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Charge/discharge characteristics of Li‐ion batteries with two‐phase active materials: a comparative study of LiFePO 4 and LiCoO 2 cells
Author(s) -
Jung Seunghun,
Jung HoYoung
Publication year - 2016
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.3540
Subject(s) - electrode , materials science , electrical resistivity and conductivity , ohmic contact , phase (matter) , conductivity , ion , coating , lithium iron phosphate , electrical conductor , analytical chemistry (journal) , composite material , chemistry , electrochemistry , electrical engineering , chromatography , organic chemistry , engineering
Summary A comparative study of LiFePO 4 and LiCoO 2 cells was conducted using two mathematical models to identify the physical characteristics of the two‐phase electrode compared with the single‐phase electrode under both charge and discharge conditions. First, the electrical conductivity of the LiFePO 4 electrode was examined applying a two‐dimensional electrical conduction model. The calculation results showed that the electrical conductivity of the LiFePO 4 electrode could be improved significantly by coating the LiFePO 4 particles with a conductive substance. Second, a modified physics‐based cell model was applied to simulate the phase‐change phenomena at the equilibrium boundary inside the LiFePO 4 particles. The cell performance using LiFePO 4 electrode was degraded significantly owing to the increase in ohmic loss and concentration loss caused by the low electrical conductivity and phase‐change characteristics of LiFePO 4 under high C‐rate conditions. The present model was validated with experimental data and showed good agreement. Copyright © 2016 John Wiley & Sons, Ltd.