Nanoarchitectonics of ternary NixCo1-xSe2 electrocatalysts on Ni-foams combined with Pt-loaded carbon clothes as the air-cathodes in Zn-air energy storage systems

Background: Large-scale application of renewable energy with energy storage system is important for the reduction of influence on global warming effect without decreasing industrial activities. To develop an energy storage system is thus an important way for industrial application. Methods: Ternary Ni_xCo_1-xSe₂ electrocatalysts were prepared in an ethanol bath with reaction temperature of 70 °C in 10 min using a simple chemical synthesis method. Samples after post-selenization process as the electrocatalysts on nickel (Ni)-foams with Pt-loading carbon clothes were employed in Zn-air batteries. Significant findings: The X-ray diffraction patterns of samples showed ternary Ni_xCo_1-xSe₂ samples with high Se-vacancies. Therefore, the post-selenization process with temperature of 500 °C for 30 min was applied on these samples with various weights of Se powders. Samples as the electrocatalysts showed good stabilities in our homemade Zn-air batteries with the minimum voltage difference for oxygen evolution/reduction reactions of 0.91 V. Our cell with NiCo_1-xSe₂ electrocatalyst (Ni:Co:Se=0.21:0.29:0.50)@Ni foam + Pt-loading carbon cloth as the air-cathode showed the charge/discharge voltages of 2.05 and 1.08 V at charge/discharge current density of 10 mA/cm², respectively, and could be applied in industrial energy storage system.