Application of DFSS for Optimizing Thermal Protection in Electric Vehicles During Battery Thermal Runaway Events

Battery thermal runaway is a major safety concern in electric vehicles because of the extreme heat and hazardous gases released during cell failure. These venting events can quickly raise the temperature of the battery enclosure and cabin floor, threatening occupant safety. To address this challenge, this study employs the Design for Six Sigma (DFSS) methodology to design and optimize a thermal protection system that delays and limits heat transfer to the cabin. A physics based transient heat transfer model was combined with DFSS principles to systematically evaluate insulation materials, shield layouts, surface emissivity, and layer geometry. An L 18 orthogonal array was used to identify key parameters and quantify their influence on thermal robustness. The optimized architecture reduced cabin floor temperature rise under severe runaway conditions (600–900 °C vent gas), meeting occupant egress safety requirements. Findings confirm DFSS as an effective framework for developing high robustness EV thermal protection systems under uncertainty and extreme boundary conditions.