Cross-Linked Polymer Composite Electrolyte Incorporated with Waste Seashell Based Nanofiller for Lithium Metal Batteries

The next-generation electric vehicle requires superior safety and high-energy-density batteries for better performance. Currently, solid polymer electrolytes provide better safety, high mechanical stability, and a desirable electrode-to-electrolyte interface in lithium-ion batteries compared to those in conventional battery systems. However, the ionic conductivity of solid-state electrolytes remains challenging at room and low operating temperatures. Herein, we report that incorporating a greener calcium hydroxide (CH) based nanofiller derived from natural waste seashells with polymer electrolyte gives a tremendously increased lithium-ion conductivity of 4.12 × 10–5 S cm–1 at 25 °C. The cross-linked composite polymer electrolyte (CCPE) was prepared with PEO, LiClO4 salt, greener nanofiller, and cross-linking monomers via the facile ultraviolet (UV) polymerization technique. The photosensitive vinyl groups of diacrylate and the thio groups of the tetrathiol monomer undergo a thiol–ene click reaction to form a highly cross-linked network with homogeneously distributed LiClO4 and CH nanofiller. The incorporation of 15 wt % of CH greener nanofiller significantly improved the amorphous phase of the composite electrolyte and showed a wide electrochemical window of 5 V. The fine porous structure of CH greener nanofiller incorporated in the solid-state cross-linked network electrolyte channelizes for smooth lithium-ion mobility. The fabricated full cell exhibits good discharge capacity, of 160 mAh g–1 to 150 mAh g–1 at 0.1 C over 50 cycles with a high Coulombic efficiency of 95 % at 60 °C. Naturally derived, cost-effective greener nanofiller from waste seashells acts as a prominent additive to prepare solid-state electrolytes with high stability in lithium metal batteries.