Scientists invent lithium-ion battery that's less likely to explode on you

Researchers at Stanford University used nanotechnology to solve a longstanding problem among electrically-driven devices, from airplanes to so-called hoverboards.

Researchers at Stanford University have created a lithium-ion battery that won’t catch fire, following a rash of incidents involving devices powered by the rechargeable batteries.

The batteries are made to turn off before they can reach temperatures causing them to overheat, according to an announcement made by the university on Monday. The study appeared in the journal Nature Energy.

The invention may mitigate the drumbeat of recalls of products that run on lithium-ion batteries, which are used in an array of electronic contraptions from vehicles and airplanes to computers and so-called hoverboards.

Zhenan Bao, a professor of chemical engineering at Stanford who is part of a team of researchers who worked on the study, said the sensors stop the battery from operating before it can overheat.

"People have tried different strategies to solve the problem of accidental fires in lithium-ion batteries," said Dr. Bao in a Stanford press release. "We've designed the first battery that can be shut down and revived over repeated heating and cooling cycles without compromising performance.”

Bao and her research team used nanotechnology to address the problem of overheating by preventing electrons from flowing to the battery when temperatures rise.

Safety issues have slowed large-scale production of the batteries, the study notes. For years, rechargeable batteries using lithium have been blamed for a series of fires and explosions, but their ability to hold a high amount of energy continues to make them attractive to companies and consumers.

In 2006, Sony recalled millions of lithium-ion batteries after hundreds overheated and several were found to have triggered fires.

The US Federal Aviation Administration temporarily grounded Boeing's new 787 Dreamliners in January 2013 after two of the aircraft caught fire while using the batteries. In December 2015, several large airlines banned so-called hoverboards on planes because of their propensity to catch fire. 

The Stanford University study said the standard lithium-ion battery contains electrodes and electrolytes that carry charged particles between them. When these items are perforated, the battery can overheat, and when temperatures exceed 300 degree Fahrenheit “the electrolyte could catch fire and trigger an explosion.”

In recent years, some improvements have been made with lithium-ion batteries to prevent fires, including the addition of flame-retardants to the electrolyte.

Last year, MIT researchers developed a progressive manufacturing approach for lithium-ion batteries they said would cut costs in half and make them simpler to recycle. Stanford researchers also recently created a smart battery that delivers a warning when a device is overheating. 

"Unfortunately, these techniques are irreversible, so the battery is no longer functional after it overheats," said the study’s co-author Cui, an associate professor of materials science and engineering and of photon science. "Clearly, in spite of the many efforts made thus far, battery safety remains an important concern and requires a new approach."

The new lithium-ion battery is not yet ready for production. 

[Editor's note: The original article incorrectly stated that Boeing had scrapped its 787 fleet. In fact, in January 2013, the Federal Aviation Administration grounded 787s after two battery fire incidents. Additionally, an earlier version of this story contained incorrect information about Tesla Motors' efforts to improve the safety of their cars' batteries.]