Delineating the kinetic limitations of Mn 2+/3+ redox in LiMn x Fe 1− x PO 4 cathodes for lithium-ion batteries

Novel operando impedance spectroscopy methods conducted on various LiMn x Fe 1− x PO 4 (LMFP) cathodes reveal the asymmetric behavior of the Mn 2+/3+ redox couple. Significant impedance growth during Mn 2+ oxidation in high-Mn LMFP limits its performance.