Phosphate Ion-Modified RuO₂/Ti₃C₂ Composite as a High-Performance Supercapacitor Material

Pseudocapitor materials, usually metal oxides, are used as active materials in an electrode to achieve high energy density. However, these kinds of materials often suffer from poor conductivity and high cost. Herein, a phosphate ion-modified RuO₂/Ti₃C₂ composite is prepared via a chemical solution synthesis followed by an annealing process. In this composite material, Ti₃C₂ layers are introduced to improve the conductivity and the binary material is doped with phosphate ions into to increase the number of active reaction sites. As a result, the phosphate ion-modified RuO₂/Ti₃C₂ delivers a high specific capacitance of 612.72 F g^-1 at a current density of 2 A g^-1 in H₂SO₄ electrolyte. What is more, the capacitance of the phosphate ion-modified RuO₂/Ti₃C₂ can retain 97.95% (600.14 F g^-1) of the original value even after 10,000 cycles at a current density of 2 A g^-1.