非整比Li_(4-x)Ti_5Sn_yO_(12)化合物的合成及电化学性能的研究  

Synthesis and the Electrochemical Performance for Non-stoichiometric Spinel Li_(4-x)Ti_5Sn_yO_(12)

作　　者：汤晶[1] 冯传启[1] 江雪娅[1] 但美玉[1] 郑浩[1] 

机构地区：[1]湖北大学化学化工学院,武汉430062

出　　处：《无机化学学报》2012年第10期2193-2197,共5页Chinese Journal of Inorganic Chemistry

基　　金：湖北省教育厅重点课题(No.20101006)资助项目

摘　　要：采用流变相法合成了锡掺杂的非整比锂钛氧尖晶石化合物,并研究了不同比例的Sn髧离子掺杂对锂钛氧尖晶石结构及性能的影响。采用XRD、SEM技术对合成材料的晶体结构和微观形貌进行表征,采用恒流充、放电系统及交流阻抗测试法对合成材料的电化学性能进行了测试,结果表明:Sn髧离子掺杂在一定程度上改善了锂钛氧尖晶石作为负极材料时,不同的掺杂量,对材料的电化学性能影响不同,其中Li4-xTi5Sn0·3O12材料的性能为最佳,当电池在较低电流密度下(50 mA·g-1)充、放电时,Li4-xTi5Sn0·3O12材料的首次放电比容量为236 mAh·g-1,在随后提高充、放电倍率过程中(由1C增到4C进行充、放电),当循环105次后,Li4-xTi5Sn0·3O12材料的放电比容量仍保持在109.8 mAh·g-1,与纯样品或其它非整比掺杂样品锂钛氧尖晶石比较,Li4-xTi5Sn0·3O12表现优良的电化学循环性能。本文还对锡掺杂导致锂钛尖晶石材料性能改善的原因也进行了初步探索。A of different characterized galvanostatic non-stoichiometric Spinel Li4-xTi5SnyO12 was synthesized by rheological phase method, and the effects tin-doping ratios on Li4-xTi5SnyO12 were studied. The crystal structure and microstructure were by XRD and SEM. And the electrochemical properties of the samples were investigated by charge/discharge testing system and electrochemical impedance spectroscopy. The results showed that suitable tin doping in Li4TisOlz has better high-rate performance and cycling stability. Li4-xTi5SnyO12（nTi：nSn= 1：0.06） exhibited the best electrochemical performance. The first discharge specific capacity was 236 mAh-g-1 at 50 mA. g-1. When rate of charge and discharge is increased to 4C, the discharge specific capacity remained 109.8 mAh .g-1 after 105 cycles. The Li4-xTisSna3Ol2 behaved outstanding electrochemical performances. The reason for Li4-xTi5SnyO12 to be improved at electrochemical properties was discussed also.

关 键 词：锂离子电池 负极材料 LI4TI5O12 流变相反应法 

分 类 号：TM912.9[电气工程—电力电子与电力传动]