Ni/Co-based metal organic frameworks rapidly synthesized in ambient environment for high energy and power hybrid supercapacitors

Metal organic framework (MOF)-based electrode materials, which could be rapidly synthesized in ambient environment with low cost but also provide a remarkable high-energy density, are ideal candidates for developing high-performance and cost-effective supercapacitors. Herein, a facile room-temperature solution-phase based method is employed for fast and large-scale synthesis of Ni/Co-based MOFs with low crystallinity, which surprisingly exhibit extraordinary charge storage capability. In particular, the Ni₂Co-MOF shows the highest structure disorder and the smallest nanosheet feature size among these MOFs, offers a specific capacity of 2149 mC cm⁻² (or 1074.5 C g⁻¹) at a discharge current of 1 mA cm⁻², and 1654 mC cm⁻² (or 827 C g⁻¹) at 20 mA cm⁻². Moreover, with Ni₂Co-MOF as the positive electrode and activated carbon as the negative electrode, hybrid supercapacitors operating at 1.6 V deliver superior energy densities of 66.1 and 41.3 W h kg⁻¹ at power densities of 800 and 8000 W kg⁻¹, respectively. The findings in this study provide a promising electrode material for high-performance supercapacitors, and possibly break a new path toward MOF material synthesis in a cost-effective way but with outstanding charge storage capability.