Fish bone-derived N, S co-doped interconnected carbon nanofibers network coupled with (Fe, Co, Ni)9S8 nanoparticles as efficient bifunctional electrocatalysts for rechargeable and flexible all-solid-state Zn-air battery

Rational design of efficient, cost-effective and robust bifunctional oxygen electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is of vital significance to the large-scale application of rechargeable Zn-air battery (ZAB). Herein, we demonstrate a novel and simple strategy for the synthesis of (Fe, Co, Ni)(9)S-8 nanoparticles embedded in nitrogen and sulfur co-doped interconnected carbon nanofibers network ((Fe, Co, Ni)(9)S-8/NSCFs) derived from fish bone as an efficient bifunctional catalyst. The (Fe, Co, Ni)(9)S-8/NSCFs shows large specific surface area (750 m(2) g(-1)), well-defined interconnected nanofibers network structure with high conductivity, synergistic chemical coupling effects between (Fe, Co, Ni)(9)S-8 and NSCFs with doped heteroatoms of N and S. As expected, in alkaline medium, excellent catalytic activity and outstanding durability toward both ORR and OER are obtained. Moreover, the homemade all-solid-state ZAB based on (Fe, Co, Ni)(9)S-8/NSCFs displays outstanding battery capacity and power density together with excellent durability and flexibility. As an additional advance, a digital display screen powered by (Fe, Co, Ni)(9)S-8/NSCFs-based rechargeable ZAB works steadily at twisted, extruded, combusting, and punctured states, making our bifunctional electrocatalysts attractive for wearable energy storage applications. (C) 2021 Elsevier Ltd. All rights reserved.