采用复合锂源制备的LiFePO4/C材料及其碳含量优化
Preparation by Employing Mixed Lithium Source and Carbon Content Optimization of LiFePO4/C Materials
作者单位E-mail
吴关 武汉科技大学, 省部共建耐火材料与冶金国家重点实验室, 武汉 430081  
周盈科 武汉科技大学, 省部共建耐火材料与冶金国家重点实验室, 武汉 430081 Zhouyingke@wust.edu.cn 
摘要: 采用Li2CO3与LiOH·H2O为复合锂源制备LiFePO4/C材料,同时优化了材料中的碳含量。由于氢氧化锂的熔点低于碳酸锂,在同样的烧结温度下,采用复合锂源可以获得更佳的熔融状态,在高温合成过程中使锂离子具有更高的扩散性,能够更顺利地得到高纯度的LiFePO4晶相。通过优化碳包覆量达到提高导电性与控制晶粒尺寸的目的,使材料晶相结构完整,纯度高,表现出优秀的加工性能与电化学性能。所制得的LiFePO4/C材料放电克容量达到158.2 mAh·g-1,在全电池中经过100 d存储后容量保持率仍然高于94.0%,具有优异的长期可靠性。
关键词: 磷酸铁锂  锂源  碳含量  长期可靠性
基金项目: 国家自然科学基金(No.51372178)和湖北省自然科学杰出青年基金(No.2013CFA021)资助项目。
Abstract: The LiFePO4/C composites have been successfully synthesized by adopted Li2CO3 and LiOH·H2O as mixed lithium source, the carbon content of the as-prepared LiFePO4/C materials have been optimized. Since the melting point of LiOH is lower than that of Li2CO3, adopt mixed lithium source can achieve better melting state at the same temperature, and favors the conductivity of lithium ions during the high temperature synthetic process to obtain pure LiFePO4 structure. The carbon content of LiFePO4/C composites were optimized to improve the electroconductivity and control the particle size. The LiFePO4/C cathode displayed excellent crystal structure, processability and electrochemical performances. The discharge capacity of the as-obtained LiFePO4/C composites is as high as 158.2 mAh·g-1, after 100 days storage, the capacity retention of full cells is still maintained higher than 94.0%, representing the superior long-term reliability of the optimized LiFePO4/C material.
Keywords: LiFePO4  lithium source  carbon content  long-term reliability
投稿时间:2017-12-19 修订日期:2018-03-12
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吴关,周盈科.采用复合锂源制备的LiFePO4/C材料及其碳含量优化[J].无机化学学报,2018,34(5):850-856.
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