Layered Double Hydroxide@Polydopamine Core-Shell Nanosheet Arrays Derived Bi-Functional Electrocatalyst for Efficient Flexible All-Solid-State Zinc-Air Battery

Designing of highly efficient bifunctional electrocatalysts that can simultaneously catalyze the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is the key to the development of sustainable, clean energy storage, and conversion technologies. Herein, we report a flexible electrode based on Co-CoO chi/N-C nanosheet arrays (NSAs) directly grown on a carbon cloth fabricated by pyrolysis of the core-shell CoAl-LDH@polydopamine (CoAl-LDH@PDA) NSA precursor. The as-synthesized Co-CoO chi/N-C NSAs exhibit excellent bifunctional electrochemical activity for the ORR and OER, with a small potential gap (0.678 V) and excellent durability. Furthermore, a high power density (20.7 mW cm(-2)), superior flexibility, and cycling stability for flexible all-solid-state zinc-air battery is achieved on Co-CoO chi/N-C NSAs. The excellent performance of Co-CoO chi/N-C NSAs comes from its integrated nanosheet array architecture and the synergetic effect between Co-CoO chi and N-C. This in situ synthesis strategy builds up a general approach for fabricating other multifunctional electrodes toward a large variety of important electrochemical processes.