title: Mitigating Voltage Decay of Li-Rich Cathode Material via Increasing Ni Content for Lithium-Ion Batteries.
abstract: Li-rich layered materials have been considered as the most promising cathode materials for future high-energy-density lithium-ion batteries. However, they suffer from severe voltage decay upon cycling, which hinders their further commercialization. Here, we report a Li-rich layered material 0.5Li2MnO3·0.5LiNi0.8Co0.1Mn0.1O2 with high nickel content, which exhibits much slower voltage decay during long-term cycling compared to conventional Li-rich materials. The voltage decay after 200 cycles is 201 mV. Combining in situ X-ray diffraction (XRD), ex situ XRD, ex situ X-ray photoelectron spectroscopy, and scanning transmission electron microscopy, we demonstrate that nickel ions act as stabilizing ions to inhibit the Jahn-Teller effect of active Mn(3+) ions, improving d-p hybridization and supporting the layered structure as a pillar. In addition, nickel ions can migrate between the transition-metal layer and the interlayer, thus avoiding the formation of spinel-like structures and consequently mitigating the voltage decay. Our results provide a simple and effective avenue for developing Li-rich layered materials with mitigated voltage decay and a long lifespan, thereby promoting their further application in lithium-ion batteries with high energy density.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences (CAS) , Beijing 100190, P. R. China.|University of Chinese Academy of Sciences , Beijing 100049, P. R. China.
authors.forename: Ji-Lei
authors.initials: JL
authors.lastname: Shi
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences (CAS) , Beijing 100190, P. R. China.
authors.forename: Jie-Nan
authors.initials: JN
authors.lastname: Zhang
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences (CAS) , Beijing 100190, P. R. China.
authors.forename: Min
authors.initials: M
authors.lastname: He
authors.affiliation: Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences (CAS) , Beijing 100190, P. R. China.|University of Chinese Academy of Sciences , Beijing 100049, P. R. China.
authors.forename: Xu-Dong
authors.initials: XD
authors.lastname: Zhang
authors.affiliation: Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences (CAS) , Beijing 100190, P. R. China.
authors.forename: Ya-Xia
authors.initials: YX
authors.lastname: Yin
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences (CAS) , Beijing 100190, P. R. China.
authors.forename: Hong
authors.initials: H
authors.lastname: Li
authors.affiliation: Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences (CAS) , Beijing 100190, P. R. China.|University of Chinese Academy of Sciences , Beijing 100049, P. R. China.
authors.forename: Yu-Guo
authors.initials: YG
authors.lastname: Guo
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences (CAS) , Beijing 100190, P. R. China.
authors.forename: Lin
authors.initials: L
authors.lastname: Gu
authors.affiliation: Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences (CAS) , Beijing 100190, P. R. China.|University of Chinese Academy of Sciences , Beijing 100049, P. R. China.
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Wan
keywords: Li-rich; cathode materials; high-capacity; lithium batteries; voltage decay