Supercapacitive amino-functionalized cobalt and copper metal-organic frameworks with varying surface morphologies for energy storage

Abstract

• Two MOFs with Cobalt and Copper metal centres were analysed for SC application. • Co-BDC-NH 2 display superior capacitive behaviour than Cu-BDC-NH 2 . • Co-BDC-NH 2 electrode has specific capacitance of 291 F g −1 at current density of 1 A g −1 . • Co-BDC-NH 2 preserved 86 % of its initial capacity after 1000 cycles. • Nitrogen containing Co-BDC-NH 2 electrode proved to be a promising contender for SCs. In this study, two amino functionalized metal-organic frameworks, Co-BDC-NH 2 and Cu-BDC-NH 2 , using Cobalt and Copper as a metal sources were synthesized, extensively characterised, and employed as an electrode material in supercapacitors (SCs). Their synthesis provides an affordable and cost-effective technique in the energy sector because these MOFs are created from an inexpensive and easily accessible metal salts and ligands. FTIR, Raman, PXRD, TGA, FESEM, TEM and XPS analysis confirm the formation of Co-BDC-NH 2 and Cu-BDC-NH 2 . Co-BDC-NH 2 as an electrode material shows great cycling stability, high specific capacitance (291 F g −1 at 1 A g −1 ), high energy and power density as compared to Cu-BDC-NH 2 . The Co-BDC-NH 2 //3MKOH//Co-BDC-NH 2 symmetric supercapacitor has an energy density of 1.67 W h kg −1 with a power density of 299.7 W kg −1 at 1 A g −1 current density whereas the Co-BDC-NH 2 //3MKOH//AC asymmetric supercapacitor delivered a maximum energy density of 17.6 Wh kg −1 at a power density of 746 W kg −1 within the voltage range of 0 to 1.5 V, which are higher than those of PCN//AC BSH devices (16.0 Wh kg −1 at 749 W kg −1 ). Furthermore, there was a consistent cycling performance of ∼ 86 % capacitance following 1000 cycles for symmetric supercapacitor. These findings indicate that Co-BDC-NH 2 with rich nitrogen content forms a promising basis for improving high-performance electrochemical energy storage systems, and that such materials are extremely attractive for future energy advancement.