High-nickel single-crystal layered oxide material has become the most promising cathode material for electric vehicle power battery due to its high energy density.However,this material still suffers from structural degradation during cycling and especially the severe interfacial reactions at elevated temper-atures that exacerbate irreversible capacity loss.Here,a simple strategy was used to construct a dual-function Li1.5Al0.5Ge1.5P3O12(LAGP)protective layer on the surface of the high-nickel single-crystal(SC)cathode material,leading to SC@LAGP material.The strong Al-O bonding effectively inhibits the release of lattice oxygen(O)at elevated temperatures,which is supported by the positive formation energy of O vacancy from first-principal calculations.Besides,theoretical calculations demonstrate that the appropri-ate amount of Al doping accelerates the electron and Li+transport,and thus reduces the kinetic barriers.In addition,the LAGP protective layer alleviates the stress accumulation during cycling and effectively reduces the erosion of materials from the electrolyte decomposition at elevated temperatures.The obtained SC@LAGP cathode material demonstrates much enhanced cycling stability even at high voltage(4.6 V)and elevated temperature(55℃),with a high capacity retention of 91.3％after 100 cycles.This work reports a simple dual-function coating strategy that simultaneously stabilizes the structure and interface of the single-crystal cathode material,which can be applied to design other cathode materials.

Ying-De Huang;Han-Xin Wei;Pei-Yao Li;Yu-Hong Luo;Qing Wen;Ding-Hao Le;Zhen-Jiang He;Hai-Yan Wang;You-Gen Tang;Cheng Yan;Jing Mao;Ke-Hua Dai;Xia-Hui Zhang;Jun-Chao Zheng

School of Metallurgy and Environment,Central South University,Changsha 410083,Hunan,China;National Engineering Laboratory for High Efficiency Recovery of Refractory Nonferrous Metals,Central South University,Changsha 410083,Hunan,China;Engineering Research Center of the Ministry of Education for Advanced Battery Materials,Central South University,Changsha 410083,Hunan,China;Hunan Provincial Key Laboratory of Chemical Power Sources,College of Chemistry and Chemical Engineering,Central South University,Changsha 410083,Hunan,China;School of Mechanical,Medical and Process Engineering,Queensland University of Technology,Brisbane 4001,Queensland,Australia;School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,Henan,China;College of Chemistry,Tianjin Normal University,Tianjin 300387,China;School of Mechanical and Materials Engineering,Washington State University,Pullman 99164,Washington,USA

能源化学

[1]Ying-De Huang;Han-Xin Wei;Pei-Yao Li;Yu-Hong Luo;Qing Wen;Ding-Hao Le;Zhen-Jiang He;Hai-Yan Wang;You-Gen Tang;Cheng Yan;Jing Mao;Ke-Hua Dai;Xia-Hui Zhang;Jun-Chao Zheng-.Enhancing structure and cycling stability of Ni-rich layered oxide cathodes at elevated temperatures via dual-function surface modification)[J].能源化学,2022(12):301-309

5Ge1,5P3O12,LAGP

Enhancing,structure,cycling,stability,rich,layered,oxide,cathodes,elevated,temperatures,dual,function,surface,modification,High,nickel,single,crystal,has,become,most,promising,electric,vehicle,power,battery,due,high,energy,density,However,this,still,suffers,from,structural,degradation,during,especially,severe,interfacial,reactions,that,exacerbate,irreversible,capacity,loss,Here,simple,strategy,was,used,construct,Li1,5Al0,protective,SC,leading,strong,bonding,effectively,inhibits,release,lattice,oxygen,which,supported,by,positive,formation,vacancy,first,principal,calculations,Besides,theoretical,appropri,amount,doping,accelerates,electron,Li+transport,thus,reduces,kinetic,barriers,In,addition,alleviates,stress,accumulation,erosion,materials,electrolyte,decomposition,obtained,demonstrates,much,enhanced,even,voltage,retention,after,cycles,This,work,reports,coating,simultaneously,stabilizes,interface,applied,design,other

0.532163