In Situ-Formed Adhesive Gel Polymer Electrolyte for Stabilizing High-Curvature Interfaces in Fiber Lithium-Ion Batteries.

Fiber lithium-ion batteries (FLIBs) are promising power sources for wearable electronics. However, the radially divergent arrangement of particles on cylindrical current collectors creates an inherently porous active layer, allowing unconstrained binder swelling and subsequent particle detachment, which causes irreversible capacity loss. Here, we report an adhesive gel polymer electrolyte (AGPE) formed by the in situ polymerization of 2-perfluorohexyl ethyl acrylate (TFOA) and triethylene glycol diacrylate (TEGDA), in which precursor infiltration into the porous active layer and interfacial anchoring mediated by perfluorinated dangling chains help preserve interparticle adhesion, while the crosslinked TEGDA network provides dimensional stability. The resulting AGPE-based FLIBs deliver stable cycling over 800 cycles and exhibit improved structural stability under diverse aging conditions, retaining 87.8% of their initial capacity after 500 days of storage at 25°C and over 90% after 14 days of thermal aging at 60°C. This strategy provides a molecular approach for stabilizing high-curvature fiber electrodes, thereby broadening the applicability of fiber-based energy-storage technologies in wearable electronics.