Flexible graphene supercapacitors printed on textiles for wearable electronics

Printed graphene supercapacitors may gerat the potential of wearable electronic devices. This paper reports the use of graphene oxide and screen printing techniques to print solid state flexible supercapacitor devices on textiles. After printing, in order to avoid the use of any reducing agent that may damage the textile substrate, we quickly reduce the graphene oxide by electrochemical methods. Printed electrodes exhibit excellent mechanical stability due to the strong interaction between the ink and the textile substrate. The unique layered porous structure of the electrode promotes ion diffusion and maximizes the available surface area of ​​the electrolyte/active material interface. The obtained device exhibited excellent cycle stability in 10,000 cycles and maintained excellent mechanical flexibility, which is necessary for the application of the wearable technology. Such a simple printing technique is easy to expand and avoids the problems associated with the preparation of supercapacitor devices from conductive yarns.

A flexible and durable SC device was prepared by printing GO on cotton fabric. First, the printed electrode is reduced in an aqueous solution using electrochemical techniques. The reduction process removes most of the oxygen-containing functional groups from the surface of the graphene to provide a network of electrically conductive interconnects. The conductive mesh acts both as a current collector and as an active SC material. The capacitance obtained is as high as 2.5 mF cm-2 and still retains 95.6% of its value under bending conditions. Solid state SC devices have excellent electrochemical stability and maintain 97% of their original capacitance after 10,000 cycles.

Related research results are published on 2D Materials (iopscience.iop.org/article/10.1088/2053-1583/aa7d71).