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Among a large variety of energy storage technologies, supercapacitors possess special advantages such as rapid charge/discharge, high power density, safety, and environmental friendliness to meet the requirement of specific applications. The common electrode materials of supercapacitors, including porous carbon, conductive polymers, and metal oxides/hydroxides, have their own benefits and drawbacks in energy density and stability. Owing to the big surface area and controllable porosity, the metal-organic frameworks (MOFs) have been explored as important candidates for supercapacitor applications. This mini-review focuses on the recent advances of MOF-based materials including pristine MOFs, MOFs composite materials, and MOF-derived materials in the development of long cycling life supercapacitors. The devices discussed here mean those with capacitive retention rates of more than 90% after 10,000 cycles and high energy density. In addition, we also describe the fundamental knowledge of supercapacitors, highlight the stabilization mechanism of MOFs, and propose the strategies to enhance the stability of MOF-based supercapacitor electrodes. • The fundamental knowledge of supercapacitor is illustrated. • The fundamental mechanisms of MOFs stabilization are emphasized. • Recent advances of MOF-based long cycling stability supercapacitors are reviewed. • The strategies to enhance the stability of MOF-based supercapacitors are proposed. [ABSTRACT FROM AUTHOR]

A metal porous carbon (Ni@NC) supported nickel/cobalt layered double hydroxide (NiCo-LDH) (Ni@NC@NiCo-LDH) with a cauliflower morphology was synthesized by a successive double template method. At first a nickel metal-organic framework (Ni-MOF) was prepared and used as a sacrifice template to produce metal porous carbon (Ni@NC). Then the prepared conductive porous carbon material was exploited as a substrate for in-situ growing of ZIF-67 on its surface. Lastly the obtained Ni@NC@ZIF-67 was further used as a sacrifice template to prepare the final electrode material Ni@NC@NiCo-LDH by Ni2+ etching and co-precipitation. The cooperation of Ni@NC with excellent conductivity and NiCo-LDH with superior pseudocapacitive property yielded a synergistic effect, which effectively improved the electrochemical performance of the resulted electrode material. And the special flower morphology exposed more redox active sites and provided proper charge transport path for enhanced electrochemical performance. The prepared Ni@NC@NiCo-LDH exhibited a high specific capacitance of 1761.8 F·g−1 at the current density of 1 A·g−1. The assembled Ni@NC@NiCo-LDH//AC asymmetric supercapacitor also displayed an acceptable energy density (39.27 Wh·kg−1 at the power density of 757.21 W·kg−1) and ultrahigh cycling stability (94.74% capacitance retention after 25000 cycles at 10 A g−1). [Display omitted] • Ni@NC@NiCo-LDH was prepared by combination of Ni@NC and NiCo-LDH for the first time. • Ni@NC@NiCo-LDH had a big specific capacitance. • The assembled supercapacitor with Ni@NC@NiCo-LDH and AC had excellent cycle stability. [ABSTRACT FROM AUTHOR]

The application of MOF materials in supercapacitors has been greatly restricted due to the poor conductivity and structural stability. Given that, this work improves the conductivity and stability of Ni-MOF by self-assembled strategy. We report here the Mo-doped Ni-MOF nanosheets (M-NMN), in which the Mo-based clusters are encapsulated in the holes of the Ni-MOF frame structure by self-assembly. The results show that the M-NMN-1 material with a Mi/Mo molar ratio of 1: 1 exhibits an excellent electrochemical performance. Furthermore, the nanosheet structure of the M-NMN-1 materials acts as a "superhigh way" for charge transport to accelerate charge transfer rate and enhance the conductivity of the electrode materials. As-prepared M-NMN-1 electrode material exhibits high specific capacity of 802 C g−1 at 1 A g−1. Furthermore, assembled battery-supercapacitor hybrid device exhibits an excellent energy density of 59 Wh kg−1 at a power density of 802 W kg−1, and superior cycle retention of 93% after 20,000 cycles. Image 1 • Design and fabrication of self-assembled Mo-doped Ni-MOF nanosheets (M-NMN-1). • The M-NMN-1 material exhibits the improved the conductivity and stability. • The ultrahigh specific capacity of 802 C g-1 at 1 A g-1 in three electrode system. • High energy density of 59 Wh kg-1 at power density of 802 W kg-1 in hybrid device. [ABSTRACT FROM AUTHOR]