Jet Printing of MXene-Based Inks for Micro-Supercapacitors and Emerging Energy-Storage Applications

The increasing demand for miniaturized, flexible and wearable electronics has accelerated the development of printed electrochemical energy-storage devices capable of combining high performance with scalable and cost-effective manufacturing. Among emerging electrode materials, MXenes have attracted significant attention owing to their exceptional electrical conductivity, hydrophilic surface chemistry, tunable interlayer structure and excellent solution processability, making them particularly suitable for jet printing technologies. In particular, inkjet printing (IJP) and aerosol jet printing (AJP) enable maskless, high-resolution and material-efficient fabrication of micro-scale energy-storage devices while offering excellent compatibility with flexible substrates. This review provides a comprehensive overview of the use of MXene-based inks in jet-printed energy-storage devices, emphasizing the relationships between MXene physicochemical properties, ink formulation, printing processes and electrochemical performance. First, the structural characteristics, synthesis strategies and electrochemical charge-storage mechanisms of MXenes are discussed, together with the rheological, colloidal and stability requirements governing ink printability. The fundamental principles of IJP and AJP are then critically analyzed, highlighting the influence of solvent systems, printability criteria, processing parameters and deposition conditions. Recent advances in jet-printed MXene-based supercapacitors and micro-supercapacitors are comprehensively and critically reviewed, with particular attention to how material design, ink formulation, and printing strategies affect device performance. Battery-related studies, which remain comparatively limited, are discussed as an emerging application area highlighting the broader potential of jet-printed MXenes for electrochemical energy storage. Finally, the major challenges hindering the large-scale implementation of MXene-based printed energy-storage systems, including oxidation stability, restacking, ink shelf life, and manufacturing scalability, are critically discussed.