以NH_4FePO_4·H_2O为前驱体微波法合成LiFePO_4及其性能研究  

Characteristics of LiFePO_4 Synthesized from NH_4FePO_4·H_2O via Microwave Processing

作　　者：李维[1] 应皆荣[1] 万春荣[1] 姜长印[1] 唐昌平[1] 雷敏[1] 

机构地区：[1]清华大学,北京102201

出　　处：《稀有金属材料与工程》2007年第6期1046-1050,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50002006);清华大学基础研究基金(JCqn2005043)资助

摘　　要：用FeSO4、H3PO4、(NH4)2HPO4、NH3·H2O为原料合成NH4FePO4·H2O前驱体,再与LiCO3和蔗糖均匀混合,烘干后埋入活性炭粉中,在最大功率为800W的家用微波炉中以320～640W功率加热一定时间,获得LiFePO4。用扫描电镜和X射线衍射分析对NH4FePO4·H2O和LiFePO4的形貌结构进行了表征。研究了微波输入功率、加热时间对LiFePO4结构和电化学性能的影响。研究表明,在320W下微波加热15min得到的LiFePO4材料,具有良好的电化学性能。在0.05C放电倍率下可达到156mAh/g的放电比容量,在0.5C放电倍率下仍可达到115mAh/g的放电比容量。LiFePO4 cathode material is synthesized by means of microwave processing. The homogeneous mixture of Li2CO3, sugar and NH4FePO4·H2O precursor synthesized from FeSO4, H3PO4 and NH3·H2O was put inside the alumina crucible filled with activated carbon. The microwave irradiation to the crucible was conducted with an import power between 320-640 W for few minutes to obtain the LiFePO4 by using a domestic microwave oven of maximum power of 800 W. The NH4FePO4·H20 and LiFePO4 structures are characterized by XRD and SEM. The relationships of the import power and sintering time with the structure and electrochemical performances of LiFePO4 were studied. As a result, the sample obtained under an import power of 320 W and heated for 15 rain shows the best electrochemical performance, The cathode material has the initial discharge specific capacity of 156 mAh/g at 0.05 C and 115 mAh/g at 0.5 C, respectively.

关 键 词：锂离子电池 NH4FePO4·H2O LIFEPO4 

分 类 号：TM910.4[电气工程—电力电子与电力传动]