Abstract
Integration of different active sites by heterostructure engineering is pivotal to optimize the intrinsic activities of an oxygen electrocatalyst and much needed to enhance the performance of rechargeable Zn–air batteries (ZABs). Herein, a biphasic nanoarchitecture encased in in situ grown N-doped graphitic carbon (MnO/Co-NGC) with heterointerfacial sites are constructed. The density functional theory model reveals formation of lattice oxygen bridged heterostructure with pyridinic nitrogen atoms anchored Co species, which facilitate adsorption of oxygen intermediates. Consequently, the well-designed catalyst with accessible active sites, abundant oxygen vacant sites, and heterointerfacial coupling effects, simultaneously accelerate the electron/mass transfer and thus promotes the trifunctional electrocatalysis. The assembled aqueous ZAB delivers maximum power density of ≈268 mW cm−2 and a specific capacity of 797.8 mAh gzn−1 along with excellent rechargeability and extremely small voltage gap decay rate of 0.0007 V h−1. Further, the fabricated quasisolid-state ZAB owns a remarkable power density of 163 mW cm−2 and long cycle life, outperforming the benchmark air-electrode and many recent reports, underlining its robustness and suitability for practical utilization in diverse portable applications.