High-performance aqueous asymmetric pseudo-supercapacitor using potassium doped Maganese oxide and resorcinol-formaldehyde aerogel for extended voltage operation

• K-δMnO 2 /RF aerogel electrode material has been fabricated successfully. • An unprecedented wide potential window of 1.6 V has been achieved for the electrode. • The working potential window of the device K-δMnO 2 /RF//AC is 2.6 V. • The chronopotentiograms exhibited the quasi-rectangular shapes with redox peaks attributed to pseudo-capacitive behavior of MnO 2 . • Superior power density 1.6 kW/Kg and energy density 251 Wh/Kg has been achieved for K-δ-MnO 2 /RF//AC. Herein, we reports the fabrication of potassium doped manganese dioxide coupled with carbon aerogel derived from donor-acceptor resorcinol formaldehyde polymer (K-⸹MnO 2 /RF) which resulted in enhanced surface area (231.064 m 2 /g), high pore volume (0.113 cc/g), enhanced charge conductivity, widened potential window of -0.1 to 2.5 V and highly redox reversible gravimetric capacitance of 663 F/g and areal capacitance 184 mAh/g. The porous carbon aerogel is believed to assist the intercalation-de-intercalation thereby, boosting the Faradic process of pseudo-capacitive performance of the heterojunction. An efficient aqueous asymmetric super-capacitor (K-δMnO 2 /RF//AC) was devised which demonstrated steady operating potential window of -0.1to 2.5 V in 1M Na 2 SO 4 aqueous solution as electrolyte. The fabricated aqueous asymmetric pseudo-super capacitor has enhanced energy density of 251 Wh/Kg Power density of 1.6 kW/Kg and specific capacitance of 322 F/g and an extended cycle execution with capacitance retention of 98% over 10,000 cycles.