Synthesis and Electrochemical Study of Calcium-Doped Spinel LiMn2O4 Cathode

Abstract

In this work, Ca-doped lithium manganese oxides Li0.98Ca0.02Mn2O4 were successfully synthesized via a facile hydrothermal method followed by calcination. The evolution of the microstructures and electrochemical performance were investigated in detail. XRD identified that pure spinel phase with the enlarged lattice constants were observed in Ca-doped samples. SEM revealed that powders had a hollow hemispherical morphology composed of stacked nanoparticles. Ca doping can improve the electrochemical performance of LiMn2O4. Galvanostatic charge-discharge tests demonstrated that Li0.98Ca0.02Mn2O4 calcined at 550°C could deliver the initial discharge capacity of 108.6 mA h/g with the capacity retention of 91.4% after 100 cycles at 2 C. The results indicate that Ca-doped LiMn2O4 is a promising cathode material.