Effect of Al-Doping on Electrochemical Performance of LiMn2O4

Abstract

Spinel LiMn2O4 and LiAlXMn2-XO4(G X , X = 0, 1, 2, 3, 4) have been synthesized by solid-state method. The synthesized samples were characterized by following methods: X-ray diffraction, scanning electron microscopy. Results showed that LiAl0.3Mn1.7O4(G 3) was spinel structure which space group was Fd3m. The spinous substances were not observed on its spherical-structured surface. Experimental battery E X (X = 0, 0.1, 0.2, 0.3, 0.4) was assembled by using G X as cathode electrode, active carbon as conductive agent and Li plate as the anode electrode. The E X (X = 0, 0.1, 0.2, 0.3, 0.4) was characterized by electrochemical impedance spectroscopy, cyclic voltammetry and charge-discharge studies. Results indicated that Al-substitution decreased the internal resistance of E X. Charge-discharge cycling studies and cyclic voltammetry test showed that Al-substitution substantially improved the capacity retention of the E X .