Ink transfer for printed flexible microsupercapacitors

Printed microsupercapacitors (MSCs) with graphene rapidly evolved into one of the promising energy supplies for future flexible integrated electronic device. Gravure printing, as a leading technology, is promising for the large-scale manufacture of printed MSCs. However, ink transfer, a seemingly simple operation that is still not well understood. Herein, ink rheological principles and corresponding ink dynamic transfer are investigated by corresponding printing detail based on a kind of hierarchical porous graphene microsphere ink. Through modifying the rheological properties and ink bridge's slipping, high quality MSCs were printed with the hierarchical porous graphene microsphere ink. Benefiting from abundant ion accessible channels, the printed MSCs achieved the diffusion rate (9.2 x 10(-10) cm(2) s(-1)) of H+ ion, leading to the high areal special capacitance of 43.5 mF/cm(2). The areal energy density of 6.1 mu Wh cm(-2) is achieved at areal power density of 3.6 mW cm(-2). (C) 2021 Elsevier Ltd. All rights reserved.