Mechanically Alloyed Sn‐Fe(‐C) Powders as Anode Materials for Li‐Ion Batteries: III. Sn2Fe : SnFe3 C Active/Inactive Composites

摘要: The authors have prepared intermetallic phases and mixtures of such in the Sn-Fe-C Gibbs` triangle by mechanical alloying methods or direct melting. This third paper a three-part series focuses on composites Sn{sub 2}Fe SnFe{sub 3}C made elemental powders. grains which comprise powder particles were about 10 nm size. Seven samples composition 2}Fe, 25% (by weight) 2}Fe/75% 3}C, 24% 2}Fe/72% 3}C/4% C, 36% 2}Fe/63% 3}C/1% 45% 2}Fe/55% 66% 2}Fe/34% studied. Using situ X-ray diffraction electrochemical methods, reversible reaction Li with these materials was is an active phase, that is, it reacts completely to form Li{sub 4.4}Sn Fe, inactive very little Li. Thus, since there two-phase tie line connecting phase ternary diagram, fact generally produces small grains, possible produce compositesmore » controlled amounts phases. best material gives volumetric capacity 1600 mAh/cm{sup 3}, has average voltage near 0.4 V vs. metal, shows stable cycling for over 80 charge-discharge cycles. Materials like this may ultimately replace graphite as anode choice Li-ion battery.« less