无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2023, Vol. 55 ›› Issue (7): 51-57.doi: 10.19964/j.issn.1006-4990.2022-0548

• 研究与开发 • 上一篇    下一篇

硝酸铁和磷酸共沉淀法制备电池级磷酸铁工艺研究

王紫涵(), 李军, 陈明, 周青禺   

  1. 四川大学化学工程学院,四川 成都 610065
  • 收稿日期:2022-09-11 出版日期:2023-07-10 发布日期:2023-07-13
  • 作者简介:王紫涵(1998— ),女,硕士,主要研究方向为无机化工新技术新工艺研发;E-mail:w_zh0102@163.com

Study on preparation of battery grade ferric phosphate by co-precipitation of ferric nitrate and phosphoric acid

WANG Zihan(), LI Jun, CHEN Ming, ZHOU Qingyu   

  1. School of Chemical Engineering,Sichuan University,Chengdu 610065,China
  • Received:2022-09-11 Published:2023-07-10 Online:2023-07-13

摘要:

以硝酸铁和磷酸为原料,利用共沉淀法制备了电池级磷酸铁,研究了反应温度、反应物浓度、投料比和反应时间对磷酸铁产率和粒径的影响,并通过正交优化得到了最佳的工艺条件:硝酸铁浓度为1.1 mol/L、投料比(磷酸与硝酸铁物质的量比)为1.1、反应温度为90 ℃、反应时间为8 h。采用扫描电镜(SEM)、激光粒度仪、X射线衍射仪(XRD)、热重-差式扫描量热仪(TG-DTA)等对制备的磷酸铁进行表征分析。分析结果表明:在优化条件下得到的二水磷酸铁为单斜晶,纯度高,二次粒径D50为2.41 μm,均符合电池级磷酸铁的要求。以磷酸铁为前驱体制备的LiFePO4/C性能良好,将其作为正极材料组成的电池在0.05C、0.1C、1C倍率下首次放电比容量分别为143.9、136.8、131.4 mA·h/g。

关键词: 硝酸铁, 磷酸铁, 共沉淀法, 磷酸铁锂, 正交实验

Abstract:

By using ferric nitrate and phosphoric acid as raw materials,the co-precipitation method was used to prepare the battery grade ferric phosphate.The effects of reaction temperature,reactant concentration,feeding proportion and reaction time on the yield and particle size of ferric phosphate were studied,and the optimal process conditions were obtained through orthogonal optimization:the solution concentration of Fe(NO33 was 1.1 mol/L,the feed ratio of phosphoric acid to ferric nitrate was 1.1,the reaction temperature was 90 ℃,and the reaction time was 8 h.The prepared iron phosphate was characterized by scanning electron microscopy(SEM),laser particle size analyzer,X-ray diffractometer(XRD) and TG-DTA.The analysis results showed that the obtained ferrophosphate dihydrate was monoclinic crystal with high purity and secondary particle size D50 of 2.41 μm,which met the requirements of battery grade ferrophosphate.The performance of LiFePO4/C prepared by the precursor system of iron phosphate was good.The initial discharge specific capacity of the battery composed of iron phosphate as cathode materials were 143.9,136.8 and 131.4 mA·h/g at 0.05C,0.1C and 1C,respectively.

Key words: ferric nitrate, ferric phosphate, co-precipitation method, lithium iron phosphate, orthogonal experiment

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