Oxygen-defects evolution to stimulate continuous capacity increase in Co-free Li-rich layered oxides

作     者：Yibin Zhang Xiaohui Wen Zhepu Shi Bao Qiu Guoxin Chen Zhaoping Liu Yibin Zhang;Xiaohui Wen;Zhepu Shi;Bao Qiu;Guoxin Chen;Zhaoping Liu

作者机构：Ningbo Institute of Materials Technology and Engineering(NIMTE)Chinese Academy of Sciences(CAS)Ningbo 315201ZhejiangChina School of Materials Science and Chemical EngineeringNingbo UniversityNingbo 315201ZhejiangChina Department of Chemical and Environmental EngineeringFaculty of Science and EngineeringUniversity of Nottingham Ningbo Chin1Ningbo 315199ZhejiangChina 

出 版 物：《Journal of Energy Chemistry》 (能源化学（英文版）)

年 卷 期：2023年第82卷第7期

页      面：259-267,I0006页

核心收录：

学科分类：0808[工学-电气工程] 08[工学] 0807[工学-动力工程及工程热物理] 080501[工学-材料物理与化学] 0804[工学-仪器科学与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 

基　　金：supported by the National Natural Science Foundation of China(52272253) the"Lingyan"Research and Development Plan of Zhejiang Province(2022C01071) the S&T Innovation 2025 Major Special Programme of Ningbo(2018B10081) the Natural Science Foundation of Ningbo(202003N4030) the Youth Innovation Promotion Association of Chinese Academy of Sciences(2022299)。 

主　　题：Li-rich layered oxide Irreversible oxygen loss Nano-scale oxygen defect Li_(2)MnO_(3)-domain activation 

摘      要：Though oxygen defects are associated with deteriorated structures and aggravated cycling performance in traditional layered cathodes,the role of oxygen defects is still ambiguous in Li-rich layered oxides due to the involvement of oxygen redox.Herein,a Co-free Li-rich layered oxide Li_(1.286)Ni_(0.071)Mn_(0.643)O_(2)has been prepared by a co-precipitation method to systematically investigate the undefined effects of the oxygen defects.A significant O_(2)release and the propagation of oxygen vacancies were detected by operando differential electrochemical mass spectroscopy(DEMS)and electron energy loss spectroscopy(EELS),respectively.Scanning transmission electron microscopy-high angle annular dark field(STEMHAADF)reveals the oxygen vacancies fusing to nanovoids and monitors a stepwise electrochemical activation process of the large Li_(2)MnO_(3)domain upon cycling.Combined with the quantitative analysis conducted by the energy dispersive spectrometer(EDS),existed nano-scale oxygen defects actually expose more surface to the electrolyte for facilitating the electrochemical activation and subsequently increasing available capacity.Overall,this work persuasively elucidates the function of oxygen defects on oxygen redox in Co-free Li-rich layered oxides.