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Enhanced Electrochemical Capability of LiNi 1/3 Co 1/3 Mn 1/3 O 2 Cathode Materials Coated with Fluoroborate Glass for Lithium‐Ion Batteries
Author(s) -
Zhang Qibing,
Wang Lei,
Zhu Chunhua,
Sun Zhipeng,
Cheng Wenhua,
Lv Dingding,
Ren Wei,
Bian Liang,
Xu Jinbao,
Chang Aimin
Publication year - 2017
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201600828
Subject(s) - electrochemistry , lithium (medication) , materials science , scanning electron microscope , transmission electron microscopy , analytical chemistry (journal) , cathode , ion , electrode , chemistry , nanotechnology , composite material , medicine , organic chemistry , chromatography , endocrinology
A LiNi 1/3 Co 1/3 Mn 1/3 O 2 (NCM) cathode material is coated with fluoroborate glass ( x Li 2 O‐ y B 2 O 3 ‐ z LiF) to improve the electrochemical performance of lithium‐ion batteries. An x Li 2 O‐ y B 2 O 3 ‐ z LiF layer was successfully coated onto the surface of NCM by using a solution‐phase method. The resulting materials are characterized by using X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy. The x Li 2 O‐ y B 2 O 3 ‐ z LiF‐coated NCM exhibits a superior discharge capacity, rate capability, and cycling stability than those of the uncoated material. Notably, the initial discharge capacity of bare and 2Li 2 O‐B 2 O 3 ‐LiF‐coated NCM were 182.1 and 207.5 mAhg −1 , respectively, in the voltage range from 2.5 to 4.5 V. At a rate of 5C, the discharge capacity of Li 2 O‐B 2 O 3 ‐LiF‐coated NCM is 144.4 mAhg −1 , whereas that of bare NCM is 76.7 mAhg −1 . After 50 cycles at a rate of 0.2C, the capacity retentions of Li 2 O‐B 2 O 3 ‐LiF‐, 2Li 2 O‐B 2 O 3 ‐LiF‐, Li 2 O‐2B 2 O 3 ‐LiF‐, and Li 2 O‐B 2 O 3 ‐2LiF‐coated NCM are 96.8, 97.2, 95.6, and 95.2%, respectively, whereas the capacity retention of bare NCM is 81.4%. Cyclic voltammetry and electrochemical impedance spectroscopy results indicate that the x Li 2 O‐ y B 2 O 3 ‐ z LiF coating reduces electrode polarization and decreases charge‐transfer resistance at the electrolyte–electrode interface, further improving the electrochemical activity of the NCM cathode material.