The reversible intercalation of cadmium into the ternary phase In2Mo15Se19 was realized electrochemically at 60°C. This over-intercalation increases the cell volume and expands the channels which contain In+ and Cd2+ cations. The increase in the size of the cavities is favourable to total cadmium and to partial indium deinsertion during anodic scans. We made several intercalation cycles and after about thirty cycles, the indium was totally removed from the host lattice at the deinsertion step of the scans. The ß-Mo15Se19 binary has thus been obtained for the first time at low temperature.