  The entropic coefficient of a lithium-ion battery cell is used to calculate
the reversible heat of a battery during operation, which is a non-negligible
part for the battery thermal modelling. The contribution of this article is to
propose a novel method to establish the entropic coefficient profile of a 26 Ah
commercial pouch cell, and compare the results with those obtained from the
traditional potentiometric and calorimetric methods, and all are found to be in
a good agreement. The originality of this work is to use a method which
consists of supplying a square pulse current wave form at a certain frequency
and thus the resulting heat variation could be successfully linked to the input
current using Fourier analysis. The current magnitude used were 1 C and 1.5 C,
which are representative for the normal operation current in an electrified
vehicle application. The method proposed is found to be cost efficient with a
short experiment time and simple experiment setup. In fact, it can be used to
characterize cells that are already mounted in a pack without the access to a
climate chamber or calorimeter.
