| 偏铝酸锂/环化聚丙烯腈共包覆改性高镍层状正极材料的制备 | |
| Preparation of modified high-nickel layered cathode with LiAlO2/cyclopolyacrylonitrile dual-functional coating | |
| 摘要: 构建表面无机-有机复合包覆层，用于改善高镍层状(NCM811)正极材料结构和界面不稳定问题。复合包覆层由纳米偏铝酸锂(LiAlO2，LAO)和环化聚丙烯腈(cPAN)构成。该复合包覆层中LAO是一种典型的锂离子导体，可提供Li+迁移通道；PAN环化后，可产生离域的π键，形成具有电子导电性的cPAN。材料表面复合包覆层的结构及成分研究表明，该复合包覆层均匀分布在 NCM811 材料表面。半电池测试结果表明，在 2.7~4.3 V(vs Li/Li+)电压范围内，在 180 mA·g-1电流密度下，改性后的NCM811材料循环150周后容量保持率为84.8%。而同样条件下，原始NCM811材料容量保持率为65.5%。该复合包覆层可有效提升NCM811结构和界面稳定性，减少电解液分解，降低界面阻抗。 | |
| 关键词: 锂离子电池 高镍层状正极 复合包覆 界面稳定性 离子电导率 | |
| 基金项目: 国家重点研发专项课题 (No. 2022YFB2502103)、国家自然科学基金 (No. 22279107，22309153)和中央高校基本科研业务费(No.20720230039)资助。 | |
| Abstract: The structural and interfacial instability of high nickel layered cathode material (NCM811) were improved by the construction of inorganic-organic dual-coating. The dual-coating layer was composed of nano lithium metaluminate (LiAlO2, LAO) and cyclopolyacrylonitrile (cPAN). The LAO is a typical lithium-ion conductor, which can be used as a surface coating material to ensure rapid Li+ migration at the interface. In addition, the polyacrylonitrile (PAN) undergoes cross-linked cyclization reactions, resulting in the formation of a delocalized π bond and the formation of the cPAN with electronic conductivity after low-temperature heat treatment. The structure and composition of the dual-coating layer were carefully characterized, which indicates its uniform distribution on the surface of the NCM811 material. The as-obtained modified sample showed an electrochemical capacity retention of 84.8% after 150 cycles in the voltage range of 2.7-4.3 V (vs Li/Li+) at the current density of 1C (180 mA·g-1). Under the same test conditions, the capacity retention of pristine NCM811 was only 65.5%. The dualcoating layer can effectively protect the active material and could reduce the electrolyte decomposition on the material surface to a certain extent, leading to a decrease in interfacial impedance. | |
| Keywords: Li-ion battery Ni-rich layered cathode composite coating interfacial stability ion conductivity | |
| 投稿时间：2024-05-22 修订日期：2024-07-05 | |
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| 刘君珂,郑坤贵,孙雯静,白高杨,白国栋,尹祖伟,周尧,李君涛.偏铝酸锂/环化聚丙烯腈共包覆改性高镍层状正极材料的制备[J].无机化学学报,2024,40(8):1461-1473. | |
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