Critical analysis of open circuit voltage and its effect on estimation of irreversible heat for Li-ion pouch cells

Research output: Contribution to journalArticleScientificpeer-review

Researchers

Research units

  • Swinburne University of Technology

Abstract

Battery polarisation is not only responsible for reducing battery available capacity but also for controlling heat generation characteristics of batteries. This phenomenon was therefore carefully studied and modelled by Newman, Tiedemann and Gu (NTG). The NTG model is now widely used for simulating battery thermal behaviour and has even been adopted by CD-adapco for their proprietary battery modelling software - Battery Design Studio. The model however revolves around an idealised battery cell. It may thus not be applicable to commercial battery cells. This paper scrutinises the effect of open circuit voltage (OCV), a key parameter in the NTG model, on the irreversible heat generation of a commercial cell under a controlled environment by differentiating the OCV recorded immediately after the current stops flowing through the cell and the OCV corresponding to the equilibrium state of the cell. It is noticed that the NTG model underestimates the irreversible heat generation rates for a 20 Ah Li-ion pouch cell by approximately 0.15 W and 0.22 W for discharge currents at 0.33C and 0.5C at an operating temperature of 27 °C, respectively. It is also observed that the accuracy of the NTG model is significantly improved in simulating thermal behaviour of commercial battery cells when the OCV is representative of the cell equilibrium voltage.

Details

Original languageEnglish
Pages (from-to)117-126
Number of pages10
JournalJournal of Power Sources
Volume350
Publication statusPublished - 2017
MoE publication typeA1 Journal article-refereed

    Research areas

  • Battery design studio, Battery polarisation, Calorimeter, Concentration gradient, Equilibrium state, Solid electrolyte interphase film resistance

ID: 14902507