One-step growth of additive free Ni-BDC electrode as high performance asymmetric supercapacitor device

Abstract

The pristine nickel metal-organic framework (Ni-BDC) without the inclusion of any external agents has been successfully synthesized by the solvothermal method because of its excellent conductive frame network and electrochemical activities. Electrochemical investigations unveiled that the synthesized Ni-BDC exhibited outstanding specific capacity, reaching an impressive 707.85 C/g at 1 A/g, a record-breaking achievement within the realm of pristine Ni-BDC materials, as per our comprehensive analysis. Synthesized material demonstrates capacity persistence of 75.5 % across 2200 charge-discharge rotations at 10 A/g. The microsheet-like structure of Ni-BDC enhances the number of electrochemically active sites and suppresses the distance for ion intercalation and deintercalation, thereby enhancing its electrochemical performance. Furthermore, to delve into the practical applications of Ni-BDC in real-world scenarios, we have fabricated a Ni-BDC//AC-based asymmetrical supercapacitor device. At a current density of 2 A/g, the asymmetric device has an optimum capacitance (244.3 F/g at 2 A/g) with a high specific energy of 66.5 Wh/kg at a specific power value of 579.6 W/kg. The device demonstrates a remarkable 91.6 % capacitance retention at 8 A/g throughout 4500 GCD cycles. After charging the Ni-BDC//AC asymmetric device for just 1 min, it successfully powered a green LED light for 47 min by combining three devices in a series. These findings collectively suggest that Ni-BDC is a viable material for electrodes with fantastic characteristics for supercapacitors.