Efficient improvement in electrochemical properties of high-voltage Li-rich Mn-based layered oxide cathode by addition of 1,3-divinyltetramethyldisiloxane to electrolyte

1,3-Divinyltetramethyldisiloxane (DTMS) is a multifunctional additive that is used to improves the cycling stability and capacity retention of Li-rich Mn-based layered oxide cathodes (LRMs). Cycling performance evaluations demonstrate that LRM/Li cells without the additive exhibit lower capacity retention. DTMS can significantly improve the capacity retention of LRM/Li cells from 42.8% to 75% at 0.5C. Theoretical calculations indicate that DTMS is preferentially oxidized on the LRM surface. Physical characterization results reveal that DTMS generates a layer on the LRM surface that is both less resistive and thinner than the LRM by reacting with HF/F− from the electrolyte. This DTMS-derived layer inhibits adverse reactions between the cathode and electrolyte, thus, effectively maintaining the cathode structure.