Lee Daeyeon, Jung Ha Young, Park Moon Jeong
Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Korea.
ACS Macro Lett. 2018 Aug 21;7(8):1046-1050. doi: 10.1021/acsmacrolett.8b00474. Epub 2018 Aug 10.
Miktoarm star copolymers composed of three poly(ethylene oxide) (PEO) arms connected to one polystyrene (PS) chain, i.e., PS-(PEO), demonstrated synergistic improvements in the ionic conductivity and mechanical strength by factors of 2-30 compared to those shown by PS-PEO diblock copolymers. Entropic constraints for the chain stretching of (PEO) gave rise to notably reduced domain sizes of PS-(PEO) electrolytes, compared with the values of PS-PEO analogues. Further, the melting transition of PS-(PEO) with PEO molecular weight of = 2 kg mol was vanished with lithium salt doping at [Li]/[EO] = 0.06 under such confinements, resulting in an order of magnitude increase in the room temperature conductivity. The fact that lithium ion transport in PEO-based copolymers can be tunable by the way PEO chains are connected to hard polymers can lead to innovative designs for solid-state polymer electrolytes.
由连接到一条聚苯乙烯（PS）链上的三条聚环氧乙烷（PEO）臂组成的米克托臂星型共聚物，即PS-(PEO)，与PS-PEO二嵌段共聚物相比，在离子电导率和机械强度方面协同提高了2至30倍。与PS-PEO类似物的值相比，（PEO）链拉伸的熵约束导致PS-(PEO)电解质的域尺寸显著减小。此外，在这种限制条件下，当PEO分子量为 = 2 kg/mol且锂盐掺杂浓度为[Li]/[EO] = 0.06时，PS-(PEO)的熔融转变消失，导致室温电导率提高了一个数量级。基于PEO的共聚物中锂离子传输可通过PEO链与硬聚合物的连接方式进行调节，这一事实可为固态聚合物电解质带来创新设计。
