Graphene-enhanced, thin, flexible printed battery for electronic wearable and IoT devices - (FLEXIBAT)

The recent boom in wearable and Internet of Things technology, such as smart sensors, fitness watches, has not yet reached its full potential 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 batteries each have their advantages and disadvantages. Lithium-ion batteries are cheap to produce, but relatively thick and do not have 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 than lithium-ion. 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.

Furthermore, lithium-ion, lithium and zinc batteries utilise 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 increases corrosion that results from the chemical reactions within the battery. This limits the battery power and life time.

The **FLEXIBAT** project will develop a novel single-use battery for electronic wearables and Internet of Things devices, based on zinc-carbon chemistry and metal collectors. The focus of the development is on a special corrosion protective layer for the metal collectors and electrodes using graphene, which will enable a thinner, more flexible and a higher energy battery. We will ultimately develop a technology demonstrator prototype of the full battery system and test it in a controlled environment.

To successfully achieve this, the project consortium features the relevant expertise for making the battery, including battery manufacture, materials development, graphene coating, and flexible integrated circuit development and manufacture.