Synthesis and electrochemical performance of nano-sized Li4Ti5O12 with double surface modification of Ti(III) and carbon
Synthesis and electrochemical performance of nano-sized Li4Ti5O12 with double surface modification of Ti(III) and carbon
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DOI：
10.1039/b908025b
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发表时间：
2009-09
影响因子：
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通讯作者：
Yonggang Wang;Haimei Liu;Kaixue Wang;Hosono Eiji;Yarong Wang;Haoshen Zhou
中科院分区：
文献类型：
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作者：
Yonggang Wang;Haimei Liu;Kaixue Wang;Hosono Eiji;Yarong Wang;Haoshen Zhou
以聚苯胺 (PANI) 包覆的 TiO2 颗粒和锂盐为前驱体，通过简便的固相反应合成了具有 Ti(III) 和碳双导电表面修饰的尖晶石 Li4Ti5O12 纳米颗粒。在含5%H2的氩气气氛下进行热处理时，PANI的碳化有效限制了Li4Ti5O12的粒径长大，并将表面Ti(IV)还原成Ti(III)。表面改性与定制粒径相结合可以提高表面电导率并缩短锂离子扩散路径。此外，Ti(III) 表面改性和定制颗粒 (50–70nm) 都有可能在电化学过程中增加固溶体（单相插入/脱出）。电化学分析表明固溶体的存在有利于锂离子的迁移率。由此，制备的Li4Ti5O12表现出高功率性能。
Spinel Li4Ti5O12 nano-particles with double conductive surface modification of Ti(III) and carbon were synthesized by a facile solid-state reaction, in which the polyaniline (PANI) coated TiO2 particles and a lithium salt were used as precursors. On heat treatment under an argon atmosphere containing 5% H2, the carbonization of PANI effectively restricted the particle-size growth of Li4Ti5O12 and reduced the surface Ti(IV) into Ti(III). The surface modification combined with tailored particle size can improve the surface conductivity and shorten the Li-ion diffusion path. Furthermore, both the Ti(III) surface modification and the tailored particles (50–70nm) have the potential to increase the solid solution (single-phase insertion/extraction) during the electrochemical process. Electrochemical analysis indicated that the presence of the solid solution is beneficial for Li-ion mobility. Thereby, the prepared Li4Ti5O12 displays high power performance.