微波辅助溶胶-凝胶法合成锂离子电池负极材料Li_4Ti_5O_(12)

SYNTHESIS OF LITHIUM-ION BATTERY ANODE MATERIAL Li_4Ti_5O_(12) BY THE MICROWAVE ASSISTED SOL-GEL METHOD

以微波辅助溶胶-凝胶法合成Li4Ti5O12、Al或C掺杂的Li4Ti5O12样品。用X射线衍射仪、扫描电子显微镜分别表征所得产物的结构和形貌,研究不同样品在恒流充放电条件下的电化学性能。结果表明:合成Li4Ti5O12粉体的最佳微波处理条件为800℃、40min;微波热处理合成样品颗粒尺寸为100nm左右,掺Al或C样品颗粒的分散性要优于未掺样品的。首次充放电结果表明:所有样品的放电平台平稳,掺Al或C样品的首次放电容量均高于未掺样品的,掺C样品的首次放电容量为162mA·h/g,更接近Li4Ti5O12的理论容量(175mA·h/g)。

Li4Ti5O12 and Al or C doped Li4Ti5O12 samples were synthesized by the microwave assisted sol-gel method.Structural characterization and surface morphology of products synthesized were analyzed by the X-ray diffraction and scanning electron microscopy,respectively,and electrochemical property of different samples was studied by galvanostatic charge and discharge.The results indicate that the optimal temperature and heating time for Li4Ti5O12 synthesis are 800 ℃ and 40 min.The particle size of samples synthesized by microwave heating was about 100 nm.The particle distribution of the Al or C doped Li4Ti5O12 samples was better than the undoped samples.The result of first charge and discharge shows that all the samples have a stable voltage plateau and the Al or C doped Li4Ti5O12 samples have better first discharge capacity than the undoped Li4Ti5O12 sample.The first discharge capacity of C doped Li4Ti5O12 is 162 mA·h/g,which is close to the theoretical value of Li4Ti5O12（175 mA·h/g）.