Insight 17: Improving the Safety of Lithium-ion Battery Cells
Summary
Lithium-ion battery cells in electric vehicles are already safe and failure incidents are very rare. But with increasing use across automotive, stationary storage, aerospace and other sectors, there is a need to make them even safer. Whilst lithium ion cell fires are extremely infrequent, they can occur under conditions of mechanical, thermal or electrical stress or abuse. Building safer and more reliable lithium-ion battery packs, as well as improving the design and optimisation of safety systems, will help to decrease the risks associated with rising lithium-ion battery usage.
Focus of the Insight
This Insight looks at the routes to LiB failure, the different risks involved and the way fires in EVs differ to those in internal combustion engine (ICE) vehicles. It considers current mitigations in place and the additional mitigations that could be implemented to further reduce these risks. It also sets out the work that the Faraday Institution SafeBatt project is undertaking to develop even safer LiBs.
Conclusion
Rates of catastrophic LiB failure remain extremely low, but with EV demand increasing and new applications and technologies emerging, there is a need to enhance LiB safety and the understanding of safety further. The economic case for building safer LiBs is compelling, the key benefits being lower warranty costs and a reduction in the financial cost of damage to EVs from a pack failing catastrophically. Warranty costs for EV automakers in the UK are expected to reach around £780 million per annum by 2030, and in this context, even small safety improvements will have a significant positive economic benefit.
The SafeBatt initiative represents a pivotal step in enhancing LiB safety, which is vital for supporting the growing demand and expanding applications of LiBs. Alongside this ongoing research, the safety of batteries will also be an important cross departmental government concern, that requires a coordinated approach involving activities such as:
- Educating end-users, the emergency services and other stakeholders on safety risks, mitigation measures and how to deal with any fires will be critical as the UK battery industry moves forward.
- The development of a coherent UK framework and industry-recognised guidelines for the safe handling, recycling and disposal of used and damaged EV LiBs to minimise safety risks.
- International collaboration to establish global standards of testing and legislation for LiBs across different applications and geographies, including repurposed and second-life batteries.
The need for an integrated understanding of the science of LiB safety will only increase with time. Next generation LiBs will contain even more energy as automakers seek to extend EV range. LiBs are also expanding into ever-increasing applications, such as e-scooters, aviation, marine, and domestic and industrial energy storage systems, as well as starting to permeate second-life applications and enter recycling facilities. Managing the risks associated with these new applications will require a combination of regulation, dissemination of best practices and ongoing scientific research to ensure safety across all sectors.