Constructing in-situ polymerized electrolyte on lithiophilic anode for high-performance lithium–air batteries operating in ambient conditions

Abstract

The only way for commercial application of Li−air batteries with open structure is to receive O2 from ambient air. Nevertheless, H2O-containing ambient air easily induces Li passivation/dendrites and electrolyte decomposition. Apart from above issues, volatilization and leakage of organic liquid electrolytes and relatively infinite dimension variation of metallic Li also seriously discount performance of Li−air batteries. Herein, Li coating polythiophene-derived (S-doped) carbon fiber-based electrode (Li/SC) is prepared by simple rolling method and then in situ coated with deep eutectic solvent-based polymer electrolyte (DES-PE), which are further applied as anode and electrolyte of Li−air battery, respectively. Theoretical/experimental data suggest that SC skeleton possess excellent lithiophilicity/stability which restrain dendritic Li formation and reduce electrode structure damage over cycles. Furthermore, DES-PE not only possesses high ionic conductivity (1.19*10−3 S cm−1, 30 °C), wide electrochemical window (5.0 V), no-leakage and excellent interfacial compatibility, but also combine with SC framework to greatly reduce Li passivation induced by ambient air. Hence, DES-PE@Li/SC based Li−air battery could exhibit extra-large capacity of 15,310 mAh g−1 at 100 mA g−1, high-capacity retention even under high current (11,896 mAh g−1 at 500 mA g−1) and extra-long cycling life up to 300 cycles under fixed capacity. This result provides enlightment for the advancement of Li−air batteries.