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Improving the Electrochemical Performance of Ni‐Rich LiNi 0.8 Co 0.1 Mn 0.1 O 2 by Enlarging the Li Layer Spacing
Author(s) -
Wu Kang,
Jia Guofeng,
Shangguan Xuehui,
Yang Guowei,
Zhu Zenghu,
Peng Zhengjun,
Zhuge Qin,
Li Faqiang,
Cui Xiaoling,
Liu Suqin
Publication year - 2018
Publication title -
energy technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.91
H-Index - 44
eISSN - 2194-4296
pISSN - 2194-4288
DOI - 10.1002/ente.201700939
Subject(s) - electrochemistry , materials science , cathode , doping , sintering , lithium (medication) , analytical chemistry (journal) , impurity , electrode , metallurgy , chemistry , medicine , optoelectronics , organic chemistry , chromatography , endocrinology
Ni‐rich cathode materials have high capacities but exhibit serious capacity attenuation. Therefore, a strategy for modifying a LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode material by Na doping of the Li + sites is proposed to improve its electrochemical performance. In this work, Li 1−x Na x Ni 0.8 Co 0.1 Mn 0.1 O 2 (x=0, 0.01, 0.03) materials are synthesized by a co‐precipitation and solid‐state sintering method, and their structures and electrochemical properties are analyzed. X‐ray diffraction (XRD) results suggest that all the prepared materials have a typical hexagonal layered structure with no impurities. The spacing of the Li layers increases from 2.59251 Å to 2.59805 Å, which shows that a small amount of larger Na ions (0.102 nm) occupy the Li sites (0.076 nm). Additionally, electrochemical measurements show that the high‐rate performance and cycling stability are significantly improved when some of the Li + sites in LiNi 0.8 Co 0.1 Mn 0.1 O 2 are occupied by Na + . Specifically, the capacity retention of Li 0.99 Na 0.01 Ni 0.8 Co 0.1 Mn 0.1 O 2 is 91 % after 100 cycles at a rate of 10 C. Meanwhile, the mechanism about electrochemical performance was improved by doping Na + into Li + sites of LiNi 0.8 Co 0.1 Mn 0.1 O 2 has been further discussed.