The US Consumer Product Safety Commission has documentation on 339 cases of lithium and lithium-ion batteries in portable devices overheating, emitting smoke and fumes or exploding since 2003.
The Federal Aviation Administration also logged 60 such incidents in aircraft of airports since 1991.
During the past two years, six incidents have occurred on aircraft, including five fires plus a overheating torch that "had to be handled with oven mitts".
The WSJ notes the case of Lufthansa Flight 435 which on May 15 was sat at Chicago O'Hare International Airport preparing for a nine-hour flight to Munich, when, according to witnesses, smoke began to float from the luggage bin above seat 2A.
A smoking case was tossed out of the plane before erupting into flames. Inside, investigators discovered a "charred laptop computer and a six-pack of melted lithium-ion batteries," the Journal notes
The owner of the laptop confessed to having bought non-standard batteries on eBay.
After a number of scares involving non-rechargeable lithium batteries, these were banned from flights by the FAA in 2004.