Binder-Free Porous 3D-ZnO Hexagonal-Cubes for Electrochemical Energy Storage Applications

Considerable efforts are underway to rationally design and synthesize novel electrode materials for high-performance supercapacitors (SCs). However, the creation of suitable materials with high capacitance remains a big challenge for energy storage devices. Herein, unique three-dimensional (3D) ZnO hexagonal cubes on carbon cloth (ZnO@CC) were synthesized by invoking a facile and economical hydrothermal method. The mesoporous ZnO@CC electrode, by virtue of its high surface area, offers rich electroactive sites for the fast diffusion of electrolyte ions, resulting in the enhancement of the SC’s performance. The ZnO@CC electrode demonstrated a high specific capacitance of 352.5 and 250 F g⁻¹ at 2 and 20 A g⁻¹, respectively. The ZnO@CC electrode revealed a decent stability of 84% over 5000 cycles at 20 A g⁻¹ and an outstanding rate-capability of 71% at a 10-fold high current density with respect to 2 A g⁻¹. Thus, the ZnO@CC electrode demonstrated improved electrochemical performance, signifying that ZnO as is promising candidate for SCs applications.