Radinger Hannes
Institute for Applied Materials, Karlsruhe Institute of Technology, 76344, Eggenstein-Leopoldshafen, Germany.
Chemphyschem. 2021 Dec 13;22(24):2498-2505. doi: 10.1002/cphc.202100623. Epub 2021 Oct 29.
The market breakthrough of vanadium flow batteries is hampered by their low power density, which depends heavily on the catalytic activity of the graphite-based electrodes used. Researchers try to increase their performance by thermal, chemical, or electrochemical treatments but find no common activity descriptors. No consistent results exist for the so-called oxygen functional groups, which seem to catalyze mainly the V /V but rarely the V O /V O redox reaction. Some studies suggest that the activity is related to graphitic lattice defects which often contain oxygen and are therefore held responsible for inconsistent conclusions. Activation of electrodes does not change one property at a time, but rather surface chemistry and microstructure simultaneously, and the choice of starting material is crucial for subsequent observations. In this contribution, the literature on the catalytic and physicochemical properties of activated carbon-based electrodes is analyzed and evaluated. In addition, an outlook on possible future investigations is given to avoid the propagation of contradictions.
钒液流电池的市场突破受到其低功率密度的阻碍，而功率密度在很大程度上取决于所使用的石墨基电极的催化活性。研究人员试图通过热、化学或电化学处理来提高其性能，但未找到通用的活性描述符。对于所谓的氧官能团，不存在一致的结果，这些官能团似乎主要催化V /V，但很少催化V O /V O氧化还原反应。一些研究表明，活性与石墨晶格缺陷有关，这些缺陷通常含有氧，因此导致了不一致的结论。电极的活化不会一次改变一种性质，而是同时改变表面化学和微观结构，起始材料的选择对于后续观察至关重要。在本论文中，对基于活性炭的电极的催化和物理化学性质的文献进行了分析和评估。此外，还对未来可能的研究进行了展望，以避免矛盾的传播。
