Micro-supercapacitors have recently emerged as promising microscale power sources for portable and wearable microelectronics. However, most reported planar micro-supercapacitors suffer from low energy density and the complexity of fabrication, which calls for their further development. In recent years, the fortification of graphene has enabled the dramatic improvement of planar micro-supercapacitors by taking full advantage of in-plane interdigital architecture and the unique features of graphene. The development of viable printing technologies has also provided better means for manufacturing, bringing micro-supercapacitors closer to practical applications. This review summarizes the latest advances in graphene-based planar micro-supercapacitors, with specific emphasis placed on formulation of graphene-based inks and their fabrication routes onto interdigital electrodes. Prospects and challenges in this field are also discussed towards the realization of graphene-based planar micro-supercapacitors in the world of microelectronics.
Keywords: energy storage; graphene inks; micro-supercapacitors; microelectronics; printing techniques.