因鋰鐵磷酸鹽LiFePO4具有成本低、穩定度高等特性，且所含元素皆為環境友善，所以被當成熱門研究之鋰離子正極材料，但目前遇到最主要的問題為材料本身導電度太差，改善方法可分為兩部份:一為減小particle size 其中採用溶液法來合成鋰鐵磷酸(LiFePO4)，本研究係以溶膠凝膠法(sol-gel method)製備LiFePO4二次鋰離子電池用正極材料，利用抗壞血酸做為還原劑;二為添加導電性物質，如碳源之類的有機物質或導電金屬，本研究係以果糖來添加，並以各種不同的熱處理溫度來找出最佳的合成條件。
磷酸鋰鐵粒徑隨著熱處理溫度升高而升高，本實驗發現熱處理溫度在500℃有較佳粒徑和在600℃有較低直流電阻抗。
由實驗結果發現而隨著燒結溫度增加 (500~700)℃，其結晶強度、粉體粒徑亦隨之增大。
再添加導電物質方面，添加果糖或抗壞血酸等碳源對導電度有明顯提升，而且對其粒徑縮小也有所幫助但是添加過多時對導電度的提升也是效果有限。

LiFePO4 has been actively investigated as cathode material for Li ion secondary batteries. LiFePO4 has attracted great interest due to its low cost , thermal stability, and environment benignity of its element. The major obstacles of LiFePO4 are two intrinsic conductivity. Improving the conductivity have two methods to solve via two main techniques; One is the reduction of the grain size, it is achieved by solution methods make LiFePO4. In this study, we synthesize LiFePO4 by sol-gel method for cathode material of secondary Li ion batteries, and use ascorbic acid as reducing agent; Two is the manufacture of LiFePO4 coated with high conductivity material; like organic material of carbon source and electronically metal. In this study, we aid fructose and try to find out the best synthetic condition by various thermal treatment.
The grain size of LiFePO4 is increasing with the thermal treatment temperature. We also find that the optimum particle size (32-38nm) are sintered at 500℃ and the lower DC electrical resistivity is at 600℃ in this experiment.
From this experiment, when sintered temperature approximately (500-700℃) increase , the crystalline strength and grain size also increase with temperature.
In the conductive substance addition, the source of carbon which is fructose or ascorbic acid added to LiFePO4 that could increase conductivity of materials obviously, and decrease particle size. The conductivity increasing limit to the quantity of additions.

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