Poor capacitive behavior caused by low electronic conductivity and slow reaction kinetics is the main obstacle faced by the MnO electrode materials in current supercapacitors. Herein, the influence of Ni doping on the capacitive behavior of α-MnO synthesized by a low-cost and one-pot chemical coprecipitation method was investigated. During the doping process, the amount of Ni was increased from 0.05 mmol to 0.45 mmol in steps of 0.1 mmol. The structure and chemical composition of Ni-doped MnO (MnO-Ni) were characterized by XRD, FTIR, SEM, EDS, and XPS. Comprehensive studies show that no change in the crystal phase structure of MnO, while the decrease in the nanoparticle size and the increase in electronic conductivity by Ni doping, which improve the capacitive behavior of α-MnO. With specific capacitance values increasing with increasing amounts of Ni up to a certain limit 0.25 mmol, the specific capacitance of 325.8 F/g was given by MnO-Ni electrode at a current density of 0.5 A/g, which was nearly 1.72 times that of MnO electrode of 189.47 F/g. Moreover, the MnO-Ni electrode showed excellent capacitance retention (112%) than the MnO electrode (109.5%) after 3000 cycles.

中文翻译：

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增强一锅法制备的 Ni 掺杂 α-MnO2 超级电容器的电化学性能


电子电导率低和反应动力学慢导致的电容行为差是当前超级电容器中MnO电极材料面临的主要障碍。本文研究了Ni掺杂对低成本一锅化学共沉淀法合成的α-MnO电容行为的影响。在掺杂过程中，Ni 的量以 0.1 mmol 的步长从 0.05 mmol 增加到 0.45 mmol。通过 XRD、FTIR、SEM、EDS 和 XPS 对 Ni 掺杂 MnO (MnO-Ni) 的结构和化学成分进行了表征。综合研究表明，Ni掺杂没有改变MnO的晶相结构，但纳米颗粒尺寸减小，电子电导率增加，从而改善了α-MnO的电容行为。随着 Ni 含量的增加，比电容值增加到一定限度 0.25 mmol，MnO-Ni 电极在电流密度为 0.5 A/g 时，比电容达到 325.8 F/g，几乎是普通电极的 1.72 倍。 MnO 电极为 189.47 F/g。此外，在3000次循环后，MnO-Ni电极表现出比MnO电极（109.5%）优异的电容保持率（112%）。