3D Printed Template-Assisted Assembly of Additive-Free Ti3C2Tx MXene Microlattices with Customized Structures toward High Areal Capacitance

Ti3C2Tx MXene is a promising material for electrodes in microsupercapacitors. Recent efforts have been made to fabricate MXene electrodes with designed structures using 3D printing to promote electrolyte permeation and ion diffusion. However, challenges remain in structural design diversity due to the strict ink rheology requirement and limited structure choices caused by existing extrusion-based 3D printing. Herein, additive-free 3D architected MXene aerogels are fabricated via a 3D printed template-assisted method that combines 3D printed hollow template and cation-induced gelation process. This method allows the use of MXene ink with a wide range of concentrations (5 to 150 mg mL-1) to produce MXene aerogels with high structural freedom, fine feature size (>50 μm), and controllable density (3 to 140 mg cm-3). Through structure optimization, the 3D MXene aerogel shows high areal capacitance of 7.5 F cm-2 at 0.5 mA cm-2 with a high mass loading of 54.1 mg cm-2. It also exhibits an ultrahigh areal energy density of 0.38 mWh cm-2 at a power density of 0.66 mW cm-2.