Asynchronous stoichiometric response in lithium iron phosphate batteries

William A. Paxton, E. Koray Akdoʇan, Ilyas Sąvkliyildiz, Ankur U. Choksi, Scott X. Silver, Thomas Tsakalakos, Zhong Zhong

Research output: Contribution to journalArticle

3 Scopus citations


Operando energy-dispersive X-ray diffraction (EDXRD) was carried out on a newly formed 8 Ah lithium iron phosphate (LiFePO4) battery with the goal of elucidating the origin of asynchronous phase transformation commonly seen with in situ X-ray diffraction studies. The high-energy photons at the NSLS X17B1 beamline allow for penetration into a fully assembled battery and therefore negate any need for a specially designed in situ cell which often uses modified current collectors to minimize X-ray attenuation. Spatially-andorally resolved phase-mapping was conducted with a semiquantitative reference intensity ratio (RIR) analysis to estimate the relative abundance of the delithiated phase. The data show an asynchronous response in the stoichiometry versus the electrochemical profile and suggest limited diffusion in the electrode toward the end of discharge. Our results confirm that the asynchronous electrode response is not just limited to specially designed cells but occurs in fully assembled cells alike. We attribute this behavior to be a consequence of performing a local measurement over a wide-area heterogeneous reaction.

Original languageEnglish (US)
Pages (from-to)417-423
Number of pages7
JournalJournal of Materials Research
Issue number3
Publication statusPublished - Feb 14 2015


All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Cite this

Paxton, W. A., Akdoʇan, E. K., Sąvkliyildiz, I., Choksi, A. U., Silver, S. X., Tsakalakos, T., & Zhong, Z. (2015). Asynchronous stoichiometric response in lithium iron phosphate batteries. Journal of Materials Research, 30(3), 417-423.