Editable 3D Micro-Supercapacitor with High Energy Density Based on Mortise-Tenon Joint Structures.

Three-dimensional micro-supercapacitors (3D MSCs) have accelerated the development of microenergy-storage modules for miniaturized and portable electronics. However, the low energy density, complex construction strategy, and low assembly accuracy of a 3D MSC restrict its practical application. Herein, we design a simple construction strategy for a 3D MSC with high energy density by mortise and tenon structures. Wood-derived carbon modified by nitrogen-doped carbon nanotube arrays (N-CNT-WDC) provides an ordered ion transport channel and a large active specific surface area, availing the improvement of the energy density of a 3D MSC. Its strong carbon skeleton structure supports the construction of 3D interdigital electrodes with a tenon structure by laser, realizing precise and regulable assembly of 3D MSCs through a mortise and tenon joint. The prepared 3D MSC based on N-CNT-WDC shows an excellent volumetric capacitance of 93.66 F cm, a high volumetric energy density of 12 mW h cm at 600 mA cm, and an 85% retention rate of capacitance after 10,000 cycles of charge and discharge at 1000 mA cm. Furthermore, the mortise and tenon structure realizes diversified integration of 3D MSCs, making the integrated manufacturing of 3D microdevices more convenient and promoting their application in microelectronic devices.