LiFePO4 - Activated Carbon Composite Electrode as Symmetrical Electrochemical Capacitor in Mild Aqueous Electrolyte
In this study, a symmetric electrochemical capacitor has been fabricated by adopting the lithiated compound (LiFePO4)-activated carbon (AC) composite as the core electrode materials. The electrochemical performances of the prepared supercapacitor were studied using cyclic voltammetry (CV) in 1.0 M Na2SO3 solution. Experimental results reveal that the maximum specific capacitance of 112.41 F/g is obtained in 40 wt % LiFePO4 loading on AC electrode in comparison to that of pure AC electrode (76.24 F/g) in 1 M Na2SO3. The enhanced capacitive performance of the 40 wt % LiFeO4 –AC composite electrode is believed attributed to the contribution of synergistic effect of electric double layer capacitance (EDLC) on the surface of AC as well as pseudocapacitance via intercalation/extraction of Na+, SO32-and Li+ ions in LiFePO4 lattices. The composite electrodes can sustain a stable capacitive performance at least 1000 cycles with only ~5 % specific capacitance loss after 1000 cycles. Based on the findings above, 40 wt % LiFeO4 –AC composite electrodes which utilise low cost materials and environmental friendly electrolyte is worth being investigated in more details.
Bale V. Reddy, Shishir Kumar Sahu, A. Kandasamy and Manuel de La Sen
M.Y. Ho et al., "LiFePO4 - Activated Carbon Composite Electrode as Symmetrical Electrochemical Capacitor in Mild Aqueous Electrolyte", Applied Mechanics and Materials, Vol. 627, pp. 3-6, 2014