Gadolinium-based olivine phosphate for upgradation of cathode material in lithium ion battery

Abstract

A structurally modified cathode material for Lithium ion battery is reported in this study. This study was based on first principle calculations to study the electronic, ionic, and diffusion properties of olivine phosphate family of cathode material. The attempt was made to modify the conventionally used cathode material LiFePO4 by substituting Rare earth Gd on Fe sites. The Gd-4f’s electrostatic interaction, exchange coupling, impact on lithium’s intercalation, and ability to modify the crystal structure upon doping in the crystalline environment of the host have been studied and discussed in detail. The calculations on electronic structure, charge transfer between atoms, Li intercalation voltage, electron localization function (ELF) analysis, steric interaction between Li ion and metal cation (Fe and Gd) in both LiFePO4 and LiGdPO4 were carried out using prescribed methods. This trend of intercalation is related to structural relaxation in the vicinity of Gd which expedites the Li ion mobility without compromising the structural stability of the material. The analysis of interatomic steric interactions and ELF analysis helped to visualize the interactions in the cathode material. The findings of this study revealed that LiGdPO4 could be a potential candidate for its use as cathode in lithium ion battery and relevant devices.