Effect of Y(PO3)3 double-coating modification on the electrochemical properties of Li[Ni0.8Co0.15Al0.05]O2
李泓漪 大连理工大学材料科学与工程学院, 辽宁省能源材料及器件重点实验室, 大连 116024  
吴爱民 大连理工大学材料科学与工程学院, 辽宁省能源材料及器件重点实验室, 大连 116024 aimin@dlut.edu.cn 
赵刘洋 大连理工大学材料科学与工程学院, 辽宁省能源材料及器件重点实验室, 大连 116024  
刘新朋 大连理工大学材料科学与工程学院, 辽宁省能源材料及器件重点实验室, 大连 116024  
陈凤琴 陕西煤业化工技术研究院有限责任公司, 西安 710065  
李爱魁 大连理工大学电气工程学院, 大连 116024 liaikui@dlut.edu.cn 
黄昊 大连理工大学材料科学与工程学院, 辽宁省能源材料及器件重点实验室, 大连 116024  
摘要: 在镍钴铝酸锂正极材料 Li[Ni0.8Co0.15Al0.05]O2(NCA)制备过程中表面遗留的碱性物质会严重影响其循环稳定性能,针对这一难题,提出使用Y(PO3)3对其进行表面包覆改性,利用Y(PO3)3与表面残留的LiOH反应消除表面残碱,并探讨包覆改性对NCA整体性能的影响机制。测试分析结果表明,在低温煅烧过程中前驱体表面会形成均匀致密的Y(PO3)3和LiPO3包覆层,LiPO3有较高的离子电导率,双包覆层能够防止活性物质在电化学循环过程中与电解液相互接触时发生有害副反应,提高电极材料的循环稳定性。其中Y(PO3)3包覆量(质量分数)为1%的样品在0.1C下的首次库仑效率从未改性样品的78.65%提高到88.50%,在1C下循环150圈后容量保持率从59.38%提高到85.33%,相比于未改性样品具有更高的首次库仑效率和更优异的循环性能。
关键词: 电化学  高镍正极材料  磷酸盐  表面涂层  循环稳定
基金项目: 陕煤-秦岭基础科学研究五年行动计划资助。
Abstract: Aiming at the difficulty that the alkaline substances left on the surface of Li[Ni0.8Co0.15Al0.05]O2 (NCA) precursor preparation and lithium preparation sintering process can seriously affect its cycling stability performance, a proposal was made to employ Y(PO3)3 for surface coating modification. This modification involves utilizing Y(PO3)3 to react with the surface residual LiOH to eliminate surface residual alkali and investigate the impact mechanism of coating modification on the overall performance of NCA. The thickness of the cladding layer was not affected by the residual alkali content on the surface. Test analysis results demonstrate that during low-temperature calcination, a uniform and dense coating layer of Y(PO3)3 and LiPO3 formed on the precursor's surface. LiPO3 exhibited higher ionic conductivity, and the dual coating layer can prevent harmful side reactions between the active material and the electrolyte during the electrochemical cycling process, enhancing the cycling stability of the electrode material. Specifically, for samples with a mass fraction of 1% Y(PO3)3 coating, at 0.1C, the initial Coulombic efficiency increased from 78.65% for unmodified samples to 88.50%. After 150 cycles at 1C, the capacity retention rate increased from 59.38% to 85.33%. Compared to unmodified samples, it showed higher initial Coulombic efficiency and superior cycling performance.
Keywords: electrochemistry  high nickel cathode material  phosphate  surface coating  cyclic stability
投稿时间:2023-12-20 修订日期:2024-05-07
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