Stable metal-organic frameworks with Zr6 clusters for alkaline battery-supercapacitor devices

An alkaline-stable Zr-based material, PCN-777, has been elected and solvothermally prepared by reacting ZrOCl2 with the tripodal linker 4,4′,4″-s-triazine-2,4,6-triyl-tribenzoate (H3TATB). This powder material exhibits an irregular octahedron motif, providing good stability and high-power density when it is employed as electrode material for supercapacitors (SCs). The results indicate that the specific capacity, under a three-electrode configuration, is 291.9 C g−1 at a current density of 1.5 A g−1 obtained from the chronopotentiometry charge-discharge test. Assembled into a two-electrode system with activated carbon (AC) negative, the corresponding battery-supercapacitor device denoted as PCN-777//AC delivers a specific capacitance of 48.72 F g−1 at the constant current-density value of 0.5 A g−1. Besides, this device delivered a maximum energy density of 17.3 Wh kg−1 within the power-density value of 399 W kg−1, an excellent alkaline-endurance life during 2000 unceasing cycles and practical applications in powering LEDs, suggesting the potential practicality under strong alkaline surroundings. Furthermore, the structural alteration before and after long-term cycling has also been investigated. An alkaline-stable Zr-based material, PCN-777, has been fabricated and utilized as SCs active electrode, and the relationship between structural changes and stability before and after cycling has also been investigated. [Display omitted] •An alkaline-stable Zr-based material has been documented for supercapacitor electrodes.•Assembling with the activated carbon negative electrodes to obtain the device that can deliver high energy density and power density.•The structural alteration before and after long-term cycling has also been investigated.