Multi-doped spinels, namely LiMn204 and LiZnxHoyMn2 x yO4 （x=0.10-0.18; y= 0.02-0.10）, for use as cathode materials for lithium-ion rechargeable batteries were synthesized via sol-gel method, using lauric acid as th...Multi-doped spinels, namely LiMn204 and LiZnxHoyMn2 x yO4 （x=0.10-0.18; y= 0.02-0.10）, for use as cathode materials for lithium-ion rechargeable batteries were synthesized via sol-gel method, using lauric acid as the chelating agent, to obtain micron-sized particles. The physical properties of the synthesized samples were investigated using differential thermal analysis, Fourier-transform infrared spectroscopy, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy, energy-dispersive X-ray analysis, and electrochemical methods. XRD showed that LiMn204 and LiZnxHoyMn2_x y04 have high degrees of crystallinity and good phase purities. The SEM images of LiMn204 showed an ice-cube morphology with particles of size 1 μm. Charge-discharge studies showed that undoped LiMn2 O4 delivered the discharge capacity of 124 mA h/g with coulombic efficiency of 95% during the first cycle, whereas doped spinels delivered discharge capacities of 125, 120, and 127 mA h/g in the first cycle with coulombic efficiencies of 96%, 91%, and 91%, respectively.展开更多
文摘Multi-doped spinels, namely LiMn204 and LiZnxHoyMn2 x yO4 （x=0.10-0.18; y= 0.02-0.10）, for use as cathode materials for lithium-ion rechargeable batteries were synthesized via sol-gel method, using lauric acid as the chelating agent, to obtain micron-sized particles. The physical properties of the synthesized samples were investigated using differential thermal analysis, Fourier-transform infrared spectroscopy, X-ray diffraction （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy, energy-dispersive X-ray analysis, and electrochemical methods. XRD showed that LiMn204 and LiZnxHoyMn2_x y04 have high degrees of crystallinity and good phase purities. The SEM images of LiMn204 showed an ice-cube morphology with particles of size 1 μm. Charge-discharge studies showed that undoped LiMn2 O4 delivered the discharge capacity of 124 mA h/g with coulombic efficiency of 95% during the first cycle, whereas doped spinels delivered discharge capacities of 125, 120, and 127 mA h/g in the first cycle with coulombic efficiencies of 96%, 91%, and 91%, respectively.
