Influence of calcination atmosphere on structure and electrochemical behavior of LiNi0.6Co0.2Mn0.2O2 cathode material for lithium-ion batteries. (10th March 2017)

• Record Type: Journal Article
• Authors: Yuan, Jing; Wen, Jianwu; Zhang, Jinbo; Chen, Daoming; Zhang, Dawei
• Is Part Of: Electrochimica acta. Volume 230(2017)
• Page Start: 116
• Page End: 122
• Publication Date: 2017-03-10
• Subjects: lithium-ion batteries -- LiNi0.6Co0.2Mn0.2O2 -- cation mixing -- calcination atmosphere; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2017.01.102
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: The specific influence of calcination atmosphere (oxygen or air) on the structure, morphology and electrochemical properties of Ni-rich LiNi0.6 Co0.2 Mn0.2 O2 material was individually investigated in detail. The functional mechanism of oxygen instead of air atmosphere during heat-treatment on improving electrochemical performance of LiNi0.6 Co0.2 Mn0.2 O2 was revealed using electrochemical charge/discharge test, EIS and XPS. Abstract: Layered Ni-rich LiNi0.6 Co0.2 Mn0.2 O2 (LNCMO) materials are prepared by calcining the mixture of Ni0.6 Co0.2 Mn0.2 (OH)2 precursor (co-precipitation method) and Li salts (Li2 CO3 ). Two different caicination atmosphere (air and oxygen) are adopted to obtain final two samples of LNCMO-A (air) and LNCMO-O (oxygen) to individually investigate the influence of oxygen instead of air atmosphere on the structure and electrochemical behavior of the LNCMO materials. Both two samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electrochemical charge/discharge tests including cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). XRD and SEM results show the LNCMO-O sample possesses relatively smaller Li + /Ni 2+ cation mixing, better layer-structure ordering and smaller primary particle size. The electrochemical charge/discharge test results show the LNCMO-O sample exhibits superior discharge capacity (184.6 mAh g −1 at 0.1C), higher cycling retention (91.4% after 100 cycles at 0.5C) and promoted rate performance. Further XPS, CV and EIS analyses on the promotion mechanism demonstrate that the oxygen-atmosphere calcination is important and beneficial to improve the electrochemical performance for Ni-rich LiNi0.6 Co0.2 Mn0.2 O2 material.