The electrochemical properties of hydrothermal VS2 cathodes were studied in a water-in-salt electrolyte (WISE) using zinc foil as the anode coated with a layer of carbon black. The role of the carbon coating was to inhibit the formation of dendrites, homogenizing the electric field and ion flux in the proximity of the anode, and retard the corrosion of zinc, which would cause capacity loss and decrease the cycling stability. The highly concentrated electrolyte (30m ZnCl2) was chosen to prevent the dissolution of VS2 observed in conventional aqueous electrolytes. In contrast to previous works, the dissolution of VS2 in 3M ZnSO4 was evidenced by a change in the colour of the solution, which turned bright yellow (Figure ). The strong UVvis absorption below ~ 550 nm can be attributed to the presence of VO2 + ions in the sample, resulting from the oxidation of VS2 (Figure ). In contrast, the WISE electrolyte remained clear with no evident absorption peak in the visible range, which indicates the stability of VS2 in the WISE electrolyte resulting from the absence of free uncoordinated water molecules. Cyclic voltammograms in the conventional 3M ZnSO4 electrolyte are characterized by a progressive reduction of the redox current caused by the dissolution of the active material (Figure ), whereas the current progressively increases in the WISE electrolyte, until it reaches a stable value after 5 cycles (Figure ). The WISE electrolyte also enables to access a larger potential window (1.5