Ti-doped nonstoichiometric LiFePO4, i.e. Li0.95Fe0.95Ti0.05PO4 was synthesized by solid-state reaction method. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM...Ti-doped nonstoichiometric LiFePO4, i.e. Li0.95Fe0.95Ti0.05PO4 was synthesized by solid-state reaction method. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM) and electrochemical charge and discharge tests were used to characterize the as-prepared sample. The results indicate that Li0.95Fe0.95Ti0.05PO4 used as the cathode material for lithium-ion battery exhibits improved cyclic stability and rate capability than those of undoped LiFePO4. 150 mAh·g-1 of discharge capacity was achieved at 0.1 C (17 mA ·g-1) at room temperature.展开更多
A series of single phase LixNi0.8-yCo-（0.2）ZnyOp （0.96 ≤ x ≤ 1.10, 0 ≤ y ≤ 0.05, 2 ≤ p ≤ 2（1+ y） ） （different in the y values） were synthesized by a two step solid state reaction method, in which LiOH...A series of single phase LixNi0.8-yCo-（0.2）ZnyOp （0.96 ≤ x ≤ 1.10, 0 ≤ y ≤ 0.05, 2 ≤ p ≤ 2（1+ y） ） （different in the y values） were synthesized by a two step solid state reaction method, in which LiOH· H2O, Zn doped spherical Ni（OH）2 and Co2O3 were used as the precursors. The ICP AES analyses proved that the Zn doped compounds synthesized had the nonstoichiometric form. The results of the XRD, SEM identified that the uniform particles of the as prepared materials having a good layered structure were fine, narrowly distributed and well crystallized. The electrochemical performance test was carried out and the results showed that the as prepared Zn doped materials had not only a high capacity, but also a better cycling stability characterization than the un doped one. The Li1.06Ni0.75Co0.22Zn0.03O2.03 material has an initial reversible capacity as high as 160.5mAh· g- 1; and a first discharge efficiency 89.2% , and exhibits satisfactory cyclic stability with 90% retainable capacity after 50 cycles.展开更多
文摘Ti-doped nonstoichiometric LiFePO4, i.e. Li0.95Fe0.95Ti0.05PO4 was synthesized by solid-state reaction method. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM) and electrochemical charge and discharge tests were used to characterize the as-prepared sample. The results indicate that Li0.95Fe0.95Ti0.05PO4 used as the cathode material for lithium-ion battery exhibits improved cyclic stability and rate capability than those of undoped LiFePO4. 150 mAh·g-1 of discharge capacity was achieved at 0.1 C (17 mA ·g-1) at room temperature.
文摘A series of single phase LixNi0.8-yCo-（0.2）ZnyOp （0.96 ≤ x ≤ 1.10, 0 ≤ y ≤ 0.05, 2 ≤ p ≤ 2（1+ y） ） （different in the y values） were synthesized by a two step solid state reaction method, in which LiOH· H2O, Zn doped spherical Ni（OH）2 and Co2O3 were used as the precursors. The ICP AES analyses proved that the Zn doped compounds synthesized had the nonstoichiometric form. The results of the XRD, SEM identified that the uniform particles of the as prepared materials having a good layered structure were fine, narrowly distributed and well crystallized. The electrochemical performance test was carried out and the results showed that the as prepared Zn doped materials had not only a high capacity, but also a better cycling stability characterization than the un doped one. The Li1.06Ni0.75Co0.22Zn0.03O2.03 material has an initial reversible capacity as high as 160.5mAh· g- 1; and a first discharge efficiency 89.2% , and exhibits satisfactory cyclic stability with 90% retainable capacity after 50 cycles.
