The reaction of lithium with Sn-Mn-C intermetallics prepared by mechanical alloying

Intermetallic phases and mixtures of intermetallic phases in the Sn-Mn-C ternary system were prepared by mechanical alloying. The reaction of lithium with these phases was studied using in situ X-ray diffraction and electrochemical methods. Studies concentrated on Sn2Mn, SnMn1.77, SnMn3, and SnMn3C. Nanoscale two-phase mixtures of Sn2Mn/SnMn1.77 and Sn2Mn/SnMn3C were also prepared and studied. When Sn2Mn is mixed with sufficient amounts of a second phase, electrodes capable of delivering over 200 mAh/g for more than 50 cycles can be prepared. Grain boundary tin atoms in nanostructured SnMn3C appear to be able to react reversibly with lithium for hundreds of cycles. (C) 2000 The Electrochemical Society. S0013-4651(00)03-042-1. All rights reserved.