Aspergillus Niger Derived Wrinkle-Like Carbon as Superior Electrode for Advanced Vanadium Redox Flow Batteries

The scarcity of high electrocatalysis composite electrode materials has long been suppressing the redox reaction of V(II)/V(III) and V(IV)/V(V) couples in high performance vanadium redox flow batteries (VRFBs). Herein, through ingeniously regulating the growth of Aspergillus Niger, a wrinkle-like carbon (WLC) material that possesses edge-rich carbon, abundant heteroatoms, and nature wrinkle-like structure is obtained, which is subsequently successfully introduced and uniform dispersed on the surface of carbon fiber of graphite felt (GF). This composite electrode presents a lower overpotential and higher charge transfer ability, as the codoped multiheteroatoms increase the electrocatalysis activity and the wrinkled structure affords more abundant reaction area for vanadium ions in the electrolyte when compared with the pristine GF electrode, which is also supported by the density functional theory (DFT) calculations. Hence, the assembled battery using WLC electrodes achieves a high energy efficiency of 74.5% for 300 cycles at a high current density of 200 mA cm⁻², as well as the highest current density of 450 mA cm⁻². The WLC material not only uncovers huge potential in promoting the application of VRFBs, but also offers referential solution to synthesis microorganism-based high-performance electrode in other energy storage systems.