title: Intrinsic Origins of Crack Generation in Ni-rich LiNi0.8Co0.1Mn0.1O2Layered Oxide Cathode Material.
abstract: Ni-rich LiNi0.8Co0.1Mn0.1O2layered oxide cathodes have been highlighted for large-scale energy applications due to their high energy density. Although its specific capacity is enhanced at higher voltages as Ni ratio increases, its structural degradation due to phase transformations and lattice distortions during cycling becomes severe. For these reasons, we focused on the origins of crack generation from phase transformations and structural distortions in Ni-rich LiNi0.8Co0.1Mn0.1O2using multiscale approaches, from first-principles to meso-scale phase-field model. Atomic-scale structure analysis demonstrated that opposite changes in the lattice parameters are observed until the inverse Li content x = 0.75; then, structure collapses due to complete extraction of Li from between transition metal layers. Combined-phase investigations represent the highest phase barrier and steepest chemical potential after x = 0.75, leading to phase transformations to highly Li-deficient phases with an inactive character. Abrupt phase transformations with heterogeneous structural collapse after x = 0.81 (~220 mAh g-1) were identified in the nanodomain. Further, meso-scale strain distributions show around 5% of anisotropic contraction with lower critical energy release rates, which cause not only micro-crack generations of secondary particles on the interfaces between the contracted primary particles, but also mechanical instability of primary particles from heterogeneous strain changes.
authors.affiliation: Department of Mechanical and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
authors.forename: Jin-Myoung
authors.initials: JM
authors.lastname: Lim
authors.affiliation: Department of Mechanical and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
authors.forename: Taesoon
authors.initials: T
authors.lastname: Hwang
authors.affiliation: Department of Mechanical and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
authors.forename: Duho
authors.initials: D
authors.lastname: Kim
authors.affiliation: Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin 17104, Republic of Korea.
authors.forename: Min-Sik
authors.initials: MS
authors.lastname: Park
authors.affiliation: Department of Mechanical and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.|Department of Materials Science and Engineering and Department of Physics, University of Texas at Dallas, Richardson, TX 75080, USA.
authors.forename: Kyeongjae
authors.initials: K
authors.lastname: Cho
authors.affiliation: Department of Mechanical and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea.
authors.forename: Maenghyo
authors.initials: M
authors.lastname: Cho