Enhancing the electrochemical and mechanical performance of LiFePO4 cathode material by ternary doping of Mn, Ti, and N

Abstract

This study employs a first-principles approach based on density functional theory to analyze the electrochemical and mechanical properties of LiFePO4 system with Mn, Ti, and N ternary doping. Computational findings reveal a formation energy of −1.98 eV, affirming excellent stability. Doping generates impurity bands, reducing the bandgap to 1.21 eV and enhancing conductivity. Doping significantly improves Li-ion diffusion, increasing the coefficient by 6 orders of magnitude and reducing the energy barrier by 0.35 eV. Moreover, Ti doping induces favorable local structural changes and enhances Li-ion diffusion. Mechanical performance calculations indicate improved stability, toughness, and isotropy. Ternary doping raises de-lithiation voltage, optimizing charge–discharge curves without compromising the capacity of LiFePO4, enhancing electrochemical performance.