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.

Rechargeable aluminum batteries (RABs) are amongst the most promising post-lithium energy storage systems (ESS) with a substantially higher specific volumetric capacity (8046 mA h cm ⁻³ ), higher safety and lower cost.