节省锂资源的磷酸铁锂水热合成路径

Lithium saving route for hydrothermal synthesis of LiFePO_4

水热晶化工艺可以显著减轻产物颗粒团聚的不利影响。以硫酸亚铁为铁源的磷酸铁锂水热合成法,所耗氢氧化锂达到化学计量的3倍,严重浪费锂资源。研究发现以碳酸亚铁为铁源,在合适的酸度条件下,可以通过水热晶化工艺制备出颗粒团聚轻微的磷酸铁锂正极材料,与硫酸亚铁水热法相比能有效节省2/3的锂源,在0.1C条件下,包覆3%(wt,质量分数)碳制得的磷酸铁锂正极材料具有较高的放电比容量,达到161mAh/g。

Hydrothermal crystallization may significantly alleviate the negative effects due to aggregation of product particles.The hydrothermal synthesis of LiFePO_4 using ferrous sulfate as the iron source consumed lithium hydroxide to three times of its stoichiometric amount,which wasted lithium resource.LiFePO_4 with less-aggregated particles may be hydrothermally synthesized at suitable acidity using ferrous carbonate as the iron source was found,which effectively saved 2/3 of the lithium source compared with the hydrothermal method using ferrous sulfate.The lithium iron phosphate coated with 3 wt% carbon exhibitd a high discharge capacity of 161 mAh/g at 0.1 C.