In this work, carbon cloth (CC) was employed as a substrate onto which α-MnO2 nanowires were grown hydrothermally as a secondary support structure. In NaBH4 aqueous solution, the surface of the MnO2 was reduced at room temperature to form α-MnO2/Mn3O4 hierarchical structure. At a current density of 2 A g−1, the specific capacitance of the α-MnO2/Mn3O4@CC was found to be 181 F g−1. The energy density of the asymmetric supercapacitor (ASC) assembled by α-MnO2/Mn3O4@CC and activated carbon reaches 118.3 Wh kg−1. After 4000 cycles at a current density of 1 A g−1, the 88% of the capacitance was retained demonstrating good cycle stability. The designed multi-level structure can effectively prevent the stacking and agglomeration of the nanowires, and provides high energy density and good cycle stability in ASC. These results provide a good experimental foundation for the development of advanced, wearable, and energy storage devices.

中文翻译：

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α-MnO2/Mn3O4分层结构在碳布上自组装用于对称超级电容器

在这项工作中，碳布（CC）被用作基底，在其上水热生长 α-MnO2 纳米线作为二级支撑结构。在 NaBH4 水溶液中，MnO2 表面在室温下被还原，形成 α-MnO2/Mn3O4 分层结构。在 2 A g-1 的电流密度下，发现 α-MnO2/Mn3O4@CC 的比电容为 181 F g-1。由α-MnO2/Mn3O4@CC和活性炭组装的非对称超级电容器（ASC）的能量密度达到118.3 Wh kg-1。在 1 A g-1 的电流密度下循环 4000 次后，88% 的电容得以保留，证明了良好的循环稳定性。设计的多级结构可以有效防止纳米线的堆叠和团聚，并在 ASC 中提供高能量密度和良好的循环稳定性。