Integration of fast electrochemical double-layer capacitance and large pseudocapacitance is a practical way to improve the overall capability of supercapacitor, yet remains challenging. Herein, an effective cyanogel synthetic strategy was demonstrated to prepare ultrathin Ni(OH)₂ nanosheets coupling with conductive reduced graphene oxide (rGO) (rGO-Ni(OH)₂) at ambient condition. Ultrathin Ni(OH)₂ nanosheet with 3–4 layers of edge-sharing octahedral MO₆ maximally exposes the active surface of Faradic reaction and promotes the ion diffusion, while the conductive rGO sheet boosts the electron transport during the reaction. Even at 30 A g⁻¹, the optimal sample can deliver a specific capacitance of 1119.52 F g⁻¹, and maintain 82.3% after 2000 cycles, demonstrating much higher electrochemical capability than bare Ni(OH)₂ nanosheets. A maximum specific energy of 44.3 W h kg⁻¹ (148.5 W kg⁻¹) is obtained, when assembled in a two-electrode system rGO-Ni(OH)₂//rGO. This study provides an insight into efficient construction of two dimensional hybrid electrodes with high performance for the new-generation energy storage system.

快速电化学双层电容和大伪电容的集成是提高超级电容器整体性能的实用方法，但仍具有挑战性。在本文中，证明了一种有效的氰基凝胶合成策略，可在环境条件下制备与导电还原氧化石墨烯（rGO）（rGO-Ni（OH）₂）偶联的超薄Ni（OH）₂纳米片。具有3-4个边缘共享八面体MO ₆层的超薄Ni（OH）₂纳米片最大程度地暴露了法拉第反应的活性表面并促进了离子扩散，而导电rGO片则促进了反应过程中的电子传输。即使在30 A g ^-1时，最佳样品也可以提供1119.52 F g的比电容^-1，并在2000次循环后保持82.3％，这表明其电化学性能比裸露的Ni（OH）₂纳米片高得多。当在双电极系统rGO-Ni（OH）₂ // rGO中组装时，获得的最大比能为44.3 W h kg ^-1（148.5 W kg ^-1）。这项研究为新一代储能系统提供了高效构建高性能二维混合电极的见解。