Motorola Knowledge Event Series 2022
Operational response and lithium-ion batteries - Proceedings

October 2022

AFAC, with the support of Motorola Solutions Foundation, presented a Knowledge Event Series across nine locations in Australia and New Zealand in October 2022.

Participants heard an international expert perspective from guest presenter Professor Paul Christensen. Paul holds the Chair of Pure and Applied Electrochemistry at Newcastle University and is Senior Advisor to the UK National Fire Chiefs Council.

He serves on the UK Cross-government Technical Steering Group for EV fire safety, and the UK BEIS Energy Storage Health and Safety Governance and Fire Service Working Groups.

His research includes ignition tests on Electric Vehicle (EV) batteries and EVs, with the aim of researching thermal runaway in large lithium-ion batteries and informing the standard operational procedures of first responders. His expertise in this field has seen him assisted fire and rescue services across the UK and around the world.

Research into thermal runaway

Touching on several different research projects that he has been involved in, Paul explained the outcomes of these tests including the effect of state-of-charge on thermal runaway, the impacts of thermal and mechanical abuse of pouch cells and the identification and analysis of vapour clouds. The research identified that the first obvious indication of thermal runaway is the ejection of white vapour, often mistaken for smoke: if this ignites, the obvious hazard is fire. If, however, the vapour does not ignite, it poses an entirely different hazard in terms of high toxicity and the potential for a violent vapour cloud explosion. This is the first mention of such a phenomenon linked to lithium-ion batteries in the academic literature. Paul also highlighted the absence of research and testing results globally in this space, including into the potential hazards and chemical make-up of the vapour cloud. This is of relevance to firefighters who may not be fully aware of the health impacts of exposure to a lithium-ion battery vapour cloud.

Extinguishing method tests

During tests funded by Defence and several fire and rescue services in the UK, extinguishing methods were tested to halt or slow propagation of thermal runaway to neighbouring cells inside a lithium-ion battery. Limited testing indicated that the likely most effective suppressant is a water mist. It also identified that close proximity fire suppression activities are a high risk activity due to directional heat release rates and the potential exposure to toxic vapour.

International incidents of note

Paul showed videos of thermal runaway events around the world and clearly identified risks such as the vapour cloud explosion and the fast escalation of fire behaviour. Incidents of note that he discussed included bus fires across Europe, EV fires in North America, scooter and e-bike fire frequency globally and large-scale BESS incidents such as the McMicken BESS explosion in Surprise, Arizona. He highlighted how technology and the DIY battery construction and charging culture is creating, in some cases, fatal incidents. This discussion also emphasised the gap in regulation and public education of everyday lithium-ion battery risks.

Policy

Professor Christensen explained how UK policy development is lagging behind the growth of energy storage usage in the UK. He also explained how second-life batteries are an emerging risk as the cells become more unstable with age.

Australia and New Zealand have created some world-leading guidance including the CFA Guidelines for Renewable Energy Installations. The UK National Fire Chiefs Council are also currently reviewing the AFAC Guideline for Incidents Involving Electric Vehicles with a view to adopting the guideline across the UK.

Paul highlighted the substantial absence of research that can be used to inform policy. Further research globally is required to assist with comprehending risks and therefore informing decision making and policy recommendations.

Public Safety

Professor Christensen explained how a public education campaign is necessary to enhance consumer literacy in relation to risks associated with lithium-ion batteries. Paul noted that without adequate safety messaging, consumers have a propensity to ‘mix and match’ batteries and charging stations, especially individuals who rely on micro-mobility devices (delivery drivers on e-bikes were a commonly cited example). This poses a serious risk because charging protocols differ in profound ways between brands and battery types. Based on these behaviours, and the risks posed by thermal runaway and a potential vapour cloud explosion, he highlighted that the primary risk to the public at this stage is from micro-mobility devices.

Fire and Rescue NSW have developed public messaging that is available on their website relating to battery and charging safety.

 The 2022 Motorola Knowledge Event Series is available to view on AFAC Youtube: