球形磷酸铁锂材料的制备及其18650电池的测试

采用高能球磨和喷雾干燥法制备了球形磷酸铁锂材料LFP-1,并制作18650实装电池,测试电极片的压实密度,同时选择一种商业化磷酸铁锂材料LFP-2作为对比。测试结果显示,2种LFP材料均由平均粒径为300~500nm的一次颗粒组成,比表面积为13~15m2/g,碳质量分数为1.5%左右。通过CR2032纽扣型电池充放电测试表明,在0.2C时,LFP-1的比放电容量约为165mA·h/g,与商业化磷酸铁锂材料LFP-2相近。制备18650电池的结果表明,商业化磷酸铁锂LFP-2材料制备的电极片的最高压实密度可以达到2.52g/cm3,显著高于实验室制得的磷酸铁锂材料LFP-1的最高压实密度2.25g/cm3,这可能与材料的颗粒粒度分布不同有关。

Preparation of spherical lithium iron phosphate material and its 18650 battery test

A spherical lithium iron phosphate material LFP-1 was prepared by high-energy ball milling and spray drying,and the 18650 battery was fabricated to measure the compacted density of the electrode sheet.At the same time,a commercial lithium iron phosphate material LFP-2 was selected as a comparison.The test results showed that both LFP materials consist-ed of particles with an average particle size of 300~500 nm,a specific surface area of 13~15 m²/g and a carbon mass fraction of about 1.5%.The charge and discharge test of the CR2032 button battery showed that the specific discharge capacity of LFP-1 was approximately 165 mA·h/g at 0.2C,which was similar to that of commercial lithium iron phosphate material LFP-2.The results of the prepared 18650 cell showed that the highest compacted density of the electrode sheet prepared from the commercial lithium iron phosphate LFP-2 could reach 2.52 g/cm³,which was significantly higher than that 2.25 g/cm³ of the LFP-1,which may be related to the different particle size distribution of the material.