The MnO₂/Micro-nano Ni-filled Ni foam (MNFNF) hybrids were systematically studied as supercapacitor electrodes. Micro-nano Ni-filled Ni foam (MNFNF) was prepared via a facile NiC₂O_4·2H₂O coating process on foam, followed by sintering treatment, and then employed as substrate for electrodeposition of MnO₂. The morphology of the MNFNF substrate exhibited an obviously second-porous structure, deriving from dehydration, decarboxylation, and the lattice contraction occurred in the sintering treatment process of NiC₂O_4·2H₂O. The structure of pores was irregular with 0.05~2 μm in diameter, and the pore walls were composed of nanoparticles with 200~500 nm in diameter. Such porous MNFNF not only provided a conductive network to enhance the charge transport and mass transfer in the electrochemical process but also achieved a large MnO₂ mass loading capacity. Electrochemical test showed the MnO₂/MNFNF electrode exhibited a mass specific capacitance (SC) of 723.7 F g⁻¹ and an areal specific capacitance of 1.16 F cm⁻² at a current rate of 0.25 A g⁻¹. The asymmetric supercapacitor device based on the MnO₂/MNFNF electrode and active carbon electrode could supply an energy density of 24.5 Wh kg⁻¹ at the maximum power density of 4.4 kW kg⁻¹. Meanwhile, the supercapacitor device also exhibited a good cycling stability along with 93.2% specific capacitance retained after 5000 cycles. These results demonstrated that the MnO₂/MNFNF electrode could be one of the potential electrode material for energy storage applications.

中文翻译：

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用于高性能超级电容器的MnO 2 /微纳镍填充泡沫镍的构造

MnO ₂ /微纳镍填充镍泡沫（MNFNF）杂化物被系统地研究作为超级电容器电极。通过在泡沫材料上进行便捷的NiC ₂ O _4· 2H ₂ O涂覆工艺，然后进行烧结处理，制备了微纳米Ni填充镍泡沫材料（MNFNF），然后将其用作电沉积MnO _2的基材。NiNF ₂ O _2· 2H ₂的烧结处理过程中，MNFNF基体的形貌表现出明显的二次孔结构，是由脱水，脱羧引起的，晶格收缩。O.孔的结构是不规则的，直径为0.05〜2μm，孔壁由直径为200〜500 nm的纳米颗粒组成。这种多孔的MNFNF不仅提供了导电网络以增强电化学过程中的电荷传输和质量传递，而且还实现了大的MnO ₂质量负载能力。电化学测试表明，MnO ₂ / MNFNF电极在0.25 A g ^-1的电流速率下显示出723.7 F g ^-1的质量比电容（SC）和1.16 F cm ^-2的面积比电容。基于MnO ₂ / MNFNF电极和活性炭电极的非对称超级电容器装置可提供24.5 Wh kg ^-1的能量密度最大功率密度为4.4 kW kg ^-1时。同时，超级电容器器件还表现出良好的循环稳定性，并在5000次循环后保留了93.2％的比电容。这些结果表明，MnO ₂ / MNFNF电极可能是用于能量存储应用的潜在电极材料之一。