In situ encapsulation of tin oxide and cobalt oxide composite in porous carbon for high-performance energy storage applications

• Published in: Journal of electroanalytical chemistry (Lausanne, Switzerland) Vol. 817; pp. 217 - 225
• Main Authors: Pal, Bhupender, Krishnan, Syam G., Vijayan, Bincy Lathakumary, Harilal, Midhun, Yang, Chun-Chen, Ezema, Fabian I., Yusoff, Mashitah Mohd, Jose, Rajan
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.05.2018; Elsevier Science Ltd
• Subjects: Charge Storage Materials; Chemical synthesis; Cobalt oxides; Electrochemical analysis; Electrochemical double layer capacitors; Electrochemical impedance spectroscopy; Electrodes; Electrolytes; Encapsulation; Energy storage; Hybrid Capacitors; Ionic mobility; Pseudocapacitors; Renewable Energy; Scanning electron microscopy; Sodium sulfate; Tin dioxide; Tin oxides; X ray powder diffraction; X-ray diffraction; Electrochemical double layer capacitors; Hybrid Capacitors; Renewable Energy; Charge Storage Materials; Pseudocapacitors
• ISSN: 1572-6657; 1873-2569
• DOI: 10.1016/j.jelechem.2018.04.019

Herein, we report the preparation of porous carbon from palm kernel shell and loading of tin oxide‑cobalt oxide in its pores using a facile in-situ encapsulation synthesis strategy. The as-synthesized SnO2/Co3O4@C composite was characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy and field-emission scanning electron microscopy techniques. This composite was used as an electrode for supercapacitors. Electrochemical charge storage capabilities of the composite were measured using cyclic voltammetry, charge-discharge cycling and electrochemical impedance spectroscopy in aqueous 6 M KOH and 1 M Na2SO4 electrolytes. The SnO2/Co3O4@C composite showed over 70% higher specific capacitance (177 F g−1) than the pure porous carbon (106 F g−1) in 6 M KOH. Among these electrolytes, the composite exhibited an enhanced electrochemical performance in KOH electrolyte due to its smaller hydrated ion radius, high ionic mobility and lower equivalent series resistance than Na2SO4. [Display omitted] •In situ encapsulation of tin oxide and cobalt oxide in porous carbon.•The SnO2/Co3O4@C composite showed 70% higher CS than porous carbon in 6 M KOH.•Best electrochemical behaviors are shown in 6 M KOH electrolyte than 1 M Na2SO4.•The SnO2/Co3O4@C composite showed lower resistance in 6 M KOH than 1 M Na2SO4.•The mobility and conductivity of hydrated ions play vital in electrode performance.