Core-shell structured lead sulfide encapsulated Co-MOF as a battery-type electrode for supercapattery

A novel combination of PbS with ZIF-67 as a core-shell structured nanocomposite has been prepared by simple in- situ chemical method. The physical and chemical properties of prepared nanocomposites have been analysed by XRD, FTIR, FESEM-EDS and HRTEM analyses. The prepared core-shell nanocomposites exhibit remarkable electrochemical characteristics as an electrode in redox additive electrolyte (RAE) with an impressive specific capacitance and excellent cycling stability with 84.32 % retention after GCD 10,000 cycles. The PbS@ZIF-67 nanocomposite exhibited a highest specific capacitance of 450.59 F g- 1 (1 A g- 1) and 1442.86 F g- 1 (6 A g- 1) for KOH and RAE, respectively. By employing RAE to operate at current densities up to 70 A/g, the shape of the GCD profiles remains unchanged, therefore enhancing the rate capability even at elevated current densities. The core-shell nanocomposites have an energy density of 10.82 Wh kg-1 with a power density of 176.82 W kg- 1. A higher capacitance retention of 80.61 % after 10,000 cycles is indicated by the practical application for the fabricated device.