Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10150402 | Electrochimica Acta | 2018 | 35 Pages |
Abstract
The surface coating of dual-conductive layers is implemented to optimize the electrochemical performance of LiNi0.6Co0.2Mn0.2O2 (NCM) under high cut-off voltage (4.5â¯V) by the integrated use of sol-gel method and in-situ chemical polymerization. The X-ray powder diffraction (XRD) and Rietveld refinements results indicate that the dual-conductive layers hardly affect the crystal structure of NCM. Field emission scanning electron microscopy (FESEM), Energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), selected area electron diffraction (SAED), and field emission transmission electron microscopy (FETEM) results confirm that the dual-conductive layers with Li3VO4 and polypyrrole (PPy) are successfully coated on the spherical particle surface and inhibit the dissolution of transition metals from crystal structure. The Li3VO4-PPy coated NCM sample exhibits excellent cycling stability at 0.5â¯C (1â¯Câ¯=â¯180â¯mAh/g) under high cut-off voltage (4.5â¯V), with a retention rate of 93.7% compared to 73.6% for the pristine NCM after 100 cycles. Moreover, it also shows super cycling performance at large current (2â¯C) with a retention rate of 93.8%, whereas the pristine NCM is only 61.6% after 100 cycles.
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Authors
Qiwen Ran, Hongyuan Zhao, Youzuo Hu, Qianqian Shen, Wei Liu, Jintao Liu, Xiaohui Shu, Meiling Zhang, Shanshan Liu, Ming Tan, Hao Li, Xingquan Liu,