本研究利用溶膠凝膠法在800oC空氣下煅燒12小時成功製備不同複合比例xLi2MnO3(1-x)LiNi1/3Mn1/3Co1/3O2 (x = 0, 0.3, 0.5, 0.7 and 1.0) 富鋰層狀正極材料，通過X-ray繞射儀(XRD) 和電化學測試等檢測方式了解所得樣品的晶體結構與電化學性能，XRD結果顯示Li2MnO3組成含量提高時，可觀察到(020)面及(110)面之繞射峰強度增高及2θ = 64o~66o的繞射峰往高角度偏移，其原因可歸咎於超晶格結構的增加及平均離子半徑的下降。充放電結果顯示Li2MnO3組成的添加可以提升層狀正極材料的電容量及穩定性，同時Li2MnO3組成也會造成不可逆反應，使電容量下降。因此研究結果顯示到在x = 0.5 的比例下具有最高的電容量，放電電容量高達250.1 mAh/g。
另一方面，本研究使用Li1.2Ni0.13Mn0.54Co0.13O2 (5:5)富鋰正極材料分析材料的衰退行為，充放電結果顯示在0.05C充放電條件下，放電電容量從276 mAh/g (第1圈)下降到169 mAh/g (第30圈)，TEM分析結果證明富鋰層狀正極材料在充放電循環後材料表面會由layer層狀結構相變成spinel尖晶石結構以及表面超晶格結構的消失，其現象可以用過渡金屬離子的遷移到過渡金屬離子層及鋰離子層中的鋰離子空缺來解釋。HRTEM顯示充放電循環後的材料可以觀察到非晶相區域及晶格扭曲的現象，本研究推測非晶相區域及晶格扭曲可能會阻礙鋰離子的移動，造成越來越少的鋰離子可以作嵌出嵌入的充放電行為，因此造成電容量的衰退。

Recently, lithium-rich layered oxides have became attractive cathode materials for high storage energy applications. Lithium rich layered oxides materials, represented by the general formula xLi2MnO3‧(1 - x)LiMO2 in which M is Mn、Ni and Co are of interest for both high-power and high capacity lithium ion cells. In this study, a series of cathode materials with molecular notation of xLi2MnO3(1-x)LiNi1/3Mn1/3Co1/3O2 (x = 0, 0.3, 0.5, 0.7 and 1.0) were synthesized by sol–gel method to investigate their structure and electrochemical properties. The crystal structure of the samples were examined by X-ray diffraction. It is show that the structure of xLi2MnO3(1-x)LiNi1/3Mn1/3Co1/3O2 possessed the composite characteristic composite. Its electrochemical performance is examined with galvanostatic charge/discharge. Increasing Li2MnO3 content may stabilize Li rich structure to increase capacity but the irreversible reaction of Li2MnO3 would reduce capacity. These factors resulted that 0.5Li2MnO30.5LiNi1/3Mn1/3Co1/3O2 cathode exhibited best electrochemical performance with discharge capacity 250 mAh/g.. To understand the capacity fading for Li-rich cathode materials, Li[Li0.2Mn0.54Ni0.13Co0.13]O2 as a cathode material for Li-ion battery has been investigated. It exhibited high initial charge/discharge capacity of 327 mAh/g and 276 mAh/g at 0.05C rate (15mA/g) respectively. After 30 cycles, the discharge capacity decayed 169 mAh/g. Transmission electron microscopy (TEM) images along with nano beam diffraction pattern (NDP) results showed the presence of spinel phases on the particles surface, indicating a layered to spinel like phase transformation. The results obtained from derivation of reaction equation and diffraction studies provided the fundamental understanding of the structural transformation pathways in Li-rich cathodes and the lattice distortion and amorphous region were found by HRTEM image, which may block removing of Li ions then resulting capacity fading.

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