利用缺陷工程提高碳毡电极对钒离子的氧化还原催化活性

Boosting catalytic activities of carbon felt electrode towards redox reactions of vanadium ions by defect engineering

钒氧化还原液流电池(钒液流电池)因其安全性、高效性、灵活性和可扩展性成为最有前途的储能系统之一。然而,现有的碳基电极较低的电化学性能阻碍了钒液流电池的商业化应用,缺陷工程是提高钒液流电池用碳基电极氧化还原催化活性的有效策略。本文采用氩气等离子体刻蚀法在碳毡电极表面引入均匀的碳缺陷结构,使其具有更高的比表面积和额外的催化位点,促进了钒离子氧化还原反应的可逆性。结果表明,采用等离子体处理碳毡电极的钒液流电池的功率密度提高到1018.3 mW/cm^(2),能量效率为84.5%,且在1000次充放电循环后仍能保持稳定。

Vanadium redox flow batteries(VRFBs)are one of the most promising energy storage systems owing to their safety,efficiency,flexibility and scalability.However,the commercial viability of VRFBs is still hindered by the low electrochemical performance of the available carbon-based electrodes.Defect engineering is a powerful strategy to enhance the redox catalytic activity of carbon-based electrodes for VRFBs.In this paper,uniform carbon defects are introduced on the surfaces of carbon felt(CF)electrode by Ar plasma etching.Together with a higher specific surface area,the Ar plasma treated CF offers additional catalytic sites,allowing faster and more reversible oxidation/reduction reactions of vanadium ions.As a result,the VRFB using plasma treated electrode shows a power density of 1018.3 mW/cm^(2),an energy efficiency(EE)of 84.5%,and the EE remains stable over 1000 cycles.