Well-developed crystalline LiNi0.5Mn1.5O4 was prepared by solid-state reaction using Li2CO3, NiO and electrolytic MnO2 at high heating and cooling rate. X-ray diffraction (XRD) patterns and scanning electron microscop...Well-developed crystalline LiNi0.5Mn1.5O4 was prepared by solid-state reaction using Li2CO3, NiO and electrolytic MnO2 at high heating and cooling rate. X-ray diffraction (XRD) patterns and scanning electron microscopic (SEM) images showed that LiNi0.5Mn1.5O4 synthesized at 900 ℃ and 950 ℃ had cubic spinel structure with clearly defined shape. LiNi0.5Mn1.5O4 spinel phase decomposed at 1 000 ℃ accompanying with structural and morphological degradation. TG measurement revealed that the weight loss during heating process could be mostly gained in cooling process, and the upward tendency of weight loss during heating process decreased, while that of irreversible weight loss rapidly increased with the increase of temperature. LiNi0.5Mn1.5O4 powders prepared at 900 ℃ for 12 h delivered the maximum discharge capacity of 134 mAh·g-1 with good cyclic performance at 2/7 C. In addition, by adjusting the calcination time at 900 ℃, the capacity and cycling performance of LiNi0.5Mn1.5O4 were further enhanced.展开更多
文摘Well-developed crystalline LiNi0.5Mn1.5O4 was prepared by solid-state reaction using Li2CO3, NiO and electrolytic MnO2 at high heating and cooling rate. X-ray diffraction (XRD) patterns and scanning electron microscopic (SEM) images showed that LiNi0.5Mn1.5O4 synthesized at 900 ℃ and 950 ℃ had cubic spinel structure with clearly defined shape. LiNi0.5Mn1.5O4 spinel phase decomposed at 1 000 ℃ accompanying with structural and morphological degradation. TG measurement revealed that the weight loss during heating process could be mostly gained in cooling process, and the upward tendency of weight loss during heating process decreased, while that of irreversible weight loss rapidly increased with the increase of temperature. LiNi0.5Mn1.5O4 powders prepared at 900 ℃ for 12 h delivered the maximum discharge capacity of 134 mAh·g-1 with good cyclic performance at 2/7 C. In addition, by adjusting the calcination time at 900 ℃, the capacity and cycling performance of LiNi0.5Mn1.5O4 were further enhanced.
