High mass-loading of nickel‑cobalt layered double hydroxide on 3D-printed electrode for cathode of asymmetric supercapacitor

Abstract

To achieve high-performance supercapacitors, the fabrication of electrodes with a high mass loading of active species without sluggish ion diffusion is a key process. Herein, we report nickel‑cobalt layered double hydroxide (NiCo-LDH) electrodeposited on 3D-printed electrodes (3D-PEs) prepared via 3D printing fused deposition modeling (FDM) technique after the surface modification of 3D PEs to achieve high loading mass cathode electrode (NiCo-LDH@3D-PEs) for asymmetric supercapacitor. As fabricated 1.6 mm-thick NiCo-LDH@3D-PE exhibits high mass loading (15.3 mg cm−2) with a capacitance of 25.9 F cm−2 (1690 F g−1) at 10 mA cm−2 current density. These improved activities are mainly due to the intrinsic properties of multilayered 3D-PEs which increase the number of ion-accessible sites and shorten the ion diffusion because of multiple orthogonal layers. Furthermore, an asymmetric supercapacitor was also examined with acid-treated carbon cloth (ATCC) as a negative and NiCo-LDH@3D-PE as a positive electrode. As we expected, the NiCo-LDH@3D-PE//ATCC device resulted in high energy density (1.26 mWh cm−2) and power density (4.74 mW cm−2). In addition, 93 % of its initial capacitance was observed after 10,000 cycles respectively. The outstanding performance of NiCo-LDH@3D-PEs authorizing the 3D printing FDM technique efficiently supports high mass-loading cathodes for asymmetric supercapacitors.