fig2

Figure 2. CV curves at 25 °C with different scan rates of (A) LiDFOB + DMS/HFE/FEC and (B) LiPF₆ + EC/DMC electrolytes. Nyquist plots at (C) 25 °C and (D) -20 °C. Long-term cycling performance of LiCoO₂||Li cells with different electrolytes at (E) 25 °C and (F) -20 °C. (G-J) Corresponding charge/discharge curves with LiDFOB + DMS/HFE/FEC and LiPF₆ + EC/DMC electrolytes at 25 and -20 °C. (K-N) Rate capability and corresponding Coulombic efficiency with different electrolytes at 25 and -20 °C.