The battery could be used in wearables such as watches, fitness bands and smart-clothing.

Its capacity is small, meaning it would not be suitable for power-intensive smartphones at this stage.

Experts said it was "an exciting development" but Panasonic was not the first company to work on this.

Ben Wood, an analyst with research company CCS, told the BBC: "Other manufacturers such as LG and Samsung are also putting huge efforts into more flexible technology, be that in batteries, screens or more."

"I'd wager that Panasonic's new technology is just one piece of a more complex jigsaw, and it will be some time before we see truly disruptive devices emerging."
Sea-of-sameness

Designed for use in "card-type and wearable devices", Panasonic's flexible battery is 0.55mm (0.022in) thick with a maximum "bend" of 25 degrees.

The company said that the battery could "retain its characteristics" even after being repeatedly bent.

Smart-cards, often carried in wallets and pockets, require internal components that can withstand bending and twisting, but they can also degrade as they are flexed.

Curved smartphones have been around for a while, but foldable displays remain conceptual.

Designing such batteries could "provide scope for disruptive new curved designs," said Mr Wood, something all manufacturers craved as they "seek to deliver exciting new devices in the growing sea of sameness that characterises electronic products".

But, he added, there remained challenges ahead.

"Flexible batteries alone do not solve all the design challenges as the other materials and components also need to be flexible," he said.

Samsung is believed to be working on a flexible phone, and recent patents revealed on Patently Mobile appear to show designs for a rolled up smartphone.

Panasonic's bendable batteries would begin shipping at the end of October, the company said.