Safety Performance of High-Demand Lithium-Ion Batteries

In the relentless push towards a net-zero future, lithium-ion batteries (LIBs) stand at the forefront of technological innovation. Lithium Ion batteries are pivotal in driving the adoption of electric vehicles (EVs), supporting grid storage, and enabling portable electronics. Yet, as demand surges, safety concerns under abnormal conditions, particularly thermal runaway (TR), have become a pressing issue for manufacturers and users alike. In recent months we have become aware of a range of incidents (and advice from fire authorities) involving small Lithium Ion batteries (including fires generated in toolbars of tradespersons). In this article we explore some recent research in thermal battery runaway

Recent incidents of lithium-ion battery fires that have occurred include:

• a lithium-ion battery caught fire while being transported in a tool bag in the back of a work utility at a mine. The battery was free to move within the tool bag and was possibly short circuited.

• a lithium-ion battery caught fire while connected to a charger at an underground mine. The primary causation factor  was moisture ingress, which led to thermal runaway of the battery.

• a lithium-ion battery was left unattended on the back seat of a utility. The inside temperature of the vehicle exceeded the maximum recommended temperature for the battery and resulted in the battery catching fire

• a lithium-ion battery caught fire when run over after falling out of a man basket at a mine site.

A comprehensive study recently published in the Journal of Energy Storage delves into the behaviour of three types of commercially available 18650 cylindrical LIBs, all boasting a nominal capacity of around 3 Ah. Focusing on nickel-rich cathode chemistries, such as NCA (nickel manganese aluminium oxide) and NMC (nickel manganese cobalt oxide), the study reflects the industry’s shift towards these high-performing materials.

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The study has highlighted that Thermal Runaway can be triggered by various abuse methods — thermal, electrical, and mechanical. Previous research often emphasised overcharging or external heating, overlooking the full spectrum of potential hazards. This study bridges this gap by employing a suite of abuse tests: over-temperature, short circuit, overcharge, and nail penetration, accompanied by detailed gas analysis post-failure.

By maintaining consistent electrical properties and form factor, the study isolates the variable of cathode chemistry, offering a clearer comparison of failure modes. The findings of the study reveal that, despite similar self-heating temperatures, the failure events differ not only among cell types but also between repeated tests on the same cell. Interestingly, variances were observed in visual inspections and temperature data, suggesting a complex interplay of factors influencing the safety and performance of these cells.

Do you want to understand the Lithium Ion Battery Safety Standards in Australia? Here’s a quick guide to the Standards.

As the broader Australian industry gravitates towards nickel-rich LIBs, such insights are invaluable for workplaces and users of batteries alike. The study suggests that while modern NMC cells (with a probable Ni:Mn:Co ratio of 8:1:1) are now predominant, the literature on their failure outcomes is fairly scant, particularly when pitted against NCA chemistry cells.

Safety, a critical aspect often overshadowed by performance metrics, is brought to the limelight here. This study not only aids in enhancing the safety protocols for the current generation of LIBs but also provides a robust framework for future research. As LIBs continue to evolve, ongoing investigations like this are essential in navigating the complex landscape of battery technology, ensuring that the march towards cleaner energy does not compromise the integrity and safety of these indispensable units.

If you need advice and programs on managing battery safety risks at your workplace, Safetysure Health & Safety Consultants have a range of technical specialist that may be able to assist. Call us on 1300 087 888 for more information.

The ACCC has recently published a report on Lithium-ion batteries and consumer product safety that you might also find useful