Synthesis and characterization of spinel Li4Ti5O12 anode material by oxalic acid-assisted sol–gel method
Synthesis and characterization of spinel Li4Ti5O12 anode material by oxalic acid-assisted sol–gel method
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DOI：
10.1016/j.jpowsour.2005.09.063
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发表时间：
2006-08
影响因子：
9.2
通讯作者：
Yan-Jing Hao;Q. Lai;Ji-Zheng Lu;Hong-li Wang;Yuan-Duan Chen;X. Ji
中科院分区：
文献类型：
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作者：
Yan-Jing Hao;Q. Lai;Ji-Zheng Lu;Hong-li Wang;Yuan-Duan Chen;X. Ji
以草酸为螯合剂，Li 2CO 3和钛酸四丁酯[Ti（OC 4 H9）4]为原料，采用溶胶-凝胶法制备了锂离子电池正极材料Li 4 Ti 5 O 12。研究了各种初始条件，以找到合成Li 4 Ti 5 O 12的最佳条件。该方法以草酸为燃料，在低温下分解金属配合物，生成游离杂质Li 4 Ti 5 O 12化合物。热分析（TG-DTA）和XRD数据表明，在800°C下生长16 h的粉末具有尖晶石结构（Fd 3 m空间群）。SEM分析表明，所制备的Li 4 Ti 5 O 12粉体具有均匀的立方形貌，平均粒径为200 nm。研究了合成条件对材料电化学性能的影响。在最佳合成条件下，800°C，20 h，草酸钛比R=1.0合成的Li 4 Ti 5 O 12首次循环放电容量为171 mAhg-1，35次循环后放电容量为150 mAhg-1。非常平坦的充放电曲线表明基于Ti 4 +/Ti 3+氧化还原对的电化学反应是典型的两相反应。
Anode material Li4Ti5O12for lithium-ion batteries has been prepared by a novel sol–gel method with oxalic acid as a chelating agent and Li2CO3and tetrabutyl titanate [Ti(OC4H9)4] as starting materials. Various initial conditions were studied in order to find the optimal conditions for the synthesis of Li4Ti5O12. Oxalic acid used in this method functioned as a fuel, decomposed the metal complexes at low temperature and yielded the free impurity Li4Ti5O12compounds. Thermal analyses (TG–DTA) and XRD data show that powders grown with a spinel structure (Fd3m space group) have been obtained at 800°C for 16h. SEM analyses indicated that the prepared Li4Ti5O12powders had a uniform cubic morphology with average particle size of 200nm. The influence of synthesis conditions on the electrochemical properties was investigated and discussed. The discharge capacity of Li4Ti5O12synthesized with an oxalic acid to titanium ratio R=1.0 was 171mAhg−1in the first cycle and 150mAhg−1after 35 cycles under an optimal synthesis condition at 800°C for 20h. The very flat discharge and charge curves indicated that the electrochemical reaction based on Ti4+/Ti3+redox couple was a typical two-phase reaction.