As the use of Li-ion batteries is spreading, incidents in large energy storage systems (stationary storage containers, etc.) or in large-scale cell and battery storages (warehouses, recyclers, etc.), often leading to fire, are occurring on a regular basis. Water remains one of the most efficient fire extinguishing agents for tackling such battery incidents, and large quantities are usually necessary. Since batteries contain various potentially harmful components (metals and their oxides or salts, solvents, etc.) and thermal-runaway-induced battery incidents are accompanied by complex and potentially multistage fume emissions (containing both gas and particles), the potential impact of fire run-off waters on the environment should be considered and assessed carefully. The tests presented in this paper focus on analyzing the composition of run-off waters used to spray NMC Li-ion modules under thermal runaway. It highlights that waters used for firefighting are susceptible to containing many metals, including Ni, Mn, Co, Li and Al, mixed with other carbonaceous species (soot, tarballs) and sometimes undecomposed solvents used in the electrolyte. Extrapolation of pollutant concentrations compared with PNEC values showed that, for large-scale incidents, run-off water could be potentially hazardous to the environment.

With the rise of electric vehicles (EVs) and thus lithium‐ion batteries (LIBs), the number of end‐of‐life (EoL) LIBs after their first life in EVs is about to increase significantly. These end‐of‐first‐life (EoFL) EV LIBs still have sufficient energy density for less‐demanding second‐life applications like stationary battery energy storage systems (BESSs) or mobile applications (e.g., forklifts, tools). Repurposing EoFL EV LIBs extends their lifespan, offering sustainability benefits and supporting several United Nations (UN) Sustainable Development Goals (SDGs). However, prevailing market entry barriers, such as high repurposing costs, little information on battery history and aging, or lacking performance indicators, hinder the widespread implementation of second‐life applications. Thus, this study aims to identify preconditions for considering and selecting useful EoFL LIBs and to determine key performance indicators (KPIs) to minimize economic risks for a successful second‐life market launch. KPIs were rated according to importance using a Likert scale, and reference values were introduced. A mixed‐methods approach, using expert interviews, an exploratory workshop, and an online survey, was applied. Twelve important preconditions were identified, with the “availability of information on battery specification” and “compliance with standards and regulations” considered very important. In addition, 12 KPIs were derived, covering six economic, three environmental, and three technical and safety‐related indicators. The KPIs “state of safety (SoS)” and “resource savings (R_sav)” were rated as highly important. Overall, the findings provide performance measurement guidance for repurposing companies, facilitating the market launch and adoption of second‐life applications. Future research can build on these results and investigate variations among different battery types, ultimately promoting a circular economy.

As Li-ion batteries use is spreading, incidents in large energy storage systems (stationary storage containers, …) or in large-scale cell and battery storages (warehouse, recyclers, …), often leading to fire, are occurring on regular basis. Water remains one of the most efficient fire extinguishing agents for tackling those battery incidents and large quantities are usually necessary. Since bat-teries contains various potentially harmful components (metals and their oxides or salts, sol-vents…) and that thermal runway induced battery incidents are accompanied with complex and potentially multistage fume emissions (containing both gas and particles) the potential impact of fire run-off water on the environment should be considered and assessed carefully. The tests presented in this paper focus on the analysis of the composition of run-off waters used to spray NMC Li-ion modules under thermal runaway. It highlights that waters used for fire-fighting are susceptible to contain many metals, including Ni, Mn, Co, Li and Al mixed with other carbonaceous species (soot, tarballs) and sometimes undecomposed solvents used in the elec-trolyte. Extra-polation of pollutant concentrations compared with PNEC values showed that, for large scale incidents, run-off water could be potentially hazardous to the environment.