使用基于平面波展开的第一原理赝势法,计算了锂离子电池非碳基负极材料Li2.5 Cu0.5N在各种脱锂量下的“脱嵌形成能以及相应的体积变化,讨论了脱锂前后材料的电荷密度,电子状态密度等电子性质.计算表明,Li2.5Cu0.5N晶体中LiN层的锂的脱出能要比LiCu层的锂小得多,即LiN层中的锂更容易脱嵌.结果还表明,各种脱锂量的Li脱嵌能大致在-2.72~-4.08eV/Li2之间,当脱锂量小于30%,材料的体积变化较小,随着脱锂量的增大,材料的体积变化较大.
The ab initio pseudopotential method with the plane wave expansion of the crystal wavefunction was employed to study the non-carbon-basing anode material Li2.5 Cu0.5 N for lithium ion batteries. The lithium deintercalation formation energies and the corresponding changes of crystal volumes under various amounts of lithium deintercalations are presented. The charge densities and the electronic density of states for the lithium extraction in Li2.5 Cu0.5 N are also discussed. The calculation results show that the Li extraction in the LIN layer is much easier than that in the LiCu layer. The deintercalation formation energies per lithium are around -2.72 eV to -4. 08 eV for different amount of lithium extracted. The changes of volume are small for lithium extraction at 〈30 %, however,the changes are large when the extractions are further increased.