High stable N doped carbon felts achieves 10000 cycles operation of vanadium flow battery

The low efficiency and insufficient long-term cycling stability under high current density remains one of the bottleneck issues restricting the development of vanadium flow batteries. Based on the integrated ‘rigid-flexible’ characteristics, carbonized polypyrrole/polyvinylpyrrolidone interlaced architectures are constructed on the carbon felts to synergistically enhance the electrochemical activity and long-term cycling stability. The modified electrode (N-NCF) achieves a specific surface area of 11.98 m 2 /g, which is 6.34 times that of the pristine carbon felt (PCF). Under 280 mA cm −2 , N-NCF maintains an energy efficiency of 73.1 %, representing a 5 % improvement over PCF. Furthermore, the nanofiber-interlaced architectures enable N-NCF to exhibit exceptional long-term cycling stability. After over 10,000 cycles under 280 mA cm −2 , the energy efficiency remains 66.4 %, with an extremely low decay rate of 0.000899 %. The optimized N-doping and nanofiber-interlaced architectures synergistically enhance the electrochemical activity and stability of the carbon felts, thereby establishing a long-term stable electrochemical catalytic network. This work provides referencing strategies for the stable electrodes of vanadium flow batteries.