Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
THERMAL ANALYSIS DURING AGING OF A LITHIUM-ION CELL USING A MODIFIED DIFFERENTIAL VOLTAGE TECHNIQUE
Submission Author:
Luis Françoso , SP , Brazil
Co-Authors:
Luis Françoso, Santiago del Rio Oliveira, Rodolfo Castanho Fernandes
Presenter: Luis Françoso
doi://10.26678/ABCM.COBEM2019.COB2019-0173
Abstract
The study of thermal performance of battery cells is extremely important once it directly impacts on user safety. This paper aims to analyze the thermal behavior of a cylindrical lithium-ion cell LiFePO4 8000 mAh, 38120 size to better understand the effect of aging due to repetitive charge-discharge cycling on the surface temperature and thus estimate the internal temperature using an iterative method named differential voltage technique. Comparing the literature, the present paper adds some improvements such as the inclusion of radiation and the use of an internal resistance as a function of cycle number obtained experimentally, in addition to proposing a comparison of two alternatives for calculating the generated heat: the first, only with the effect of reversible heat and the second one omitting reversible heat term. Under the experiment conditions, the cell was placed at ambient temperature of 308 K and at a discharge C-rate of 2C. After 600 cycles under these conditions, it was possible to verify the effects of aging through the decrease of ohmic resistance and increase in the cell temperature after the discharge phase.
Keywords
thermal behavior, lithium-ion cell, differential voltage technique, aging effect
