Characterization and Li reactivity of electrodeposited copper-tin nanoalloys prepared under spontaneous current oscillations

Films of nanometric Cu-Sn intermetallic compounds have been prepared by electrodeposition under spontaneous current oscillations from a single bath containing both sulfate salts and the specific inhibitor substance Amiet THD/32. Several experimental parameters have been adjusted in order to obtain an oscillatory electrodeposition having the smallest frequency and amplitude in order to favor a better tin incorporation in the deposits. From several characterizations, the film's composition can be described as a mixture of two copper-rich high-temperature solid solutions denoted delta-Cu41Sn11 and zeta-Cu10Sn3. These electrodeposits have been tested as electroactive materials vs Li and compared with the performance of micrometric tin powders. After 20 cycles, the specific capacity of the deposits vs Li is maintained at an average value of 400 mAh/g of equivalent Sn, which is approximately four times greater than what can be obtained from a powdered tin electrode. (c) 2005 The Electrochemical Society.