Recently, news reports described new harrowing details following a Florida Tesla crash that occurred last September. The National Transportation Safety Board (NTSB) conducted an investigation and reported that that the car flew through a yellow light at around 90 miles per hour. The speed limit in the neighborhood was 30 mph. Apparently, as the driver approached reached the intersection, he hit the accelerator to 100%. The driver then sped through the light and slammed into two trees in succession. Following the impact, the car’s battery exploded and burst into flames. The fire reignited at least one time which caused firefighters to experience challenges when trying to extinguish the explosion. The 20-year-old driver and his 19-year-old passenger died at the scene of the accident.
Tesla is frequently under fire for its self-driving or “autonomous” driving options. Many argue that these functions are not nearly as safe as the company touts, and a lack of driver experience and company oversight leads to deadly consequences. However, this accident seems to involve another issue concerning lithium batteries. The NTSB has repeatedly voiced concerns about lithium battery fires in aircraft, Teslas, and other vehicles. The agency has issued safety recommendations urging regulators, manufacturers, and firefighters to prevent and prepare for these types of fires.
Lithium-ion batteries have been the source of highly publicized investigations and recalls. Lithium is the lightest metal with the least dense solid element thereby creating a high-energy-density. This density allows lithium to store more energy over a longer time, compared to traditional batteries. Despite this benefit, the battery poses a serious danger because of its combustible material. A single cell can get hot to the point where it catches fire and spreads to the next cell. This “thermal runaway” effect essentially makes the battery easily catch fire or explode quickly.