The practical implementation of supercapacitors is hindered by low utilization and poor structural stability of electrode materials. Herein, to surmount these critical challenges, a three-dimensional hierarchical α-Co(OH)₂/α-Ni(OH)₂ heterojunction nanorods are built in situ on Ni foam through a mild two-step growth reaction. The unique lamellar crystal structure and abundant intercalated anions of α-M(OH)₂ (M = Co or Ni) and the ideal electronic conductivity of α-Co(OH)₂ construct numerous cross-linked ion and electron transport paths in heterojunction nanorods. The deformation stresses exerted by α-Co(OH)₂ and α-Ni(OH)₂ on each other guarantee the excellent structural stability of this heterojunction nanorods. Using nickel foam with a three-dimensional network conductive framework as the template ensures the rapidly transfer of electrons between this heterojunction nanorods and current collector. Three-dimensional hierarchical structure of α-Co(OH)₂/α-Ni(OH)₂ heterojunction nanorods provides a large liquid interface area. These result together in the high utilization rate and excellent structure stability of the α-Co(OH)₂/α-Ni(OH)₂ heterojunction nanorods. And the capacitance retention rate is up to 93.4% at 1 A g⁻¹ from three-electrode system to two-electrode system. The α-Co(OH)₂/α-Ni(OH)₂//AC device also present a long cycle life (the capacitance retention rate is 123.6% at 5 A g⁻¹ for 10000 cycles), a high specific capacitance (207.2 F g⁻¹ at 1 A g⁻¹), and high energy density and power density (72.6 Wh kg⁻¹ at 196.4 W kg⁻¹ and 40.9 Wh kg⁻¹ at 3491.8 W kg⁻¹), exhibiting a fascinating potential for supercapacitor in large-scale applications.

超级电容器的实际应用由于电极材料的利用率低和结构稳定性差而受到阻碍。在本文中，为了克服这些关键挑战，通过温和的两步生长反应，在Ni泡沫上原位构建了三维分层α-Co（OH）₂ /α-Ni（OH）₂异质结纳米棒。α-M（OH）₂（M = Co或Ni）的独特层状晶体结构和丰富的嵌入阴离子以及α- Co（OH）₂的理想电子电导率在异质结纳米棒中构成了许多交联的离子和电子传输路径。α-Co（OH）₂和α-Ni（OH）₂施加的形变应力彼此保证了这种异质结纳米棒的出色的结构稳定性。使用带有三维网络导电框架的泡沫镍作为模板，可以确保电子在此异质结纳米棒和集电器之间快速转移。α-Co（OH）₂ /α-Ni（OH）₂异质结纳米棒的三维层次结构提供了较大的液体界面面积。这些共同导致α-Co（OH）₂ /α-Ni（OH）₂异质结纳米棒的高利用率和优异的结构稳定性。从三电极系统到两电极系统，在1 A g ^-1时，电容保持率高达93.4％。α-Co（OH）₂ /α-Ni（OH）₂ // AC设备还呈现长的循环寿命（电容量保持率是123.6％在5 A G ^-1为10000次循环），高的比电容（207.2 F G ^-1 1 A G ^-1）和高能量密度和功率密度（72.6瓦千克^-1在196.4千克w ^ ^-1和40.9瓦千克^-1在3491.8W¯¯千克^-1），表现出在大规模应用超级电容器一个引人入胜的潜力。