Synthesis of mesoporous Sn-Cu composite for lithium ion batteries

Mesoporous Sn-Cu composite consisting of Cu6Sn5 (active), Cu3Sn (inactive), and Sn is prepared by using silica SBA-15 as the hard template. As-prepared composite has a large BET surface area of 197.8 m(2) g(-1) and a large pore volume of 0.517 cm(3) g(-1). As the anode material for lithium ion batteries, no obvious capacity decay can be observed from 2nd to 20th cycles when the current density is 500 mAg(-1). It delivers much better cycling performance than bulk Sn-Cu composite without porous structure. The mesoporous structure can provide sufficient contact of the active material with the electrolyte, and can buffer volume changes of Sn in the electrochemical process. Charge transfer process is also found to be favored by using EIS measurements. (C) 2012 Elsevier B.V. All rights reserved.