摘要:
采用第一性原理超软赝势平面波方法计算了Sn3InSb4的嵌Li性能,得到各种嵌Li相的嵌Li形成能、理论质量比容量、体积膨胀率、能带结构、态密度和差分电荷密度等.从能量角度分析,Li在嵌入时,优先占据晶胞的四面体间隙位置,然后逐步挤出处于节点位置的Sn原子和In原子.在嵌Li过程中,材料表现出较大的体积膨胀率（11.74%—43.40%）,这是导致Sn3InSb4作为Li离子电极材料循环性能差的重要原因.态密度计算表明,体系的导电性能首先随嵌Li量的增加而增加,当所有的间隙位置被Li填满,发生Sn的替换反应时,富Li态合金相的导电性反而下降.
Abstract:
The mechanism of Li insertion into Sn3InSb4 alloy is investigated by means of the first-principle plane-wave pseudo-potential method.The lithium intercalation formation,the theoretical capacity,the volume expansion ratio and the electronic structures are calculated.In the intercalation process,lithium atoms firstly fill the interstitial sites,and then lithium atoms continue to replace the metal atoms.Large expansion ratio from 11.74%to 43.40%would lead to the bad cycle stability for Sn3InSb4 alloy as the lithium battery electrode material.The conduct electricity is improved with lithium content increasing,then the conduct electricity decreases with interstitial sites being filled with lithium atoms and Sn-replacement reaction occurring.
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