二水磷酸铁煅烧过程对磷酸铁品质的影响研究  

Study on the influence of calcination process of iron phosphate dihydrate on ferric phosphate quality

作　　者：吴松 彭海南 冷国琴 张雷 WU Song;PENG Hainan;LENG Guoqin;ZHANG Lei(Guizhou Phosphating New Energy Technology Co.,Ltd.,Guiyang 550300,China)

机构地区：[1]贵州磷化新能源科技有限责任公司,贵州贵阳550300

出　　处：《生态产业科学与磷氟工程》2024年第11期13-17,共5页Eco-industry Science & Phosphorus Fluorine Engineering

基　　金：磷酸铁反应连续化关键技术与产业化研究(新能源科技YF(2023)017)。

摘　　要：磷酸铁作为磷酸铁锂的前驱体,其水分、比表面积、硫含量对磷酸铁锂电池的电荷转移阻抗、充放电倍率等性能有重要影响。采用均相共沉淀法合成二水磷酸铁,研究煅烧过程中磷酸铁水分、比表面积、硫含量随保温时间和烧结温度的变化规律,以及煅烧过程中发生的相转变及煅烧温度对磷酸铁形貌的影响。结果表明,大部分结晶水在300℃以前脱除;脱硫主要发生于400~500℃;当温度高于500℃后,硫含量变化不再明显,此时开始发生粒子融合,且煅烧温度升高会增加粒子融合现象;转晶行为发生于530℃,在550℃下煅烧6 h时可以转晶完全。Iron phosphate,as the precursor of lithium iron phosphate,it’s water content,specific surface area and sulfur content have important effects on the electrical performance of lithium iron phosphate batteries,such as charge transfer impedance and charge-discharge rate.Iron phosphate dihydrate is synthetized by homogeneousco precipitation method,the changes of water content,specific surface and sulfur content of iron phosphate with holding time and sintering temperature,as well as the phase transformation and morphology changes with calcination temperature are studied.It is found that the dehydration mainly occurres before 300℃and desulfurization process mainly occurres between 400-500℃.When the temperature is higher than 500℃,the sulfur content changes no longer significantly,the particle fusion occurs at this time and will be aggravated under the higher temperature.Phase transition begins at 530℃,and can be completely transformed at 550℃for 6 h.

关 键 词：二水磷酸铁 煅烧 转晶 形貌 

分 类 号：TQ126.35[化学工程—无机化工]