We evaluated (1) thermal and electrochemical stability and (2) ion-dissociation ability of PF6-n(CF3)n- anions by computational method. The thermal stability order by ΔΔE (anion) is PF4(CF3)2- > PF5(CF3)- > PF3(CF3)3- > PF6-. The ion-dissociation ability order by ΔΔE (Li salts) is LiPF3(CF3)3 > LiPF4(CF3)2 > LiPF5(CF3) > LiPF6. The conductivity of electrolyte solution with LiPF4(CF3)2 (3.9 mS/cm) was a little lower than that of LiPF6 (4.4 mS/cm) in 0.1 mol/l Li salt/PC:DME electrolyte, while the oxidation potential of LiPF4(CF3)2 in PC was higher than that of LiPF6. The LiPF4(CF3)2-cell showed better cycle characteristics than LiPF6-cell.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering