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Synthesis and electrochemical properties of cation‐disordered rock‐salt x Li 3 NbO 4 ·(1 − x ) NiO compounds for Li‐ion batteries
Author(s) -
Wu Zongjian,
Luo Qi,
Lin Lin,
Yang Wei,
Zou Hanbo,
Yu Haijun,
Chen Shengzhou
Publication year - 2020
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.6050
Subject(s) - non blocking i/o , electrochemistry , x ray photoelectron spectroscopy , salt (chemistry) , analytical chemistry (journal) , rietveld refinement , cathode , redox , chemistry , materials science , crystal structure , crystallography , inorganic chemistry , chemical engineering , electrode , catalysis , biochemistry , chromatography , engineering
Summary In this study, Li‐excess cation‐disordered rock‐salt cathode materials, x Li 3 NbO 4 ·(1 − x ) NiO (LNNO, 0.55 ≤ x ≤ 0.7), are synthesized to explore the effect of composition on the structure and electrochemical performance using a sol‐gel method for the first time. X‐ray diffraction results combined with Rietveld refinements demonstrate that pure cation‐disordered rock‐salt structure can be obtained at x ≥ 0.6. The electron microscopy results of samples demonstrate the irregular particles with size of 1 to 10 μm and rock‐salt structure is further confirmed. The samples with x = 0.6, 0.65, and 0.7, respectively, exhibit the much higher reversible capacity than their theoretical Ni 2+ /Ni 3+ capacity attributing to anionic redox reaction. The LNNO6 sample deliver the first discharge capacity 155.35 mAh/g and 82.9% capacity retention after 40 cycles. In addition, X‐ray photoelectron spectroscopy analyses and d V /d Q measurements are utilized to investigate the restricted electrochemical behaviors and performances which are constrained by the competition between Ni 2+ /Ni 3+ and O 2− /O − .