Multi-Functional Adaptive Biomimetic High Energy-Density Battery Enclosure

The anticipated global count of passenger vehicles is projected to increase from 1,102 million in 2017 to 1,980 million by 2040. This sector is a significant contributor to global CO2 emissions, accounting for approximately 23% of the total, with road transportation alone contributing around 72% of this figure. Lightweighting is particularly relevant to promote the widespread adoption of battery electric vehicles. Structural weight reductions lead to higher energy density, allow for larger battery packs and hence extend the range of electric vehicles. Battery enclosures constitute one of the largest weight-saving opportunities for battery electric vehicles, with fiber reinforced composites playing a key role in achieving the desired weight targets. In fact, empty metallic battery enclosures add 110-160 kilograms to vehicle mass and are now the heaviest component on battery electric vehicles. Battery enclosures need to meet a broad range of multifunctional requirements which are currently achieved via separate and independent designs requiring costly integration and assembly. Amongst the most relevant functions of the enclosure, high crashworthiness (especially impact protection from road impacts and from rapid energy release events in case of battery failure and thermal runaway) and thermal management are critical to ensure passengers safety, the longevity and correct functioning of the battery pack. To this end, multifunctional and intelligent composites that can sense, diagnose, and respond for adjustment with minimum external intervention and that allow alternation of functionality and mechanical properties on demand are ideal to make a step change in battery enclosure design and vehicle energy efficiency. Based on the needs for disruptive multifunctional composite materials enabling lighter and more integrated automotive components for electric vehicles, in this Phase I project, we propose an innovative approach that integrates a multifunctional active cooling system designed using topology optimization and a biomimetic self-sensing and adaptive lightweight composite laminate designed for superior impact protection and safe containment of rapid energy release events during thermal runaway to drastically reduce the thermal runaway risk, hence allowing for battery-packs with higher energy density and uncompromised passenger safety. This aligns with the goal of achieving high-performance, low cost and efficient vehicles while enhancing safety and reliability, crucial for wider battery electric vehicles adoption. The Phase I goal is to demonstrate via experimental testing and finite element analysis a multi-material design for the creation of a thermo-mechanical battery enclosure with a high degree of functional integration, high safety and autonomous response to critical battery failure events and road impact to maximize passengerĺs safety while minimizing the final cost and weight. This objective will be achieved via integrating matrix systems with different properties to bioinspired fiber architectures and active cooling systems. Experimental and numerical activities will be performed to optimize the innovative battery enclosure. The resulting optimized structure will be rated with a rigorous decision matrix and compared against state-of-the-art battery enclosures based on the level of production cost, specific mechanical performance, and carbon footprint. Following this Phase I project, the innovative high-performance and multifunctional composite design for thermo-mechanical battery enclosures will be scaled up throughout Phase II and III, leveraging partnerships with key automotive and raw material suppliers. A pilot application for commercial automotive will be targeted to deliver to market more than 450,000 battery enclosures by 2030 integrating the newly developed self-sensing and adaptive composite technology and cooling unit. The innovation will have a wider impact to extensively enable the use of highly multifunctional and ôsmartö composite designs in other applications requiring high mechanical performance, damage tolerance and thermal control including road transportation, marine, rail and green powered aviation.