Due to the increasingly growing demands for reliable and high capacity energy storage in mobile devices and electric vehicles, tremendous efforts are being made to improve life-length, performance, and safety of lithium-ion batteries (LIBs). For LIBs the solid electrolyte interphase (SEI), formed by electrolyte reduction on the anode surface, is a key element and one way to improve LIBs is to control the process of SEI formation, rather than relying on spontaneous formation by electrolyte decomposition. Application of special molecules, SEI-forming additives, is a viable approach.

We here present a systematic study of several different sulfonyl compounds, as SEI-forming additives for a standard LP30 battery electrolyte. Electrochemical analysis of the resulting electrolytes shows a notable difference in reduction ability. The compositions of the formed SEI-layers were examined and all experimental data confronted with DFT calculations to better understand the influence of the chemical structure of the additives on the reduction properties. Finally, the electrolytes were cycled in graphite/LFP full cells to study the long-term stabilization properties of the SEI-layers formed.