水热法制备LiNi_(0.5)Mn_(1.5)O_4及其电化学性能的研究

以LiOH·H2O、MnSO4·H2O和NiSO4·6H2O等为原料,采用水热法合成尖晶石LiNi0.5Mn1.5O4材料.利用扫描电子显微镜、粉末X-射线衍射仪、电化学测试分别对材料形貌、结构和电化学性能进行表征.研究加入不同锂量和热处理对尖晶石LiNi0.5Mn1.5O4材料的初始容量、放电平台以及循环性能的影响.结果表明:经过850℃热处理所合成的材料分布均匀、结晶和电化学性能良好.当LiOH溶液为0.162 g·mL-1时,尖晶石LiNi0.5Mn1.5O4材料在1 C倍率电流(140 mAh g-1)条件下,首次放电比容量为111.0 mAh·g-1.且该样品的循环性能优越:经150充放电循环后的容量衰减率仅为4.5%.

Hydrothermal Synthesis of a Nanosized LiNi0.5Mn1.5O4 and Its Electrochemical Property

LiNi0.5MnO4 materials were synthesized using LiOH·H20 and MnCO3 as the raw materials via the hydrothermal reaction. The crystal structure and electrochemical performance of the LiNi0.5 MnO4 cathode materials were characterized with modem analyzing techniques, such as XRD, SEM, and charge-discharge test method. The effects of lithium salt dosage and the electrochemical performance of the as-prepared materials were investigated. The results showed that the material prepared at 850℃ exhibited good electrochemical performance. When the concentration of the LiOH solution was 0. 162 g·mL^-1 ,the initial discharge capacity of the sample was 111 mAh ·mL^-1 at 1C rate and retained 106 mAh·mL^-1 after 150 cyeles,i, e. ,only 4.5 % of its initial capacity decayed after 150 cycles.