Interlayer-spacing-regulated MXene/rGO Foam for Multi-functional Zinc-ion Microcapacitors

The traditional 3D porous structures often sacrifice density for high porosity, which is not conducive for energy storage under a limited space. So, it is a challenge to seek the strategy to well balance of the density and porosity in foam materials. In this work, we fabricated MXene based foam by the hydrazine vapor-induced reduction, which can achieve the precise regulation on the density (100–360 mg cm−3) and pore size (5.08–61.04 μm) while maintaining its high porosity over 77.9%. And it is carried out by simply tuning the oxygenated functional group concentration of the original MXene/GO films. Then the interlayer-spacing-regulated 3D MXene/rGO foams was used to construct the multifunctional Zinc ion microcapacitor (ZIMC) by the laser engraving processes, which is simple and suitable for large-scale process production. The final ZIMC exhibited a low self-discharge rate of 2.75 mV h−1, a large area-specific capacitance of 83.96 mF cm−2, and maintained an initial capacitance of 86.3% after five self-healing processes. In addition, the ZIMC-powered integrated pressure sensing system enables real-time monitoring of human physiological signals. Combining these prominent performance with the simple device-assembly method makes this microcapacitor highly potential in the next-generation electronics.