Synthesis and Electrochemical Performance of Urea Assisted Pristine LiMn2O4 Cathode for Li Ion Batteries

Resumo

We report the synthesis of electrochemically active LiMn₂O₄ nanoparticles at varied temperature and pH values by sol–gel method using urea as a chelating and combusting agent. The effect of pH and annealing temperature on the structure, morphology and electrochemical performance was evaluated. The results obtained by XRD, SEM, TEM, and FTIR show that LiMn₂O₄ has uniform porous morphology and highly crystalline particles that can be obtained at pH 7.0 and 8.0 and at a relatively lower temperature of 600°C. Cyclic voltammetry measurements showed reversible redox reactions with fast kinetics corresponding to Li ions intercalation/deintercalation at 600°C at neutral pH 7.0. Charge/discharge studies carried out at a current rate of 40 mA g^–1 reveal that LiMn₂O₄ synthesized at 600°C and pH 7.0 has the best structural stability and excellent cycling performance.