| 초록 |
The introduction of a trimethylsilyl (TMS) motif in electrolyte additives for lithium-ion batteries is regarded as an effectual approach to remove corrosive HF that damages the electrode−electrolyte interface and gives rise to transition metal dissolution from the cathode. Herein, we present that additives with TMS moieties lead to capacity loss of polycrystalline NCM811 cathodes compared to additives without TMS as the cycle progresses. Through a comparative study using additives with and without TMS moieties, it is revealed that the TMS group react with residual lithium compounds, in particular, LiOH on the PC-NCM811 cathode, and the resulting TMS-OH triggers the decomposition of PF5 created by the autocatalytic decomposition of LiPF6 that generates reactive HF and POF3. This work aims to offer a way to build favorable interface structures for Ni-rich cathodes covered with residual lithium compounds through a study to figure out the roles of TMS moieties of electrolyte additives. |
