The synthesizing of porous anode materials processed via rapid solidification of Si-Sn-Al alloys for Li-ion batteries

In this study, Si x -Sn 6- Al (94− x ) ( x = 40, 50, 60, 70) alloy ribbons were obtained by melt spinning, and the ribbons were ball-milled into fine powders. The powders of −500 mesh (< 25 μ m) were screened by sieving, followed by etching the Al element to produce porous Si alloy powders. The Burnauer-Emmett-Teller surface area of the porous Si alloy powder increased with increasing Al content. On the contrary, the Batter-Joyner-Halenda pore radius decreased with increasing Al content, which was caused by the very finely solidified Al phase due to its low latent heat in addition to the effective etching to make the porous structure. Of the Si x -Sn 6- Al (94− x ) alloy powders, the porous et-Si 40 Sn 6 Al 54 powder obtained by acid etching showed the best electrochemical properties with a well-developed porous structure.