Abstract <p>This paper presents the results of studying the effect of partial substitution of Fe by Mn in the TiFe alloy used as a hydrogen storage material. The phase composition of the obtained alloys was studied using X‑ray diffraction, and the elemental composition and microstructure of the samples were studied using a scanning electron microscope. The samples were obtained by electron-arc melting; however, when studying the phase composition of the samples, the nonhydride-forming phase TiFe₂ and the oxide phase Ti₄Fe₂O were detected. A thermohydrogen dispersion technique was also developed. According to the data obtained, a partial substitution of iron by manganese in the amount of 2.6 at % reduces the enthalpy by 15% compared to the initial value, and the activation temperature, from 400 to 100°C. This effect is achieved by increasing the lattice parameters, since during substitution, atoms of a smaller radius (<i>R</i>_Fe = 1.24 Å) are replaced by manganese atoms of a larger radius (<i>R</i>_Mn = 1.35 Å). In addition, such a replacement makes it possible to increase the hydrogen capacity of the alloy from 1.2 to 1.4 wt %. The results obtained in this study can be used in the future for the development of hydrogen storage materials.</p>