LiMnPO4 – A next generation cathode material for lithium-ion batteries

Abstract

Development of an eco-friendly, low cost and high energy density (∼700 W h kg⁻¹) LiMnPO₄ cathode material became attractive due to its high operating voltage ∼4.1 V vs. Li falling within the electrochemical stability window of conventional electrolyte solutions and offers more safety features due to the presence of a strong P–O covalent bond. The vacancy formation energy for LiMnPO₄ was 0.19 eV higher than that for LiFePO₄, resulting in a 10⁻³ times-diluted complex concentration, which represents the main difference between the kinetics in the initial stage of charging of two olivine materials. This review highlights the overview of current research activities on LiMnPO₄ cathodes in both native and substituted forms along with carbon coating synthesized by various synthetic techniques. Further, carbon coated LiMnPO₄ was also prepared by a solid-state approach and the obtained results are compared with previous literature values. The challenges and the need for further research to realize the full performance of LiMnPO₄ cathodes are described in detail.