Poly(ε-caprolactone)-block-poly(ethylene glycol)-block-poly (ε-caprolactone)-based hybrid polymer electrolyte for lithium metal batteries

The novel hybrid triblock polymer electrolytes (HTPEs) with the high mechanical strength were fabricated via initiator-free thiol-ene photopolymerization of poly(epsilon-caprolactone) (PCL)-based crosslinker and thiolterminated polyhedral oligomeric silsesquioxane (POSS-SH). Incorporation of PCL segment in the cross-linked network of HTPEs was endowed to not only promote the flexibility and mechanical properties, but also enhance the ionic conductivity in a wide temperature range and lithium-ion transference number. Moreover, HTPE20 fabricated via thiol-ene reaction of POSS-SH and PCL-based macromolecular crosslinking agent (PCL20-PEG-PCL20-DMA) exhibited good thermal stability up to 283 degrees C with 5% decomposition of the polymer matrix and 9.57 MPa of tensile strength. Notably, the Li/HTPE20/LiFePO4 possessed good reversible specific capacity and considerable rate capability.