超临界水热合成法制备磷酸铁锂正极材料的改性研究  

Modification of lithium iron phosphate as anode material by supercritical hydrothermal method

作　　者：孟华[1] 王兵[1] 韩丽娜[1,2] 鲍卫仁[1] 常丽萍[1] 王建成[1] 

机构地区：[1]太原理工大学煤科学与技术山西省和教育部重点实验室,太原030024 [2]太原理工大学材料科学与工程学院,太原030024

出　　处：《化工新型材料》2016年第5期169-172,共4页New Chemical Materials

基　　金：国家自然科学基金资助项目(21476154);山西省自然科学基金资助项目(2014011003-3)

摘　　要：利用超临界水热合成法制备了磷酸铁锂(LiFePO_4)纳米颗粒,并通过直接向原料中加入碳源和还原剂考察原位碳包覆和还原效果。结果表明:抗坏血酸和柠檬酸都可有效防止Fe^(2+)的氧化,抗坏血酸的还原效果更优,最佳添加量为5%(wt,质量分数,下同)。多壁碳纳米管具有较好的碳包覆效果,最佳碳包覆量为5%,蔗糖包覆效果较差。将优化条件下添加5%的多壁碳纳米管和抗坏血酸制备的LiFePO_4进行电化学性能测试,在0.1C电流密度下的首次充放电比容量可分别达到134.0和123.0mAh/g,充放电效率为91.79%。Nano-sized lithium iron phosphate（LiFePO_4）particles were synthesized under supercritical water conditions in a tube reactor.Sucrose and multi-walled carbon nanotubes were used as carbon precursor,the ascorbic acid and citric acid were used as reducing agent.Both the effects of contents and precursors on the formation of LiFePO_4 anode material were studied.Ascorbic acid and citric acid showed good reduction role,moreover the ascorbic acid was a better candidate as the reducing agent for LiFePO_4 and the best addition content was 5wt%.The multi-walled carbon nanotubes had good carbon coating effect and the best addition was 5wt%,while the coating effect of sucrose was relative poor.The initial charge and discharge specific capacity of LiFePO_4 synthesized under optimal conditions added with 5wt%multi-walled carbon nanotubes and ascorbic acid reached 134.0mAh·g-1 and 123.0mAh·g-1 respectively at 0.1Crate with coulombic efficiency of 91.79%.

关 键 词：磷酸铁锂 正极材料 超临界水热合成 还原剂 碳包覆 

分 类 号：TQ131.11[化学工程—无机化工]