Fluorine Doping Induced Crystal Space Change and Performance Improvement of Single Crystalline LiNi 0.6 Co 0.2 Mn 0.2 O 2 Layered Cathode Materials
Fluorine Doping Induced Crystal Space Change and Performance Improvement of Single Crystalline LiNi 0.6 Co 0.2 Mn 0.2 O 2 Layered Cathode Materials
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DOI：
10.1002/celc.202100756
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发表时间：
2021-08
期刊：
影响因子：
4
通讯作者：
Huang Xiao;Pengfei Zhang;Zhaofeng Liu;Ben Ma;Yingke Zhou;Xiaohui Tian
中科院分区：
文献类型：
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作者：
Huang Xiao;Pengfei Zhang;Zhaofeng Liu;Ben Ma;Yingke Zhou;Xiaohui Tian
Li-Ni-Co-Mn-O层状正极材料由于其适中的成本和高的比容量而具有用于先进锂离子电池的前景。然而，需要克服高电流下的低电子电导率和差的稳定性，以满足不断增长的需求。本文采用水热法合成了六方结构的LiNi 0. 6Co 0. 2 Mn 0. 2 O2单晶纳米片，并对其进行了可控的氟掺杂以提高其储锂性能。氟掺杂不仅可以改善层状结构，还可以增加晶格氧含量，促进锂离子迁移和层状LiNi0.6Co0.2Mn0.2O2的晶体结构稳定性。优化的氟掺杂导致单晶LiNi0.6Co0.2Mn0.2O2纳米片具有优异的容量和循环稳定性，其原始容量为168.3 mAh g−1，并且在1.0 C下超过100次循环的优异容量留存率为94.5%，其上级优于对照样品并且保持了锂离子电池应用的潜力。
The Li−Ni−Co−Mn−O layered cathode materials are promising for the advanced lithium‐ion batteries due to their moderate cost and high specific capacity. However, the low electronic conductivity and poor stability at high currents need to be overcome to meet the ever‐growing demands. In this work, single crystal hexagonal nanosheets of LiNi0.6Co0.2Mn0.2O2are synthesized by the hydrothermal process, which are further controllably doped with fluorine to improve the lithium storage performance. The fluorine doping can not only improve the layered structure, but also increase the lattice oxygen content, to promote the lithium‐ion migration and crystal structure stability of the layered LiNi0.6Co0.2Mn0.2O2. Optimized fluorine doping leads to excellent capacity and cyclic stability of the single crystal LiNi0.6Co0.2Mn0.2O2nanosheets with an original capacity of 168.3 mAh g−1, and an excellent capacity retention rate of 94.5 % at 1.0 C over 100 cycles, which are superior to the control samples and hold potential for the lithium‐ion battery applications.