文摘
LiAlO2-surface modified LiMn1.58Ni0.42O4 spinel cathode materials have been prepared by coating Al2O3 on Mn0.79Ni0.21CO3 precursors, followed by post-sintering with Li2CO3 at 900?¡ãC. X-ray diffraction and FT-IR analyses indicate that during the calcination process aluminum ions not only react with Li2CO3 to form a strengthened LiAlO2 coating layer but also migrate from the surface into the spherical particles. The LiAlO2-surface modified LiMn1.58Ni0.42O4 samples exhibit excellent electrochemical performance compared to that of the bare one in terms of rate capability and cyclability. In particular, the 1?mol. % LiAlO2-surface modified sample can deliver a discharge capacity of 100.6?m?Ah?g?1 even at a high current density of 4?C-rate, while the bare one only has a discharge capacity of 49.5?m?Ah?g?1. At 55?¡ãC, the 1?mol. % LiAlO2-surface modified LiMn1.58Ni0.42O4 sample shows outstanding cyclability with less than 5 % capacity fade after 150 cycles. Based on these results, coating on the precursors to prepare a strengthened LiAlO2 coating layer would be a promising method to enhance the electrochemical performance of 5?V spinel cathode materials.