UV-cured polymer electrolyte for LiNi0.85Co0.05Al0.1O2//Li solid state battery working at ambient temperature

Abstract A novel solid state polymer electrolyte with high ionic conductivity was fabricated by “solvent-free” photo-polymerization method and applied in solid state lithium battery with high-voltage cathode. The polymer structure was confirmed by FT-IR, and polymer electrolyte exhibits high ionic conductivity of 2.35×10− -4 S cm −1 at ambient temperature, wide electrochemical window of 0–4.63 V (vs. Li + /Li), excellent compatibility with lithium metal electrode for over 2000 h without short-circuit occurrence. Besides, LiMn 0.8 Fe 0.2 PO 4 //Li batteries were assembled to evaluate battery performance, delivering maximum discharge capacity of 168.7 mAh g −1 at 0.1 C and 154.7 mAh g −1 at 0.5 C with capacity retention of 89.72% after 450 th cycle at 60 °C. Also, the battery operated well at ambient temperature with capacity of 124.6 mAh g −1 and the capacity retention was 92.1% after 200 cycles. Importantly, the new polymer electrolyte is qualified to be applied in high-voltage cathode of LiNi 0.85 Co 0.05 Al 0.1 O 2 , delivering 108.8 mAh g -1 after 100 th cycle at 0.5 C at 40 °C. The integrated cathode with electrolyte reducing interfacial resistance contributes excellent battery performance. The results demonstrate that this solid polymer electrolyte (SPE) is a promising candidate electrolyte for high energy density solid-state lithium metal battery.