Prussian Red Anions Immobilized Freestanding Three-Dimensional Porous Carbonaceous Networks: A New Avenue to Attain Capacitor- and Faradic-Type Electrodes in a Single Frame for 2.0 V Hybrid Supercapacitors
Gunendra Prasad Ojha, Bishweshwar Pant, Jiwan Acharya, Mira Park
Abstract
The purpose behind this work is to reduce the reliance on different negative and positive electrodes and the complication of mass and charge balance for the fabrication of hybrid devices. Here, the “Prussian red” [Fe(CN)63–] anions are confined into the three-dimensional porous carbon nanofiber network as positive and negative electrodes showing outstanding electrochemical performances in an aqueous electrolyte. The Fe(CN)63– ions bridged to the positively charged carbon connected with the oxygen functional groups via the electrostatic force of attraction provide extra spatial charge storage properties to the negative terminal and pseudocapaciatance to the positive terminal. Therefore, with a difference in their charge storage mechanisms, a 2.0 V hybrid device is assembled without balancing charge and mass. Impressively, the as-fabricated hybrid device delivered an outstanding areal energy and power densities (2790 μW h cm–2 at 20 000 μW cm–2) and almost cent-percent cyclic durability (only 2.8% capacitance fade is observed). The obtained results provide an innovative idea to fabricate a hybrid device using the same material in both positive and negative terminals.