Abstract The development of cost‐effective catalysts for zinc–air batteries (ZABs) remain challenging due to the sluggish kinetics of oxygen reduction (ORR) and evolution (OER) at the cathode. In this context, a novel N‐doped graphitic shell‐encapsulated cobalt catalyst is presented as an air electrode with exceptional bifunctional activity, achieving an ORR half‐wave potential ( E 1/2 ) of 0.81 V and an OER overpotential of 349 mV in an alkaline medium. The catalyst demonstrated excellent cycling durability and delivered superior power density in both liquid and solid‐state ZABs. Furthermore, a quasi‐solid‐state ZAB is assembled with the catalyst, and it maintained a stable open‐circuit voltage (OCV) of 1.360 V for >10 000 s. The catalyst achieved a peak power density of 127 mW cm −2 —significantly outperforming the benchmark Pt/C + RuO 2 system (74 mW cm −2 ). When two tandem‐junction ZABs are connected in series, they achieved an OCV of 2.75 V and powering a “ZAB” LED strip and a mini fan. Furthermore, Density Functional Theory (DFT) calculations revealed that the enhanced performance resulted from optimized binding energies between the Co@N(py) active sites and reaction intermediates. An in situ Raman study is carried out to understand the catalytic mechanism through transient intermediate detection.
Banerjee et al. (2025) studied this question.