653
Investigations on Mechanisms of Ionic Transport and Phase Transition in Insertion Electrode Materials for Lithium/Sodium-Ion Batteries
Friday, 13 June 2014
Cernobbio Wing (Villa Erba)
X. Huang (Institute of Physics, Chinese Academy of Sciences), Y. Sun (Institute of Physics, CAS), X. Lu (Institut de recherche d’Hydro-Québec (IREQ),), H. Pan, L. Zhao (Institute of Physics, CAS), Y. S. Hu, L. Gu, H. Li (Institute of Physics, Chinese Academy of Sciences), L. Chen (Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences), and R. Xiao (Institute of Physics, Chinese Academy of Sciences)
Insertion electrode materials are included in the majority of ambient-temperature Li/Na-ion batteries, which attract increasing attention in energy storage. Being a commercialized cathode material of Li ion battery, olivine LiFePO
4 has undergone intensive research. Previously, the two-phase separation mechanism upon charging was well accepted, while recent experimental results indicates a more subtle atomic structure, lithium-staging, exists upon charging. We show that, through first-principles calculations, the observed lithium-staging configuration in partially delithiated LiFePO
4is a kinetically controlled thermodynamically metastable state. Our results shed light on the interactions between electron and ion and hence may have general implications for investigating the ionic transport in other strongly correlated mixed conductor materials. [1]
Spinel Li4Ti5O12 is well-known as a “zero-strain” anode for lithium-ion batteries. We found that it can also accommodate sodium ions, displaying an average storage voltage of 0.91V vs. Na+/Na. Through combined density functional theory calculations and scanning transmission electron microscope imaging techniques, a three-phase separation reaction, which has never been seen in any insertion electrode materials for lithium- or sodium-ion batteries, is confirmed in the sodiation process of Li4Ti5O12. Furthermore, interfacial structure is clearly resolved at an atomic scale in electrochemically sodiated Li4Ti5O12for the first time via the advanced electron microscopy. [2]
Acknowledge:
This work was supported by funding from the “863” Project (2009AA033101), “973” Projects (2013CB934002,2009CB220104)
Reference:
[1] Yang Sun, Xia Lu, Ruijuan Xiao, Hong Li, and Xuejie Huang. Chem. Mater. 24 (2012) 4693.
[2] Yang Sun, Liang Zhao, Huilin Pan, Xia Lu, Lin Gu, Yong-Sheng Hu, Hong Li, Michel Armand, Yuichi Ikuhara, Liquan Chen and Xuejie Huang. Nat. Commun. 4 (2013) 1870
