Porous cobalt metal-organic framework with ultracapacitor activity

[Display omitted] •One pot synthesis of porous hydrated cobalt organic frameworks (HCoMOF).•High capacitance of 446.6 F g−1 at 1 A g−1 for HCoMOF.•Superb stability as 97.1% capacity retains for 2000 cycles at 2.5 A g−1 for HCoMOF.•High-performance rouses by their micro/mesopores of particles with hydrous regions. Porous hydrated cobalt-based metal-organic framework (HCoMOF) was prepared as high storage ultracapacitor electrode for the first time. HCoMOF showed specific capacitance of 446.6 F g−1 at 1.0 A g−1 and superior stability of 97.1% capacity retention after 2000 cycles at 2.5 A g−1 using a three-electrode configuration in 1.0 M H3PO4 aqueous electrolyte. The maximum energy density of 89.3 Wh kg−1 achieves at a power density of 431.8 W kg−1 using the current density of 1.0 mA g−1. Excellent performance attributed to the presence of micro/mesopores of particles and hydrous regions in materials that provides sufficient space for storage and electrolyte diffusion.