Hydrothermal synthesis of manganese phosphate/graphene foam composite for electrochemical supercapacitor applications.

Author(s) Mirghni, A.Abdallah; Madito, M.Jack; Masikhwa, T.Moureen; Oyedotun, K.O.; Bello, A.; Manyala, N.
Journal J Colloid Interface Sci
Date Published 2017 May 15
Abstract

Manganese phosphate (Mn3(PO4)2 hexagonal micro-rods and (Mn3(PO4)2 with different graphene foam (GF) mass loading up to 150mg were prepared by facile hydrothermal method. The characterization of the as-prepared samples proved the successful synthesis of Mn3(PO4)2 hexagonal micro-rods and Mn3(PO4)2/GF composites. It was observed that the specific capacitance of Mn3(PO4)2/GF composites with different GF mass loading increases with mass loading up to 100mg, and then decreases with increasing mass loading up to 150mg. The specific capacitance of Mn3(PO4)2/100mg GF electrode was calculated to be 270Fg(-1) as compared to 41Fg(-1) of the pristine sample at a current density of 0.5Ag(-1) in a three-electrode cell configuration using 6M KOH. Furthermore, the electrochemical performance of the Mn3(PO4)2/100mg GF electrode was evaluated in a two-electrode asymmetric cell device where Mn3(PO4)2/100mg GF electrode was used as a positive electrode and activated carbon (AC) from coconut shell as a negative electrode. AC//Mn3(PO4)2/100mg GF asymmetric cell device was tested within the potential window of 0.0-1.4V, and showed excellent cycling stability with 96% capacitance retention over 10,000 galvanostatic charge-discharge cycles at a current density of 2Ag(-1).

DOI 10.1016/j.jcis.2017.01.098
ISSN 1095-7103
Citation Mirghni AA, Madito MJ, Masikhwa TM, Oyedotun KO, Bello A, Manyala N. Hydrothermal synthesis of manganese phosphate/graphene foam composite for electrochemical supercapacitor applications. J Colloid Interface Sci. 2017;494:325-337.