Journal title
Journal of The Electrochemical Society
DOI
10.1149/2.0301910jes
Issue
12
Volume
166
Last updated
2024-03-24T14:20:13.63+00:00
Abstract
An isothermal porous-electrode model of a discharging lead-acid battery is
presented, which includes an extension of concentrated-solution theory that
accounts for excluded-volume effects, local pressure variation, and a detailed
microscopic water balance. The approach accounts for three typically neglected
physical phenomena: convection, pressure diffusion, and variation of liquid
volume with state of charge. Rescaling of the governing equations uncovers a
set of fundamental dimensionless parameters that control the battery's
response. Total volume change during discharge and nonuniform pressure prove to
be higher-order effects in cells where variations occur in just one spatial
dimension. A numerical solution is developed and exploited to predict transient
cell voltages and internal concentration profiles in response to a range of
C-rates. The dependence of discharge capacity on C-rate deviates substantially
from Peukert's simple power law: charge capacity is concentration-limited at
low C-rates, and voltage-limited at high C-rates. The model is fit to
experimental data, showing good agreement.
presented, which includes an extension of concentrated-solution theory that
accounts for excluded-volume effects, local pressure variation, and a detailed
microscopic water balance. The approach accounts for three typically neglected
physical phenomena: convection, pressure diffusion, and variation of liquid
volume with state of charge. Rescaling of the governing equations uncovers a
set of fundamental dimensionless parameters that control the battery's
response. Total volume change during discharge and nonuniform pressure prove to
be higher-order effects in cells where variations occur in just one spatial
dimension. A numerical solution is developed and exploited to predict transient
cell voltages and internal concentration profiles in response to a range of
C-rates. The dependence of discharge capacity on C-rate deviates substantially
from Peukert's simple power law: charge capacity is concentration-limited at
low C-rates, and voltage-limited at high C-rates. The model is fit to
experimental data, showing good agreement.
Symplectic ID
1083076
Submitted to ORA
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Publication type
Journal Article
Publication date
03 Jul 2019