Engineering a “nanonet”-reinforced polymer electrolyte for long-life Li–O₂ batteries

Safe, high-energy-density and long-life Li metal batteries (LMBs) are highly attractive as a power source. However, the development of LMBs encounters serious challenges due to the formation of Li dendrites and the leakage and flammability of organic liquid electrolytes. Herein, a novel nanowire-film-reinforced hybrid gel polymer electrolyte (HGPE) is developed. The interconnected porous nanowire film as the backbone not only strengthens the mechanical structure of GPEs but also ensures the continuity for Li+ conduction. The designed HGPE can simultaneously achieve the suppression of Li dendrites and high ionic conductivity (1.04 × 10−3 S cm−1). The films with controllable thicknesses offer the ability to prepare ultrathin HGPEs with great mechanical properties. With these merits, the Li metal symmetric cells exhibit significantly enhanced cycling stability for over 2100 h with low overpotential. The Li–O2 battery using the HGPE also delivers an ultralong cycle life of up to 494 cycles. The present study may open a new window for reinforcing GPEs and offer an opportunity for developing quasi-solid-state LMBs.