For Zinc Metal Batteries, How Many Electrons go to Hydrogen Evolution? An Electrochemical Mass Spectrometry Study
For Zinc Metal Batteries, How Many Electrons go to Hydrogen Evolution? An Electrochemical Mass Spectrometry Study
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对于锌金属电池，有多少电子去析氢？
DOI：
10.1002/anie.202319010
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发表时间：
2024
期刊：
影响因子：
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通讯作者：
Dick, Jeffrey E.
中科院分区：
文献类型：
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作者：
Roy, Kingshuk;Rana, Ashutosh;Heil, Joseph N.;Tackett, Brian M.;Dick, Jeffrey E.
尽管水性锌（Zn）金属电池（AZMB）具有高比容量（820 mAh g-1和5，854 mAh cm-3）、低氧化还原电位（相对于标准氢电极为-0.76 V）、低成本、水相容性和安全性等优点，但实际相关电池的开发受到几个问题的困扰，如不希望的析氢反应（HER）、Zn基底（绝缘ZnO、Zn（OH）2、Zn（SO 4）x（OH）y、Zn（ClO 4）x（OH）等）的腐蚀。 钝化层）和枝晶生长。控制和抑制HER活性与AZMB的长期周期性密切相关。因此，需要一种精确的定量技术来监测锌电沉积过程中析氢的真实的时间动态。在这项研究中，我们量化氢的演变使用原位电化学质谱（ECMS）。这种方法使我们能够确定一个校正因子的法拉第效率，该系统具有无与伦比的精度。例如，在铜基底上以1.5 mA/cm 2的电流密度电沉积锌600秒期间，总电荷的0.3%归因于HER，而其余部分则归因于锌电沉积。 乍一看，这似乎只是一小部分，但它可能对AZMB的长期循环性能有害。此外，我们的研究结果提供了深入了解HER和电沉积锌的多孔形态之间的相关性，解开在充电过程中存在的捕获H2和锌腐蚀。总的来说，这项研究建立了一个平台，以准确地确定锌电沉积的法拉第效率，并提供了一个强大的工具，用于评估电解质添加剂，盐和电极修饰，旨在提高长期稳定性和抑制水溶液锌电池中的HER。
Despite the advantages of aqueous zinc (Zn) metal batteries (AZMB) like high specific capacity (820 mAh g−1and 5,854 mAh cm−3), low redox potential (−0.76 V vs. the standard hydrogen electrode), low cost, water compatibility, and safety, the development of practically relevant batteries is plagued by several issues like unwanted hydrogen evolution reaction (HER), corrosion of Zn substrate (insulating ZnO, Zn(OH)2, Zn(SO4)x(OH)y, Zn(ClO4)x(OH)yetc. passivation layer), and dendrite growth. Controlling and suppressing HER activity strongly correlates with the long‐term cyclability of AZMBs. Therefore, a precise quantitative technique is needed to monitor the real‐time dynamics of hydrogen evolution during Zn electrodeposition. In this study, we quantify hydrogen evolution using in situ electrochemical mass spectrometry (ECMS). This methodology enables us to determine a correction factor for the faradaic efficiency of this system with unmatched precision. For instance, during the electrodeposition of zinc on a copper substrate at a current density of 1.5 mA/cm2for 600 seconds, 0.3 % of the total charge is attributed to HER, while the rest contributes to zinc electrodeposition. At first glance, this may seem like a small fraction, but it can be detrimental to the long‐term cycling performance of AZMBs. Furthermore, our results provide insights into the correlation between HER and the porous morphology of the electrodeposited zinc, unravelling the presence of trapped H2and Zn corrosion during the charging process. Overall, this study sets a platform to accurately determine the faradaic efficiency of Zn electrodeposition and provides a powerful tool for evaluating electrolyte additives, salts, and electrode modifications aimed at enhancing long‐term stability and suppressing the HER in aqueous Zn batteries.