FePO4 Coating Modification of LiNi0.8Co0.15Al0.05O2 Cathode Materials
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, 先进材料与纳米技术研究院, 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, 先进材料与纳米技术研究院, 武汉 430081 
摘要: 使用液相包覆工艺对LiNi0.8Co0.15Al0.05O2(NCA)材料进行FePO4包覆改性,利用FePO4优异的结构稳定性与热稳定性,对NCA的长期可靠性与安全性能进行改良。重点研究FePO4包覆对NCA材料的改性效果,以及不同包覆量造成的NCA材料电化学性能差异。表面包覆的FePO4保护层,能够防止NCA材料与电解液直接接触发生副反应,抑制长期循环过程中过渡金属离子的溶出,保持结构的长期稳定性。当包覆量为1.0%(w/w)时,NCA材料表现出最优的综合性能,充放电循环800次后,容量保持率依然高达95%,25℃下存储100 d后,容量保持率也高于95%,达到了兼顾能量密度、使用寿命及安全性能的理想效果。
关键词: LiNi0.8Co0.15Al0.05O2  FePO4  包覆  安全性能  电化学性能
基金项目: 国家自然科学基金(No.51372178)和湖北省杰出青年基金(No.2013CFA021)资助项目。
Abstract: The surface modification of LiNi0.8Co0.15Al0.05O2 (NCA) material was conducted by FePO4 coating through a liquid synthetic process. The excellent structural and thermal stability of FePO4 was utilized to improve the long-term reliability and safety of NCA material. The different electrochemical properties of NCA material caused by different coating amount were intensively studied. The FePO4 coating layer is able to prevent the side reaction between NCA particles and electrolytes, suppress the transition metal dissolve from the layered structure, and maintain the long-term stability. The optimum coating content of FePO4 is 1.0% (w/w) best overall performances can be achieved in this situation, after 800 charge-discharge cycles, the capacity retention rate is still as high as 95%. After 100 days storage at 25℃, the capacity retention tate maintains higher than 95%, the energy density, service life and safety of NCA materials are well balanced after modification.
Keywords: LiNi0.8Co0.15Al0.05O2  FePO4  coating  safety  electrochemical performance
投稿时间:2018-03-21 修订日期:2018-04-21
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