CHARACTERIZATION OF NANOSTRUCTURE TIN ALLOYS AS ANODES IN LITHIUM-ION BATTERIES

摘要

Several tin-antimony nano-structure alloys were electroplated from an acid bath on a copper foil. They have been characterized as potential high capacity anodes for lithium-ion battery applications. SEM micrographs of these alloys reveal nano ― size particles, which aggregate into larger agglomerates of fractal shapes. The composition of one series of alloys was Sn:Sb atomic ratio 1.4:1 to 9:l; another alloy consisted of Sn:Sb:Cu in atomic ratio 34:10:4. All contained about 5% carbon and about 20% oxygen. Alloys with low antimony content have high reversible capacity (up to 700mAh/g), low irreversible capacity (about 24%), a better rate capability, and a lower average working potential vs. Li, whereas alloys rich in antimony have longer cycle life, but poor rate capability and a high average working potential vs. Li. The addition of copper to the alloy improved cycle life and reduced irreversible capacity.