An inkjet-printing ink based on porous NiS/N-MXene for high-performance asymmetric micro-supercapacitors and self-powered microelectronics

With the rapid development of inkjet printing in the field of extensible and miniaturized energy storage devices, the inkjet printing ink of a single material has been unable to meet the requirements of microelectronics. The preparation of composites dispersed stably in solvent is a new direction to essentially improve the performance of microelectronic device. Herein, an inkjet-printing ink based on porous NiS/N-MXene is developed to directly inkjet-printing asymmetrical micro-supercapacitors (AMSCs) with excellent performance, seamless integration, and desirable customization. This composite material combines the advantages of NiS and N-MXene into one. The AMSCs outperform previously reported inkjet-printed MSCs with a wide voltage window of 1.5 V, an unparalleled volumetric capacitance of 429F cm−3, and a phenomenal energy density of 33.5 mWh cm−3. Such exceptional performance is partly due to a combination of the complementary advantages of NiS and N-MXene with extraordinary pseudo-capacitance, cycle stability, and a unique porous structure, which inhibits MXene restacked and increases active sites. Moreover, our AMSCs can achieve a nearly double rise in voltage and capacitance by seamlessly integrating numerous devices in series and parallel through a simple pattern design and inkjet printing. Furthermore, the response of a printable pressure sensor combined by AMSCs and a solar cell is efficient. As a result, this ink with novel structure has effectively achieved the performance improvement of MSCs by inkjet printing, opening up a wide range of application space for miniaturization and high-suitability, self-powered micro-systems for printable electronics.