Graphene-enhanced, thin, flexible printed battery for electronic wearable and Internet of Things (IoT) devices
The boom in wearable and Internet of Things (IOT) technology, such as smart sensors and fitness watches, has not reached its full potential as yet due to one component restricting further development: the battery source. As a result, devices often have bulky batteries, must be plugged in frequently or use workarounds such as spare batteries, fast charging or smart software. State-of-the-art flexible batteries, such as lithium-ion, vacuum-deposited lithium or zinc, each have their advantages and disadvantages. Lithium-ion batteries are cheap to produce, but relatively thick and do not have the high power suitable for some wearable or smart packaging applications. Lithium batteries can be very thin, but are more expensive and have even less energy capacity, while zinc batteries are very cheap, have a higher energy capacity than lithium-ion, but are only suitable for low power. These constraints all limit the flexibility and form-factor (shape) of batteries for devices.
In addition lithium-ion, lithium and zinc batteries use carbon collectors and electrodes which, although contributing to the batteries' light weight, limits their electrical conductivity. Replacing the carbon parts with metal would increase the conductivity, and hence power, but crucially this also increases corrosion that results from chemical reactions within the battery, and this limits battery power.
To address this, FLEXIBAT developed a novel, single-use battery for electronic wearables and IoT devices, based on zinc-carbon chemistry and metal collectors. The project focused on creating a special corrosion-protective layer for battery metal collectors and electrodes, using graphene to enable a thinner, more flexible and higher energy battery, and then developing a technology demonstrator prototype of the full battery system which was tested in a controlled environment. FLEXIBAT was delivered successfully as a result of the combined expertise of the consortium members in battery manufacture, materials development, graphene coatings, and flexible, integrated circuit development and manufacture.
Partners: Zinergy UK Ltd and the Materials Innovation Centre (MatIC).
FLEXIBAT was funded by Innovate UK.