Zeolitic Imidazolate Framework Film Derived CoFe-N-C Nanofoams for Reliable Zn-air Batteries

The design of the efficient, flexible air electrode for enhancing the Zn-air batteries (ZABs) performance is vital in developing a new portable rechargeable power supply. Emerging research indicates that non-precious metal materials have promising activity for oxygen reduction/evolution in alkaline conditions while constructing a high-performance and reliable electrode is still a big challenge at the present stage. In this work, a bimetal doped zeolitic imidazolate framework (ZIF) film is synthesized by fast current-driven synthesis (FCDS) on a thin carbon nanotube film (CNTF). After carbonization at 950 °C, CoFe-N-C nanofoam formed on the CNTF, resulting in binder-free, flexible electrodes. It exhibits excellent activity and stability toward oxygen reduction and evolution. The CoFe-N-C/CNTF-based liquid-state ZAB shows an output power density of 294 mW cm −2 . When applied in solid-state ZAB, the flexible battery shows high power density and excellent cycling stability.