Li(Ni1/3Co1/3Mn1/3)O2正極材料之共沉製程研究

The Effects of Co-precipitation Process on the Properties of Li(Ni1/3Co1/3Mn1/3)O2 Cathode Materials

林祐助(Yu-chu Lin)

指導教授 ： 吳溪煌

大同大學/工程學院/材料工程學系所/碩士(2006年)

摘要

利用共沉法並進行800到1000oC的熱處理合成層狀的Li(Ni1/3Co1/3Mn1/3)O2正極材料，並藉由XRD、SEM及循環充放電分析結果對合成粉末之特性及電化學性質進行研究。為了改善Li(Ni1/3Co1/3Mn1/3)O2正極粉末之循環充放電性，分別在共沉法合成過程中，在前驅物中添加乙炔碳黑，在過渡金屬離子溶液中添加PEG或蔗糖等改良製程進行合成Li(Ni1/3Co1/3Mn1/3)O2。以在過渡金屬離子溶液中添加蔗糖是最為有效的改善方法。雖然在前驅物中添加乙炔碳黑能也可使晶粒細化，略為改善其循環充放電特性，但合成粉末中卻會生成CoCx雜相。而在過渡金屬離子溶液中添加PEG對Li(Ni1/3Co1/3Mn1/3)O2正極材料特性反而有負面的影響。

關鍵字

層狀結構

並列摘要

Layered Li(Ni1/3Co1/3Mn1/3)O2 cathode materials were prepared with co-precipitation method followed by heat-treatment at temperatures between 800 and 1000oC. The characterization and electrochemical properties of the prepared powders were studied with XRD, SEM, and capacity retention study. In order to improve the cycleability and rate capability of Li(Ni1/3Co1/3Mn1/3)O2 cathode material, amended co-precipitation methods with addition of acetylene black in precursor for heat-treatment and addition of PEG or sucrose into transition metal ion solution before co-precipitation were used to prepared Li(Ni1/3Co1/3Mn1/3)O2 powders. Among them, the co-precipitation with method sucrose added into transition metal ion solution before co-precipitation is the most effective one. Though the average particle size and cycleability can be improved by adding acetylene black in precursor for heat-treatment, CoCx phase forms in the prepared powder. The addition of PEG into the transition metal ion solution before co-precipitation shows negative effects on particle reduction and cycleability.

並列關鍵字

layered structure

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