Structural, morphological, and electrochemical capacitive properties of sputtered ZrN thin films for supercapacitor

Transition metal nitrides are potential electrode materials for supercapacitors because of their high specific capacitance, excellent conductivity, high melting point, and chemical stability. Herein, we fabricated zirconium nitride (ZrN) thin films using reactive direct-current (DC) magnetron sputtering at various sputtering power and further investigated their morphologies and electrochemical capacitive performance as an electrode material for supercapacitors. All films, consisting of ZrN and Zr 3 N 4 , are continuous and homogeneous with a fine columnar structure. As the sputtering power increases, the grain size becomes smaller and the content of Zr atoms increases. Electrochemical capacitance performance tests show that the T3 film electrode achieves the highest areal specific capacitance of 1.19 mF cm −2 at a current density of 0.05 mA cm −2 due to higher porosity, better wettability, and lower charge transfer resistance. Cycling tests show that the T3 film achieves an areal specific capacitance of 117% of its initial value and then remains stable, demonstrating the best cycling stability.