Durable ZrB₂–ZrC Composite Materials as Advanced Electrodes for High-Performance Supercapacitors

Boride and carbide-based materials attract increasing attention as promising options for energy storage applications. This research focuses on synthesizing pure boride and carbide compounds of zirconium (ZrB₂ and ZrC) and their composite powders using mechanical activation-assisted route and subsequent heating processes. The chemical and microstructural characterization results indicate that the synthesized composite powders are of high purity, possess submicron-scale particle sizes (below 400 nm), and exhibit a high surface area of up to 9.41 m²/g. Supercapacitor devices, using the resulting powders as symmetrical electrodes, exhibit high energy density values ranging from 5.8 to 8.8 Wh/kg. The ZrB₂-15 wt % ZrC composite sample achieves the highest power density at 155 W/kg, compared to 118 W/kg for the pure ZrB₂ sample. Cycling tests demonstrate exceptional capacitance retention (99.4-99.9%) and cyclic stability, even after 5000 cycles, highlighting the high durability of the composite samples. These findings show that ZrB₂-ZrC composites exhibit high energy and power density values and excellent cycling performance, making them strong candidates for use in high-performance supercapacitor devices.