A polypyrrole-adorned, self-supported, pseudocapacitive zinc vanadium oxide nanoflower and nitrogen-doped reduced graphene oxide-based asymmetric supercapacitor device for power density applications†
Herein, a distinctive approach has been implemented for exploiting a typical battery material zinc vanadium oxide (ZV) as a supercapacitor electrode material. Aiming to achieve fascinating capacitive properties, a hybrid (ZnV2O6@PPy) of the conducting polymer polypyrrole (PPy)-decorated ZV was synthesized via a hydrothermal protocol, followed by low-temperature in situ oxidative polymerization. The hybrid electrode ZnV2O6@PPy (ZVP) benefited from its interconnecting network architecture, mesoporous feature, conductive feature, and rich redox chemistry, which contributed to the charge storage performance to ensure a remarkable specific capacitance (Cs) of 723.6 F g−1 at 1 A g−1 current density that outweighed the Cs of ZV at 402 F g−1. Moreover, an asymmetric supercapacitor (ASC) device (based on ZnV2O6@PPy as the positive electrode and the nitrogen-doped reduced graphene oxide (NG) as the negative electrode) delivered a maximum Cs of 109.2 F g−1 at 1 A g−1 within an impressive voltage window of 0–1.5 V. The ASC provided a maximum energy density of 34 W h kg−1 at a power density of 748.7 W kg−1, maintaining a reliable cycle life of 93% over 3000 galvanostatic charge–discharge cycles. Two serially associated ASC devices can power up the red LED indicator for quite a long time. The comprehensive experimental output of the ASC supports the promising application of the device as a supercapacitor electrode application.