TITLE:
Simple Rational Model for Discharge of Batteries with Aqueous Electrolytes, Based on Nernst Equation
AUTHORS:
Panagis G. Papadopoulos, Christopher G. Koutitas, Christos G. Karayannis, Panos D. Kiousis, Yannis N. Dimitropoulos
KEYWORDS:
Battery, Aqueous Electrolyte, Discharge, Nernst Equation, Daniel Cell, Lead-Acid Battery, Temperature Effect
JOURNAL NAME:
Open Journal of Physical Chemistry,
Vol.11 No.1,
February
3,
2021
ABSTRACT: A simple rational model is proposed for discharge of batteries with aqueous
electrolytes, based on Nernst equation. Details of electrode kinetics are not
taken into account. Only a few overall parameters of the battery are
considered. A simple algorithm, with variable time step-length Δt, is presented, for proposed model. The model is
first applied to Daniel cell, in order to clarify concepts and principles of battery operation. It is
found that initial pinching, in time-history curve of voltage E-t, is due to initial under-concentration
of product ion. Then, model is applied to a lead-acid battery. In absence of an ion product,
and in order to construct nominator of Nernst ratio, such an ion, with
coefficient tending to zero, is assumed, thus yielding unity in nominator.
Time-history curves of voltage, for various values of internal resistance, are
compared with corresponding published experimental curves. Temperature effect
on voltage-time curve is examined. Proposed model can be extended to other
types of batteries, which can be considered as having aqueous electrolytes,
too.