Highly bonded T-Nb2O5/rGO nanohybrids for 4 V quasi-solid state asymmetric supercapacitors with improved electrochemical performance
solid-state supercapacitor, nanohybrid electrode, ionogel polymer electrolyte, electrochemical performance
ABSTRACT T-Nb2O5/reduced graphene oxide nanohybrids were fabricated via the hydrothermal attachment of Nb2O5 nanowires to dispersed graphene oxide nanosheets followed by a high-temperature phase transformation. Electrochemical measurements showed that the nanohybrid anodes possessed enhanced reversible capacity and superior cycling stability compared to those of a pristine T-Nb2O5 nanowire electrode. Owing to the strong bonds between graphene nanosheets and T-Nb2O5nanowires, the nanohybrids achieved an initial capacity of 227 mAh·g−1. Additionally, non-aqueous asymmetric supercapacitors (ASCs) were fabricated with the synthesized nanohybrids as the anode and activated carbon as the cathode. The 3 V Li-ion ASC with a LiPF6-based organic electrolyte achieved an energy density of 45.1 Wh·kg−1 at 715.2 W·kg−1. The working potential could be further enhanced to 4 V when a polymer ionogel separator (PVDF-HFP/LiTFSI/EMIMBF4) and formulated ionic liquid electrolyte were employed. Such a quasi-solid state ASC could operate at 60 °C and delivered a maximum energy density of 70 Wh·kg−1 at 1 kW·kg−1.
Tsinghua University Press
Yuzhi Jiao,Haitao Zhang,Hailang Zhang,Ao Liu,Yanxia Liu,Suojiang Zhang, Highly bonded T-Nb2O5/rGO nanohybrids for 4 V quasi-solid state asymmetric supercapacitors with improved electrochemical performance. NanoRes.2018, 11(9): 4673–4685