Nanostructured Cu3P–CoP Cathodes with 3D Urchin Morphology for Hybrid Supercapacitors

Abstract

A highly functioning copper cobalt-based ternary phosphide (CCP) cathode was engineered from a copper cobalt carbonate hydroxide (CCH) material via a gas–solid thermal route, resulting in a 3D spatial morphology with a hierarchical architecture and porosity. Preliminary electrochemical testing revealed the superiority of the CCP cathode with a specific capacity value of 2392 C g^–1 at 10 A g^–1 and a capacity retention of 94.4% over 5000 cycles at 40 A g^–1. The morphological advantages of CCP with its 3D hierarchical architecture, highly porous network, and numerous nanospikes with sharp edges and surface defects offer tremendous active sites and ion transport channels for better charge storage performance. The CCP//activated carbon electrode (ACE) hybrid supercapacitor (HSC) device delivered a capacity value of 284.5 C g^–1 at 10 A g^–1 and a 92.3% retention in capacity for 10 000 cycles at a high current density of 30 A g^–1. Furthermore, the fabricated device provided high energy and power density values of 129.15 Wh kg^–1 and 66.4 kW kg^–1, respectively, and powered a red LED for 1 min. Thus, this work efficiently provides knowledge on the development of a Cu₃P–CoP electrode material from optimizing morphological features and synthetic routes, which leads to achieving superior functioning cathode materials for hybrid supercapacitors in the current energy storage era.