The novel use of foam-based solutions for the containment of thermal runaway sidewall rupture

Prevention of thermal runaway propagation is a key requirement of battery pack safety across transport sectors, particularly for aerospace. Sidewall rupture is the most violent and likely failure to result in propagation but is less studied as it is difficult to initiate reliably and repeatably. Recent studies that reliably initiate sidewall rupture have allowed testing of interstitial materials under such failure modes. Our research studies the novel application of interstitial foam materials under sidewall rupture. Materials were found that successfully contain sidewall rupture and prevent thermal runaway propagation. Additionally, sufficient thermal insulation was provided to allow cells immediately proximate to a runaway to maintain their open circuit potential, potentially allowing recovery and continued future operation of adjacent cells. An additional study, documented here, was included on the effect of lid-plates on solutions to explore more representative experimental methods. Removing lid-plates was found to allow lower density foam materials to be competitive and outperform higher densities. • Propagation prevention materials tested under a sidewall rupture failure mode. • Higher density foams at greater performance due to their structural integrity. • Differing failure modes identified, immediate propagation and delayed propagation. • Pack design causes a significant impact, such as lid-plate spacing.