Abstract
The electrochemical thermodynamic and kinetic characteristics of rechargeable batteries are critically influenced by the ordering of mobile ions in electrodes or solid electrolytes. However, because of the experimental difficulty of capturing the lighter migration ion coupled with the theoretical limitation of searching for ordered phases in a constrained cell, predicting stable ordered phases involving cell transformations or at extremely dilute concentrations remains challenging. Here, a group-subgroup transformation method based on lattice transformation and Wyckoff-position splitting is employed to predict the ordered ground states. We reproduce the previously reported Li0.75CoO2, Li0.8333CoO2, and Li0.8571CoO2 phases and report a new Li0.875CoO2 ground state. Taking the advantage of Wyckoff-position splitting in reducing the number of configurations, we identify the stablest Li0.0625C6 dilute phase in Li-ion intercalated graphite. We also resolve the Li/La/vacancy ordering in Li3xLa2/3−xTiO3 (0 < x < 0.167), which explains the observed Li-ion diffusion anisotropy. These findings provide important insight towards understanding the rechargeable battery chemistry.
Highlights
The ever-growing demands for electrical energy storage have led to the higher performance requirements for rechargeable batteries[1,2,3,4,5]
The immobile La in the solid electrolyte Li3xLa2/3−xTiO3, we reveal that the Li-ion diffusion anisotropy is caused by the blocking stability of the O1 host is demonstrated to be restricted to zero Li concentration
Constructing convex hull of LixCoO2 within transformed lattices concentration that can be obtained in this host with x = 0.5 in
Summary
The ever-growing demands for electrical energy storage have led to the higher performance requirements for rechargeable batteries[1,2,3,4,5]. A key commonality of the above electrolytes and electrodes is that their properties (e.g., ionic conductivity for electrolytes, phase stability, and voltage for electrodes) are closely linked to the concentrations of mobile ions and the corresponding ordered ground states during either the preparation or ion-intercalation process. It is difficult to determine the ordered ground states in these systems because of the low sensitivity of current spectroscopic techniques to the light elements (e.g., H and Li)[13]. Even neutron scattering cannot detect the precise occupation of Li+ in Licontaining compounds, only giving a “disordered” distribution of these ions in an averaged manner. It is difficult to directly obtain the precise arrangements of mobile ions at the atomic scale
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
