Abstract We investigated NiF2 as an energy storage material in asymmetric supercapacitor together with activated carbon (AC) as the counter electrode. Cyclic voltammetry and galvanostatic charge-discharge profile are carried out to investigate the oxidation-reduction process and capacitive behavior of the NiF2 sample. The interfacial electron transport properties of the sample are also explored using Nyquist plots in two and three electrodes configurations of electrochemical impedance spectroscopy. A very high specific capacitance of 751 F/g is achieved at 1 A/g current density in three electrode system. Further, the asymmetric supercapacitor device based on NiF2//AC structure reveals high capacitance of 175 F/g at 1 A/g in the high window potential of 1.8 V. The fabricated device retained 93% of its initial capacitance after 1000 cycles at 3 A/g current density affirms high electrochemical stability of the device. Ragone plot depicts high energy density of 79.65 Wh/kg with power density of 1727.35 W/kg for 1.8 V window potential at 1 A/g current density. High electrochemical stability of NiF2 sample endures the tetragonal phase even after electrochemical measurement which can be more useful in recycling the electrode material for future recycled supercapacitor devices.

中文翻译：

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NiF2 作为一种具有 1.8 V 高窗口电位的高效电极材料，用于高能量和功率密度的非对称超级电容器

摘要 我们研究了 NiF2 作为非对称超级电容器中的储能材料以及活性炭 (AC) 作为对电极。进行循环伏安法和恒电流充放电曲线以研究 NiF2 样品的氧化还原过程和电容行为。还使用电化学阻抗谱的两个和三个电极配置中的奈奎斯特图来探索样品的界面电子传输特性。在三电极系统中以 1 A/g 的电流密度实现了 751 F/g 的非常高的比电容。此外，基于 NiF2//AC 结构的非对称超级电容器器件在 1.8 V 的高窗口电位下在 1 A/g 下显示出 175 F/g 的高电容。制造的器件在 3 A/g 电流密度下循环 1000 次后仍保持其初始电容的 93%，这证实了器件的高电化学稳定性。Ragone 图描绘了 79.65 Wh/kg 的高能量密度和 1727.35 W/kg 的功率密度，1.8 V 窗口电位在 1 A/g 电流密度下。NiF2 样品的高电化学稳定性即使在电化学测量后也能承受四方相，这对于回收电极材料用于未来回收的超级电容器装置更有用。