London: Remember the scare last year caused by some Nokia batteries that were found to be overheating while charging -- leading to their worldwide recall?

Such scares will soon be a thing of the past.

German researchers have developed a safer lithium-ion battery that is virtually non-inflammable, addressing concerns of mobile phones users worldwide.

The new prototype is based on a polymer electrolyte, which unlike liquid electrolyte in conventional cell phone batteries is not inflammable.

Lithium-ion batteries power cell phones and PDAs and larger devices like laptops, cordless screwdrivers and lawnmowers. But they are inflammable. Many in the past had to be recalled for this reason alone.

A prototype of the new lithium-ion batteries developed by researchers of Fraunhofer Institute for Silicate Research ISC in Germany will be presented at Hannover Messe, but a marketable version will take another four or five years.