氧化鋯披覆鋰錳氧電極之製備與分析

本實驗分別以溶膠凝膠法(sol-gel)和流體化床輔助化學氣相沉積(fluidized-bed chemical vapor deposition)的方式，批覆氧化鋯(ZrO2)於鋰錳氧(LiMn2O4)表面，並且以此材料為鋰離子二次電池的正極材料進行分析。經由X光繞射圖譜顯示出批覆於鋰錳氧表面的氧化鋯是非晶體(amorphous)的結構。掃瞄式電子顯微鏡以及穿透式電子顯微鏡的結果顯示出經由上述方法，氧化鋯均勻的批覆於鋰錳氧的表面。相對於未做任何表面處理的鋰錳氧，以氧化鋯批覆鋰錳氧電極所組成的電池不論在室溫或是高溫(55℃)下的充放電性能皆有明顯的改善。實驗結果顯示批覆於鋰錳氧表面的氧化鋯可以有效的抑制Jahn-Teller distortion，使得鋰錳氧結構在充放電過程中更加穩定，因此可以有效的延長其循環壽命。

關鍵字

鋰離子二次電池；表面改質；氧化鋯

並列摘要

Two synthetic routes including sol-gel process and fluidized-bed chemical vapor deposition (FBCVD) process were introduced to the preparation of ZrO2-coated LiMn2O4 as cathode materials for lithium ion secondary batteries. X-ray diffraction (XRD) spectra from the ZrO2-coated LiMn2O4 indicated that ZrO2 exist as amorphous phase. The morphology of ZrO2-coated samples were observed by scanning electron microscope (SEM) and transmission electron microscope (TEM), which revealed that the zirconium oxide attached smoothly onto the surface of LiMn2O4. The surface-modified LiMn2O4 samples showed much better capacity retention than the unmodified LiMn2O4 cathode at both room temperature and 55℃. The improved cycle life performance could be due to a suppression of the Jahn-Teller distortion which took place at low voltage during cycling.

並列關鍵字

zirconia ； Li-ion battery ； surface modification

參考文獻

[33] J. Cho, T. J. Kim, Y. J. Kim, and B. Park, “High-performance ZrO2-coated LiNiO2 cathode material”, Electrochem. Solid-State Lett., 4, A159-A161 (2001)

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國際替代計量

氧化鋯披覆鋰錳氧電極之製備與分析

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