| 초록 |
Polymer electrolytes have attracted attention as ion-conductive soft materials because of their safety (not flammable and no leakage), flexibility and light weight, therefore they can be useful for solid-state lithium-ion secondary batteries. Unfortunately, the polymer electrolytes have still very low conductivity, limited to 10-4 S/cm at room temperature in contrast with most liquid, ceramic and gel-type electrolytes. For fast migration of ions in the polymer, a novel technique that can prepare many mobile ions without large increase in glass transition temperature is strongly needed. Recently, we are focusing on carbon dioxide, especially supercritical carbon dioxide (scCO2), as a unique material for polymer electrolytes. We have already reported that processing into scCO2 as a solvent is effective in improving the electrolytes in solid state and gives rise to large increases in room temperature conductivities of polyether/salt complexes and the clay composites. Moreover, we used CO2 as a monomer for synthesis of copolymers with epoxides and were able to evaluate the copolymers as novel ion-conductive polymer electrolytes. |
