Rate Properties and Elevated-Temperature Performances of LiNi0.5 − xCr2xMn1.5 − xO4 ( 0 ≤ 2x ≤ 0.8 ) as 5 V Cathode Materials for Lithium-Ion Batteries

Abstract

A series of Cr-substituted spinel cathodes has been prepared and their electrochemical properties were characterized at different C rates and temperatures. Although the pristine showed a capacity loss from at 0.2C to at 10C at room temperature, showed capacity retention after 400 cycles under the same conditions and gave the best rate property. At , retained of its capacity after 50 cycles; 98, 92.1, and 91.7% capacities were still observed for , , and , respectively. Structural analyses and surface morphology changes show that although no second phase was detected during cycling, there is a surface rearrangement on the electrodes. Elemental analyses indicated that the Cr substitution helps to suppress the surface atomic rearrangement, which improves the electrochemical performance.