In summary, on the premise of ensur

In summary, on the premise of ensuring high electrical conductivity of printed patterns, we fabricate a kind of high concentration screen printing conductive ink with graphene powders produced by jet cavitation and carbon black jointly as conductive fillers, and the whole preparation and application process of this ink are simple, efficient and cost-effective, without solvent exchange and high temperature or long-term lower temperature or photonic annealing, making this conductive ink compatible with a wide range of substrates and possible to be applied to Roll-to-Roll production process. The influence of carbon black content and graphene properties on the ink rheological behavior and printed pattern electrical conductivity was investigated. With the increase of the carbon black content from 0 to 20% of the total conductive fillers, the elasticity of the conductive ink increases, and the conductivity of printed patterns increases firstly and decreases later peaking at 15%. Proven by XPS and Raman spectrum, two kinds of graphene powders possess very few defects, which is in favor of high conductivity. The higher conductivity has been obtained by patterns printed with inks made of graphene powders containing thicker smaller-area flakes whose positive effects on dispersion is considered as the main reason. When the carbon black content is 15%, the inks with graphene powders containing thicker smaller-area flakes show excellent screen printability down to lines of 90 μm in width and high printed pattern electrical conductivity of 2.15 × 104 S/m at 7 μm thickness, along with good mechanical properties. Highly conductive graphene/carbon black screen printing inks reported here hold great promise in the field of flexible printed electronics, like RFID tag, microwave antenna and healthcare monitor. In the future, improvement of graphene-based screen printing conductive ink for higher electrical conductivity and its application in RFID tag and other fields will be focused on.