so far not been a focus. In this study, the influence of battery electrode chemistry on electrolyte decomposition is highlighted by investigating three different electrode materials in model battery systems: carbonaceous (glassy carbon), semi‐conducting (silicon), and metallic (copper). Electrochemical methods including linear sweep voltammetry and chronoamperometry in combination with hard X‐ray photoelectron spectroscopy are used to unravel how and in which order SEI components nucleate depending on surface material and potential. The impact of the alkali metal cation (lithium vs sodium) upon SEI formation is additionally investigated. The findings reveal that SEI formation is highly dependent on the electrode material, reduction potential, and choice of alkali cation, emphasizing its non‐universal nature. These insights highlight the need for a thorough understanding of SEI formation mechanisms when designing advanced electrode materials and electrolytes for next‐generation batteries.