关键词: 碱性全铁液流电池, 石墨毡, 硫酸氧化改性, 电化学性能

Abstract: The electrode with excellent electrochemical performance is one of the keys to the cycling stability of an alkaline all-iron flow battery. In this paper，the graphite felt electrode was modified with concentrated sulfuric acid oxidation. The effects of the modified electrode on the performance of an alkaline all-iron flow battery were studied by CV，EIS， and single-cell cycle tests. The physical and chemical structure of graphite felt modified with sulfuric acid oxidation was analyzed by scanning electron microscope（SEM），contact angle measuring instrument，Fourier transform infrared spectroscopy（FT-IR），and X ray photoelectron spectroscopy（XPS）. The results showed that the content of oxygen containing functional groups，such as carboxyl groups，on the surface of the graphite felt electrode increased when the graphite felt electrode was modified with sulfuric acid oxidation，which improved the hydrophilicity of the graphite felt electrode. Meanwhile， many defective structures appeared on the surface，which increased the electrochemical reaction active site. In the charge and discharge process of single-cell tests，the DIPSO Fe2+/DIPSO-Fe3+ pair had better electrochemical activity when the modified electrode was used as the negative electrode，and the battery's capacity retention rate increased by 15 % when the current density was 120 mA/cm2.

Key words: alkaline all-iron flow battery, graphite felt, sulfuric acid oxidation modification, electrochemical performance