溶剂热法制备高性能LiFePO4正极材料及其应用研究  

Preparation and application of high performance LiFePO_(4)cathode material by solvothermal method

作　　者：曹景河 李开阳 李孟桃 欧俊科 CAO Jing-he;LI Kai-yang;LI Meng-tao;OU Jun-ke(College of Mechanical Engineering,Chengdu University,Chengdu 610106,China;Institute for Advanced Study,Chengdu University,Chengdu 610106,China)

机构地区：[1]成都大学机械工程学院,四川成都610106 [2]成都大学高等研究院,四川成都610106

出　　处：《化学研究与应用》2024年第4期833-840,共8页Chemical Research and Application

基　　金：成都大学启动资金(2081919032)资助。

摘　　要：本文报道了以磷酸和亚磷酸为磷源,采用溶剂热法成功合成了锂离子电池磷酸铁锂正极材料。在亚磷酸和乙二醇的共同作用下,可以很容易的实现磷酸铁锂晶体从微米级块状颗粒到分布均匀纳米颗粒的形貌改变,同时亚磷酸也防止了部分Fe2+的氧化。晶粒尺寸减小的磷酸铁锂纳米颗粒缩短了Li+脱出/嵌入的扩散距离,从而提高了磷酸铁锂纳米颗粒的电化学性能。采用多种表征技术对溶剂热法制备的磷酸铁锂材料进行了系统研究。结果表明,用亚磷酸和乙二醇合成的磷酸铁锂材料具有更小的均匀粒径,更好的晶粒间电接触,更快的电子和锂离子扩散。因此,我们认为用亚磷酸和乙二醇合成的磷酸铁锂材料是一种很有前途的高性能锂离子电池正极材料。This paper reports the successful synthesis of lithium iron phosphate cathode materials for lithium ion batteries using phosphoric acid and phosphorous acid as phosphorus sources bysolvothermal method.Under the combined action of phosphite and ethylene glycol,the morphology of LiFePO_(4)crystals can be easily changed from micron-sized massive particles to uniformly distributed nanoparticles,and phosphite can also prevent part of Fe^(2+)oxidation.The reduced grain size of LiFePO_(4)nanoparticles reduces the diffusion distance of Li^(+)removal/embedding,thereby improving the electrochemical performance of LiFePO_(4) nanoparticles.LFP/PA/EG materials prepared by solvothermal method were systematically studied by various characterization techniques.The results show that the LFP/PA/EG material has smaller uniform particle size,better intergranular electrical contact,and faster electron and lithium ion diffusion.Therefore,we believe that LFP/PA/EG material is a promising positive electrode material for high-performance lithium ion batteries.

关 键 词：溶剂热法 亚磷酸 乙二醇 磷酸铁锂 

分 类 号：O614.1[理学—无机化学]