| Abstract: | A skutterudite-related antimonide, CoFe3Sb12, was prepared with vacuum melting. XRD analysis showed the material contained Sb, FeSb2, CoSb2 and CoSb3 phases. The electrochemical properties of the ball-milled CoFe3Sb12-10 wt% graphite composite were studied using pure lithium as the reference electrode. A maximal lithium inserting capacity of about 860 mAh/g was obtained in the first cycle. The reversible capacity of the material was about 560 mAh/g in the first cycle and decreased to ca. 320 mAh/g and 250 mAh/g after 10 and 20 cycles respectively. Ex-situ XRD analyses showed that the antimonides in the pristine material were decomposed after the first discharge and that antimony was the active element for lithium to insert into the host material. |
