Thermal Design of an Electric Vehicle Battery Module

Background

The research study presented an analytical and numerical investigation of heat dissipation characteristics in electric-vehicle battery modules of varying geometries, material properties, and thermal boundary conditions. A one-dimensional conduction model was developed to quantify temperature distribution under uniform volumetric heat generation, with convection considered at the external surfaces. Key thermal parameters, including thermal conductivity k, convection heat transfer coefficient ℎ, the Biot number (Bi), and transient response time t, were evaluated to determine their influence on steady-state temperature and thermal response in general.

Methodology & Results

Rectangular and cylindrical modules were simulated using SOLIDWORKS software and compared to analytical predictions. The results obtained showed mutual agreement between the analytical and numerical solutions, with temperature deviations of less than 1%, confirming the validity of the heat transfer assumptions and boundary conditions used. For the rectangular cell, a maximum temperature of 320.15 K at the mid-plane and a surface value of 318.15 K were recorded, matching the analytical model with 100% accuracy. Similarly, the cylindrical module exhibited a maximum temperature of 309.15 K. 

Analysis

A parametric sustainability study revealed that increasing thermal conductivity reduces thermal gradients and accelerates heat dissipation, while applying insulation significantly elevates internal temperatures and delays thermal stabilization due to increased thermal resistance. Module thickness was shown to scale the transient response proportionally, showing geometry dependent sensitivity. The overall results confirmed that battery module geometry, material conductivity, and boundary conditions significantly govern heat transfer behavior and operational safety and these insights.

Recommendations for Electric Vehicles

EV manufacturers should favor cylindrical battery modules over rectangular ones for superior thermal management, and pair them with high-conductivity casing materials while avoiding excessive insulation. Faster heat dissipation reduces peak operating temperature, lowering risks of thermal runaway, degradation, and fire hazards, while improving battery lifespan and charge/discharge efficiency. This research contributes to the automotive industry by providing a validated analytical-numerical framework (within 1% deviation) for predicting thermal behavior early in design, enabling engineers to optimize module geometry, material selection, and cooling systems before costly prototyping, supporting safer, more reliable, and higher-performing EV battery packs.