Origin of the Phase Transition in Lithium Garnets

被引:59
作者
Chen, Fei [1 ]
Li, Junyang [1 ]
Huang, Zhifeng [1 ]
Yang, Ying [2 ]
Shen, Qiang [1 ]
Zhang, Lianmeng [1 ]
机构
[1] Wuhan Univ Technol, State Key Lab Adv Technol Mat Synth & Proc, Wuhan 430070, Hubei, Peoples R China
[2] Wuhan Univ Technol, Dept Engn Struct & Mech, Wuhan 430070, Hubei, Peoples R China
基金
中国国家自然科学基金;
关键词
LI ION CONDUCTORS; NEUTRON-DIFFRACTION; CRYSTAL-STRUCTURE; LI7LA3ZR2O12; CONDUCTIVITY; LI-7-XLA3ZR2-XTAXO12; DYNAMICS; ELECTROLYTES; SIMULATION; OXIDES;
D O I
10.1021/acs.jpcc.7b10911
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Molecular dynamic and density functional theory based simulations were performed to obtain a better understanding of the origin of phase transition in garnet-type Li7La3Zr2O12 solid electrolyte. The phase transition coincided with the lithium redistribution among all sites. With the investigation of lithium distribution and dynamics, we found one temperature-dependent lithium migration pathway in lithium garnets. Lithium ions exhibited uniformly 3-dimensional diffusion in cubic LLZO, while the lithium diffusion in tetragonal LLZO was mainly in the a and b direction. The constrained diffusion in the c direction in tetragonal LLZO could be ascribed to the blocking effect of 16f sites which were found to be thermodynamically more stable than tetragonal 8a and 32g sites through density functional theory based calculations. Besides, the stabilizing effect of supervalent doping on cubic phase was also studied through Ta-doped LLZO. Further site occupancy investigations indicated that supervalent doping introduced lithium vacancies and reduced octahedral sites (tetragonal 16f and 32g sites) occupancy due to site energy preference. The reduced octahedral sites occupancy weakened the blocking effect of tetragonal 16f sites, promoted the lithium redistribution, and eventually lowered the phase transition temperature.
引用
收藏
页码:1963 / 1972
页数:10
相关论文
共 48 条
  • [1] Ion transport and phase transition in Li7-xLa3(Zr2-xMx)O12 (M = Ta5+, Nb5+, x=0, 0.25)
    Adams, Stefan
    Rao, Rayavarapu Prasada
    [J]. JOURNAL OF MATERIALS CHEMISTRY, 2012, 22 (04) : 1426 - 1434
  • [2] Crystal Structure of Fast Lithium-ion-conducting Cubic Li7La3Zr2O12
    Awaka, Junji
    Takashima, Akira
    Kataoka, Kunimitsu
    Kijima, Norihito
    Idemoto, Yasushi
    Akimoto, Junji
    [J]. CHEMISTRY LETTERS, 2011, 40 (01) : 60 - 62
  • [3] Neutron powder diffraction study of tetragonal Li7La3Hf2O12 with the garnet-related type structure
    Awaka, Junji
    Kijima, Norihito
    Kataoka, Kunimitsu
    Hayakawa, Hiroshi
    Ohshima, Ken-ichi
    Akimoto, Junji
    [J]. JOURNAL OF SOLID STATE CHEMISTRY, 2010, 183 (01) : 180 - 185
  • [4] Synthesis and structure analysis of tetragonal Li7La3Zr2O12 with the garnet-related type structure
    Awaka, Junji
    Kijima, Norihito
    Hayakawa, Hiroshi
    Akimoto, Junji
    [J]. JOURNAL OF SOLID STATE CHEMISTRY, 2009, 182 (08) : 2046 - 2052
  • [5] PROJECTOR AUGMENTED-WAVE METHOD
    BLOCHL, PE
    [J]. PHYSICAL REVIEW B, 1994, 50 (24): : 17953 - 17979
  • [6] Sparse Cyclic Excitations Explain the Low Ionic Conductivity of Stoichiometric Li7La3Zr2O12
    Burbano, Mario
    Carlier, Dany
    Boucher, Florent
    Morgan, Benjamin J.
    Salanne, Mathieu
    [J]. PHYSICAL REVIEW LETTERS, 2016, 116 (13)
  • [7] Lithium metal electrode kinetics and ionic conductivity of the solid lithium ion conductors "Li7La3Zr2O12" and Li7-xLa3Zr2-xTaxO12 with garnet-type structure
    Buschmann, Henrik
    Berendts, Stefan
    Mogwitz, Boris
    Janek, Juergen
    [J]. JOURNAL OF POWER SOURCES, 2012, 206 : 236 - 244
  • [8] Data mining of molecular dynamics data reveals Li diffusion characteristics in garnet Li7La3Zr2O12
    Chen, Chi
    Lu, Ziheng
    Ciucci, Francesco
    [J]. SCIENTIFIC REPORTS, 2017, 7
  • [9] Structure and ionic conductivity in lithium garnets
    Cussen, Edmund J.
    [J]. JOURNAL OF MATERIALS CHEMISTRY, 2010, 20 (25) : 5167 - 5173
  • [10] Synthesis of lithium garnets from La2Zr2O7 pyrochlore
    Deviannapoorani, C.
    Ramakumar, S.
    Janani, N.
    Murugan, Ramaswamy
    [J]. SOLID STATE IONICS, 2015, 283 : 123 - 130