▎ 摘　　要

We report a high-performance bi-functional electrocatalyst composed of 3D crumpled graphene (CG)-cobalt oxide nanohybrids. This is the first report on using CG coupled with nanocrystals as both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalysts. The nitrogen-doped CG-CoO hybrid exhibits excellent catalytic activity and durability, making it a high-performance non-precious metal-based bi-functional catalyst for both ORR and OER.