Boeing chose to use the most combustible of the standard lithium-ion chemistries on the market in its flagship 787 Dreamliner. The advanced aircraft is grounded around the world after a battery burst into flames.
The suspension of all 50 working Dreamliners follows a Jan. 16 emergency landing by an All Nippon Airways pilot after he smelled something burning, and saw a cockpit warning light up indicating a battery problem. It turned out that one of the plane’s batteries had caught fire. Investigators are working to determine why—faulty wiring, design, system assembly, or the battery itself.
Boeing, for whom the Dreamliner is key to the company’s growth plans, has been the target of scrutiny because of a long series of failures in the aircraft. Now the glare is focused on its lithium ion batteries. But blaming this type of battery for the fault would be like scorning all automobiles because of the Ford Pinto. In fact, lithium ion batteries are not all the same.
Experts note that Boeing chose to rely on a lithium cobalt oxide battery configuration for the 787, a chemistry that, while delivering powerful performance, has in the past been responsible for fires (paywall) in laptop computers and cellphones. The 787 battery is manufactured by Japan’s GS Yuasa, one of the most respected lithium-ion battery-makers in the world.
In its hybrid-electric Volt car, for example, GM chose to use a battery combining lithium with two ion chemistries—nickel manganese cobalt, and manganese spinel. China’s BYD uses yet a third chemistry: lithium iron phosphate. What all three have in common, experts say, is that they are far less flammable than lithium cobalt oxide. “It’s essentially due to the crystalline structure,” Shu Sun, an analyst with Bloomberg New Energy Finance, told me in an email exchange. “The olivine and spinal structure of [lithium iron phosphate and manganese spinel] make them safer.”
All five experts interviewed for this post also emphasized that, while the chemistry is important, safety comes as well in the design of the battery system and the electronics installed to govern its use. “I suspect the real problem lies in the cell assembly by [GS Yuasa] and, perhaps more important, the control circuitry design,” said Ralph Brodd, one of the world’s most respected battery experts.
Brodd said that Tesla, for example, uses a nickel cobalt aluminum chemistry. “Tesla developed a sophisticated algorithm to measure voltage, current and temperature for each cell in their pack,” Brodd told me. “If one fails or acts up, it can disconnect that individual cell without interrupting the operation of the battery. That is what Boeing needs to do.”
A Boeing spokeswoman, asked to respond to this, said, “Lithium ion batteries were selected after a careful review of available alternatives because they best met the performance and design objectives of the 787. There are multiple backups to ensure the system is safe. These include protections against over-charging and over-discharging.”
The makers of vehicles and electronic devices make a choice in their battery selection, depending on their requirements: What chemistry will deliver electricity the fastest, with the most punch, and the longest period of time? Electronics can help correct for error if you get greedy and demand too much. But the chemistry does in fact matter. As one battery expert told me, “Batteries are inherently unstable devices (we call them ‘charged’ for a reason!).”