奈米α-LiFeO2 正極材料之合成及特性研究

The Preparation and Characterization of Nano-sized α-LiFeO2-based Cathode Materials

林經堯(Cheng-Yao 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(2008年)

摘要

奈米尺寸顆粒的岩鹽鑛相(α-LiFeO2) 鋰鐵氧基鋰離子電池正極材料可以由FeCl3水溶液水解而得的β-FeOOH為起始材料，藉由離子置換法及固態反應法製得。以感應耦合電漿原子發射光譜儀、X光繞射儀與掃瞄式電子顯微鏡鑑定合成粉末之化學組成、結晶結構與表面形貌。以循環伏安與循環充放電檢測材料之電化學特性。以臨場X光繞射檢驗充放電過程中電極材料結晶結構之改變。本研究中以離子置換法於110oC下合成與固態反應法於300oC下合成之奈米級α-LiFeO2基粉末具有Fe2+/ Fe3+ 氧化還原對之電化學活性，其可逆比電容量達100~120 mAh/g。

關鍵字

正極材料 ； 鋰離子電池 ； 岩鹽鑛相鋰鐵氧 ； 離子置換法

並列摘要

Nano-sized α-LiFeO2 powders as cathode material for lithium batteries were prepared by a solid-state reaction and an ion-exchanging methods by having LiOH‧H2O reacts with β-FeOOH that was derived from the hydrolysis of FeCl3 in aqueous solutions. The composition, the crystalline structure, and the morphology of the prepared powders were determined with ICP, XRD, and SEM, respectively. The electrochemical properties, reaction occurred, and structure change upon cycling are investigated with capacity retention study, cyclic voltammetry, and in-situ XRD. The nano-sized α-LiFeO2 powders prepared by the ion-exchange reaction and solid-state reaction methods in the study are electrochemical active. The samples prepared by solid-state reaction at 300oC and ion-exchange reaction in 2-ethoxythanol at 110oC exhibit reversible capacities ranging between 100 and 120 mAh/g due to the reaction of Fe2+/Fe3+ redox couple.

並列關鍵字

lithium battery ； cathode material ； α-LiFeO2

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