Suppression of Jahn–Teller distortion of spinel LiMn2O4 cathode

Jahn–Teller distortion is one of the most important reasons of capacity fade for spinel LiMn2O4 as cathode material for lithium ion batteries. In this work, we proposed an approach to prepare the modified spinel LiMn2O4 to suppress this distortion. Transmission electron microscopy (TEM) indicated that the LiNixMn2−xO4 shell/LiMn2O4 core particle was successfully formed. The modified LiMn2O4 results in the lattice shrinkage and increases Mn–O bond strength, improving the spinel structural stability. During charge and discharge cycle, the modified LiMn2O4 is beneficial to the suppression of Jahn–Teller distortion at the surface of LiMn2O4 particles, which is confirmed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analysis. This suppression of Jahn–Teller distortion is attributed to the shell of LiNixMn2−xO4 solid solution formed on the surface of LiMn2O4 particles.