EXPLORATION OF THE EFFECTIVE LOCATION OF SURFACE OXYGEN DEFECTS IN GRAPHENE-BASED ELECTROCATALYSTS FOR THE ALL-VANADIUM REDOX FLOW BATTERIES

摘要

Recently, the electrocatalyst research on the vanadium redox reactions has been extensively studied in order to improve their catalytic activity for better electron conductivity and mass transfer kinetics. The investigation of various electrocatalysts for the VRFBs can be categorized to metal-based and carbon-based nanomaterials. In the latter case, the carbon-based catalysts such as carbon nanotube (CNT), carbon nanofiber (CNF), and graphene are considered as promising candidates due to their large surface area, high conductivity, and stability at concentrated acidic conditions. These nanomaterials are usually used by coating them on the carbon felt or carbon paper electrode. Recently, nitrogen-doped CNT, multi-walled CNT, and CNT/CNF hybrid coated carbon felt electrodes have been reported, where oxygen or nitrogen atoms at carbon structure help the vanadium redox reactions.