In summary, we demonstrate how a two-component polyoxovanadate compound, {MV13} (nBu4N)4[MV13O33Cl] (M= V=O2 + {V14} or MgOH + {MgV13}), can be used as a stable, highperformance active compound for symmetric non-aqueous redoxflow batteries. Our studies show that under NRFB conditions in acetonitrile, {MV13} shows multiple reversible electrons transfer with excellent electron transfer kinetics. Under standard operating conditions, the system showed a coulombic efficiency of 93% at 0.6 mA cm -2 and a high stability with a capacity fading rate of 0.074% per cycle. Mechanistic studies utilizing operando UV-Vis and Raman spectroscopies provided initial understanding of the structural stability and reversible charging/discharging of {MV13} during NRFB operation. Future studies on {MV13} will be focused on exploring how to improve solubility in acetonitrile or other suitable NRFB solvents. One promising approach is cation metathesis, where introduction of long-chain alkylammonium cations might be a promising route to increase solubility. In sum, this study demonstrates how symmetric NRFBs can be designed based on suitable mixed-valent V(IV/V) polyoxovanadate clusters.