Gd^(3+)掺杂纳米SnO_2锂离子电池负极材料的制备与电化学性能研究

Preparation and Electrochemical Performance of Gd^(3+) Doping SnO_2 Nanocrystals as Anode Material for Lithium Ion Batteries

以SnCl4为锡源,Gd3+为掺杂离子,采用水热法制备出不同掺杂浓度的SnO2纳米晶.运用XRD、TEM、FT-IR以及充放电测试等手段对其结构、形貌、电化学性能进行了表征.结果表明所制备样品为四方晶系金红石型SnO2,Gd3+以替位方式掺入SnO2纳米晶中.当名义Gd3+掺杂浓度达到15%时,SnO2纳米颗粒转变为纳米棒.电化学性能表征发现SnO2纳米棒的首次充放电容量、循环稳定性以及库伦效率都要高于纳米颗粒,并且经过50次循环后SnO2纳米棒的比容量仍保持有370mAh/g.研究结果表明,由于掺杂的作用,调节了材料的形貌与尺寸,改善了SnO2纳米晶的电化学性能.

Doped SnOz nanocrystals were prepared via a hydrothermaL method using tin tetrachLoride as tin precursor, Gda＋ ions as doped ions. The XRDjTEM,FT-IR spectra results indicate that the as-synthe- sized samples are tetragonal rutile SnOz and Gd3＋ ions exist as the formation of substituting Sn4＋ ion. Doped SnO2 nanocrystals are converted to nanorods from quasi-spherical nanoparticles when the Gd＋ doping con- centrations is beyond 15mol. The electrochemical properties of as-synthesized samples show that the ini- tial discharge and charge capacities, cycle performance and coulombic efficiency of Gd3＋ doped SnOz nano- rods are better than those of SnO2 nanoparticles. Moreover, Gd3＋ doped SnOz nanorods show a reversible capacity of 370 mAh/g after 50 cycles. The results demonstrate as Gd3＋ ions are introduced, the shape and size of SnOz nanocystals can be changed and the electrochemical property be improved.