am7b18684_si_001.pdf (1.14 MB)
Download file

Co3O4/MnO2/Hierarchically Porous Carbon as Superior Bifunctional Electrodes for Liquid and All-Solid-State Rechargeable Zinc–Air Batteries

Download (1.14 MB)
journal contribution
posted on 04.04.2018, 00:00 by Xuemei Li, Fang Dong, Nengneng Xu, Tao Zhang, Kaixi Li, Jinli Qiao
The design of efficient, durable, and affordable catalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is very indispensable in liquid-type and flexible all-solid-state zinc–air batteries. Herein, we present a high-performance bifunctional catalyst with cobalt and manganese oxides supported on porous carbon (Co3O4/MnO2/PQ-7). The optimized Co3O4/MnO2/PQ-7 exhibited a comparable ORR performance with commercial Pt/C and a more superior OER performance than all of the other prepared catalysts, including commercial Pt/C. When applied to practical aqueous (6.0 M KOH) zinc–air batteries, the Co3O4/MnO2/porous carbon hybrid catalysts exhibited exceptional performance, such as a maximum discharge peak power density as high as 257 mW cm–2 and the most stable charge–discharge durability over 50 h with negligible deactivation to date. More importantly, a series of flexible all-solid-state zinc–air batteries can be fabricated by the Co3O4/MnO2/porous carbon with a layer-by-layer method. The optimal catalyst (Co3O4/MnO2/PQ-7) exhibited an excellent peak power density of 45 mW cm–2. The discharge potentials almost remained unchanged for 6 h at 5 mA cm–2 and possessed a long cycle life (2.5 h@5 mA cm–2). These results make the optimized Co3O4/MnO2/PQ-7 a promising cathode candidate for both liquid-type and flexible all-solid-state zinc–air batteries.