First lithiation of graphite electrode in 1 mol/L LiPF6-EC:DEC:DMC electrolyte was investi- gated by electrochemical impedance spectroscopy (EIS). The results illustrated that the first arc in the high-frequency range...First lithiation of graphite electrode in 1 mol/L LiPF6-EC:DEC:DMC electrolyte was investi- gated by electrochemical impedance spectroscopy (EIS). The results illustrated that the first arc in the high-frequency range observed in the Nyquist dia- gram appears near 0.9 V in the initial lithiation of graphite electrode, and its diameter increases with the decrease of polarization potential. These EIS features were attributed to the formation and growth of SEI film. Appropriate equivalent circuit was pro- posed to fit the experimental EIS data. The fitting results revealed the process of the formation and growth of SEI film, and evaluated quantitatively the resistance of charge transfer, as well as the capaci- tance of double layer along with the increase of po- larization potentials.展开更多
A novel composite microporous polymer elec- trolyte composed of poly(vinylidene fluoride-co-hexafluorop- ropylene) (PVdF-HFP) and mesoporous SBA-15 was pre- pared. The composite solid polymer electrolyte (CSPE) ex- hi...A novel composite microporous polymer elec- trolyte composed of poly(vinylidene fluoride-co-hexafluorop- ropylene) (PVdF-HFP) and mesoporous SBA-15 was pre- pared. The composite solid polymer electrolyte (CSPE) ex- hibits ionic conductivity as high as 0.30 mS·cm?1 with a composition of SBA-15︰PVdF-HFP=3︰8 at room tem- perature. Infrared transmission spectroscopic results sug- gested that the mechanism of micropore formation is similar to that of the phase inversion. X-ray diffraction (XRD) results demonstrated that the addition of SBA-15 inhibits the crys- tallization of PVdF-HFP, while the SBA-15 preserves well its ordered mesoporous structure during the course of prepara- tion. The Li/CSPE/MCF of half-cell was assembled, and it showed a good electrochemical and cyclability performance during charge-discharge cycles.展开更多
文摘First lithiation of graphite electrode in 1 mol/L LiPF6-EC:DEC:DMC electrolyte was investi- gated by electrochemical impedance spectroscopy (EIS). The results illustrated that the first arc in the high-frequency range observed in the Nyquist dia- gram appears near 0.9 V in the initial lithiation of graphite electrode, and its diameter increases with the decrease of polarization potential. These EIS features were attributed to the formation and growth of SEI film. Appropriate equivalent circuit was pro- posed to fit the experimental EIS data. The fitting results revealed the process of the formation and growth of SEI film, and evaluated quantitatively the resistance of charge transfer, as well as the capaci- tance of double layer along with the increase of po- larization potentials.
基金supported by the National Key Basic Research and Development Program(Grant No.2002CB211804)the National Natural Science Foundation of China(Grant Nos.90206039 and 20173045)the Technological Innovation Program of Xiamen University(Grant No.XDKJCX20041012).
文摘A novel composite microporous polymer elec- trolyte composed of poly(vinylidene fluoride-co-hexafluorop- ropylene) (PVdF-HFP) and mesoporous SBA-15 was pre- pared. The composite solid polymer electrolyte (CSPE) ex- hibits ionic conductivity as high as 0.30 mS·cm?1 with a composition of SBA-15︰PVdF-HFP=3︰8 at room tem- perature. Infrared transmission spectroscopic results sug- gested that the mechanism of micropore formation is similar to that of the phase inversion. X-ray diffraction (XRD) results demonstrated that the addition of SBA-15 inhibits the crys- tallization of PVdF-HFP, while the SBA-15 preserves well its ordered mesoporous structure during the course of prepara- tion. The Li/CSPE/MCF of half-cell was assembled, and it showed a good electrochemical and cyclability performance during charge-discharge cycles.
