Abstract Developing hybrid supercapacitor-battery energy storage devices for applications in electric vehicles is attractive because of their high energy density and short charge/discharge time. In this study, flexible MnO2 nanoparticle-coated air-oxidized carbon nanotube (MnO2/aCNT) electrodes are fabricated by the in situ redox reaction of KMnO4 and aCNTs at room temperature. The MnO2 nanoparticles have diameters of ∼10 nm. There is a strong chemical interaction between the MnO2 active material and aCNTs as a result of the Mn–O–C linkage. The flexible aCNT network can alleviate the strain from the MnO2 volume change and maintain the electrode integrity during rapid charge/discharge. The aCNT framework also provides a continuous and rapid electron pathway and ensures uniform dispersion of the MnO2 nanoparticles. The presence of MnO2 nanoparticles provides short pathways for Li-ion diffusion and allows interfacial capacitive lithium storage for ultrafast and reversible lithium storage. We report the best high-current performance to date for MnO2/C electrodes, of 395.8 mA h g−1 at 10 A g−1, and 630.2 mA h g−1 after 150 cycles at 2 A g−1. The excellent electrochemical performance, combined with the capacitive dominating process of the electrode, will further the design of high-performance hybrid supercapacitor-battery energy storage devices.

中文翻译：

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MnO 2 纳米颗粒锚定在碳纳米管上，具有混合超级电容器-电池性能，用于超快锂存储

摘要 开发用于电动汽车的混合超级电容器-电池储能装置因其能量密度高和充放电时间短而具有吸引力。在这项研究中，通过 KMnO4 和 aCNTs 在室温下的原位氧化还原反应制备了柔性 MnO2 纳米颗粒涂覆的空气氧化碳纳米管 (MnO2/aCNT) 电极。MnO2 纳米颗粒的直径约为 10 nm。由于 Mn-O-C 键合，MnO2 活性材料和 aCNT 之间存在强烈的化学相互作用。灵活的 aCNT 网络可以减轻 MnO2 体积变化带来的应变，并在快速充电/放电过程中保持电极完整性。aCNT 框架还提供了一个连续和快速的电子通路，并确保 MnO2 纳米颗粒的均匀分散。MnO2 纳米粒子的存在为锂离子扩散提供了短路径，并允许界面电容锂存储用于超快和可逆锂存储。我们报告了迄今为止 MnO2/C 电极的最佳高电流性能，在 10 A g-1 下为 395.8 mA h g-1，在 2 A g-1 下循环 150 次后为 630.2 mA h g-1。优异的电化学性能，结合电极的电容主导过程，将进一步推动高性能混合超级电容器-电池储能装置的设计。