Ni-rich layered oxides(Ni>80%)with high energy density have become a mainstream cathode material for Li-ion batteries.However,irreversible phase transitions and interface instability are deep-seated challenges in c...Ni-rich layered oxides(Ni>80%)with high energy density have become a mainstream cathode material for Li-ion batteries.However,irreversible phase transitions and interface instability are deep-seated challenges in commercializing Ni-rich materials.This study used a collaborative modification strategy involving doping and coating with quadrivalent elements to construct Ni-rich materials.In particular,introducing tetravalent Zr makes the valence change of Ni(2+to 4+)more accessible to complete spontaneously during the charging and discharging processes,which significantly suppresses the cationic mixing and irreversible phase transition(H2?H3).Combining the strategy of constructing CeO_(2) coatings on the surface and interfacial spinel-like phases improves the Li+diffusion kinetics and interfacial stability.Simultaneously,part of the strongly oxidizing four-valence Ce^(4+)diffuses to the surface layer,further increasing the average valence state of Ni.Therefore,LiNi_(0.83)Co_(0.11)Mn_(0.06)O_(2)(NCM)-Zr@Ce achieves 78.5%outstanding retention at1.0C after 200 cycles within 3.0-4.3 V compared to unmodified NCM with 41.4%retention.The improved cyclic stability can be attributed to the collaborative modification strategy of the quadrivalent elements,which provides an effective synergistic modification strategy for developing high-performance Li-ion battery cathode materials.展开更多
基金financially supported by the Department of Science and Technology of Guangxi Province (Nos.2022JBGS004,AB21220027,AD19110090 and AD19110077)the National Natural Science Foundation of China (Nos.21805055 and12172096)+2 种基金Guangxi Natural Science Foundation (Nos.2020GXNSFAA159059 and 2020GXNSFAA159037)Guangxi Key Laboratory of Manufacturing Systems Foundation (No.20-065-40-005Z)the Engineering Research Center Foundation of Electronic Information Materials and Devices (No.EIMD-AA202005)。
文摘Ni-rich layered oxides(Ni>80%)with high energy density have become a mainstream cathode material for Li-ion batteries.However,irreversible phase transitions and interface instability are deep-seated challenges in commercializing Ni-rich materials.This study used a collaborative modification strategy involving doping and coating with quadrivalent elements to construct Ni-rich materials.In particular,introducing tetravalent Zr makes the valence change of Ni(2+to 4+)more accessible to complete spontaneously during the charging and discharging processes,which significantly suppresses the cationic mixing and irreversible phase transition(H2?H3).Combining the strategy of constructing CeO_(2) coatings on the surface and interfacial spinel-like phases improves the Li+diffusion kinetics and interfacial stability.Simultaneously,part of the strongly oxidizing four-valence Ce^(4+)diffuses to the surface layer,further increasing the average valence state of Ni.Therefore,LiNi_(0.83)Co_(0.11)Mn_(0.06)O_(2)(NCM)-Zr@Ce achieves 78.5%outstanding retention at1.0C after 200 cycles within 3.0-4.3 V compared to unmodified NCM with 41.4%retention.The improved cyclic stability can be attributed to the collaborative modification strategy of the quadrivalent elements,which provides an effective synergistic modification strategy for developing high-performance Li-ion battery cathode materials.
