Constructing a High-Performance Semi-interpenetrating Gel Polymer Electrolyte via In Situ Polymerization for Lithium Metal Batteries

Solid-state lithium metal batteries (LMBs) are considered as one of the promising contenders for next-generation energy storage systems because of their high energy density and high safety performance. Since all-solid-state electrolytes are still hampered by low electrical conductivity and interfacial incompatibility, gel polymer electrolytes (GPEs) are more preferable with high ionic conductivities comparable to liquid electrolytes at room temperature and good contact with the electrodes. In this study, a high-performance composite GPE of semi-interpenetrating polymer networks, denoted as NVPH, was synthesized by in situ copolymerization of neopentyl glycol diacrylate (NPGDA) and vinyl ethylene carbonate monomers in an electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofiber matrix. NVPH shows a high ionic conductivity (2.89 × 10–3 S cm–1), a high voltage resistance (up to 5.2 V), enhanced mechanical strength (13.8 MPa), and a large lithium transfer number (0.57) at room temperature. Most importantly, it also exhibits high stability to lithium metal anodes and effectively prevents lithium dendrite growth for long cycle life in LFP|NVPH|Li batteries, which will facilitate the practical application of LMBs.