| 초록 |
Ni-rich cathode has several significant challenges such as low thermal stability and structural deterioration, leading poor cycling performance and electrode degradation. In particular, transition metal ion dissolution and its deposition on anode, has shown to be a critical challenge in cell performance, as the Ni content increases. Herein, we introduce a novel strategy with multifunctional additive by ensuring stable cathode-electrolyte interphase and trapping Ni ion in Ni-rich cathode system. With 31P NMR analysis, it has been shown phosphine group of additive can chelate dissolved Ni2+ ion to inhibit its deposition on anode. In addition, additive stabilizes PF5 with electron-rich phosphorus atom, suppressing the hydrolysis of LiPF6 and HF formation. Based on these advantages, electrolyte with 0.1% additive exhibits enhanced capacity retention of 83.4% after 300 cycles at 45 oC in full cell, while the capacity retention of the cell without additive is 60.1%. |
