Chopade Sujay A, So Soonyong, Hillmyer Marc A, Lodge Timothy P
Department of Chemical Engineering and Materials Science and ‡Department of Chemistry, University of Minnesota , Minneapolis, Minnesota 55455-0431, United States.
ACS Appl Mater Interfaces. 2016 Mar 9;8(9):6200-10. doi: 10.1021/acsami.5b12366. Epub 2016 Feb 29.
Solid-state polymer electrolyte membranes (PEMs) exhibiting high ionic conductivity coupled with mechanical robustness and high thermal stability are vital for the design of next-generation lithium-ion batteries and high-temperature fuel cells. We present the in situ preparation of nanostructured PEMs incorporating a protic ionic liquid (IL) into one of the domains of a microphase-separated block copolymer created via polymerization-induced microphase separation. This facile, one-pot synthetic strategy transforms a homogeneous liquid precursor consisting of a poly(ethylene oxide) (PEO) macro-chain-transfer agent, styrene and divinylbenzene monomers, and protic IL into a robust and transparent monolith. The resulting PEMs exhibit a bicontinuous morphology comprising PEO/protic IL conducting pathways and highly cross-linked polystyrene (PS) domains. The cross-linked PS mechanical scaffold imparts thermal and mechanical stability to the PEMs, with an elastic modulus approaching 10 MPa at 180 °C, without sacrificing the ionic conductivity of the system. Crucially, the long-range continuity of the PEO/protic IL conducting nanochannels results in an outstanding ionic conductivity of 14 mS/cm at 180 °C. We posit that proton conduction in the protic IL occurs via the vehicular mechanism and the PEMs exhibit an average proton transference number of 0.7. This approach is very promising for the development of high-temperature, robust PEMs with excellent proton conductivities.
具有高离子电导率、机械强度和高热稳定性的固态聚合物电解质膜（PEMs）对于下一代锂离子电池和高温燃料电池的设计至关重要。我们展示了通过聚合诱导微相分离制备的微相分离嵌段共聚物的一个区域中掺入质子离子液体（IL）的纳米结构PEMs的原位制备方法。这种简便的一锅合成策略将由聚环氧乙烷（PEO）大链转移剂、苯乙烯和二乙烯基苯单体以及质子IL组成的均匀液体前驱体转变为坚固且透明的整体材料。所得的PEMs呈现出由PEO/质子IL导电通路和高度交联的聚苯乙烯（PS）区域组成的双连续形态。交联的PS机械支架赋予PEMs热稳定性和机械稳定性，在180°C时弹性模量接近10 MPa，同时不牺牲体系的离子电导率。至关重要的是，PEO/质子IL导电纳米通道的长程连续性导致在180°C时具有14 mS/cm的出色离子电导率。我们推测质子在质子IL中的传导通过载流子机制发生，并且PEMs的平均质子迁移数为0.7。这种方法对于开发具有优异质子电导率的高温、坚固的PEMs非常有前景。
