Polyoxometalate hybrid comb-like crosslinked polymer networks for anhydrous proton conductors

The development of proton conductors that demostrate high conductivity with mechanical resilience is critical for advancing energy devices operating under harsh conditions. Polymer nanocomposites offer a promising route to reconcile these competing requirements through strategic material design. In this work, we report an anhydrous proton-conducting nanocomposite composed of a comb-like crosslinked polymer network and superacidic polyoxometalate (POM) clusters. Poly(glycidyl methacrylate) (PGMA) serves as a comb-like scaffold, rapidly crosslinking with amino-terminated polyethylene glycol (PEG-BA) through a simple blending process. The incorporation of H₃PW₁₂O₄₀ (PW) functions not only as a proton source but also as a mechanical reinforcer via interfacial interactions. The crosslinked framework provides structural stability, while the compatibility between PW and PEG-BA enables continuous proton-conduction pathways through hydrogen bonding and ionic interactions. The optimized nanocomposite achieves a proton conductivity of 8.5 × 10⁻⁴ S·cm⁻¹ at 130 °C and, at the highest crosslinking ratio, a Young’s modulus of 18.1 MPa, along with stable performance over 160 h of extended operation. The modular tunability of both polymer topology and inorganic clusters establishes this approach as a generalizable platform for tailoring ion-transport materials and opens new avenues for high-performance energy technologies.