Self-assembly formation of Bi-functional Co\u2083O\u2084/MnO\u2082-CNTs hybrid catalysts for achieving both high energy/power density and cyclic ability of rechargeable zinc-air battery

\u3b1-MnO\u2082 nanotubes-supported Co\u2083O\u2084 (Co\u2083O\u2084/MnO\u2082) and its carbon nanotubes (CNTs)-hybrids (Co\u2083O\u2084/MnO\u2082-CNTs) have been successfully developed through a facile two-pot precipitation reaction and hydrothermal process, which exhibit the superior bi-functional catalytic activity for both ORR and OER. The high performance is believed to be induced by the hybrid effect among MnO\u2082 nanotubes, hollow Co\u2083O\u2084 and CNTs, which can produce a synergetic enhancement. When integrated into the practical primary and electrochemically rechargeable Zn-air batteries, such a hybrid catalyst can give a discharge peak power density as high as 450 mW cm 12\ub2. At 1.0 V of cell voltage, a current density of 324 mA cm 12\ub2 is achieved. This performance is superior to all reported non-precious metal catalysts in literature for zincair batteries and significantly outperforms the state-of-the-art platinum-based catalyst. Particularly, the rechargeable Zn-air battery can be fabricated into all-solid-state one through a simple solid-state approach, which exhibits an excellent peak power density of 62 mW cm 12\ub2, and the charge and discharge potentials remain virtually unchanged during the overall cycles, which is comparable to the one with liquid electrolyte.Peer reviewed: YesNRC publication: Ye