Electrohydrodynamic 3D printing of orderly carbon/nickel composite network as supercapacitor electrodes

Electrohydrodynamic (EHD) 3D printing of carbon-based materials in the form of orderly networks can have various applications. In this work, microscale carbon/nickel (C-Ni) composite electrodes with controlled porosity have been utilized in electrochemical energy storage of supercapacitors. Polyacrylonitrile (PAN) was chosen as the basic material for its excellent carbonization performance and EHD printing property. Nickel nitrate (Ni(NO3)2) was incorporated to form Ni nanoparticles which can improve the conductivity and the capacitance performance of the electrode. Well-aligned PAN-Ni(NO3)2 composite structures have been fabricated and carbonized as C-Ni electrodes with the typical diameter of 9.2±2.1 μm. The porosity of the as-prepared C-Ni electrode can be controlled during the EHD process. Electrochemical results show the C-Ni network electrode has achieved a 2.3 times higher areal specific capacitance and 1.7 times higher mass specific capacitance than those of a spin-coated electrode. As such, this process offers a facile and scalable strategy for the fabrication of orderly carbon-based conductive structures for various applications such as energy storage devices and printable electronics.