Abstract
Li(1.27)Cr(0.2)Mn(0.53)O₂ layered cathodic materials were prepared by a nanomilling-assisted solid-state process. Whole-pattern refinement of X-ray diffraction (XRD) data revealed that the samples are solid solutions with layered α-NaFeO₂ structure. SEM observation of the prepared powder displayed a mesoporous nature composed of tiny primary particles in nanoscale. X-ray photoelectron spectroscopy (XPS) studies on the cycled electrodes confirmed that triple-electron-process of the Cr(3+)/Cr(6+) redox pair, not the two-electron-process of Mn redox pair, dominants the electrochemical process within the cathode material. Capacity test for the sample revealed an initial discharge capacity of 195.2 mAh·g(-1) at 0.1 C, with capacity retention of 95.1% after 100 cycles. EIS investigation suggested that the high Li ion diffusion coefficient (3.89 × 10(-10)·cm²·s(-1)), caused by the mesoporous nature of the cathode powder, could be regarded as the important factor for the excellent performance of the Li(1.27)Cr(0.2)Mn(0.53)O₂ layered material. The results demonstrated that the cathode material prepared by our approach is a good candidate for lithium-ion batteries.