Binder-Free Carbon Nano Network Enables High-Performance Graphite Felt for Vanadium Redox Flow Battery

Nitrogen-doped electrode materials have a good promoting effect on the adsorption of vanadium ions and electron transfer in vanadium redox flow battery (VRFB). In this work, a nitrogen-doped carbon nano-network wrapped graphite felt electrode is prepared through a simple and clean electrodeposition method. The morphology of polyaniline on graphite felt is controlled by electrodeposition time, and carbon nano-network wrapped graphite felt is obtained after calcination. The in-situ wrapped nano network can increase the specific surface area of graphite felt electrode, improve the connectivity between graphite felt and carbon nano-network, and reduce the electrode resistance. The modified cell has high stability and activity after 100 cycles of charging and discharging. At 100 mA cm -2 , the energy efficiency of modified cell is 79.2%, which is 8.8% higher than that of blank cell. Using the prepared electrode, VRFB has a discharge capacity of 350 mA h at 250 mA cm -2 , while the blank cell cannot work normally. This work proposes a method for preparing a high-performance, high-stability composite electrode, which enables the carbon nano network stably exist on the surface of graphite felt without a binder