In this study, pure perovskite NiMnO₃ and various Mn₃O₄/NiMnO₃ nanocomposites were synthesized using a hydrothermal method and applied as supercapacitor electrodes. The crystal structures, surface morphologies, and chemical species of the samples were investigated using X-ray diffraction, scanning electron microscopy, and X-ray photoelectron spectroscopy. The electrochemical properties of these materials were tested in the form of half-cells and Swagelok cells with an electrolyte comprising KOH (3 M). Cyclic voltammetry and galvanostatic charging and discharging were used to estimate the specific capacitances of the electrodes and Swagelok supercapacitors. In electrode tests, the specific capacitance of 1.0-Mn₃O₄ (the Mn₃O₄/NiMnO₃ nanocomposite; 941 F/g) was the highest among all the tested materials and 60% higher than that of pure NiMnO₃ (485 F/g). Furthermore, the Mn₃O₄/NiMnO₃ symmetric capacitor outperformed the graphene oxide-Mn₃O₄/NiMnO₃ asymmetric capacitor. Over 1,000 cycles of charging and discharging, the symmetric Swagelok cells consisting of pure Mn₃O₄/NiMnO₃ exhibited more stable behavior than the asymmetric cells. The results of this study could expedite the development of future energy storage technologies.

中文翻译：

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钙钛矿 NiMnO3、Mn3O4/NiMnO3 和氧化石墨烯-Mn3O4/NiMnO3 纳米材料在对称和非对称超级电容器中的应用研究


在这项研究中，使用水热法合成了纯钙钛矿 NiMnO₃ 和各种_{Mn 3}O₄/NiMnO₃ 纳米复合材料，并用作超级电容器电极。使用 X 射线衍射、扫描电子显微镜和 X 射线光电子能谱研究了样品的晶体结构、表面形貌和化学种类。这些材料的电化学性能以半电池和世伟洛克电池的形式进行测试，其电解质包括 KOH （3M）。循环伏安法和恒电流充电和放电用于估计电极和世伟洛克超级电容器的比电容。在电极测试中，1.0-Mn₃O₄（Mn₃O₄/NiMnO₃ 纳米复合材料;941F/g）的比电容在所有测试材料中最高，比纯 NiMnO₃ （485F/g） 高 60%。此外，Mn₃O₄/NiMnO₃ 对称电容器的性能优于氧化石墨烯 Mn₃O₄/NiMnO₃ 非对称电容器。经过 1,000 次充放电循环，由纯 Mn₃O₄/NiMnO₃ 组成的对称世伟洛克电池表现出比不对称电池更稳定的行为。这项研究的结果可以加快未来储能技术的发展。