The electrochemical properties of V^2+/V^3+ and VO_2^+/VO^2+ vanadium redox couple for electrolytes with multi-walled carbon nanotube dispersed were studied in half-cell and single cell tests. The cyclic voltammetry measurement showed in high electrochemical performance proportional to the content of MWCNTs in terms of peak separation and current separation of anode and cathode reactions. The redox reaction of MWCNT according to the weight ratio of electrolyte showed performance by increasing mass transfer, surface area, and charge transfer compared to conventional graphite felt and electrolyte system in order to 0.1 wt% > 0.2 wt% > 0.05 wt% > Pristine electrolytes in the single cell. This study investigated nanofluids for improved electrochemical activity, and better reversibility and lower polarization effects using MWCNTs. The optimum flow characteristics and electrochemical properties of the electrolyte containing MWCNT particles were found to be 0.1 wt% nanofluid, which is an optimal nanofluid with high stability.