One-dimensional ZnMn2O4 nanowires have been prepared and investigated as anode materials in Li rechargeable batteries. The highly crystalline ZnMn2O4 nanowires about 15 nm in width and 500 nm in length showed a high s...One-dimensional ZnMn2O4 nanowires have been prepared and investigated as anode materials in Li rechargeable batteries. The highly crystalline ZnMn2O4 nanowires about 15 nm in width and 500 nm in length showed a high specific capacity of about 650 mAh.g-1 at a current rate of 100 mA.g-1 after 40 cycles. They also exhibited high power capability at elevated current rates, i.e., 450 and 350 mAh.g 1 at current rates of 500 and 1000 mA.g 1, respectively. Formation of Mn3O4 and ZnO phases was identified by ex situ X-ray diffraction （XRD） and transmission electron microscopy （TEM） studies after the initial discharge-charge cycle, which indicates that the ZnMn2O4 phase was converted to a nanocomposite of Mn3O4 and ZnO phases immediately after the electrochemical conversion reaction.展开更多
We report on the preparation of spinel Li4Ti5O12 submicrospheres and their application as anode materials of rechargeable lithium-ion batteries. The spinel Li4Ti5O12 submicrospheres are synthesized with three steps of...We report on the preparation of spinel Li4Ti5O12 submicrospheres and their application as anode materials of rechargeable lithium-ion batteries. The spinel Li4Ti5O12 submicrospheres are synthesized with three steps of the hydrolysis of TiCl4 to form rutile TiO2, the hydrothermal treatment of rutile TiO2 with LiOH to prepare an intermediate phase of LiTi2O4+δ, and the calcinations of LiTi2O4+δ to obtain spinel Li4Ti5O12. The as-prepared products are investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The diameters of Li4Ti5O12 submicrospheres with novel hierarchical microstructures are about 200–300 nm with the assembly of 20–30 nm nanoparticles. The electrochemical properties of Li4Ti5O12 submicrospheres are measured by galvanostatical discharge/charge test and cyclic voltammetry (CV). The as-prepared Li4Ti5O12 display excellent discharge/charge rate and cycling capability. A high discharge capacity of 174.3 mAh/g is obtained in the first discharge at 1 C rate. Meanwhile, there is only tiny capacity fading with nearly 100% columbic efficiency in the sequential 5–50 cycles. Moreover, lithium-ion diffusion coefficient in Li4Ti5O12 is calculated to be 1.03 × 10-7 cm2/s. The present results indicate that the as-prepared Li4Ti5O12 submicrospheres are promising anode candidates of rechargeable Li-ion batteries for high-power applications.展开更多
文摘One-dimensional ZnMn2O4 nanowires have been prepared and investigated as anode materials in Li rechargeable batteries. The highly crystalline ZnMn2O4 nanowires about 15 nm in width and 500 nm in length showed a high specific capacity of about 650 mAh.g-1 at a current rate of 100 mA.g-1 after 40 cycles. They also exhibited high power capability at elevated current rates, i.e., 450 and 350 mAh.g 1 at current rates of 500 and 1000 mA.g 1, respectively. Formation of Mn3O4 and ZnO phases was identified by ex situ X-ray diffraction （XRD） and transmission electron microscopy （TEM） studies after the initial discharge-charge cycle, which indicates that the ZnMn2O4 phase was converted to a nanocomposite of Mn3O4 and ZnO phases immediately after the electrochemical conversion reaction.
基金supported by the National Natural Science Foundation of China (21076108)the National Basic Research Program of China (2011CB935902)+1 种基金MOE Innovation Team (IRT0927)Tianjin High-Tech (10ZCGHHZ01200 & 10SYSYJC27600)
文摘We report on the preparation of spinel Li4Ti5O12 submicrospheres and their application as anode materials of rechargeable lithium-ion batteries. The spinel Li4Ti5O12 submicrospheres are synthesized with three steps of the hydrolysis of TiCl4 to form rutile TiO2, the hydrothermal treatment of rutile TiO2 with LiOH to prepare an intermediate phase of LiTi2O4+δ, and the calcinations of LiTi2O4+δ to obtain spinel Li4Ti5O12. The as-prepared products are investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The diameters of Li4Ti5O12 submicrospheres with novel hierarchical microstructures are about 200–300 nm with the assembly of 20–30 nm nanoparticles. The electrochemical properties of Li4Ti5O12 submicrospheres are measured by galvanostatical discharge/charge test and cyclic voltammetry (CV). The as-prepared Li4Ti5O12 display excellent discharge/charge rate and cycling capability. A high discharge capacity of 174.3 mAh/g is obtained in the first discharge at 1 C rate. Meanwhile, there is only tiny capacity fading with nearly 100% columbic efficiency in the sequential 5–50 cycles. Moreover, lithium-ion diffusion coefficient in Li4Ti5O12 is calculated to be 1.03 × 10-7 cm2/s. The present results indicate that the as-prepared Li4Ti5O12 submicrospheres are promising anode candidates of rechargeable Li-ion batteries for high-power applications.
