Effect of Silyl Ether-functinoalized Dimethoxydimethylsilane on Electrochemical Performance of a Ni-rich NCM Cathode

Dimethoxydimethylsilane (DODSi) is developed as an interface stabilizing additive by a selective HF scavenging reaction for layered Ni-rich oxide cathodes. Ex-situ NMR analyses demonstrated that DODSi effectively removes HF in the electrolyte based on the matched chemical reactivity of Si with F- and O with H+. The cells employing DODSi exhibit higher specific capacity with retention than those cycled with a DODSi-free electrolyte even under an in-situ HF generating environment. SEM, XPS, and ICP-MS analyses indicate that DODSi effectively protects the Ni-rich oxide cathodes against HF corrosion, allowing improved surface stability of Ni-rich cathode.