Samples of a SnCoC-based electrodes, all having the molar composition Sn40Co40C20, but differing by the high energy ball milling synthesis conditions, have been tested in lithium cells. The investigation was carried out by using a series of complementary techniques, including potentiodynamic cycling with galvanostatic acceleration, galvanostatic charge–discharge cycling and impedance spectroscopy. The results confirmed the high capacity delivery of this type of ternary electrodes but also revealed that their electrochemical behaviour is influenced by the relative abundance of the nanosized domains of CoSn and CoSn2 in their structure.