3D Printing of Porous Nitrogen-Doped Ti₃C₂ MXene Scaffolds for High-Performance Sodium-Ion Hybrid Capacitors

Abstract

3D printing technology has stimulated a burgeoning interest to fabricate customized architectures in a facile and scalable manner targeting wide ranged energy storage applications. Nevertheless, 3D-printed hybrid capacitor devices synergizing favorable energy/power density have not yet been explored thus far. Herein, we demonstrate a 3D-printed sodium-ion hybrid capacitor (SIC) based on nitrogen-doped MXene (N-Ti3C2T x ) anode and activated carbon cathode. N-Ti3C2T x affording a well-defined porous structure and uniform nitrogen doping can be obtained via a sacrificial template method. Thus-formulated ink can be directly printed to form electrode architecture without the request of a conventional current collector. The 3D-printed SICs, with a large areal mass loading up to 15.2 mg cm–2, can harvest an areal energy/power density of 1.18 mWh cm–2/40.15 mW cm–2, outperforming the state-of-the-art 3D-printed energy storage devices. Furthermore, our SIC also achieves a gravimetric energy/power density of 101.6 Wh kg–1/3269 W kg–1. This work demonstrates that the 3D printing technology is versatile enough to construct emerging energy storage systems reconciling high energy and power density.

Turning Trash into Treasure: Additive Free MXene Sediment Inks for Screen‐Printed Micro‐Supercapacitors

“…Increasing the strain beyond 40% leads the loss modulus to be higher than the storage modulus, implying a transition from solid‐like to liquid‐like behavior. [ 49 ] It is worth noting that during printing, the aqueous inks gradually lose water and thus change their own rheological properties. For instance, after printing, the solid fraction increases to 34 wt% with high apparent viscosity of 480 Pa s and high storage modulus (Figure S2, Supporting Information), which are beyond the favorable ink rheological properties for the screen printing.…”

3D Printing of NiCoP/Ti3C2 MXene Architectures for Energy Storage Devices with High Areal and Volumetric Energy Density

“…Utilizing advanced manufacturing technology to achieve tailorable electrode configurations plays a key role in boosting the electrochemical performances of energy storage devices. Along this line, extrusion-based 3D printing, a cost-effective and versatile technique relying on a three-axis motion stage to create well-defined periodic geometries via layer-by-layer stacking, has readily been employed in energy storage realm [1][2][3][4][5]. In contrast to traditional fabrication methods such as doctor blade coating, the thickness of electrodes and loading of active materials can be in target adjusted by the ink property, printing speed, and/or number of printed layers, thereby enhancing both energy density and power density of thus-constructed devices [6][7][8].…”

MXene Printing and Patterned Coating for Device Applications

“…Other than low‐concentration single‐layer MXene dispersions (<10 mg), the rheological properties of concentrated single‐layer MXene dispersions have also been studied. [ 28,53,54 ] Interestingly, Yang et al found that the viscosity values of single‐layer MXene dispersions (15 mg mL −1 ) were on the similar order of magnitude as highly concentrated multilayer MXene dispersions (2.33 g mL −1 , 70 wt%), [ 54 ] which means MXene flakes with higher aspect‐ratio can tune the rheology more effectively. Using the vacuum evaporation method, they have prepared MXene dispersion with a high concentration of up to 50 mg mL −1 .…”

“…Their ink shows elastic modulus and yield stress of 36 507 and 206 Pa, respectively. Further, Fan et al prepared nitrogen‐doped Ti 3 C 2 dispersion with concentration up to 300 mg mL −1 , while the shear stress was found to be reduced to 170 Pa. [ 53 ] Unlike these two reports, Orangi et al demonstrated high‐concentration single‐layer MXene dispersion (290 mg mL −1 ) by using superabsorbent polymer beads, [ 28 ] and they reported yield stress of 24 Pa, which was derived from the Herschel–Bulkley model. While at rest, the ink shows apparent viscoelastic behavior, because Gʹ was always higher than Gʺ within the entire range of frequency (low‐frequency region probes the long‐time microstructural rearrangement, and high‐frequency region probes shorter time scales), in agreement with other reports.…”