A polyoxovanadate as an advanced electrode material for supercapacitors

Polyoxovanadate Na₆V₁₀O₂₈ is investigated for the first time as electrode material for supercapacitors (SCs). The electrochemical properties of Na₆V₁₀O₂₈ electrodes are studied in Li⁺-containing organic electrolyte (1M LiClO₄ in propylene carbonate) by galvanostatic charge/discharge and cyclic voltammetry in a three-electrode configuration. Na₆V ₁₀O₂₈ electrodes exhibit high specific capacitances of up to 354 Fg^-1. An asymmetric SC with activated carbon as positive electrode and Na₆V₁₀O₂₈ as negative electrode is fabricated and exhibits a high energy density of 73 Whkg^-1 with a power density of 312 Wkg^-1, which successfully demonstrates that Na₆V₁₀O₂₈ is a promising electrode material for high-energy SC applications.