球形LiMnPO4/C正极材料的喷雾干燥法制备及性能研究

以氢氧化锂、乙酸锰、磷酸二氢铵和聚乙二醇为原料,采用一次喷雾干燥法制备了球形LiMnPO₄/C正极材料,并研究了煅烧温度对球形LiMnPO₄/C样品形貌、结构和电化学性能的影响。通过X射线衍射（XRD）和场发射扫描电镜（SEM）对其进行了结构和形貌的表征。结果表明,经700 ℃焙烧的LiMnPO₄/C为橄榄石型结构,在SEM下呈规则的球形,由粒径约为50 nm的一维纳米颗粒堆积而成。该样品在室温0.1C倍率下首次放电比容量可达148 mA·h/g,循环80圈后的放电比容量依然在140 mA·h/g左右,容量保持率为94.6%。

Preparation and properties of spherical LiMnPO4/C cathode materials by spray drying method

One-time spray-drying method was used to prepare spherical LiMnPO₄/C cathode materials with lithium hydroxide,manganese acetate,NH₄H₂PO₄ and polyethylene glycol as raw materials.The effect of calcination temperature on the morpho-logy,structure and electrochemical performance of spherical LiMnPO₄/C samples was studied.Its structure and morphology were characterized by X-ray diffraction（XRD）and field emission scanning electron microscopy（SEM）.The morphology and prechemical properties of LiMnPO₄/C obtained after calcination at different temperatures are quite different.The results showed that the spherical LiMnPO₄/C calcined at 700 ℃ had olivine-type crystal structure,and it showed a spherical shape composed of one-dimensional nano particles with a diameter of about 50 nm under SEM.The specific discharge capacity of this sample reached 148 mA·h/g for the first time at a rate of 0.1C at room temperature.After 80 cycles,the specific discharge capacity was still around 140 mA·h/g,and the capacity retention rate was 94.6%.