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 (1 M LiClO4 in propylene carbonate) by galvanostatic charge/discharge and cyclic voltammetry in a three‐electrode configuration. Na6V10O28 electrodes exhibit high specific capacitances of up to 354 F g−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 Wh kg−1 with a power density of 312 W kg−1, which successfully demonstrates that Na6V10O28 is a promising electrode material for high‐energy SC applications. An asymmetric supercapacitor with activated carbon as positive electrode and Na6V10O28 as negative electrode in Li+‐containing organic electrolyte is fabricated and exhibits a high energy density of 73 Wh kg−1 with a power density of 312 W kg−1. The picture shows the proposed Li+ intercalation and/or adsorption process in the Na6V10O28 electrodes.