We plotted the voltage profiles for Ti 2 CSTA x MXenes as a function of x as shown in Fig. . For the whole range of ion content (x = 0 -2), the Li electrodes has much higher voltages compared to their Mg counter parts. Table provides the average (V avg ) and maximum (V max ) voltages of each electrode. V max of both Li electrodes are around 2 V and V avg values lie between 0.85-1.017 V. Li adsorbed Ti 2 CS 2 also provide about 2 V as V max and around 1 V as V avg . V avg of Li adsorbed Ti 2 NS 2 is around 0.64 V, which is smaller than that of Ti 2 CS 2 and Ti 2 CST MXenes . Total Energy (eV/f.u) V avg voltages of Ti 2 CST monolayers are greater than that of M 2 CS 2 MXenes, where M = V, Nb, Ta, Cr, Mo and W . Mg adsorbed Ti 2 CST electrodes exhibit 4 times smaller maximum values (≈ 0.4 -0.5 V) relative to Li adsorbed that electrodes. V avg of Mg adsorbed structures are very small, which are less than 0.3 V. The previous studies also reported that Mg adsorbed S-functionalized Ti 2 C MXenes have very low voltages. Mg adsorbed Ti 2 CSO and Ti 2 CSSe electrodes provide approximately the same average voltage (0.2V) as that of Ti 2 CS 2 monolayers (0.1 V) . Thus, by functionalizing single or both sides of Ti 2 C MXenes with S, we can expect low voltages for Mg electrodes. Those Mg electrodes can be suitable as anodes to keep high voltage differences in batteries.