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.