Li-Sn合金负极材料的嵌脱锂机理研究

Investigation of lithiation/delithiation mechanism in lithium-tin alloys for anode materials

采用基于密度泛函理论的第一性原理平面波赝势方法计算了Li-Sn各种合金相的物理性质和电化学性质,计算发现Li5Sn2相对膨胀率小、对可逆容量贡献大,是理想的合金电极相.同时采用直流和射频磁控溅射方法制备了纳米Sn薄膜电极,并将测得的电化学特性与计算得到的性能进行了比较,发现理论计算的嵌锂电位与实验测得的嵌锂电位具有较好的一致性.

An ab initio method with the first-principles plane-wave pseudopotentials based on the density functional theory has been used to calculate the physical character and electrochemical performance of various alloy phases in Li-Sn alloy. The results show that Lis Sn2 alloy phase, with relatively small volume expansion ratio and large reversible capacity, is an ideal alloy electrode phase. On the other hand, many kinds of tin thin film electrodes were fabricated by direct current and radio frequency magnetic sputtering on copper foil collector as anode materials for lithium-ion batteries. The values of calculated Li intercalated potential using the CASTEP program are well consistent with the experimental values.