A First‐Principles Study of Anion Doping in LiFePO₄ Cathode Materials for Li‐Ion Batteries

Abstract

Doping anions into LiFePO4 can improve the electrochemical performance of lithium‐ion batteries. In this study, structures, electronic properties and Li‐ion migration of anion (F−, Cl−, and S2−) doping into LiFePO4 were systematically investigated by means of density functional theory calculations. Anion substitution for oxygen atoms leads to an expansion of the LiFePO4 lattice, significantly facilitating Li‐ion diffusion. For Cl− and F− anion doped into LiFePO4, the energy barrier of Li‐ion migration gets lowered to 0.209 eV and 0.283 eV from 0.572 eV. The introduction of anions narrows the forbidden band of LiFePO4, enhancing its electronic conductivity. This work pays a way towards the rational design of high‐performance lithium‐ion batteries.

Beyond conventional batteries: a review on semi-solid and redox targeting flow batteries-LiFePO4 as a case study

“…Several strategies have been developed to overcome the aforementioned issues such as particle size reduction, 35–37 surface coating, 38–41 preparation of composite electrodes, 42–44 addition of conductive binders, 45–47 and doping. 48–51 All these strategies have shown encouraging results in lithium-ion batteries, but less attention has been given to the application of these advanced LFP based materials for redox flow batteries. The development of LFP with advanced morphological and electronic properties could be a good direction to improve the performance of LFP based RFBs.…”