Novel intermetallic materials are provided that are composed of tin and one or more additional metal(s) having a formula M(1-x)-Sn5, where −0.1≦x≦0.5, with 0.01≦x≦0.4 being more preferred and the second metallic element (M) is selected from iron (Fe), copper (Cu), cobalt (Co), nickel (Ni), and a combination of two or more of those metals. Due to low concentration of the second metallic element, the intermetallic compound affords an enhanced capacity applicable for electrochemical cells and may serve as an intermediate phase between Sn and MSn2. A method of synthesizing these intermetallic materials is also disclosed.