title: Discovering a First-Order Phase Transition in the Li-CeO2System.
abstract: An in-depth understanding of (de)lithiation induced phase transition in electrode materials is crucial to grasp their structure-property relationships and provide guidance to the design of more desirable electrodes. By operando synchrotron XRD (SXRD) measurement and Density Functional Theory (DFT) based calculations, we discover a reversible first-order phase transition for the first time during (de)lithiation of CeO2nanoparticles. The LixCeO2compound phase is identified to possess the same fluorite crystal structure with FM3M space group as that of the pristine CeO2nanoparticles. The SXRD determined lattice constant of the LixCeO2compound phase is 0.551 nm, larger than that of 0.541 nm of the pristine CeO2phase. The DFT calculations further reveal that the Li induced redistribution of electrons causes the increase in the Ce-O covalent bonding, the shuffling of Ce and O atoms, and the jump expansion of lattice constant, thereby resulting in the first-order phase transition. Discovering the new phase transition throws light upon the reaction between lithium and CeO2, and provides opportunities to the further investigation of properties and potential applications of LixCeO2.
authors.affiliation: Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Kaikai
authors.initials: K
authors.lastname: Li
authors.affiliation: Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Xiaoye
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Shanghai University Materials Genome Institute and Shanghai Materials Genome Institute, Shanghai University , 99 Shangda Road, Shanghai 200444, China.
authors.forename: Anmin
authors.initials: A
authors.lastname: Nie
authors.affiliation: Shanghai University Materials Genome Institute and Shanghai Materials Genome Institute, Shanghai University , 99 Shangda Road, Shanghai 200444, China.
authors.forename: Sheng
authors.initials: S
authors.lastname: Sun
authors.affiliation: National Local Joint Engineering Laboratory of Carbon Functional Materials, Graduate School at Shenzhen, Tsinghua University , Shenzhen 518055, China.
authors.forename: Yan-Bing
authors.identifier: 0000-0001-5787-5498
authors.initials: YB
authors.lastname: He
authors.affiliation: Shanghai University Materials Genome Institute and Shanghai Materials Genome Institute, Shanghai University , 99 Shangda Road, Shanghai 200444, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ren
authors.affiliation: National Local Joint Engineering Laboratory of Carbon Functional Materials, Graduate School at Shenzhen, Tsinghua University , Shenzhen 518055, China.
authors.forename: Baohua
authors.initials: B
authors.lastname: Li
authors.affiliation: National Local Joint Engineering Laboratory of Carbon Functional Materials, Graduate School at Shenzhen, Tsinghua University , Shenzhen 518055, China.
authors.forename: Feiyu
authors.initials: F
authors.lastname: Kang
authors.affiliation: Department of Mechanical and Aerospace Engineering, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong, China.
authors.forename: Jang-Kyo
authors.initials: JK
authors.lastname: Kim
authors.affiliation: Shanghai University Materials Genome Institute and Shanghai Materials Genome Institute, Shanghai University , 99 Shangda Road, Shanghai 200444, China.
authors.forename: Tong-Yi
authors.identifier: 0000-0002-9646-9668
authors.initials: TY
authors.lastname: Zhang
keywords: CeO2; Phase transition; density functional theory; lithium; operando synchrotron XRD