It is well agreed that supercapacitors form an important class of energy storage devices catering to a variety of needs. However, designing the same using eco-friendly and earth abundant materials with high performance is still the dire need of the day. Here, we report a facile solvothermal synthesis of a porous graphene–NiFe₂O₄ (PGNF) nanocomposite. Thorough elemental, diffraction, microscopic and spectroscopic studies confirmed the formation of the PGNF composite, in which the NF nanoparticles are covered over the PG surface. The obtained 10 PGNF composite showed a surface area of 107 m² g⁻¹, with large pore volume which is favorable for charge storage properties. When utilizing the material as an electrode for a supercapacitor in a 2 M KOH aqueous electrolyte, the electrode displayed an impressive specific capacitance value of 1465.0 F g⁻¹ at a scan rate of 5 mV s⁻¹ along with a high capacitance retention of 94% after 10 000 discharge cycles. The fabricated symmetrical supercapacitor device exhibited an energy density of 4.0 W h kg⁻¹ and a power density of 3600.0 W kg⁻¹ at a high applied current density of 14 A g⁻¹. The superior electrochemical performance is attributed to the synergetic effect of the composite components which not only provided enough electroactive channels for the smooth passage of electrolyte ions but also maintained the hybrid structure intact in the ongoing electrochemical process. The obtained results underpin the promising utility of this material for future electrochemical energy storage devices.

中文翻译：

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用于储能应用的具有高电化学性能和高循环稳定性的多孔石墨烯-NiFe2O4 纳米复合材料

众所周知，超级电容器是满足各种需求的重要储能设备类别。然而，使用环保且富含地球的高性能材料进行设计仍然是当今的迫切需求。在这里，我们报告了多孔石墨烯-NiFe ₂ O ₄ (PGNF) 纳米复合材料的简便溶剂热合成。彻底的元素、衍射、显微镜和光谱研究证实了 PGNF 复合材料的形成，其中 NF 纳米颗粒覆盖在 PG 表面上。得到的 10 PGNF 复合材料的表面积为 107 m ² g ^-1，具有较大的孔体积，有利于电荷存储性能。当将该材料用作 2 M KOH 水性电解质中的超级电容器电极时，该电极在 5 mV s ^-1的扫描速率下显示出令人印象深刻的 1465.0 F g ^-1的比电容值以及 94 的高电容保持率。 10 000 次放电循环后的百分比。制造的对称超级电容器器件在14 A g ^-1的高施加电流密度下表现出 4.0 Wh kg ^-1的能量密度和 3600.0 W kg -1 的功率^密度. 优异的电化学性能归因于复合成分的协同作用，不仅为电解质离子的顺利通过提供了足够的电活性通道，而且在正在进行的电化学过程中保持了混合结构的完整性。所获得的结果支持了这种材料在未来电化学储能装置中的应用前景。