Metal-organic framework-derived hollow CoS nanobox for high performance electrochemical energy storage.

Graphical abstract Highlights • The ZIF-67-derived hollow CoS shows a high specific capacitance of 720 F g−1. • The anode and cathode of the capacitor are derived from the same precursor. • The surface capacitive contribution is dominated in hollow CoS energy storage. • Assembled capacitor shows a maximum energy density of 80 Wh kg−1. Abstract In this work, hollow CoS nanobox (noted as HCSN) have been successfully synthesized via annealing and hydrothermal process from zeolitic imidazolate framework (ZIF-67) template. When tested as positive electrode materials in alkaline aqueous electrolyte, it shows high specific capacitance of 720 F g−1 at a current density of 1 A g−1, good rate capability (82.1%) and good cycling stability with 86.4% capacitance retention over 10,000 cycles at 10 A g−1. To further demonstrate the advantages of our ZIF-67 derived materials, asymmetric energy storage device was assembled (HCSN//NC), where the as-prepared HCSN was employed as the anode and ZIF-67-derived nanoporous carbon (noted as NC) as the cathode. This device achieves high energy density (80 Wh kg−1 at a specific power density of 882 W kg−1), good rate capability (53.3 Wh kg−1 even at a specific power density of 7.9 kW kg−1) and long-term stability up to 10,000 cycles. More importantly, it could simultaneously light up 12 LEDs in parallel, demonstrating its potential in practical applications. [ABSTRACT FROM AUTHOR]