Session: 04-01: Modelling, Control and Design of Hybrid Powertrains

Paper Number: 172380

172380 - Solid Particle-Driven Ignition During Battery Thermal Runaway 

Abstract: 

Lithium-ion battery (LiB) thermal runaway events are high-risk phenomena that can lead to the rapid release of energy, gases, and solid fragments from the battery’s internal components. Among these byproducts, hot solid particles such as fragments of the cathode, separator, and anode can be expelled into the surrounding environment. These ejected particles, often at temperatures exceeding 1000°C, have the potential to ignite the flammable vent gases released during the event. These vent gases typically consist of hydrogen (H₂), methane (CH₄), carbon monoxide (CO), and other hydrocarbons, depending on the battery chemistry and state-of-charge. This study utilizes computational fluid dynamics (CFD) simulations to investigate the ignition behavior of these vent gases when exposed to hot particles. Detailed numerical models incorporate gas-phase combustion, radiation heat transfer, and adaptive mesh refinement to capture the complex physics around the particle and gas interactions. The influence of particle characteristics—such as size, surface temperature, and motion (static vs. moving)—on ignition onset and flame propagation is systematically studied. The simulation domain is designed to replicate thermal runaway-relevant conditions, including stoichiometric and fuel-rich equivalence ratios. Key findings reveal that ignition can occur through localised heating via conduction and natural convection from the hot particle to the surrounding gas. Moving particles enhance gas mixing and introduce flow asymmetry, accelerating flame kernel growth and propagation. This study offers critical insights into the role of solid particles in igniting vent gases, highlighting a potential hazard pathway that must be addressed in advanced battery safety assessments and designs used in hybrid powertrains.

Presenting Author: Dhananjay Kumar University of Wisconsin-Madison

Presenting Author Biography: Dr. Dhananjay Kumar is a postdoctoral researcher at the Engine Research Center, University of Wisconsin–Madison. He earned his Ph.D. from the Indian Institute of Technology (IIT) Kanpur, where he was associated with the Engine Research Laboratory. His research focuses on hydrogen and alternative fuels, laser ignition, combustion simulations, and battery thermal runaway in Li-ion systems. He has authored several journal papers and book chapters on clean combustion technologies involving fuels like hydrogen, methanol, and CNG.

Authors:

Dhananjay Kumar University of Wisconsin-Madison
Sage Kokjohn University of Wisconsin-Madison