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.

Xin Cao;Haifeng Li;Yu Qiao;Min Jia;Hirokazu Kitaura;Jianan Zhang;Ping He;Jordi Cabana;Haoshen Zhou

Energy Technology Research Institute,National Institute of Advanced Industrial Science and Technology (AIST),Tsukuba 305-g568,Japan;Graduate School of System and Information Engineering,University of Tsukuba,Tsukuba 305-8573,Japan;Department of Chemistry,University of Illinois at Chicago,Chicago,IL 60607,USA;College of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,China;Center of Energy Storage Materials & Technology,College of Engineering and Applied Sciences,Jiangsu Key Laboratory of Artificial Functional Materials,National Laboratory of Solid State Microstructures,and Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China

科学通报（英文版）

[1]Xin Cao;Haifeng Li;Yu Qiao;Min Jia;Hirokazu Kitaura;Jianan Zhang;Ping He;Jordi Cabana;Haoshen Zhou-.Structure design enables stable anionic and cationic redox chemistry in a T2-type Li-excess layered oxide cathode)[J].科学通报（英文版）,2022(04):381-388

12Ni0,36Mn0

Structure,design,enables,anionic,cationic,redox,chemistry,type,excess,layered,oxide,cathode,Coupled,rich,materials,are,prospective,high,energy,density,candidates,next,batteries,However,irreversible,lattice,oxygen,loss,would,exacerbate,transition,metal,migration,resulting,drastic,voltage,decay,capacity,degeneration,Herein,metastable,Li0,O2,was,developed,which,both,stacking,arrangement,coordina,environment,fundamentally,differ,from,that,conventional,O3,structures,By,means,processes,structural,evolutions,not,only,effectively,restrained,but,also,excellent,retention,achieved,upon,long,term,cycling,Moreover,activities,have,been,well,assigned,quantified,by,various,situ,spectroscopic,techniques,further,clarifying,charge,compensation,mechanism,associated,lithiation,These,findings,novel,enhanced,stability,will,vide,new,scope,development

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