Samples of Sn30TM30C40 and of Sn30Co15TM15C40, with TM=3d transition metals, were prepared by vertical-axis attritor milling. The structure and performance of these samples were studied by X-ray diffraction (XRD) and by electrochemical testing. The XRD patterns of Sn30TM30C40 show an amorphous-like diffraction pattern only for the sample with TM=Co. The other prepared samples show broadened Bragg peaks of their main starting material, along with an amorphous-like background, even after 32h of milling. Samples with TM=Co and TM=Ni show stable differential capacity versus potential plots and stable cycling for at least 100 cycles with reversible capacities of 425 and 250mAhg−1, respectively. All samples prepared with 15at.% Co show good capacity retention for at least 100 cycles ranging from 270mAhg−1 for samples with TM=Ni to 500mAhg−1 for samples with TM=Ti. The differential capacity versus potential plots for all the prepared Sn30Co15TM15C40 samples show similar structure to that of Sn30Co30C40 except when TM=Cu. This shows the possibility of preparing tin-based negative electrode materials using a combination of cobalt and TM, especially if one looks to reduce the cobalt content.