Browse

Polymorphism and phase transformations of Li2-xFeSiO4 (0 <= x <= 2) from first principles

Cited 28 time in Web of Science Cited 27 time in Scopus
Authors
Seo, Dong-Hwa; Kim, Hyungsub; Park, Inchul; Hong, Jihyun; Kang, Kisuk
Issue Date
2011-12
Citation
Physical Review B, Vol.84 No.22, p. 220106(R)
Abstract
Computational study on the phase stabilities and electrochemical properties of four polymorphs of Li2-xFeSiO4 (the beta(II), gamma(II), gamma(S), and inverse beta(II) polymorph) as cathode materials for a Li-rechargeable battery is conducted using first principles calculations. While gamma(S) polymorph is found to be the most stable ground state structure of fully lithiated state Li2FeSiO4 from first principles calculation, the difference in energies among polymorphs is relatively small suggesting the possibility of a presence of different polymorphs, depending on the synthesis condition. However, upon delithiation to LiFeSiO4, the beta(II), gamma(S), and gamma(II) polymorphs of Li2-xFeSiO4 become notably more unstable than the inverse beta(II), thus they transform into the inverse beta(II) during charge. This phase transformation accompanies the voltage drop about 0.3 V, which is in agreement with recent experimental observations. The calculated redox potential for Fe2+/Fe3+ in Li2FeSiO4 varies depending on the type of polymorph, that is, 3.102, 3.078, 3.023, and 2.823 V vs Li for beta(II), gamma(S), gamma(II), and inverse beta(II) polymorph, respectively. Further delithiation from LiFeSiO4 leads to the redox potential of 4.802 V vs Li for Fe3+/Fe4+, therefore, utilization of more than one Li in Li2FeSiO4 is expected to be challenging in conventional lithium batteries.
ISSN
2469-9950
URI
http://hdl.handle.net/10371/165169
DOI
https://doi.org/10.1103/PhysRevB.84.220106
Files in This Item:
There are no files associated with this item.
Appears in Collections:
College of Engineering/Engineering Practice School (공과대학/대학원)Dept. of Material Science and Engineering (재료공학부) Journal Papers (저널논문_재료공학부)
  • mendeley

Items in S-Space are protected by copyright, with all rights reserved, unless otherwise indicated.

Browse