With the Ultrabook fad in full-swing, and smartphone makers always keen to stress just how skinny their new devices are, there becomes a point where the power being supplied is compromised because smaller batteries simply aren't up to the job.

But that's where a new polymer jelly developed by boffins at the University of Leeds comes into play. For not only is the jelly safer than the liquid electrolyte currently used in most lithium batteries, it will also mean more power at a fraction of a cost.

"The polymer gel looks like a solid film, but it actually contains about 70 per cent liquid electrolyte," explained the study's lead author, Professor Ian Ward.

Professor Peter Bruce from the University of St Andrews added: "Safety is of paramount importance in lithium batteries. Conventional lithium batteries use electrolytes based on organic liquids; this is what you see burning in pictures of lithium batteries that catch fire.

"Replacing liquid electrolytes by a polymer or gel electrolyte should improve safety and lead to an all-solid-state cell."

The jelly should mean an end to the overheating issues that have blighted companies like Dell in the past (4 million batteries recalled in 2006) but still allow for the power of solid polymer electrolyte.

For the consumer, this should mean safer, cheaper, more powerful and even skinnier gadgets.

There are no plans for a consumer release just yet (so no Jelly and Ice Cream Sandwich, unfortunately) but the design has been licensed by the American Polystor Energy Corporation, which is now conducting industrial trials.