Xue Xinzhe, Liu Zhen, Chandrasekaran Swetha, Eisenberg Samuel, Althaus Curtis, Freyman Megan C, Pinongcos Anica, Ren Qiu, Valdovinos Logan, Hsieh Cathleen, Hu Bintao, Dunn Bruce, Orme Christine A, Wang Xiao, Worsley Marcus A, Li Yat
Department of Chemistry and Biochemistry, University of California, 1156 High Street, Santa Cruz, CA, 95064, USA.
Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA, 94550, USA.
Adv Mater. 2025 Jul;37(28):e2419505. doi: 10.1002/adma.202419505. Epub 2025 Apr 21.
Manganese dioxide (MnO) deposition/dissolution (Mn/MnO) chemistry, involving a two-electron-transfer process, holds promise for safe and eco-friendly large-scale energy storage. However, challenges like electrode/electrolyte interface environment fluctuations (H and HO activity), irreversible Mn degradation, and limited understanding of degradation mechanisms hinder the reversibility of the Mn/MnO conversion. This study demonstrates a vanadyl/pervanadyl (VO/VO ) redox-mediated interface designed for high-energy Mn/MnO batteries. Unlike flow systems, this work uncovers, for the first time, the mechanism of a static redox-mediated interface in regulating interfacial H and HO activities. Significantly, the VO/VO chemical redox mediation targets Mn intermediates, suppressing their hydrolysis and enabling 100% Mn/MnO conversion. The redox-mediated interface enhances the Mn redox electron transfer process, achieving a stable ≈95% coulombic efficiency and ultrahigh capacity of 100 mAh cm with an areal energy density of 111 mWh cm , outperforming flow systems. The electrode also exhibits an average specific capacity of 593 mAh g, approaching the theoretical limit of 616 mAh g, and a specific energy density of 721 Wh kg at high MnO loadings (50-150 mg cm). The findings highlight the critical role of interfacial redox mediation in regulating H and HO activities and underscore the significance of interface dynamics.
二氧化锰（MnO）沉积/溶解（Mn/MnO）化学过程涉及双电子转移过程，有望实现安全且环保的大规模储能。然而，诸如电极/电解质界面环境波动（H和HO活性）、不可逆的Mn降解以及对降解机制的理解有限等挑战，阻碍了Mn/MnO转化的可逆性。本研究展示了一种为高能Mn/MnO电池设计的钒酰/过钒酰（VO/VO ）氧化还原介导界面。与流动系统不同，这项工作首次揭示了静态氧化还原介导界面在调节界面H和HO活性方面的机制。值得注意的是，VO/VO 化学氧化还原介导作用针对Mn中间体，抑制其水解并实现100%的Mn/MnO转化。氧化还原介导界面增强了Mn氧化还原电子转移过程，实现了稳定的≈95%的库仑效率和100 mAh cm 的超高容量，面积能量密度为111 mWh cm ，性能优于流动系统。该电极在高MnO负载量（50 - 150 mg cm）下还表现出平均比容量为593 mAh g，接近616 mAh g的理论极限，以及721 Wh kg的比能量密度。这些发现突出了界面氧化还原介导在调节H和HO活性方面的关键作用，并强调了界面动力学的重要性。
