Ordered porous and uniform electric-field-strength micro-supercapacitors by 3D printing based on liquid-crystal V₂O₅ nanowires compositing carbon nanomaterials

The design of electrode internal structure plays an important role in improving the performance of micro-supercapacitors (MSCs). However, the complexity of the program hinders the development and application of Three-dimensional(3D)-printed MSCs. Herein, printable inks were prepared by using vanadium pentoxide nanowires as active materials, carbon nanotubes as collector and conductive agent, graphene oxide as adhesive, scaffold and water retaining agent. Benefiting from the liquid-crystal properties of materials and 3D printing technology as well as the adjustment of the materials proportion, onion-like structures with ordered porous layered structure and uniform electric-field-strength MSCs were constructed. The 3D-printed MSC has fine area capacitance (34.68 mF cm^-2) and area energy density (1.73 µWh cm^-2 at a current density of 0.24 mA cm^-2). Therefore, using the unique characteristics of materials to build an efficient 3D printing strategy is expected to provide a feasible solution for the construction of various MSCs and other high-energy storage systems.