Face-lifting the surface of LiNi0.8Co0.15Al0.05O2cathode via Y(PO3)3to form an in situ triple composite Li-ion conductor coating layer with the enhanced electrochemical performance

Wendong Cheng; Lei Li; Shuai Hao; Ling Liu; Yuxuan Wu; Jinsheng Huo; Yuyao Ji; Xingquan Liu

doi:10.1088/1361-6528/ac7577

Face-lifting the surface of LiNi_0.8Co_0.15Al_0.05O₂cathode via Y(PO₃)₃to form an in situ triple composite Li-ion conductor coating layer with the enhanced electrochemical performance

Nanotechnology. 2022 Jun 20;33(37). doi: 10.1088/1361-6528/ac7577.

Authors

Wendong Cheng¹, Lei Li¹, Shuai Hao¹, Ling Liu^{1

2}, Yuxuan Wu¹, Jinsheng Huo¹, Yuyao Ji¹, Xingquan Liu^{1

2}

Affiliations

¹ School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 610054, People's Republic of China.
² Sichuan Fuhua New Energy Hi-Tech Co., Ltd, Mianyang 621006, Sichuan, People's Republic of China.

PMID: 35654015
DOI: 10.1088/1361-6528/ac7577

Abstract

Due to the assets such as adequate discharge capacity and rational cost, LiNi_0.8Co_0.15Al_0.05O₂(NCA), a high-nickel ternary layered oxide, is regarded to be a favorable cathode contender for lithium-ion batteries. However, the superior commercial application is restricted by the surface residual alkaline lithium salt (LiOH or/and Li₂CO₃) of nickel-rich cathode materials, which will expedite the disintegration of the structure and the engendering of gas (CO₂). Therefore, in this paper, we devise and fabricate a Y(PO₃)₃modified LiNi_0.8Co_0.15Al_0.05O₂(NCA), intending to optimize the surface residual alkaline lithium salt (antecedent deportation of H₂O and CO₂) while forming anin situtriple composite Li-ion conductor coating (Y(PO₃)₃-Li₃PO₄-YPO₄) to enhance the electrochemical behavior. Under this method, the 2 mol% Y(PO₃)₃modified NCA electrode reveals exceptional rate capability (5 C/156.3 mAh g^-1) and extraordinary cycle stability after 200 cycles (2 C/88.3%), whereas the original sample is only 5 C/123.1 mAh g^-1and 2 C/71.2% after 200 cycles. Conspicuously, even under the draconian circumstances of the high temperature and the high rate at 55 °C/1 C, the 2 mol% Y(PO₃)₃modified NCA electrode sustains a high reversible capacity, with an admirable capacity retention rate of 89.4% after 100 cycles. These contented results signify that the surface remodeling tactic presents a viable scheme for ameliorating high-nickel materials' performance and appropriateness.

Keywords: Li-ion conductor coating; LiNi0.8Co0.15Al0.05O2; Y(PO3)3; cycle stability; in situ coating; rate capability; residual alkaline lithium salt.