Stamping of Flexible, Coplanar Micro-Supercapacitors Using MXene Inks

The fast growth of portable smart electronics and internet of things have greatly stimulated the demand for miniaturized energy storage devices. Micro-supercapacitors (MSCs), which can provide high power density and a long lifetime, are ideal stand-alone power sources for smart microelectronics. However, relatively few MSCs exhibit both high areal and volumetric capacitance. Here rapid production of flexible MSCs is demonstrated through a scalable, low-cost stamping strategy. Combining 3D-printed stamps with arbitrary shapes and 2D titanium carbide or carbonitride inks (Ti3C2Tx and Ti3CNTx, respectively, known as MXenes), flexible all-MXene MSCs with controlled architectures are produced. The interdigitated Ti3C2Tx MSC exhibits high areal capacitance: 61 mF cm(-2) at 25 mu A cm(-2) and 50 mF cm(-2) as the current density increases by 32 fold. The Ti3C2Tx MSCs also showcase capacitive charge storage properties, good cycling lifetime, high energy and power densities, etc. The production of such high-performance Ti3C2Tx MSCs can be easily scaled up by designing pad or cylindrical stamps, followed by a cold rolling process. Collectively, the rapid, efficient production of flexible all-MXene MSCs with state-of-the-art performance opens new exciting opportunities for future applications in wearable and portable electronics.