Flexible plane heater: Graphite and carbon nanotube hybrid nanocomposite

• The flexible plane heater is fabricated by the conventional process for mass production.
• Carbon nanotube/graphite hybrid nanocomposite is firstly applied to a flexible plane heater.
• Bare graphite flakes are used as a main filler without any chemical treatment.
• Carbon nanotubes contribute to improve both the mechanical strength and the heat conduction.
• We demonstrate that our plane heater is applicable for heating seats of commercial vehicles.

We report a facile method for fabricating a flexible plane heater on a plastic substrate using a graphite and carbon nanotube hybrid nanocomposite. To scale up to an industrial level, all the processes are applied in a conventional manner including three-roll calendar and screen printing. Bare graphite flakes are used as a main filler to increase the electrical conductivity of the nanocomposite. To preserve the high crystallinity of graphite, chemical treatments are excluded during the process. A small amount of amino-functionalized multi-walled carbon nanotubes (a-MWCNTs) (10 wt%) are added not only to increase the mechanical strength of the plane heater, but also to improve the heat conduction in the nanocomposite. Therefore, while graphite nanocomposite film mostly peeled off after an adhesion test, a-MWCNT-graphite nanocomposite film adhered on the PET substrate without noticeable change. Furthermore, the fabricated plane heater shows the high performance, compared to that of a graphite nanocomposite, a carbon black/graphite nanocomposite, and Cu wire heaters. We demonstrate that our plane heater is applicable for heating seats of commercial vehicles as well as a flexible plane heater. It will be applied to numerous areas such as heating systems in electrical vehicle and household items for heating.