The Nickel-rich layered cathode materials have been considered as promising cathode for lithium-ion bat-teries(LIBs),which due to it can achieve a high capacity of than 200 mAh g-1 under a high cutoff voltage of 4.5 V.However,the nickel-rich layered cathode materials show severely capacity fading at high voltage cycling,induced by the hybrid O anion and cation redox promote Oα-(α＜2)migration in the crystal lattice under high charge voltage,lead to the instability of the oxygen skeleton and oxygen evolution,promote the phase transition and electrolyte decomposition.Here,Li1-xTMO2-y/Li2SO4 hybrid layer is designed by a simple pyrolysis method to enhance the high voltage cycle stability of NCM.In such constructed hybrid layer,the inner spinel structure of Li1-xTMO2-y layer is the electron-rich state,which could form an electron cloud coupling with the NCM with surface oxygen vacancies,while Li2SO4 is p-type semicon-ductors,thus constructing a heterojunction interface of Li1-xTMO2-y//Li2SO4 and Li1-xTMO2-y//NCM,thereby generating internal self-built electric fields to inhibit the outward migration of bulk oxygen anions.Moreover,the internal self-built electric fields could not only strengthen the bonding force between the Li1-xTMO2-y/Li2SO4 hybrid layer and host NCM material,but also boost the charge transfer.As consequence,the modified NCM materials show excellent electrochemical performance with capacity retention of 97.7％and 90.1％after 200 cycles at 4.3 V and 4.5 V,respectively.This work provides a new idea for the development of high energy density applications of Nickel-rich layered cathode materials.

Youqi Chu;Anjie Lai;Qichang Pan;Fenghua Zheng;Youguo Huang;Hongqiang Wang;Qingyu Li

Guangxi Key Laboratory of Low Carbon Energy Materials,School of Chemistry and Pharmaceutical Sciences,Guangxi Normal University,Guilin 541004,Guangxi,China;Guangxi New Energy Ship Battery Engineering Technology Research Center,Guangxi Normal University,Guilin 541004,Guangxi,China

能源化学

[1]Youqi Chu;Anjie Lai;Qichang Pan;Fenghua Zheng;Youguo Huang;Hongqiang Wang;Qingyu Li-.Construction of internal electric field to suppress oxygen evolution of Ni-rich cathode materials at a high cutoff voltage)[J].能源化学,2022(10):114-125

xTMO2

Construction,internal,electric,suppress,oxygen,evolution,rich,cathode,materials,high,cutoff,voltage,Nickel,layered,have,been,considered,promising,lithium,bat,teries,LIBs,which,due,achieve,capacity,than,mAh,under,However,nickel,show,severely,fading,cycling,induced,hybrid,redox,promote,migration,crystal,lattice,charge,lead,instability,skeleton,phase,transition,electrolyte,decomposition,Here,Li1,Li2SO4,designed,simple,pyrolysis,method,enhance,NCM,In,such,constructed,inner,spinel,structure,electron,state,could,cloud,coupling,surface,vacancies,while,type,semicon,ductors,thus,constructing,heterojunction,interface,thereby,generating,self,built,fields,inhibit,outward,bulk,anions,Moreover,not,only,strengthen,bonding,force,between,host,but,also,boost,transfer,consequence,modified,excellent,electrochemical,performance,retention,after,cycles,respectively,This,work,provides,new,idea,development,energy,density,applications

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