Polyester-Zro2 Nanocomposite Electrolytes With High Li Transference Numbers For Ambient Temperature All-Solid-State Lithium Batteries

Polyester- and polycarbonate-based polymer electrolytes have attracted great interest after displaying promising functionality for solid-state Li batteries. In this present work, poly(epsilon-caprolactone-co-trimethylene carbonate) electrolytes are further developed by the inclusion of ZrO2 particles, prepared by an in situ sol-gel method. SEM micrographs show that the ZrO2 particles are uniform and 30-50 nm in size. Contrary to many studies on filler-polymer electrolytes, the changes in ionic conductivity are less significant upon addition of zirconia filler to the polymer electrolyte, but remain at similar to 10(-5) S cm(-1) at room temperature. This can be explained by the amorphous nature of the polymer. Instead, high lithium transference numbers (0.83-0.87) were obtained. Plating/stripping tests with Li metal electrodes show long-term cycling performance for >1000 cycles at 0.2 mA cm(-2). Promising solid-state lithium battery cycling results at ambient temperature using the material are also shown.