| 초록 |
Solid-state polymer electrolytes have extensively been studied to improve the stability of lithium ion batteries. Most polymer electrolytes are based on poly(ethylene oxide) (PEO)/lithium salt complexes, aiming to achieve synergistic improvements of mechanical strength and ionic conductivity. In this study, we investigate the miktoarm star copolymer electrolytes comprising three PEO arms, covalently connected to polystyrene (PS) block, i.e., PS-(PEO)3., PS-PEO linear diblock copolymers were used as controls. Intriguingly, PS-(PEO)3 doped with lithium salt showed 5 to 30 times higher ionic conductivity and 2 times improved mechanical strength than PS-PEO analogs. The results were rationalized by confinement effects of (PEO)3 phases having entropic restriction so as to increase the local lithium salt concentration. In addition, such confinement was effective means of suppressing PEO crystallization to enhance room temperature conductivity by factor of 30 when compared with PS-PEO. |
