A mixed valence V₄O₉ with a tunnel structure and room temperature metallic properties was prepared via partially reducing vanadium pentoxide. Its unique tunnel structure and metallic characteristics are beneficial for fast zinc ion and electron diffusion. A Zn//V₄O₉ battery displays a high rate performance of 234.4 mA h g⁻¹ at 50C, a large reversible capacity of 420 mA h g⁻¹ at 0.5C, and good cycling stability. The intercalation mechanism of Zn²⁺ and H⁺ is proved by in situ XRD, ex situ XPS, and other characterization techniques, along with density functional theory calculations. This work provides a strategy to improve the electrochemical performance of vanadium oxides through valence regulation.

中文翻译：

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一种用于高功率密度水性锌离子电池的新型隧道式 V4O9 阴极

通过部分还原五氧化二钒制备了具有隧道结构和室温金属性质的混合价态V ₄ O ₉。其独特的隧道结构和金属特性有利于锌离子和电子的快速扩散。Zn//V ₄ O ₉电池在50C下显示出234.4 mA hg ^-1的高倍率性能，在0.5C下显示出420 mA hg ^-1的大可逆容量，以及良好的循环稳定性。Zn ²⁺和H ⁺的嵌入机理通过原位XRD、非原位XPS 和其他表征技术，以及密度泛函理论计算。这项工作提供了一种通过价态调节来改善钒氧化物电化学性能的策略。