Highly Dispersive Co@N‐C Catalyst as Freestanding Bifunctional Cathode for Flexible and Rechargeable Zinc–air Batteries

The design of efficient cathode with great cycle performance, high flexibility, and low cost is essential for the commercialization zinc–air battery (ZAB). Herein, we report exploration freestanding bifunctional rationally designed structures, namely, tiny Co nanoparticles embedded in N-doped carbon nanofiber aerogels, which have desired features including uniform dispersity, balanced distribution N-C species, hierarchically porous structure increased fraction meso- to micropores, moderate amounts defects. Accordingly, as-fabricated cathodes exhibit positive half-wave potential 0.82 V oxygen reduction small overpotential 350 mV at 10 mA cm−2 evolution, respectively, deliver smaller reversible electrode index (0.76 V) than commercial Pt/C+RuO2 (0.80 most Co-based electrocatalysts ever reported. Impressively, as-constructed liquid rechargeable ZAB behaves peak power density (160 mW cm−2), large specific capacity (759.7 mAh g−1 cm−2, tested after 120 h OCV tests), robust stability over 277 h. Moreover, as-assembled quasi-solid-state using such represents excellent mechanical flexibility outstanding regardless being serviced under extremely bending conditions from 0° 180°, underscoring their promising applications as durable portable metal–air batteries.