Thermal Runaway Risks in Discarded Lithium-Ion Batteries
Residual voltage in spent batteries poses significant fire hazards when exposed to external heat.
1Thermal Runaway Research Findings
The National Fire Research Institute recently conducted thermal abuse experiments on discarded lithium-ion batteries. The study aimed to identify fire risks associated with residual voltage levels. Results confirmed that external heat application can trigger thermal runaway, a phenomenon where battery temperatures rise rapidly, leading to chain-reaction fires and intense flames.
2Voltage Thresholds and Safety
Researchers categorized cylindrical waste batteries by their remaining voltage levels before applying controlled heat. Batteries with an average residual voltage of 3.45V showed gas release and electrolyte leakage but avoided thermal runaway. Conversely, batteries with 3.94V or higher experienced rapid temperature spikes and violent thermal runaway events during the testing process.
3Historical Industrial Fire Incidents
The research follows several real-world industrial accidents involving waste batteries. In January 2024, a fire broke out at a recycling facility in Pyeongtaek during battery shredding. Similarly, a 2020 incident in Goryeong involved a battery separation process where a fire escalated into a series of explosions, complicating emergency response and fire suppression efforts.
4Residual Energy Hazard Mechanism
Even batteries considered end-of-life often retain significant electrical energy. This internal energy acts as a fuel source when external heat is introduced, even if the battery is no longer functional for consumer devices. The study highlights that chemical instability persists as long as the battery maintains a specific voltage threshold.
5Risks Beyond Thermal Runaway
The experiments revealed that thermal runaway is not the only danger during storage. Even in lower voltage conditions where fire did not occur, researchers observed consistent gas emissions and electrolyte leakage. These substances pose secondary environmental and health risks, necessitating careful handling protocols during the collection and storage of waste batteries.
6Safety Management and Storage
The Fire Research Institute emphasizes that facilities must account for residual energy when storing waste batteries. Management protocols should strictly avoid placing batteries near external heat sources. Proper safety management is essential to prevent the chain-reaction fires that have historically plagued recycling centers and processing plants during routine handling operations.
7Educational Outreach and Training
The institute plans to utilize the video footage and data gathered from these experiments to develop safety training materials. These resources will be distributed to personnel working in battery collection, storage, and recycling facilities. The goal is to improve industry-wide awareness regarding the specific fire prevention measures required for lithium-ion waste.
8Future Safety Policy Implications
Kim Yeon-sang, head of the National Fire Research Institute, stated that sharing these findings is crucial for enhancing safety culture in the recycling sector. By providing empirical evidence on how residual voltage influences fire behavior, the institute hopes to reduce industrial accidents and standardize safer handling practices for all lithium-ion waste.
Original article: Kyunghyang — Thermal Runaway Risks in Discarded Lithium-Ion Batteries