Abstract High performance electrode materials have always been the key of supercapacitor research. Herein, we have prepared a kind of Ni(OH)2/g-C3N4/RGO nanosheet composite with petal-like structure, which was prepared by a simple hydrothermal method. The growth of Ni(OH)2 based on g-C3N4/RGO nanosheets owning to a more loose structure between the layers, which provided a sufficient electron transfer region for the Ni3+/Ni2+ in the redox process. In addition, the specific capacitance of Ni(OH)2/g-C3N4/RGO electrode was 543.8 F/g at 1 A/g, and also shown good cycling stability (72.7% retention over 2000 cycles). We assembled an asymmetric supercapacitor with Ni(OH)2/g-C3N4/RGO and activated carbon electrodes. The maximum energy and power density of the device were 33.38 Wh/kg and 849.8 W/kg respectively. The cyclic stability was 71.72% after 6000 cycles. Furthermore, the Ni(OH)2/g-C3N4/RGO nanosheet composite prepared provided a theoretical basis in the field of energy application research.

中文翻译：

---

一种简单的水热法制备具有良好超级电容器性能的3D花瓣状Ni(OH)2/g-C3N4/RGO复合材料

摘要 高性能电极材料一直是超级电容器研究的关键。在此，我们通过简单的水热法制备了一种具有花瓣状结构的Ni(OH)2/g-C3N4/RGO纳米片复合材料。基于 g-C3N4/RGO 纳米片的 Ni(OH)2 的生长得益于层间更松散的结构，这为氧化还原过程中的 Ni3+/Ni2+ 提供了足够的电子转移区域。此外，Ni(OH)2/g-C3N4/RGO 电极的比电容在 1 A/g 时为 543.8 F/g，并且还表现出良好的循环稳定性（2000 次循环后保持率为 72.7%）。我们用 Ni(OH)2/g-C3N4/RGO 和活性炭电极组装了一个不对称超级电容器。该装置的最大能量和功率密度分别为 33.38 Wh/kg 和 849.8 W/kg。循环稳定性为 71。6000 次循环后为 72%。此外，所制备的Ni(OH)2/g-C3N4/RGO纳米片复合材料为能源应用研究领域提供了理论依据。