Preparation of ZnCo2O4@PANI core/shell nanobelts for high-performance asymmetric supercapacitors

Abstract

The binary metal oxide ZnCo₂O₄ is considered as a potential electrode candidate for asymmetric supercapacitors due to its unique composition and battery-type features. However, its low electrical conductivity and insufficient material utilization efficiency hinder its major practical application. In this work, hierarchical polyaniline-coated ZnCo₂O₄ nanobelts have been synthesized using an economical two-step strategy (including a hydrothermal method and an in situ polymerization route) and are investigated as a supercapacitor material. Impressively, the resulting ZnCo₂O₄@PANI nanobelt electrode exhibits a remarkable specific capacitance of 1938.2 F g⁻¹ at 1 A g⁻¹ and superior cycling performance (the capacitance retains 92.4% after cycling for 10 000 cycles at 6 A g⁻¹). Furthermore, an ASC was prepared using the obtained ZnCo₂O₄@PANI electrode as a cathode and using active carbon (AC) as an anode. The constructed ASC delivers a high specific energy of 66.6 W h kg⁻¹ at a specific power of 800.1 W kg⁻¹, and attains 92.5% capacitance retention over 10 000 cycles at 8 A g⁻¹, indicating its high potential for applications in the field of high-capacitance supercapacitors. These results demonstrate the great potential of ZnCo₂O₄@PANI nanobelts as a promising cathode material for supercapacitors.