Highlights

Abstract

Graphical abstract

Keywords

Nomenclature

۱٫ Introduction

۲٫ Why focusing on LIB risk management and safety issues?

۲٫ Contextualising the relative levels of risk of electric vehicle LIBs

۳٫ Potential failure mechanisms of LIBs

۴٫ Origins and categorisation of risks associated with LIBs

۵٫ End of Life LIB incidents

۶٫ Safety measures, regulatory gaps and discussions

۷٫ Conclusions

Credit author statement

Declaration of competing interest

Acknowledgments

References

Abstract

Lithium-ion Batteries (LIB) are an essential facilitator of the decarbonisation of the transport and energy system, and their high energy densities represent a major technological achievement and resource for humankind. In this research, it has been argued that LIBs have penetrated everyday life faster than our understanding of the risks and challenges associated with them. The current safety standards in the car industry have benefited from over 130 years of evolution and refinement, and Electric Vehicle (EV) and LIB are comparably in their infancy. This paper considers some of the issues of safety over the life cycle of batteries, including: the End of Life disposal of batteries, their potential reuse in a second-life application (e.g. in Battery Energy Storage Systems), recycling and unscheduled End of Life (i.e. accidents). The failure mechanism and reports from a range of global case studies, scenarios and incidents are described to infer potential safety issues and highlight lessons that can be learned. Therefore, the safety risks of LIBs were categorised, and the regularity requirements to create and inform a wider debate on the general safety of LIBs were discussed. From the analysis, a range of gaps in current approaches have been identified and the risk management systems was discussed. Ultimately, it is concluded that robust educational and legal processes are needed to understand and manage the risks for first responders and the public at large to ensure a safe and beneficial transition to low carbon transportation and energy system.

۱٫ Introduction

Lithium-ion batteries (LIBs) have penetrated deeply into society, finding a wide range of applications in personal electronic devices since their discovery and development in the 1980s and 90s, and more recently in larger energy systems for traction and energy storage. This is mainly owing to the unique characteristics of LIB technology, i.e. high energy densities, high voltage, good stability, low self-discharge rate, long-life cycle and availability of a wide range of chemistries with diverse electrode designs [1,2]. LIBs are incorporated into ever widening application areas and are to be found at scales as diverse as their usages. This is evidenced by the growth in the uptake of LIBs having increased eight fold between 2010 and 2018 to 160 GWh [3] and the steady increase in annual sales of LIBs which are predicted to be upwards of 4 TWh by 2040 [4]. In the UK, it is forecast that the number of LIBs reaching the end of their life from automotive applications would have reached approximately 75,000 units, or 28,000 t by 2025 [5]. The advent of lithium-ion technology and the paradigm shift in the energy and power density capabilities that it represents, are perceived as the enabling technology for an extremely broad range of energy storage applications. Accordingly, LIBs are increasingly recognised as essential and integral to enable the large-scale temporary storage of electrical energy from renewable energy sources.