The transition to cleaner energy sources requires major advancements in solid-state materials for energy storage and conversion. Rechargeable lithium-ion batteries (LIBs) remain among the most promising candidates for future applications, particularly in electric mobility, due to their high energy density, stability, and low weight [1]. However, further improvements in electrode and electrolyte materials are essential for next-generation LIBs. In this seminar, I will present our research on lithium manganese phosphate (LiMnPO4), a cathode material that combines high voltage, environmental friendliness, and low cost but suffers from poor electronic and ionic conductivity. Using density functional theory (DFT) calculations, we investigated several strategies to overcome these limitations, including Ni/Fe single-doping, Ni–Fe co-doping, and biaxial strain engineering. The results reveal that Ni and Fe substitutions not only reduce the band gap and improve electronic conductivity but also lower Li-ion diffusion barriers, enhancing kinetic performance. Ni–Fe co-doping further improves structural stability, conductivity, and Li reversibility during insertion/extraction processes. Additionally, applying biaxial tensile strain significantly boosts the diffusion coefficient and reduces the band gap, leading to remarkable improvements in rate performance. These findings provide valuable insights into the design of improved phosphate-based cathode materials for LIBs.

[1] Kim et al, ACS applied materials & interfaces 12.14 (2020): 16376-16386.