Mg₂Sn as a New Lithium Storage Intermetallic Compound

Abstract

To obtain a new anode material of lithium battery, electrochemical properties were investigated on Mg₂Sn intermetallic compound synthesized by mechanical alloying (MA) method. As a result, we found that the reversible insertion-extraction of a large amount of lithium can electrochemically occur in mechanically alloyed Mg₂Sn. The Mg₂Sn changed its own crystal structure from cubic to orthorhombic with increasing MA time. The compound exhibiting good performances as an anode had a mixture of cubic and orthorhombic phases. The discharge capacity of the Mg₂Sn electrode was still maintained at 250-300 mA h g⁻¹ even after the 20 times charge-discharge cycling. The reaction proceeded without any phase separation and/or decomposition of the compound. Mg₂Sn would be a promising anode material for lithium secondary batteries.