Electrochemical evaluation of fluorination treatment on MNO2 surfaces

• Main Author: Siti Nur Najwa, Mohd Yusof
• Format: Undergraduates Project Papers
• Language: English
• Published: 2016
• Subjects: Q Science (General)
• Online Access: http://umpir.ump.edu.my/id/eprint/19494/1/Electrochemical%20evaluation%20of%20fluorination%20treatment%20on%20MNO2%20surfaces.pdf; http://umpir.ump.edu.my/id/eprint/19494/

Supercapacitors (SCs) also known as electrochemical capacitor functioning as alternative energy storage is required in most electronic devices, renewable energy system and also in hybrid vehicles that have high demand in these days. Excellent electrochemical performance, environment friendliness and low cost material are needed to fulfil the energy demand by most developed country. In this study, fluorination treatment on manganese oxide (MnO2) is considered as an effective way to develop better energy storage due to its high electronegativity and reactivity when correlate with other element. Hydrothermal method is used to synthesis fluorinated MnO2 sample and the effect of variation of MnO2 type to precursor ratio is investigated on the charge storage ability. The crystallinity and functional groups of the samples was confirmed by the X-ray diffractometry and Fourier transforms infrared spectroscopy (FTIR). The cyclic voltammetry (CV) and galvanostatic charging–discharging (CDC) analysis in 0.5 M K2SO4 electrolyte shows that F-δ-MnO2 gives the highest Cs value of 183.012 F g-1 at scan rate of 5 mV s-1 and 65.04 F g-1 at current density of 0.3 A g-1. The electrochemical impedance spectroscopy shows that the F-δ-MnO2 has the lowest electrode resistances and charge transfer resistance which contributes to high Cs and the high conductivity of electrode. Hence, F-δ-MnO2 is better electrode material for supercapacitors compared to α-MnO2, δ-MnO2 and F-α-MnO2.