Direct ink writing 3D printing of low-dimensional nanomaterials for micro-supercapacitors

Micro-supercapacitors (MSCs) have attracted significant attention for potential applications in miniaturized electronics due to their high power density, rapid charge/discharge rates, and extended lifespan. Despite the unique properties of low-dimensional nanomaterials, which hold tremendous potential for revolutionary applications, effectively integrating these attributes into MSCs presents several challenges. 3D printing is rapidly emerging as a key player in the fabrication of advanced energy storage devices. Its ability to design, prototype, and produce functional devices incorporating low-dimensional nanomaterials positions it as an influential technology. In this review, we delve into recent advancements and innovations in micro-supercapacitor manufacturing, with a specific focus on the incorporation of low-dimensional nanomaterials using direct ink writing (DIW) 3D printing techniques. We highlight the distinct advantages offered by low-dimensional nanomaterials, from quantum effects in 0D nanoparticles that result in high capacitance values to rapid electron and ion transport in 1D nanowires, as well as the extensive surface area and mechanical flexibility of 2D nanosheets. Additionally, we address the challenges encountered during the fabrication process, such as material viscosity, printing resolution, and seamless integration of active materials with current collectors. This review highlights the remarkable progress in the energy storage sector, demonstrating how the synergistic use of low-dimensional nanomaterials and 3D printing technologies not only overcomes existing limitations but also opens new avenues for the development and production of advanced micro-supercapacitors. The convergence of low-dimensional nanomaterials and DIW 3D printing heralds the advent of the next generation of energy storage devices, making a significant contribution to the field and laying the groundwork for future innovations.