Structure design enables stable anionic and cationic redox chemistry in a T2-type Li-excess layered oxide cathode

• 作者: Xin Cao Haifeng Li Yu Qiao Min Jia Hirokazu Kitaura Jianan Zhang Ping He Jordi Cabana Haoshen Zhou
• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2022,（4）
• 所属期刊栏目: ARTICLES
• 页码范围: 381-388
• 页数: 8页
• 语种: 英文

摘要

Coupled with anionic and cationic redox chemistry,Li-rich/excess cathode materials are prospective high-energy-density candidates for the next-generation Li-ion batteries.However,irreversible lattice oxygen loss would exacerbate irreversible transition metal migration,resulting in a drastic voltage decay and capacity degeneration.Herein,a metastable layered Li-excess cathode material,T2-type Li0.72[Li0.12Ni0.36Mn0.52]O2,was developed,in which both oxygen stacking arrangement and Li coordina-tion environment fundamentally differ from that in conventional O3-type layered structures.By means of the reversible Li migration processes and structural evolutions,not only can voltage decay be effectively restrained,but also excellent capacity retention can be achieved upon long-term cycling.Moreover,irre-versible/reversible anionic/cationic redox activities have been well assigned and quantified by various in/ex-situ spectroscopic techniques,further clarifying the charge compensation mechanism associated with(de)lithiation.These findings of the novel T2 structure with the enhanced anionic redox stability will pro-vide a new scope for the development of high-energy-density Li-rich cathode materials.