Effects of doping on the electronic properties of LiFePO4: A first-principles investigation

Electronic structures of pure and doped LiFePO4 have been thoroughly investigated by first-principles calculations. The effects of doping at either cation or anion sites of LiFePO4 on both crystal structure and electronic structure were mainly presented. Such ions doping did not change significantly the crystal structure of LiFePO4, except slightly altered the lattice parameters and unit cell volume. It has been found that LiFePO4 was most affected by F ion doping at O site with the narrowest band gap, followed by Mn ion doping at Fe site, and Na ion doping at Li site. The calculated results indicate that appropriate ion doping in LiFePO4 could improve its electronic conductivity.