Silk-Derived Highly Active Oxygen Electrocatalysts for Flexible and Rechargeable\nZn–Air Batteries

Abstract

Flexible and rechargeable\nZn–air batteries, because of their\nhigh energy density, low cost, and environmental and human benignity,\nare one kind of the most attractive energy systems for future wearable\nelectronics. The development of high-performance rechargeable Zn–air\nbatteries depends on the synthesis of highly efficient and highly\nstable electrocatalysts for the oxygen reduction reaction/oxygen evolution\nreaction (ORR/OER). Herein, a silk-derived defect-rich and nitrogen-doped\nnanocarbon electrocatalyst [SilkNC/Ketjenblack (KB)] is reported.\nThe SilkNC/KB is synthesized by pyrolyzing commercially available\nporous KB carbon impregnated with silk fibroin. It exhibits remarkable\nelectrocatalytic activities and long-term stability for the ORR/OER,\nenabling its applications in high-performance liquid and solid rechargeable\nZn–air batteries. Particularly, the all-solid-state Zn–air battery based on SilkNC/KB exhibits\ngood flexibility and remarkable charge/discharge stability, enabling\nits promising applications in wearable and energy-efficient batteries.