The pursuit of new categories of active materials as electrodes of supercapacitors remains a great challenge. Herein, for the first time, elemental boron as a superior electrode material of supercapacitors is reported, which exhibits significantly high capacitances and excellent rate performance in all alkaline, neutral, and acidic electrolytes. Notably, boron nanowire‐carbon fiber cloth (BNWs‐CFC) electrodes achieve a capacitance up to 42.8 mF cm⁻² at a scan rate of 5 mV s⁻¹ and 60.2 mF cm⁻² at a current density of 0.2 mA cm⁻² in the acidic electrolyte. Moreover, in all these three kinds of electrolytes, BNWs‐CFC electrodes demonstrate a decent cycling stability with >80% capacitance retention after 8000 charging/discharging cycles. The Dominating energy storage mechanism of BNWs in the different electrolytes is analyzed by looking into the kinetics of the electrochemical process. Subsequently, the BNWs‐CFC electrode is used to fabricate a flexible solid‐state supercapacitor, which reveals a specific capacitance up to 22.73 mF cm⁻² and good mechanical performance after 1000 bending cycles. This study opens a new avenue to explore elemental boron‐based new nanomaterials for the application of energy storage with superior electrochemical performance.

中文翻译：

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超级电容器用硼元素纳米线电极

追求新型活性材料作为超级电容器的电极仍然是一个巨大的挑战。在此，首次报道了元素硼作为超级电容器的优良电极材料，它在所有碱性，中性和酸性电解质中均表现出显着的高电容量和优异的倍率性能。值得注意的是，硼纳米线碳纤维布（BNWs-CFC）电极在5 mAs ^-1和60.2 mF cm ^-2的扫描速率下，在0.2 mA cm ^-2的电流密度下实现了高达42.8 mF cm ^-2的电容。在酸性电解质中。此外，在所有这三种电解质中，BNWs-CFC电极在8000次充电/放电循环后均显示出良好的循环稳定性，电容保持率> 80％。通过研究电化学过程的动力学，分析了BNWs在不同电解质中的主要储能机理。随后，BNWs-CFC电极被用于制造柔性固态超级电容器，该超级电容器在经过1000次弯曲循环后显示出高达22.73 mF cm ^-2的比电容和良好的机械性能。这项研究为探索基于元素硼的新型纳米材料开辟了一条新途径，该材料可用于具有优异电化学性能的储能应用。