Effects of Al-Doping on Properties of Ni-Rich Cathode Materials Employing Different Aluminum Sources

Authors

Dan-feng WANG, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Yi-xiao LI, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Wei-li WANG, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;
Yong YANG, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China;Follow

Corresponding Author

Yong YANG(yyang@xmu.edu.cn)

Abstract

In order to investigate the effects of Al-doping on the structure, morphology and electrochemical performance of Ni-rich layered oxides, the NCA cathode materials with a nominal chemical formula of LiNi_0.8Co_0.15Al_0.05O₂ were prepared by two methods with different aluminum sources. One was the solid phase method: the precursor (Ni_0.84Co_0.16(OH)₂) prepared by co-precipitation was mixed with lithium and aluminum source (nano-Al₂O₃ or Al(NO₃)₃) thoroughly, and calcined at 780 ℃ for 15 h under an oxygen atmosphere. The other was the co-precipitation method: the NCA precursor (Ni_0.8Co_0.15Al_0.05(OH)_2.05) was synthesized by co-pre- cipitation method employing either Al₂(SO₄)₃ or NaAlO₂ as an aluminum source, and the NCA precursor was then mixed with lithium source and sintered at 780 ℃ for 15 h under an oxygen atmosphere. The results showed that Al-doping reduced the degree of cation mixing and maintained the stability of the layered structure, thereby reducing the voltage drop and improving its cycle performance. The NCA material prepared by co-precipitation method employing NaAlO₂ as the aluminum source revealed the morphology of dense microspheres with a uniform size distribution and a well-layered structure of low Ni²⁺/Li⁺ mixing, acheving the best performance. The as-prepared NCA cathode material delivered a high discharge capacity (198 mAh·g^-1 at 0.1C) corresponding to 94.6% coulombic efficiency and good cycle stability (a capacity retention of 70% after 200 cycles at 1C) between 3.0 V and 4.3 V.

Graphical Abstract

Keywords

Lithium-ion battery, co-precipitation method, Ni-rich cathode; LiNi0.8Co0.15Al0.05O2, doping

DOI Link

https://doi.org/10.13208/j.electrochem.180328

Publication Date

2019-12-28

Online Available Date

2018-05-02

Revised Date

2018-04-23

Received Date

2018-03-28

Recommended Citation

Dan-feng WANG, Yi-xiao LI, Wei-li WANG, Yong YANG. Effects of Al-Doping on Properties of Ni-Rich Cathode Materials Employing Different Aluminum Sources[J]. Journal of Electrochemistry, 2019 , 25(6): 660-668.
DOI: 10.13208/j.electrochem.180328
Available at: https://jelectrochem.xmu.edu.cn/journal/vol25/iss6/3