Panasonic has developed a Flexible Lithium-ion Battery with a thickness of only 0.55mm, or about 0.022 inches, designed for use in card-type and wearable devices. This rechargeable battery can retain its characteristics even after repeatedly bent into a radius of 25mm or twisted to an angle of 25 degrees, according to Panasonic.

Card devices, which are often carried in wallets or pockets, require internal components that can withstand bending and twisting. Slim lithium-ion batteries are used in such devices, but these batteries can degrade when they are bent or twisted, resulting in shorter operating time for the devices.

Panasonic's new flexible battery can withstand bending and twisting beyond the Japanese Industrial Standards for identification cards (equivalent bending radius R40mm, twisting angle ±15°/85.6mm). When used in card devices such as smart cards and card keys that work on batteries, as well as body worn devices and smart clothing, this battery can retain its characteristics even if the device is frequently bent or twisted.

This new flexible battery will be on display at CEATEC JAPAN 2016 from October 4 to 7 at Makuhari Messe.

Panasonic plans to start shipping samples of the battery by the end of October 2016. Product development will continue towards mass production, with an eye to an even slimmer form factor ideal for various IoT devices such as card devices and wearable devices.

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The Flexible Lithium-ion Battery uses Panasonic's stacked electrode construction that has resistance to bending and twisting. The battery has demonstrated that it retains its characteristics during bending and twisting tests with severer conditions required by card application standards. This battery can maintain more than 99% of its initial capacity after 1,000 bends with a radius of 25mm, or after twisted 1,000 times with an angle ±25°/100mm, thanks to a newly developed laminated outer layer and newly developed internal structure.

In addition, the new battery has shown 80% initial capacity retention based on the company's testing of 1,000 times of charge and discharge cycle following either 1,000 times of bending or 1,000 times of twisting. This battery can contribute to longer operating time of card devices, wearables and other devices by reducing the battery deterioration due to bending and twisting as well as the charge and discharge cycle.

This battery uses a newly-developed laminated outer body and internal structure that make it difficult to cause leakage and abnormal heating during repeated bending and twisting. That makes this battery reliable and safe for use in wearable and body attached devices.