Electrochemical properties of melt-spun Al-Si-Mn alloy anodes for lithium-ion batteries

Al60-XSi40MnX (X=0, 1, 3, 5, 7 and 10at.%) ribbons were prepared by melt spinning. A supersaturated solid solution of Si and Mn in fcc alpha-Al with very fine microstructures have been obtained in the ribbons. The electrochemical measurements have revealed that the Al-Si-Mn alloys with some compositions can exhibit a high Li inserting specific capacity and stable cycle performance. A specific capacity of more than 500 mAh g(-1) and the cycle efficiency of 90% have been achieved in melt-spun Al55Si40Mn5 and Al53Si40Mn7 alloys after 10 cycles. An ordered phase, delta' (Al3Li), seems to be formed in the alloys after Li inserting, whereas no other Compounds with Li have been detected. It is evident that the supersaturated solid solution plays the main role in improving the specific capacity and cycle performance. Refinement of grains could facilitate the diffusion of Li atoms. The coexistence of multi-phases has limited the alloy volume expansion during Li inserting. As a result, a high-specific capacity and a stable cycle performance have been achieved. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.