利用新穎製程來改善鋰離子電池的陽極材料

鋰離子電池的主要構造為正（陰）極、負（陽）極及電解質，本實驗將從負極材料方面進行改質。 Li4Ti5O12為一新型的負極材料，其尖晶石(spinel)結構使鋰離子擴散更加快速容易，且其較高的操作電壓平台(1.55V vs Li/Li+)可避免負極表面與電解質間的還原反應產生樹枝狀鋰金屬進而避免電極的變形，但過低的導電性及鋰離子擴散速率使鋰電池的比電容量過低。本實驗以固相反應合成法，同時摻雜Zr及Cr離子於LTO中，取代Ti4+位置，再以行星式球磨機加入多壁奈米碳管(multi-wall carbon nano tube)進行球磨，使MWCNT纏繞於LTO表面，提升其導電性以改善電池之比電容量及循環壽命。Cr3+離子半徑(0.62A)和Ti4+離子(0.61A)相近；Zr4+半徑(0.72A)大於Ti4+半徑，以不同摻雜比例作為實驗參數，藉由兩種離子摻雜探討價數與離子半徑對鋰電池電性提升的影響，選出最好的參數再加入MWCNT加以纏繞，更加提升鋰鈦氧粉末間的導電率，研究同時使用兩種改質法對電性的提升。　在離子摻雜方面，Z2C3這組參數在首次充放電下電容率高達168.55 mAh/g，且循環壽命也有所改善，而MWCNT-coated的LTO方面，加入4 wt% 及6 wt% MWCNT的LTO都有提升其電性且高速衝放電循環穩定性佳，但加入4 wt% MWCNT的LTO所提升的電性又更好，所以最後會以Z3C2加入4 wt% MWCNT進行雙重改質，比較最後的結果。

關鍵字

鋰離子電池；負(陽)極材料；鋰鈦氧；離子摻雜；多壁奈米碳管纏繞

並列摘要

The main structure of the lithium-ion battery is positive (negative ) electrode, a negative ( positive ) electrode and the electrolyte , the experiment was modified from the negative aspects of the material . Li4Ti5O12 is a novel negative electrode material having the spinel (spinel) structure of the lithium ion diffusion more quickly and easily , and its platform higher operating voltage (1.55V vs Li / Li +) to prevent a reduction reaction between the electrolyte and the negative electrode surface thereby preventing the generation of dendritic lithium metal electrode is deformed , but low electrical conductivity and lithium ion diffusion rate that the low capacity than lithium . In this experiment, the solid state reaction method, while Zr and Cr -doped ions in the LTO , instead of Ti4 + position , then added a planetary ball mill MWCNTs (multi-wall carbon nano tube) ball milling , so that the winding MWCNT at LTO surface , to enhance its electrical conductivity to improve the capacity and cycle life than batteries . Cr3 + ionic radius (0.62A) and Ti4 + ions (0.61A) is similar ; Zr4 + radius (0.72A) is larger than the radius of Ti4 + with different doping ratio as experimental parameters to explore the valence and ionic radius of the lithium ion doping by two pool electrical upgrade impact , choose the best parameters MWCNT added to wound , and more to enhance the conductivity of lithium titanium oxide powder between the two studies use a modified method to enhance the electrical properties . In terms of ion doping , Z2C3 this set of parameters under the first charge and discharge the capacitor rates up 168.55 mAh / g, and the cycle life is also improved , and the LTO aspects of MWCNT coated , adding 4 wt% and 6 wt% CNT 's LTO has to enhance its stability and good electrical cycle , but the effect is almost two to cost considerations , then select 4 wt% CNT and Z3C2 to combine this respect , comparing the final result.

並列關鍵字

Li-ion battery ； Anode ； Li4Ti5O12 ； Ion doping ； MWCNT

參考文獻

[2] 吳玉祥、洪雅純，氣氛對製備Li4Ti5O12高功率鋰電池負極材料電性之影響，Journal of China University of Science and Technology, Vol.47, 2011, pp. 53-56

[1] 李孟倫，快速充電鋰離子二次電池負極覆合碳材之研究，國立清華大學碩士論文，2009年6月

[3] 張華瑭，摻雜鉻及鋯改質Li4Ti5O12作為鋰離子電池負極材料之電化學性

[7] Whittingham, M. S,”Electrical Energy Storage and Intercalation Chemistry Science,” 1976, 192, 4244, pp. 1126–1127

[10] Shuangze Ji , Junying Zhang, Wenwen Wang, Yan Huang, Zerong Feng, Zhongtai Zhang, Zilong Tang,"Preparation and effects of Mg-doping on the electrochemical properties of spinel Li4Ti5O12 as anode material for lithium ion battery ," Materials Chemistry and Physics, 123, 2010, pp. 510–515

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利用新穎製程來改善鋰離子電池的陽極材料

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