Thermal Model of Cylindrical and Prismatic Lithium-Ion Cells

Abstract

Oven exposure testing is a standard benchmark that Li-ion cells must pass in order to be approved for sale by regulating bodies. In order to test the safety of new cell designs or electrode materials, manufacturers must make small test batches of cells. This can be both costly and time consuming. Using reaction kinetics that have been developed for electrode materials with electrolyte exposed to high temperature, and thermal properties of cells from the literature, a predictive model for oven exposure testing has been developed. The model predictions are compared to oven exposure test results for E-One/Moli Energy, Canada, 18650 LiCoO2LiCoO2 /graphite cells and shown to be in good agreement. The model can predict the response of new cell sizes and electrode materials to oven exposure testing without actually producing any cells. This is illustrated with a number of examples: (i) increasing the specific surface area of the graphite electrode; (ii) using LiMn2O4LiMn2O4 or other cathode substitutes instead of LiCoO2LiCoO2 ; (iii) varying the diameter of cylindrical cells; and (iv) varying the thickness of prismatic cells. © 2001 The Electrochemical Society. All rights reserved.