Built environment paper outlines safety measures to prevent and mitigate lithium-ion battery fires

'Thermal runaway' from lithium-ion batteries in handheld devices, electric vehicles (EVs) and energy storage systems has caused large-scale fires and even explosions, requiring greater safeguards, a recent study has revealed.

A joint paper published by Collaborative Reporting for Safer Structures (CROSS-UK) and the Institution of Fire Engineers (IFE) outlines the appropriate measures that stakeholders in the built environment should take to prevent and mitigate lithium-ion battery fires. 

Aimed at a broad range of stakeholders that are responsible for designing, constructing and managing aspects of the built environment, Fire safety concerns with lithium-ion batteries draws on publicly available guidance and research as well as confidential reporting for both battery-powered devices and Battery Energy Storage Systems (BESS) to advise on the effective management of the risks associated with these batteries.

As the joint paper warns, while lithium-ion batteries have become more prevalent due to their widening use in devices and applications such as smartphones, laptops and EVs, including e-bikes, they also pose significant fire hazards, notably to residents in the built environment. 

Like other battery technologies, lithium-ion batteries require a certain amount of energy to initiate their chemical reaction, it says. However, because they have a high energy density, they can generate a significant amount of heat in a small space. This leads to thermal instability and potentially explosive failure.

"When the heat generated by a lithium-ion battery cell exceeds its ability to dissipate it, a process known as thermal runaway occurs," explains the paper. 

"This can cause a chain reaction, leading to rapid overheating, gas production, and potentially violent destruction. Thermal runaway in one cell can trigger a chain reaction, causing other cells to fail and intensify the fire. The combination of high energy density, reactive chemicals, thermal propagation, and potential hydrogen production makes lithium battery fires extremely challenging to extinguish. Furthermore, extinguishment can lead to further gas production."

Fire safety concerns with lithium-ion batteries also warns that lithium-ion battery fires are difficult to detect, control and extinguish and encourages readers to review the Faraday Institution’s work on the Science of Battery Safety (SafeBatt) project, which is briefly outlined in the joint paper.   

In response, CROSS-UK and the IFE have outlined preventative and reactive measures that will enable stakeholders to reduce the likelihood and impact of fires and improve safety.

These measures include the following:

• using a battery management system that monitors and regulates the voltage, current, and temperature of the battery cells and prevents overcharging or over discharging
• installing fire detection and suppression systems that can quickly identify and isolate the affected battery cells and apply suitable extinguishing agents
• implementing safe storage and disposal practices that avoid stacking or crushing the batteries and separate them from other flammable materials –  this is particularly relevant for batteries in handheld devices
• providing adequate ventilation and fire barriers that prevent the accumulation of flammable vapours and limit the spread of fire to other areas
• conducting regular inspection and maintenance of the batteries and their associated equipment to detect any signs of damage or deterioration; and
• following robust emergency procedures that ensure the safety of personnel and property in case of a fire incident.

The joint paper also references two CROSS Safety Reports that the collaborators advise relevant stakeholders review because they contain important information about the risks associated with lithium-ion batteries.

The first is CROSS Safety Report 1058, Fire safety risks with lithium-ion batteries, published in March 2022, which describes the increasing use of domestic lithium-ion Battery Energy Storage Systems in the UK and related issues around the rise in the second-hand market for the batteries, particularly their use in DIY projects. This report is particularly relevant to designers and fire safety engineers.

The second is CROSS Safety Report 1166, Battery Energy Storage System concerns, which covers a specific BESS built and commissioned in 2018. This report notes that BESS technology is changing and evolving rapidly and consequently could outpace current fire safety guidance and legislation. This report is particularly relevant to designers and the fire and rescue service. 

The joint paper also contains a short list of important guidance documents to assist stakeholders.

These include two from 2023: the Fire Protection Association’s Need to Know Guide RE2: Lithium-ion Battery Use and Storage, which outlines risk control recommendations for the safe use and storage of lithium-ion batteries; and the Office for Zero Emission Vehicles’ interim guidance that provides information on the fire safety considerations when installing EV charge points in covered car parks. 

The most recent is the Office for Product Safety & Standards and Department for Business and Trade’s statutory guidelines from December 2024, which set out the safety mechanisms for lithium-ion batteries used for e-bikes to manage the risk of thermal runaway.

Who should have fire safety concerns with lithium-ion batteries?

• owners and occupiers of facilities where lithium-ion battery technology may be prevalent or are planned
• fire engineers
• structural engineers
• local authorities, building control bodies
• developers, building surveyors and architects
• facilities managers and maintenance organisations; and
• fire and rescue services, and all other first responders including the police and ambulance service.

Further information

Lithium-ion batteries: canned heat

On the safe side: the stability of lithium-ion batteries

Read the full paper here.