Are Lithium-Ion Batteries Safe?

Lithium-ion batteries are widely used in a variety of electronic devices, including smartphones, laptops, electric vehicles, and energy storage systems. However, these batteries can pose a fire hazard if they are damaged, overheated, or overcharged. Lithium-ion battery fires can release toxic gases, cause explosions, and spread rapidly, making them difficult to control and extinguish.

What Do I Do If a Lithium-Ion Battery Catches Fire?

Lithium-ion batteries have the potential to produce their own fuel for fire due to their internal chemistry. These batteries use lithium salts dissolved in a non-aqueous electrolyte to facilitate the flow of ions between the battery's electrodes during charging and discharging. If a battery cell is damaged or improperly charged, it can cause a thermal runaway reaction, where the electrolyte breaks down and generates flammable gases such as hydrogen and carbon monoxide. These gases can ignite and cause a fire, which can rapidly spread to other cells and cause a chain reaction.

This screen shot was taken from a YouTube video showing the "nail test," a commonly-used method for testing battery safety. A lithium battery on fire after being punctured by a nail

If a lithium-ion battery catches fire, it is important to take immediate action to mitigate the risk of injury or property damage. The National Fire Protection Association recommends that individuals who encounter a lithium-ion battery fire follow these steps:

Evacuate the area: If possible, remove people from the area to a safe location.
Call the fire department: Alert the fire department immediately and provide them with as much information as possible about the situation.
Wear personal protective equipment: If it is necessary to approach the fire, wear appropriate personal protective equipment, including eye protection, gloves, and a respirator.
Use a Class D fire extinguisher: If a Class D fire extinguisher is available, it may be used to extinguish the fire. However, it is important to ensure that the extinguisher is compatible with lithium-ion battery fires and to follow the manufacturer's instructions carefully.
Cool the batteries: If possible, place the batteries in a salt water bath to cool the batteries and prevent the spread of the fire.
Do not attempt to extinguish large fires: If the fire is too large or has spread beyond the immediate area, evacuate the area and wait for the fire department to arrive.

2019 APS Fire in Arizona

One notable example of a lithium-ion battery fire is the APS (Arizona Public Service) fire that occurred in April 2019 in Surprise, Arizona. According to a report by the Arizona Corporation Commission, the cause of the fire was a faulty cell in one of the battery modules that had short-circuited and overheated, leading to thermal runaway and a subsequent chain reaction. The battery system had been in operation for less than a week at the time of the fire, and the report notes that inadequate training and supervision, as well as a lack of maintenance and testing, may have contributed to the incident.

A separate report by Underwriters Laboratories (UL) also investigated the incident and identified several factors that may have contributed to the severity of the fire. These factors included the close proximity of battery modules to each other, the use of flammable materials in the battery enclosure, and a lack of adequate ventilation to dissipate heat from the battery modules.

Battery system damage following the APS battery fire

To prevent similar incidents from occurring in the future, the UL report recommended that energy storage systems be designed and installed in accordance with applicable codes and standards, and that they be subject to rigorous testing and inspection. The report also emphasized the importance of ongoing maintenance and testing of energy storage systems to ensure that they are functioning correctly and are not at risk of failure.

In response to the incident, APS has implemented a number of changes to its energy storage systems, including enhanced training and supervision for personnel involved in installation and maintenance, improved testing and inspection protocols, and the installation of additional safety features such as thermal imaging cameras and gas detection systems.

The APS fire in Arizona was a stark reminder of the potential dangers of lithium-ion battery energy storage systems. By implementing best practices for design, installation, testing, and maintenance, and by taking steps to enhance safety features and training for personnel, the risk of similar incidents can be greatly reduced

Mitigating the Risk of Lithium-Ion Battery Fires

To mitigate the risk of lithium-ion battery fires, several measures can be taken. For example, batteries should be stored, handled, and charged according to the manufacturer's instructions. Overcharging, overheating, and mechanical damage can all increase the risk of a fire. Additionally, batteries should be regularly inspected and maintained to ensure that they are functioning correctly and are not damaged. Fire suppression systems, such as sprinklers or gas-based systems, can also be installed to contain and extinguish fires.

There is a considerable amount of published research on how to reduce the cause and effect of lithium-ion battery fires. Some key strategies and technologies that have been explored in the literature include:

Battery design and materials: Many researchers have explored ways to improve the design and materials of lithium-ion batteries to reduce the risk of fires. This can include the use of safer electrolytes, improved separators to prevent thermal runaway, and the development of battery chemistries that are less prone to thermal instability.
Battery management systems: Battery management systems (BMS) are critical for monitoring and controlling the charging and discharging of lithium-ion batteries to prevent overcharging or over-discharging, which can lead to thermal runaway. Researchers have explored ways to improve the accuracy and effectiveness of BMS, such as through the use of advanced sensors and control algorithms.
Fire suppression and mitigation: There has been significant research into the development of fire suppression and mitigation strategies for lithium-ion battery fires, including the use of flame retardants, coatings, and additives. In addition, researchers have explored the use of early warning systems and remote monitoring technologies to detect and respond to battery fires more quickly.
Recycling and disposal: Proper recycling and disposal of lithium-ion batteries can help to reduce the environmental impact of fires and prevent potentially hazardous materials from entering the waste stream. Researchers have explored various methods for recycling lithium-ion batteries, such as hydrometallurgical and pyrometallurgical processes.

Overall, the research in this area is ongoing and evolving as the demand for lithium-ion batteries continues to grow. By continuing to explore and implement innovative strategies and technologies for reducing the risk of fires and improving the safety of these batteries, we can help to ensure their continued use in a wide range of applications.

Conclusion

In conclusion, lithium-ion battery fires can be dangerous and costly, as demonstrated by the APS fire in Arizona. While these batteries offer many benefits, it is important to take appropriate precautions to minimize the risk of a fire. By following best practices for storage, handling, and maintenance, and by installing fire suppression systems where appropriate, the risk of a lithium-ion battery fire can be greatly reduced.