An Experimental Analysis of Entropic Coefficient of a Lithium Titanate Oxide Battery

Abstract

In order to understand the thermal behaviour of a lithium-ion battery, the heat generation within the cell should be determined. The entropic heat coefficient is necessary to determine for the heat generation calculation. The entropic heat coefficient is one of the most important factors, which affects the magnitude of the reversible heat. The purpose of this research is to analyze and investigate the effect of different parameters on the entropic coefficient of lithium titanate oxide batteries. In this research, a lithium ion pouch cell was examined in both charging and discharging situations. The state of charge levels range was considered from 10% to 90%, and vice versa, in 10% increments. The temperature levels vary from 5 °C to 55 °C and the voltage levels vary from 1.5 V to 2.8 V. The effect of different parameters such as initial temperature, state of charge, thermal cycle, time duration for thermal cycles, and procedure prior to the thermal cycle on the entropic coefficient of lithium titanate oxide batteries were investigated. It was concluded that there is a strong influence of the battery cell state of charge on the entropic heat coefficient compared with other parameters.

Experimental Study of a Direct Immersion Liquid Cooling of a Li-Ion Battery for Electric Vehicles Applications

“…The temperatures chosen for the thermal cycle have a little influence on EHC. This was also confirmed by Madani et al [30].…”

“…Rad et al [28], show that also battery surface temperature is affected by the entropic heat. In literature the EHC is usually measured through potentiometric test [24,25,29,30]. Thomas et al [29], state that is more useful to modify the temperature at a specific SOC.…”

An Electrochemical Neutralization Cell for Spontaneous Water Desalination

“…This neutralization reaction is enthalpically and entropically favorable (Calculation S1A), with DH 0 and TDS 0 (entropic heat) terms at room temperature (298 K) of À55.83 and +24.05 kJ/mol, respectively, which together corresponds to an open circuit voltage (OCV) of 0.828 V. The entropic heat corresponds to the quantity of heat exchanged between the system and surroundings, and hence, a positive TDS 0 term represents heat flow to the system from the surroundings. 36,37 While entropic heat is usually negligible in electrochemical systems, for example, $3% of DH 0 for a Daniell cell and $6% of DH 0 for a Ni-Cd cell; [38][39][40] for the electrochemical neutralization cell, the entropic heat is almost 43% of DH 0 (Calculation S1A) suggesting that the heat absorbed from the surroundings is quite significant. Therefore, the proposed electrochemical neutralization cell can harvest the heat of the reaction (DH) as well as heat from the surroundings (TDS) as electrical driving force to perform electrical work.…”

Thermal Characterizations of a Lithium Titanate Oxide-Based Lithium-Ion Battery Focused on Random and Periodic Charge-Discharge Pulses

“…Dissimilar procedures were used for the determination of entropic. In [30], a specific load profile and thermal cycles were applied to the lithium-ion battery cell, and potentiometry was employed to approximate this heat coefficient. In [31], the effect of discharge current-rates and state-of-charge on the heat loss and efficiency of a lithium-ion battery was studied.…”