Thermal runaway and combustion of lithium-ion batteries pose unique hazards due to early gas venting and intense ejection release, which can create fire and explosion hazards in battery modules and larger storage systems. The region close to a battery as it undergoes failure is critical as it defines the failure propagation in larger modules.

Our research exploits high-speed imaging and laser diagnostics to develop near-field quantification of the various phenomena defining thermal runaway including the toxic/flammable gas species, ejecta velocity/temperature distributions, and the explosion hazards from accumulated gas in storage systems. These insights inform safer energy storage system design and explosion mitigation strategies.

Current projects related to Li-ion battery thermal runaway include:

(1) Hyper-spectral imaging and laser absorption spectroscopy of flammable and toxic gas species during safety venting (collaboration with Prof. Kyle Daun, Waterloo and Prof. Aamir Farooq, KAUST)

(2) Characterization of early particle venting and development of low-cost sensors for in-situ detection

(3) Development of statistically-resolved data acquired using high-speed diagnostics of the velocity and temperature fields in the hot ejecta during thermal runaway (collaboration with Prof. Assaad Masri and Dr. Matthew Dunn, University of Sydney)

(4) Flame acceleration of thermal runaway vent gas to guide practical storage system design and explosion mitigation strategies (collaboration with Prof. Hongxia Yang, Waterloo)

Mass timber construction is being rapidly adopted in mid-rise buildings within Canada as an alternative structural material due to it's aesthetics, sustainability factors and ease of construction drivers. The contribution of mass timber elements to a fire remains a major constraint for it's proliferation, and building designers do not possess the tools to enable the safe design of mass timber. 

University of Waterloo is leads the Fire Safety theme within the NSERC NextGen Timber Alliance. We are developing cutting edge experimental research to advance our understanding of fire behaviour of timber and it's interaction with contemporary buildings. Our work aims to advance tools and codes that can be used to integrate fire safety as a design variable in tall timber buildings.

Within the Timber Alliance, we are engaged in several projects:

(1) Fire dynamics in mass timber compartments

(2) Quantifying external flaming risk onto facades in mass timber buildings

(3) Risk assessment methodology of mass timber buildings

(4) Thermal wave penetration and structural capacity of timber elements exposed to  natural fire sources (collaboration with Prof. John Gales & Mr. Ethan Phillon, University of York)

Wildfires are becoming more intense and more frequent in Canada, with the summer seasons overshadowed by persistent pollution over urban and rural areas. Understanding the flammability and emissions from wildfire fuels is critical towards directing forest management protocols, forecasting technologies, public policy, and firefighting efforts. 

Of particular interest is the role of invasive and native species in Ontario on the flammability and emissions released during the various combustion modes that may occur in a wildfire. The production of volatile organic compounds and polycyclic aromatics are of key focus as such compounds carry profound health impacts. These have been characterized using ex-situ sampling techniques such as GC-MS and FTIR, however, in-situ measurements will be performed using TR-LII and LIBS to determine the key chemical and physical pathways responsible for particulate and toxic species formation. 

Wind-driven interactions with firebrands and fire spread are also being investigated at UW using our state-of-the-art wind generation facility at large-scale. 

Fire safety risks have transformed over the past 20 years in the building, forest, marine, aerospace, and nuclear sectors with the introduction of more complex fuels. This has coincided with the phase-out of traditional fire suppression technologies such as HCFCs and PFAS containing agents due to their negative environmental impacts. Alternative suppression methods are urgently required that can deliver improved efficacy and cost optimization. 

Our work is at the forefront of developing alternative suppression technologies including chemically enhanced water mists, ecogels, and inert gases. Characterizing the efficacy of different fire suppressing technologies is challenging as it requires a detailed understanding of local flame extinction processes, thereby necessitating the use of advanced optical diagnostics. Recent work has focused on doping fine water mists with metal alkali compounds to greatly improve suppression capabilities, whilst minimizing water requirements. We have characterized the flame-droplet interactions using optical techniques such as planar laser-induced fluorescence (PLIF), Mie scattering, and Phase-Doppler Particle Analysis (PDPA) to guide next-generation suppression strategies.