橄欖石結構的LiCoPO4作為鋰離子電池的優勢是具有相對高的工作電壓(4.8 V )和理論電容，然而，實際應用被受限於較低的鋰離子傳導率和導電率。可以藉由合成或是表面改性等方法進行改善，其中離子摻雜被認為是改善鋰離子和電子傳導率的重要依據。本實驗以溶膠-凝膠法合成並以元素摻雜入LiCoPO4。第一部分，摻入不同元素觀察充放電過程中間相的產生，透過電化學測試，觀察到除了本身LiCoPO4在充放電時出現的相反應外，摻雜鎳和鋅會在充放電過程中多了一次相轉換。收集的資料和 Rietveld 精修結果表示鎳和鋅有較強的鍵結能力。第二部分，根據鎳在LiCoPO4體積收縮能力較強和較強的鍵結力，作為摻雜的元素。XRD表明鎳成功摻入LiCoPO4，SEM分析摻雜鎳的形貌變化，EDS檢視元素分布。
在1 C電性表現中，LiCo0.94Ni0.06PO4/C初始電容為114.2 mAh/g，300圈後電容量仍有77.6 mAh/g ，有相對較高的保持率。此外，相比未摻雜的LiCoPO4，鎳摻雜減緩了極化效應，提高循環穩定性。Randles – Sevcik 方程式證明少量摻雜鎳，有助於提高鋰離子的傳導率。電化學阻抗譜(EIS)分析也可知，鎳的摻雜內阻抗減小且在循環過程中內阻變化較小，這對電性穩定來說是有利的。但是過度摻雜鎳影響到鋰離子正常脫嵌，使初始容量下降。本實驗得知摻雜量應控制在6%鎳，有較優異的電性表現。

Olivine-type LiCoPO4 proves its outstanding electrochemical properties as a cathode material for lithium ion battery with the benefits of the high operating potential and the high theoretical capacity. However, practical applications are limited by the lower lithium ion conductivity and electrical conductivity. Ion doping is considered as an important strategy to improve the intrinsic electron and ion conductivity of LiCoPO4. In this experiment, LiCoPO4 was synthesized by sol-gel method. The intermediate phase of Ni and Zn-doped LiCoPO4 was observed by electrochemical test , during a charge/discharge process. The reason is that nickel and zinc have strong bonding energy. According to that research, nickel was chosen as the doping element in LiCoPO4. XRD and Rietveld refinement indicated that the dopants were successfully introduced to the olivine lattice. SEM images indicated that Ni doping does not change the morphology of the material and EDS images confirmed that Ni are evenly distributed.
LiCo0.94Ni0.06PO4/C has an initial discharge capacity of 114.2 mAh/g ,shows better capacity retention after 300 cycles at 1 C. The Randles-Sevcik equation proves that a small amount of nickel doping improves the diffusivity of lithium ions. EIS analysis also shows that the doping of nickel reduces the internal resistance and the internal resistance decreases during the cycle, which is beneficial for electrical stability. However, the excessive amount of Ni would lead to the reduction of electrochemical performance of the electrode. Therefore, the experiment shows that the doping amount should be controlled at 6% nickel, which has excellent electrical performance.

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