Mechanistic Basis of Enhanced Capacity Retention Found with Novel Sulfate-Based Additive in High-Voltage Li-Ion Batteries

1,3-propanediolcyclic sulfate (PCS) was employed as a novel sulfate-based additive for high-voltage battery applications to reduce the capacity fading that occurs during cycling. Molecular energy calculations and cyclic voltammetry (CV) both proved the PCS was reduced earlier than the ethylene carbonate (EC), which suggests a better solid electrolyte interface (SEI) was formed. The electrochemical impedance spectra results confirmed the denser SEI formed by addition of PCS additive. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and scanning electron microscopy/energy dispersive X-ray (SEM/EDX) analysis reveal the addition of PCS is able to protectively modify the anodic SEI layer in a manner that suppresses anodic deposition of manganese oxide species resulting from the “cross-talk” effect.