Carbon Nanotube@Nickel Hydroxide Nanosheets Core–Shell Nanostructures Enabling Thermally Assisted 3D‐Printed Solid‐State Microsupercapacitors

Microsupercapacitors have picked up a remarkable reputation as prospective micropower sources for compact electronics. Unfortunately, the fabricating complexity of electrode structures and preparing sophistication of electrode materials have prevented their practical deployment. Herein, a one‐step low‐temperature precipitation method is applied to straightforwardly self‐assemble porous Ni(OH)₂ nanosheets on the surface of carbon nanotubes (CNTs) surface beneath electrostatic interaction. The developed core–shell 1D CNTs@Ni(OH)₂ nanosheets nanostructures exhibit high electron and ion conductivity, a sign of excellent energy storage capability. In this vein, a thermally assisted 3D printing process is intelligently regulated to enable the fabrication of 3D interdigital electrodes from as‐obtained materials. The ultimate solid‐state microsupercapacitors of CNTs@Ni(OH)₂ nanosheets core–shell nanostructures in this way exhibit excellent cycle stability and offer an exceptional areal capacitance of 39.6 mF cm⁻², approximately a size of or two higher than that of C‐based partners. A strong foundation for high‐quality microsupercapacitors is laid by the high specific capacity of CNTs@Ni(OH)₂ nanosheets core–shell nanostructures and the ability to fabricate 3D interdigital electrodes using a thermally assisted 3D printing process.