A dealloying approach to synthesizing micro-sized porous tin (Sn) from immiscible alloy systems for potential lithium-ion battery anode applications

摘要

Dealloying is a useful approach to producing microanoporous metallic materials and has been applied to the synthesis of porous noble metals such as Au, Ag, Pt and Pd from various forms of precursor materials (e.g. amorphous, solid solution, or intermetallic compound). This study shows that dealloying can also be used to fabricate porous non-noble metals like tin (Sn) from immiscible Al–Sn alloys of Al80Sn20, Al65Sn35 and Al50Sn50 (in at.% throughout the paper). The as-dealloyed porous Sn samples showed a three-dimensionally continuous porous structure throughout each sample and sufficient mechanical integrity for assembly in lithium ion battery cells as anodes. The average pore size depends on the size of the Al phase in each precursor alloy and falls in the range of 1.58 ± 0.26 to 4.09 ± 0.85 μm with respect to the three precursor alloys used. The resulting porous Sn structures can be controlled through changing the microstructure of the precursor alloy. The as-dealloyed porous Sn anode showed an outstanding initial charging-discharging capacity and a high coulombic efficiency in lithium ion battery performance tests.