title: Crystalline Grain Interior Configuration Affects Lithium Migration Kinetics in Li-Rich Layered Oxide.
abstract: The electrode kinetics of Li-ion batteries, which are important for battery utilization in electric vehicles, are affected by the grain size, crystal orientation, and surface structure of electrode materials. However, the kinetic influences of the grain interior structure and element segregation are poorly understood, especially for Li-rich layered oxides with complex crystalline structures and unclear electrochemical phenomena. In this work, cross-sectional thin transmission electron microscopy specimens are "anatomized" from pristine Li1.2Mn0.567Ni0.167Co0.067O2 powders using a new argon ion slicer technique. Utilizing advanced microscopy techniques, the interior configuration of a single grain, multiple monocrystal-like domains, and nickel-segregated domain boundaries are clearly revealed; furthermore, a randomly distributed atomic-resolution Li2MnO3-like with an intergrown LiTMO2 (TM = transitional metals) "twin domain" is demonstrated to exist in each domain. Further theoretical calculations based on the Li2MnO3-like crystal domain boundary model reveal that Li(+) migration in the Li2MnO3-like structure with domain boundaries is sluggish, especially when the nickel is segregated in domain boundaries. Our work uncovers the complex configuration of the crystalline grain interior and provides a conceptual advance in our understanding of the electrochemical performance of several compounds for Li-ion batteries.
authors.affiliation: Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Umezono 1-1-1, Tsukuba 305-8568, Japan.|College of Materials Science and Engineering, Beijing University of Technology , Pingleyuan #100, Chaoyang District, Beijing 100124, China.
authors.forename: Haijun
authors.initials: H
authors.lastname: Yu
authors.affiliation: Institute of Engineering Innovation, School of Engineering, The University of Tokyo , Tokyo 113-8656, Japan.
authors.forename: Yeong-Gi
authors.initials: YG
authors.lastname: So
authors.affiliation: Nanostructures Research Laboratory, Japan Fine Ceramics Center , Mutsuno, Atsuta, Nagoya 456-8587, Japan.
authors.forename: Akihide
authors.initials: A
authors.lastname: Kuwabara
authors.affiliation: Institute of Engineering Innovation, School of Engineering, The University of Tokyo , Tokyo 113-8656, Japan.
authors.forename: Eita
authors.initials: E
authors.lastname: Tochigi
authors.affiliation: Institute of Engineering Innovation, School of Engineering, The University of Tokyo , Tokyo 113-8656, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Shibata
authors.affiliation: Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Umezono 1-1-1, Tsukuba 305-8568, Japan.|Institute of Engineering Innovation, School of Engineering, The University of Tokyo , Tokyo 113-8656, Japan.
authors.forename: Tetsuichi
authors.initials: T
authors.lastname: Kudo
authors.affiliation: Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) , Umezono 1-1-1, Tsukuba 305-8568, Japan.
authors.forename: Haoshen
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Institute of Engineering Innovation, School of Engineering, The University of Tokyo , Tokyo 113-8656, Japan.|Nanostructures Research Laboratory, Japan Fine Ceramics Center , Mutsuno, Atsuta, Nagoya 456-8587, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ikuhara
keywords: Atomic-resolution; Li+ migration; domain boundary; lithium-rich layered oxides; theoretical calculation; twin domain