The relationship between the structural evolution and redox of Li-rich transition-metal layered oxides(LLOs)cathodes remains ambiguous,obstructing the development of high-performance lithium-ion(Li+)battery.Herein,the coherent effects of local atomic and electronic structure in Li2RuxMn1-xO3(LRMO)with a wide voltage window(1.3-4.8 V)is identified by in situ X-ray absorption fine spec-troscopy(XAFS)and chemometrics.We not only skillfully separated the redox active structures to track the electrochemical path,but also visualized the coupling mechanism between the evolution of Ru-Ru dimer and the(de)excitation of cations and anions.Furthermore,introducing manganese triggers the"heterogeneity"of coordination environment and electronic structure between Ru and Mn after dis-charge to 3 V.The change of thermodynamic and kinetic paths affects the relithiation,and further leads to the hysteresis of the anion activation structure relaxation of Li2Ru0.4Mn0.6O3 relative to Li2RuO3(LRO).Additionally,it is demonstrated that the high charge cut-off voltage restrains the relaxation of anionic active structure in LRO from a new perspective through comparative experiments.Our work associates the evolution of atomic structure with charge compensation and negative electrochemical reactions such as voltage hysteresis(VH)and capacity attenuation,deepening the understanding electrochemical reac-tion mechanism of LLOs during the first cycle and providing a theoretical support for the further design and synthesis of high-efficiency cathodes.

Ji Li;Hongzhou Liu;Shun Zheng;Yande Li;Damning Zhu;Fanfei Sun;Jingyuan Ma;Songqi Gu;Panzhe Qiao;Shuai Yang;Xianlong Du;Xiaosong Liu;Zhi Liu;Bingbao Mei;Zheng Jiang

Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201204,China;University of Chinese Academy of Sciences,Beijing 100049,China;Shanghai Synchrotron Radiation Facility,Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201204,China;School of Physical Science and Technology,ShanghaiTech University,Shanghai 201210,China;Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China;National Synchrotron Radiation Laboratory,University of Science and Technology of China,Hefei 230029,Anhui,China;Innovation Academy for Green Manufacture,Chinese Academy of Sciences,Beijing 100190,China

能源化学

[1]Ji Li;Hongzhou Liu;Shun Zheng;Yande Li;Damning Zhu;Fanfei Sun;Jingyuan Ma;Songqi Gu;Panzhe Qiao;Shuai Yang;Xianlong Du;Xiaosong Liu;Zhi Liu;Bingbao Mei;Zheng Jiang-.Unveiling the mechanism of charge compensation in Li2RuxMn1-xO3 by tracking atomic structural evolution)[J].能源化学,2022(12):267-275

Li2RuxMn1,obstructing,chemometrics,relithiation,Li2Ru0,4Mn0,Li2RuO3

Unveiling,mechanism,charge,compensation,xO3,by,tracking,atomic,structural,evolution,relationship,between,redox,rich,transition,metal,layered,oxides,LLOs,cathodes,remains,ambiguous,development,high,performance,lithium,Li+,battery,Herein,coherent,effects,local,electronic,LRMO,wide,voltage,window,identified,situ,ray,absorption,fine,troscopy,XAFS,We,not,only,skillfully,separated,active,structures,electrochemical,but,also,visualized,coupling,dimer,excitation,cations,anions,Furthermore,introducing,manganese,triggers,heterogeneity,coordination,environment,after,dis,change,thermodynamic,kinetic,paths,affects,further,leads,hysteresis,activation,relaxation,6O3,relative,LRO,Additionally,demonstrated,that,cut,off,restrains,anionic,from,new,perspective,through,comparative,experiments,Our,work,associates,negative,reactions,such,VH,capacity,attenuation,deepening,understanding,during,first,cycle,providing,theoretical,support,design,synthesis,efficiency

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