NiMoO₄ has attracted intensive attention as one of the promising ternary metal oxides because of its high specific capacitance and electrical conductivity compared to traditional transition-metal oxides. In this study, NiMoO₄ nanorods uniformly decorated on graphene nanosheets (G-NiMoO₄) are synthesized through a facile hydrothermal method. The prepared G-NiMoO₄ composite exhibits a high specific capacitance of 714 C·g⁻¹ at 1 A·g−1 and an excellent rate capability, with a retention ratio of 57.7% even at 100 A·g⁻¹. An asymmetric supercapacitor (ASC) fabricated with the G-NiMoO₄ composite as the positive electrode and Fe₂O₃ quantum dot-decorated graphene (G-Fe₂O₃-QDs) as the negative electrode delivers an ultrahigh energy density of 130 Wh·kg⁻¹, which is comparable to those of previously reported aqueous NiMoO₄-based ASCs. Even when the power density reaches 33.6 kW·kg⁻¹, an energy density of 56 Wh·kg⁻¹ can be maintained. The ASC device exhibits outstanding cycling stability, with a capacitance retention of 113% after 40,000 cycles. These results indicate that the G-NiMoO₄ composite is a promising candidate for ASCs with ultrahigh energy density and excellent cycling stability. Moreover, the present work provides an exciting guideline for the future design of high-performance supercapacitors for industrial and consumer applications via the simultaneous use of various pseudocapacitive materials with suitable potential windows as the positive and negative electrodes.

中文翻译：

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超高能量密度电池型不对称超级电容器：NiMoO 4纳米棒修饰的石墨烯和石墨烯/ Fe 2 O 3量子点

NiMoO ₄作为有希望的三元金属氧化物之一已引起了广泛的关注，因为与传统的过渡金属氧化物相比，NiMoO ₄具有高的比电容和电导率。在这项研究中，通过简便的水热法合成了均匀装饰在石墨烯纳米片上的NiMoO ₄纳米棒（G-NiMoO ₄）。所制备的G-NiMoO ₄复合材料在1 A·g-1时显示出714 C·g ^-1的高比电容并且具有优异的倍率性能，甚至在100 A·g ^-1时的保留率为57.7％。以G-NiMoO ₄复合材料为正极和Fe ₂ O制备的不对称超级电容器（ASC）作为负极的₃量子点修饰石墨烯（G-Fe ₂ O ₃ -QDs）可提供130 Wh·kg ^-1的超高能量密度，与先前报道的基于NiMoO ₄的水性ASC相当。即使当功率密度达到33.6 kW·kg ^-1时，也可以保持56 Wh·kg ^-1的能量密度。ASC器件具有出色的循环稳定性，在40,000次循环后的电容保持率为113％。这些结果表明，G-NiMoO ₄复合材料是具有超高能量密度和出色循环稳定性的ASC的有前途的候选材料。此外，通过同时使用各种具有适当电势窗口的伪电容材料作为正电极和负电极，本工作为工业和消费类应用的高性能超级电容器的未来设计提供了令人兴奋的指南。