ShakeriHosseinabad Fatemeh, Frost Brandon, Said Samia, Xu Chaochen, Behnoudfar Diba, Amini Kiana, Momodu Damilola, Mahinpey Nader, Egberts Philip, Miller Thomas S, Roberts Edward P L
Department of Chemical and Petroleum Engineering, University of Calgary, 2500 University Drive NW, Calgary T2N 1N4, Alberta, Canada.
Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, London WC1E 7JE, U.K.
ACS Appl Mater Interfaces. 2023 Jul 26;15(29):34711-34725. doi: 10.1021/acsami.3c03785. Epub 2023 Jul 11.
Aqueous redox flow battery systems that use a zinc negative electrode have a relatively high energy density. However, high current densities can lead to zinc dendrite growth and electrode polarization, which limit the battery's high power density and cyclability. In this study, a perforated copper foil with a high electrical conductivity was used on the negative side, combined with an electrocatalyst on the positive electrode in a zinc iodide flow battery. A significant improvement in the energy efficiency (ca. 10% vs using graphite felt on both sides) and cycling stability at a high current density of 40 mA cm was observed. A long cycling stability with a high areal capacity of 222 mA h cm is obtained in this study, which is the highest reported areal capacity for zinc-iodide aqueous flow batteries operating at high current density, in comparison to previous studies. Additionally, the use of a perforated copper foil anode in combination with a novel flow mode was discovered to achieve consistent cycling at exceedingly high current densities of >100 mA cm. In situ and ex situ characterization techniques, including in situ atomic force microscopy coupled with in situ optical microscopy and X-ray diffraction, are applied to clarify the relationship between zinc deposition morphology on the perforated copper foil and battery performance in two different flow field conditions. With a portion of the flow going through the perforations, a significantly more uniform and compact zinc deposition was observed compared to the case where all of the flow passed over the surface of the electrode. Results from modeling and simulation support the conclusion that the flow of a fraction of electrolyte through the electrode enhances mass transport, enabling a more compact deposit.
使用锌负极的水系氧化还原液流电池系统具有相对较高的能量密度。然而，高电流密度会导致锌枝晶生长和电极极化，这限制了电池的高功率密度和循环寿命。在本研究中，在碘化锌液流电池的负极使用了具有高电导率的穿孔铜箔，并在正极结合了一种电催化剂。在40 mA cm的高电流密度下，观察到能量效率有显著提高（与两侧均使用石墨毡相比提高了约10%）以及循环稳定性增强。在本研究中获得了222 mA h cm的高面积容量下的长循环稳定性，与先前的研究相比，这是报道的在高电流密度下运行的碘化锌水系液流电池的最高面积容量。此外，发现使用穿孔铜箔阳极并结合一种新型流动模式能够在超过100 mA cm的极高电流密度下实现一致的循环。应用原位和非原位表征技术，包括原位原子力显微镜与原位光学显微镜以及X射线衍射相结合，以阐明在两种不同流场条件下穿孔铜箔上锌沉积形态与电池性能之间的关系。当一部分流体通过穿孔时，与所有流体都流经电极表面的情况相比，观察到锌沉积明显更加均匀和致密。建模和模拟结果支持这样的结论，即一部分电解质通过电极的流动增强了传质，从而能够实现更致密的沉积。
