EDTA辅助合成Li_2MnSiO_4/C纳米复合锂离子电池正极材料及性能  

EDTA Assisted Synthesis and Electrochemical Performance of Li_2MnSiO_4/C Nanocomposite as a Cathode Material for Lithium Ion Btteries

作　　者：李东林[1] 马守龙[1] 李严[1] 谢荣[1] 田苗[1] 樊小勇[1] 苟蕾[1] 史咏鑫 雍红团华 郝丽敏[1] 

机构地区：[1]长安大学材料科学与工程学院,长安大学新能源材料与器件研究所,西安710061

出　　处：《无机化学学报》2014年第5期1056-1062,共7页Chinese Journal of Inorganic Chemistry

基　　金：国家自然科学基金(No.21073021;20903016;21103013);教育部高等学校科学技术重大项目培育资金项目(No.708084);中央高校基本科研业务费专项资金(No.CHD2010ZD008;CHD2011ZD007)资助项目

摘　　要：以乙二胺四乙酸(EDTA)为配位剂,采用溶胶凝胶和溶剂热法相结合的方法合成了Li2MnSiO4/C纳米复合正极材料。经过EDTA配位的锂锰硅前驱体在氩气中经过700℃煅烧后,产生为颗粒尺寸约为50 nm的Li2MnSiO4/C纳米复合粉体。在0.1C=33mA·g-1进行充放电测试时,其首次充电和放电比容量分别为223和140 mAh·g-1,第5次循环放电比容量仍为138 mAh·g-1;电流密度升至0.2C=66 mA·g-1时,在第20次循环的放电比容量仍可稳定在80 mAh·g-1左右。这些结果表明,EDTA的配位作用可抑制杂相的形成,这种分散性相对较好的纳米复合粉体Li2MnSiO4正极材料表现出提高的循环稳定性。Li2MnSiO4/C nanospheres were prepared by combining the sol-gel and solvotnermal processing using ethylene diamine tetraacetic acid （EDTA） as a chelating agent. After calcined under Ar atmosphere at 700 ℃, the （Li, Mn, Si）precursor complexed by EDTA transformed into Li2MnSiO√C nanocomposite particles approximately 50 nm in diameter. The initial charge and discharge specific capacities of the sample are 223 and 140 mAh.g-1 at a current density of 33 mA＇g-1 （0.1C）, respectively, and fifth discharge specific capacity can be achieved 138 mAh-g-X. The discharge specific capacity still is stabilized at around 80 mAh＂ g-1 at a current density of 66 mA＂ g-l （0.2C） after 20 cycles. These results indicate that EDTA can prevent secondary crystalline phase of forming during calcinations. Such well-dispersed nano-powder exhibits improved cycleability for Li2MnSiO4 cathode.

关 键 词：乙二胺四乙酸(EDTA) LI2MNSIO4 锂离子电池 正极材料 

分 类 号：O611.3[理学—无机化学]