Pseudocapacitive materials are vitally important to the development of flexible supercapacitors but usually suffer from poor conductivity and stability. In this work, a Ni(OH)₂/HGO nanocomposite was fabricated by in-situ growth of Ni(OH)₂ nanoplates on highly-oxidized graphene oxide (HGO). A series of characterizations reveal the abundant out-of-plane active sites of HGO enable the uniformly grown Ni(OH)₂ nanoplates with smaller crystalline size and stronger anchoring with HGO substrates. Furthermore, benefit from the porous structure and improved conductivity of HGO substrates together with more exposed active sites of Ni(OH)₂ nanoplates, the complex Ni(OH)₂/HGO electrode exhibits a remarkable specific capacitance of 1430.9 F/g at 5 A/g, which is much higher than those of the pure Ni(OH)₂ of 329.8 F/g and Ni(OH)₂ on the untreated GO (Ni(OH)₂/GO) of 538.3 F/g. Even under an ultrahigh current density of 60 A/g, the specific capacitance of Ni(OH)₂/HGO electrodes still reach up to 850 F/g, delivering a superior rapid-charging capability. In addition, by using screen-printing techniques, an all-solid-state Ni(OH)₂/HGO//activated carbon-based asymmetric flexible supercapacitor is fabricated and displays an excellent areal specific capacitance of 322 mF/cm², outstanding energy density (0.134 mW h/cm²) and power density (33.6 mW/cm²). Moreover, the capacity of all-solid-state flexible supercapacitors (AFSCs) remains 80%, even bending to various angles and for 1000 times, showing good flexibility. This work provides inspiration for rational development of Ni(OH)₂-based pseudocapacitive materials and high-performance AFSCs for portable and wearable electronics.

赝电容材料对于柔性超级电容器的开发至关重要，但通常存在导电性和稳定性差的问题。在这项工作中，通过在高度氧化的氧化石墨烯 (HGO) 上原位生长 Ni(OH) _{2纳米片制备了 Ni(OH) 2 /HGO 纳米复合材料。}一系列表征揭示了 HGO 丰富的面外活性位点使均匀生长的 Ni(OH) ₂纳米板具有更小的晶体尺寸和更强的与 HGO 基板的锚定。此外，受益于 HGO 基板的多孔结构和改进的电导率以及 Ni(OH) ₂纳米板的更多暴露活性位点，复合物 Ni(OH) ₂/HGO 电极在 5 A/g 时表现出 1430.9 F/g 的显着比电容，远高于纯 Ni(OH) ₂的 329.8 F/g 和未处理 GO 上的Ni(OH) ₂ (Ni (OH) ₂ /GO) 为 538.3 F/g。即使在60 A/g的超高电流密度下，Ni(OH) ₂ /HGO电极的比电容仍高达850 F/g，具有优异的快充能力。此外，通过使用丝网印刷技术，制备了全固态 Ni(OH) ₂ /HGO//活性炭基非对称柔性超级电容器，并显示出 322 mF/cm ²的优异面积比电容，出色的能量密度（0.134 mW·h/cm ²) 和功率密度 (33.6 mW/cm ² )。此外，全固态柔性超级电容器（AFSCs）的容量仍然保持在80%，甚至弯曲到各种角度和1000次，显示出良好的柔韧性。这项工作为合理开发用于便携式和可穿戴电子产品的基于 Ni(OH) ₂的赝电容材料和高性能 AFSC 提供了灵感。