Fabrication of Na and K based MnO2 nanocomposites for supercapacitive applications

• Published in: Heliyon Vol. 10; no. 15; p. e35360
• Main Authors: Vashisth, Priyanka, Sharma, Aditya, Nasit, Manas, Singh, Jitendra Pal, Anjali, Varshney, Mayora, Kumar, Shalendra, Won, S.O., Shin, H.J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15.08.2024; Elsevier
• Subjects: Electrochemical; Energy storage; Supercapacitor; Supercapacitor; Electrochemical; Energy storage
• ISSN: 2405-8440; 2405-8440
• DOI: 10.1016/j.heliyon.2024.e35360

α-Na0.5Mn0.93O2@Na0.91MnO2 (NaMnO) and K0.48Mn1.94O5@Na0.91MnO2 (KNaMnO) nanocomposites have been synthesized using solid-state reaction method. FESEM results convey the formation of column-shaped morphology. FTIR exhibited a shift in the vibration frequency upon potassium loading. Cyclic voltammetric curves are scanned (0 V–0.8 V) at different scan rates (5 mV/s to 100 mV/s) in 1M KOH electrolyte. Galvanostatic charge-discharge characteristics, for different current densities, have shown non-linear or pseudocapacitive characteristics of the prepared electrodes. High specific capacitance of ∼361 F/g and ∼143 F/g, at a current density of 1A/g, has been achieved for KNaMnO and NaMnO samples, respectively. KNaMnO sample exhibited higher capacitive retention (116 %), up to 2000 cycles, and obeys lower series resistance, charge transfer resistance, and Warburg impedance parameters, thus, convey higher efficiency of this compound for supercapacitor applications. •Synthesis of Na and K based MnO2 nano-composites with column-shaped morphology.•High specific capacitance of ∼361 F/g and ∼143 F/g, at a current density of 1A/g.•Capacitive retention of 116 % and 96 %, for 2000 cycles, for KNaMNO and NaMnO samples, respectively.