3D printing-assisted gyroidal graphite foam for advanced supercapacitors

Rational design and facile construction of 3D porous carbon-based electrodes with both high capacitance and outstanding mechanical performance remains a challenge. Herein, by synergistically combining digital light processing (DLP) and chemical vapor deposition (CVD), a gyroidal 3D graphite foam (GF) with hierarchical porosity ranging from few nanometers to hundreds of micrometers was developed. The resulted GF can be directly used as a robust substrate for the loading of active materials, without using additional binders and current collectors. Through systematical finite element analyses (FEA) and compression tests, GF with the optimised gyroid unit can achieve a highest compressive strength of 1.4 Mpa and hold up approximately 16,000 times of its own weight without apparent deformation. The as-fabricated NiCo2O4/GF//N-doped carbon/GF asymmetric supercapacitor not only reveals a remarkable volumetric capacitance of 0.81F cm-3 at a high current density of 75 mA cm-3, but also shows robust mechanical property that it can maintain stable power output under strong compression. This 3D printing strategy and the promising mechanical and electrochemical properties demonstrated in current work would pave a good way for the development of customizable nextgeneration high-performance energy storage devices.