Lithium ion batteries have a higher energy density than other battery types. Their ease of charge and discharge mean you will find them in any number of items on a production, from mobile phones to generators, from hand tools to earbuds, laptops and cameras.

However, when Li-ion batteries are damaged, overcharged or overheat, it can lead to thermal runaway. This causes rapid overheating which can quickly transfer to adjacent cells. Batteries can spontaneously ignite, burning at extremely high temperatures and there have already been multiple reported instances of lithium ion battery fires or near misses on production.

Fires linked to lithium-ion batteries up 46% year-on-year with e-bikes accounting for nearly a third – a 70% increase.

How Li-ion Batteries Work

A lithium-ion (Li-ion) battery stores and releases energy by moving lithium ions between two key parts: the positive electrode (cathode) and the negative electrode (anode), through a liquid or gel-like substance called the electrolyte.

The clever bit is that the electrolyte allows lithium ions to flow between the electrodes but blocks electrons. Electrons are the charged subatomic particles that flow through a wire – ‘electricity’ is this movement of electrons.

Because electrons can’t flow through the electrolyte, this forces them to go through the external circuit, where they do useful work powering your devices. Essentially a Li-ion battery is a reversible chemical pump that pushes lithium ions back and forth between the two electrodes, generating electricity when needed.

Where It Goes Wrong

Li-ion battery fires are on the increase. It is estimated that batteries thrown in household rubbish bins cause over 1,200 fires every year nationally in dustcarts and waste processing centres: dead batteries thrown away with other waste and recycling are likely to be crushed when the waste is collected and processed.

We are seeing increasing reports of battery fires on productions too: as part of your Fire Risk Assessment you need to consider how you are going to manage the risks from these batteries.

You can read our full guidance below, and if you want help with your fire risk assessment or more information on managing the risk from Lithium Batteries, please contact our Advice Line team.