A Thermal Analysis of a Spirally Wound Battery Using a Simple Mathematical Model

Abstract

A two‐dimensional thermal model for spirally wound batteries has been developed. The governing equation of the model is the energy balance. Convective and insulated boundary conditions are used, and the equations are solved using a finite element code called TOPAZ2D. The finite element mesh is generated using a preprocessor to TOPAZ2D called MAZE. The model is used to estimate temperature profiles within a spirally wound D‐size cell. The model is applied to the lithium/thionyl chloride cell because of the thermal management problems that this cell exhibits. Simplified one‐dimensional models are presented that can be used to predict best and worst temperature profiles. The two‐dimensional model is used to predict the regions of maximum temperature within the spirally wound cell. Normal discharge as well as thermal runaway conditions are investigated.

Spatial-resolution, lumped-capacitance thermal model for cylindrical Li-ion batteries under high Biot number conditions

“…In actual battery packs, the battery cells are often stacked in series to form a battery module wrapped in an electrical insulation tape or tube causing the battery ends thermally insulated. As a result, the Li-ion cells are often treated as a radial (one-dimensional) system for thermal modeling [1,16]. The internal heat generation of Li-ion cells typically consists of reversible (entropic heating) and irreversible (Joule heating) parts [17][18][19][20][21][22] which were taken into account into the current analysis.…”

“…It is clearly explained by the fact that the zero-order approximation H 0,0 for the average temperature in Eq. (16) does not have the ambient temperature, therefore, the initial error problem does not exist. It is also interesting to see that the higher-order approximations do not always give more accurate results, especially when the ambient temperature is different from the initial temperature.…”

Modeling Heat Conduction in Spiral Geometries

“…This is the governing equation describing radial heat conduction, which, as was also considered by Evans and White, 3 can be solved in two ways as: (i) in which is different in each region as given by Eq. 6; (ii) in which is uniform and equal to an average over the whole geometry.…”

“…[1][2] For this reason, the spirally-wound design is used in a variety of battery systems ͑e.g., Li-SOCl 2 , 3 Li bromine chloride complexing additive ͑BCX͒, 4 lead-acid, 5 Zn-MnO 2 , 6 Li-ion [1][2]7 ͒. However, because of their lower surface area to volume ratio, spiral batteries retain more heat than prismatic batteries.…”

“…However, very few publications [3][4][5][6][7][8][9] exist in the literature that couple electrochemical and thermal behavior in spirally wound batteries. Rather, most thermal models of spirally wound batteries estimate the heat generation rate a priori from experimental voltage-time data.…”