Info!
UPDATED 1 Sept: The EI library in London is temporarily closed to the public, as a precautionary measure in light of the ongoing COVID-19 situation. The Knowledge Service will still be answering email queries via email , or via live chats during working hours (09:15-17:00 GMT). Our e-library is always open for members here: eLibrary , for full-text access to over 200 e-books and millions of articles. Thank you for your patience.
New Energy World magazine logo
New Energy World magazine logo
ISSN 2753-7757 (Online)

Thermal runaway: How to reduce the fire and explosion risk in BESS?

16/10/2024

8 min read

Feature

Fire engine outside a warehouse that is on fire with billowing smoke rising in the air Photo: Adobe Stock/S.Leitenberger
Although rechargeable battery fires are rare, they do happen; not only in battery energy storage centres, but also warehouses, as a French logistics firm found in January 2023

Photo: Adobe Stock/S.Leitenberger

As renewable energy infrastructure gathers pace worldwide, new solutions are needed to handle the fire and explosion risks associated with lithium-ion battery energy storage systems (BESS) in a worst-case scenario. Industrial safety solutions provider Fike and Matt Deadman, Director of Kent Fire and Rescue Service, address this serious issue.

As the world shifts towards renewable energy, the reliance on BESS and their deployment in urban locations is increasing rapidly. However, the proliferation of such systems mainly powered by lithium-ion (Li-ion) batteries, introduces significant safety challenges – particularly the threat of ‘thermal runaway’.

 

A BESS may contain hundreds or even thousands of Li-ion battery cells, any of which can unpredictably malfunction, leading to a rapid increase in temperature and the generation of flammable gases. This phenomenon, known as thermal runaway, can quickly escalate causing cascading failures across adjacent battery cells and resulting in large-scale fires or explosions.

 

The stages of cascading thermal runaway include: 

  • Exothermic reaction: Overcharging, short-circuiting, mechanical damage or exposure to high temperatures causes chemical chain reactions within the battery cell to accelerate, leading to the release of heat. The heat generated rapidly increases the battery temperature. 
  • Gas generation: The high temperatures cause the decomposition of electrolyte components, leading to the release of flammable gases such as hydrogen and carbon monoxide. The gas generation contributes to an increase in pressure within the cell. 
  • Venting and fire: At a certain temperature and pressure threshold, the cell may rupture or vent to release gases. If the released offgas comes into contact with an ignition source, such as a nearby flame or spark, or a flame from the battery itself, it can ignite and result in an even greater fire or explosion. 

 

This content is for EI members only.
or join us as an EI Member to read all our Feature articles and receive exclusive EI perks from as little as £6 a month.