Polymerization-induced microphase separation of polymer-polyoxometalate nanocomposites for anhydrous solid state electrolytes

Solid-state electrolytes(SSEs)with high ionic conductivity,mechanical stability,and high thermal stability,as well as the stringent requirement of application in high-temperature fuel cells and lithium-ion batteries is receiving increasing attention.Polymer nanocomposites(PNCs),combining the advantages of inorganic materials with those of polymeric materials,offer numerous opportunities for SSEs design.In this work,we report a facile and general one-pot approach based on polymerization-induced microphase separation(PIMS)to generate PNCs with bi-continuous microphases.This synthetic strategy transforms a homogeneous liquid precursor consisting of polyoxometalates(POMs,H_(3)PW_(12)O_(40),Li_(7)[V_(15)O_(36)(CO_(3))]),poly(ethylene glycol)(PEG)macro-chain-transfer agent,styrene and divinylbenzene monomers,into a robust and transparent monolith.The resulting POMs are uniformly dispersed in the PEG block(PEG/POM)to form a conducting pathway that successfully realizes the effective transfer of protons and lithium ions,while the highly cross-linked polystyrene domains(P(S-co-DVB))as mechanical support provide outstanding mechanical properties and thermal stability.As the POM loading ratio up to 35 wt%,the proton conductivity of nanocomposite reaches as high as 5.99×10^(-4) S/cm at 100℃ in anhydrous environment,which effectively promotes proton transfer under extreme environments.This study broadens the application of fuel cells and lithium-ion batteries in extreme environments.