Panasonic Says It Has Made A Safer Lithium-Ion BatteryPanasonic Says It Has Made A Safer Lithium-Ion Battery

Matsushita Electric Industrial Co., better known as Panasonic, says it has made a safer lithium-ion battery that won't overheat within a notebook computer or other electronic device, preventing the potential fire hazard that led to the recall earlier this year of millions of batteries.

Matsushita on Monday said it has developed a heat-resistant layer made of insulating metal oxide that would replace the polyolefin lining often used to separate cells within the battery pack. If a short circuit were to occur, the protective layer would prevent the battery from overheating and possibly bursting into flames.

Dell this year recalled 4.1 million Sony-manufactured batteries after several fires were reported as a result of the devices overheating. There were no serious injuries. The recall was the largest ever in the consumer electronics industry. Other companies also have recalled Sony batteries, including Hewlett-Packard and Apple Computer.

The battery problems stem from microscopic metal particles that float within the battery pack. The particles can't be avoided in the manufacturing process, but battery makers try to minimize the number and size. A fire hazard can result when conditions in a laptop, such as rising temperatures or the recharging process, cause the particles to move aggressively in the battery cavity. If a particle pierces the lining protecting the battery cell, a spark can result and ignite the highly flammable lithium salt electrolyte inside.

Matsushita, based in Osaka, Japan, said in a statement that even if such a spark, or short circuit, was to occur in one of its new batteries, "it will cease without causing the battery to overheat."

Matsushita's subsidiary Matsushita Battery Industrial Co. developed the patent-pending safety feature. Matsushita says it's ready to mass-produce the safer batteries.