First-principles calculations to investigate the impact of fluorine doping on electrochemical properties of Li-rich Li 2 MnO 3 layered cathode materials

• Published in: RSC advances Vol. 14; no. 36; p. 26516
• Main Authors: Zeng, Xiang-Ming, Liu, Jing, Su, Jiang-Bin, Wang, Fa-Hui, Li, Yan-Bing, Zhan, Chang-Jun, Liu, Ming, Wu, Run-Sheng, Hu, Jun-Ping, Zheng, Feng
• Format: Journal Article
• Language: English
• Published: England 16.08.2024
• ISSN: 2046-2069

Li-rich layered oxides are promising candidates for high-capacity Li-ion battery cathode materials. In this study, we employ first-principles calculations to investigate the effect of F doping on Li-rich Li MnO layered cathode materials. Our findings reveal that both Li MnO and Li MnO F exhibit significant volume changes (greater than 10%) during deep delithiation, which could hinder the cycling of more Li ions from these two materials. For Li MnO , it is observed that oxygen ions lose electrons to compensate for charge during the delithiation process, leading to a relatively high voltage plateau. After F doping, oxidation occurs in both the cationic (Mn) and anionic (O) components, resulting in a lower voltage plateau at the beginning of the charge, which can be attributed to the oxidation of Mn to Mn . Additionally, F doping can somewhat suppress the release of oxygen in Li MnO , improving the stability of anionic oxidation. However, the increase of the activation barriers for Li diffusion can be observed after F doping, due to stronger electrostatic interactions between F and Li , which adversely affects the cycling kinetics of Li MnO F . This study enhances our understanding of the impact of F doping in Li MnO based on theoretical calculations.