Fabrication of Phosphorus-Doped Cobalt Silicate with Improved Electrochemical Properties

The development of electrode materials for supercapacitors (SCs) is greatly desired, and this still poses an immense challenge for researchers. Cobalt silicate (Co₂SiO₄, denoted as CoSi) with a high theoretical capacity is deemed to be one of the sustainable electrode materials for SCs. However, its achieved electrochemical properties are still not satisfying. Herein, the phosphorus (P)-doped cobalt silicate, denoted as PCoSi, is synthesized by a calcining strategy. The PCoSi exhibits 1D nanobelts with a specific surface area of 46 m²∙g⁻¹, and it can significantly improve the electrochemical properties of CoSi. As a supercapacitor’s (SC’s) electrode, the specific capacitance of PCoSi attains 434 F∙g⁻¹ at 0.5 A∙g⁻¹, which is much higher than the value of CoSi (244 F∙g⁻¹ at 0.5 A∙g⁻¹). The synergy between the composition and structure endows PCoSi with attractive electrochemical properties. This work provides a novel strategy to improve the electrochemical performances of transition metal silicates.