Printed energy storage charges into the future with MXene inks

Researchers at Boise State University have developed a stable, high-performance Ti₃C₂T_x MXene ink formulation optimized for aerosol jet printing—paving the way for scalable manufacturing of micro-supercapacitors, sensors, and other energy storage and harvesting devices.

This work, recently published in Small Methods, marks a significant advance in the additive manufacturing of two-dimensional (2D) materials for energy storage applications.

MXenes, a family of 2D transition metal carbides, nitrides, and carbonitrides, are prized for their exceptional physical and chemical properties. MXenes have emerged as promising electrode materials for electrochemical energy storage applications due to their unique structure, with an inner conductive transition metal carbide layer, variable hydrophilic functional groups, and lamellar structure.

While many advances have been made in the solution processing of 2D materials, developing suitable and printable functional inks remains challenging and requires careful consideration before use in electronic device fabrication. MXenes can be readily dispersed in water, but such dispersions are highly susceptible to oxidation and typically degrade within a few days at room temperature. Moreover, each printing technique demands specific fluidic and rheological properties.

Therefore, there is a lack of stable, additive-free MXene inks that offer both long shelf-life and necessary rheological and drying characteristics for high-resolution and high-performance device fabrication.

The Boise State research team overcame key challenges by developing an MXene ink with long-term chemical and physical stability, enabling consistent aerosol jet printability and achieving high-resolution patterns with minimal overspray. Using this formulation, the team successfully fabricated microscale supercapacitor devices directly onto flexible and inflexible substrates such as Kapton film and alumina tubes.

These printed devices not only exhibited excellent capacitance, cycling stability, and mechanical durability, but also achieved the highest-performing printed MXene supercapacitors reported to date. This breakthrough highlights the transformative potential of aerosol jet printing with MXene inks for on-demand, scalable, and cost-effective production of next-generation electronic and electrochemical devices—including wearables, IoT sensors, and lightweight energy systems.

“Our ink formulation enables precise printing of complex structures and remains stable for more than 6 months,” said Fereshteh Rajabi Kouchi, lead author and doctoral researcher in the Micron School of Materials Science and Engineering. “This advancement opens the door to sustainable, roll-to-roll production of miniaturized energy devices.” The team demonstrated interdigitated electrode designs with micron-level resolution—achievable through aerosol jet printing’s unique ability to focus fine material streams.

The developed MXene ink achieves high-resolution prints (≈45 µm width lines) with minimal overspray. The high-resolution aerosol-jet printed MXene supercapacitor achieves an areal capacitance of 122 mF cm^-2 and a volumetric capacitance of 611 F cm^-3, placing them among the highest-performing printed supercapacitors reported to date.

Supercapacitors are energy storage devices which bridge the power density and energy density between regular capacitors and batteries—delivering high power and rapid charge-discharge cycles. The supercapacitor market is expanding rapidly, with a projected CAGR of 15.3%, expected to reach $8.3 billion by 2034, driven by demand in sectors like automotive, consumer electronics, and renewable energy. Printed supercapacitors are gaining traction due to their lightweight, flexible designs, enabling seamless integration into wearables and emerging electronic applications.

“Fereshteh’s work reflects a major step in bridging materials chemistry and scalable device fabrication,” said Prof. David Estrada, senior author of the study. “By addressing both ink formulation and process integration, our team has laid the stage for industrial applications of MXene-based energy storage.”