Safe crash integration of inherently unsafe battery technologies

Abstract

Current electrified vehicles (battery-electric BEV and plug-in hybrid vehicles PHEV) suffer from two partially dependent characteristics: high gross weight and limited pure electric driving range. The design possibilities for these vehicles are limited by crash safety requirements, among other factors. The safe battery housing and the current requirement of no-significant deformation on the battery severely restrict options for placement within the vehicle. Structural stiffening measures add additional weight to the already quite heavy battery system. To better utilize the available integration space, deformation and failure characteristics of traction batteries need to be better understood. Today’s vehicle development process relies heavily on simulation tools, where finite-element (FE) methods are the established means for full-vehicle crash simulation. Therefore, to evaluate the structural performance capabilities and failure characteristics, the battery system must be adequately modeled and integrated with these methods. The development of new simulation tools that can be used in concert with the established ones are one priority of current research. The focus of this article is on integration aspects, especially in terms of failure prediction for the battery as a component. This article gives an overview on currently developed methods enabling the design of modern, structurally integrated battery concepts, while targeting crash safety demands and increased energy density for longer-range electric driving.