| dc.description.abstract | In this research, PVDF-HFP was used as the main polymer, and PPC was mixed to tune the properties of the solid electrolyte. MWCNT, Li6.25La3Zr2Ga0.25O12 (LLZGO) or Li6.25La3Zr1.7Ga0.25Ce0.2O12 (LLZGCO) were added as the inorganic filler to form a composite solid-state electrolyte. We want to study effects of nanofillers on electrochemical properties.The composite solid electrolyte prepared in this study can not only effectively suppress the crystallinity of the system, thereby providing more movement space for lithium ions, but also take advantage of the two polymers to improve the chemical potential window and the lithium ion conductivity.
In the first part of experiment, it was found that adding different contents of multi-walled carbon nanotubes (MWCNTs) into the polymer solid electrolyte significantly improve the electrical performance of the overall solid electrolyte. It can be seen from the results that the best electrochemical performance is obtained when 1wt.% MWCNT is added:specific capacity of 198.18 mAh/g @ 25mA/g, and ionic conductivity of 7.39×10-4 S/cm. The experimental results are better than pure PVDF-HFP/PPC solid polymer electrolyte.
In the second part of experiment, LLZGO powder were added as the inorganic filler. It was found that LLZGO powder with the different doping condition has improved the electrical performance of the overall solid electrolyte. It can be found that when 10wt.% excess lithium was added, ,the cell shows the best electrochemical performance : specific capacity of 209.62 mAh/g @ 25mA/g & 119.81 mAh/g @ 300 mA/g ,and ionic conductivity of 7.02×10-4 S/cm. The experimental results are better than pure PVDF-HFP/PPC solid polymer electrolyte.
In the final part of the research, LLZGCO powder were added as the inorganic filler. It was found that LLZO powder with the different doping condition has improved the electrical performance of the overall solid electrolyte. It can be found that when 10wt.% excess lithium is added ,it has the best electrochemical performance : specific capacity of 208.10 mAh/g @ 25mA/g & 144.15 mAh/g @ 300 mA/g ,and ionic conductivity of 1.38×10-3 S/cm. The experimental results are better than pure PVDF-HFP/PPC solid polymer electrolyte.
In this study, the electrical properties of the solid electrolytes are significantly improved due to inorganic fillers. It is further confirmed that the modification of PVDF-HFP mixed with PPC and the addition of appropriate amounts of MWCNT, LLZGCO and LLZO were helpful for the future application of solid electrolytes. | en_US |