First principles investigation on the elastic and electronic properties of Mn, Co, Nb, Mo doped LiFePO4

In this work, the mechanical stability and electronic property of LiFePO4 doped with Mn, Co, Nb and Mo studied using the first principles calculation. The doped LiFePO4 has low defect formation energy and meets the criterion of mechanical stability, indicating that the doping of the four 3d transition metals can be stable. Band structure calculations depict half-metallic nature of the doping system. By calculating the Debye temperature and Poisson's ratio, it is found that the dopants can improve the mechanical stability of LiFePO4. In addition, the study of the anisotropy of the material also shows that the doping of Co can make the material tend to be more isotropic. The above shows that the doping of Mn, Nb, Mo, especially Co, can improve the mechanical stability of the material and reduce the degree of anisotropy of the material, thereby reducing the risk of microcracking and shear deformation of the material.