A Gelation-Assisted Approach for Versatile MXene Inks

Due to outstanding electrical conductivity and excellent solution processing ability, MXenes show great potential as inks for printed/coated electronic devices. To meet the rheological requirements, an ultra-high concentration is usually involved to formulate MXenes into versatile inks, however, low efficiency in rheology regulation, and restacking issues of MXene sheets hinder their further applications. Herein, a gelation-assisted approach is proposed to prepare versatile MXene inks with a 3D interlinked network to well address above issues. With an effective combination of cross-linking as well as the swelling of interlinked network, the gel ink exhibits tunable rheological properties by simply tuning the water amount within the sol-gel system. Among various applicable printing/coating techniques ranging from painting to extrusion printing, blade coating is selected to demonstrate the advantage of MXene gel ink. The smooth coating layer with interlinked 3D structures is greatly beneficial to the uniform and dense zinc deposition with high reversibility, and endows the aqueous zinc ion batteries with a remarkable rate capability. This work provides an alternative approach to prepare versatile MXene inks and would offer MXenes new opportunities for their application in advanced printable electronic devices.