SafeBatt – Science of Battery Safety
Whilst lithium-ion cell fires are rare, they can occur under various conditions of mechanical, thermal or electrical stress or abuse. As the use of lithium-ion batteries expands into automotive, stationary storage, aerospace and other sectors, there is a need to further decrease the risk associated with battery usage to enable the optimisation of safety systems.
This project is improving the fundamental understanding of the root causes of cell failure and the mechanisms of failure propagation. Working closely with industry, a multi-scale approach is being taken, from the material to the cell and module scale. Whilst the nucleation of failure may be a microscopic event, the propagation of failure, in particular cell-to-cell propagation, is macroscopic. Research spans time frames from the degradation of materials over hundreds of charging cycles, down to the nucleation and propagation of thermal runaway with characteristically sub-second events.
The project is also developing an improved understanding of processes occurring during real world failure, including the environmental consequences of lithium-ion battery fires, which will inform the further development of fire sensing and protection systems for lithium-ion battery energy storage systems and help inform first responders.
Timeline with milestone/deliverables (to March 2026)
- Understand failure events and propagation through state-of-the-art instrumentation, imaging and high speed techniques.
- Develop and demonstrate detection methods and mitigation strategies for thermal runaway and propagation.
- Understand the safety signatures of degraded cells; investigate how materials properties cause varied safety signatures.
- Develop an initial model(s) of thermal runaway, cell-to-cell propagation and reaction pathways.
- Conduct tests in larger format cells and at module level to understand how batteries fail in real-world scenarios.
- Determine the toxicity of Li-ion cell fires and run-off, and the composition and explosive behavior of the vapour cloud.
- Give a clear point of access for industry, first responders and government for knowledge and engagement on battery safety issues
Project innovations
Large-scale experiments at module level include further investigating fire extinguisher efficacy and the toxicity of fumes and run-off. Previous largescale research has been instrumental in highlighting the potential explosion hazard of the vapour cloud, which is produced by cells under certain failure conditions. This ground-breaking work is informing best practice and providing knowledge to numerous stakeholders internationally (including first responders and government working groups) on real-world lithium-ion battery failure hazards in EVs and micromobility devices, recycling facilities, and domestic and industrial energy storage facilities. This knowledge is being used to influence UK and international standards and produce safe practices for storing and charging devices such as e-scooters and e-bikes.
The understanding of cell failure modes and thermal runaway propagation that the project is developing (for example, by using high-resolution, high-speed visualisation techniques and internal sensors) is of direct relevance to automotive manufacturers and other system developers in other sectors.
Duration
1 April 2021 – 31 March 2026
Project funding
£6.1 million
Principal Investigator
Professor Paul Shearing
University of Oxford
Project Leader
Dr Julia Weaving
University College London
University Partners
University of Oxford (Lead)
University College London
University of Cambridge
King’s College London
Newcastle University
University of Sheffield
University of Warwick
