Niobium capacitor uses electrolytic Nb2O5 as dielectric layer formed on surface of porous niobium anode through electrolytic reaction. Analysis of Scanning Electronics Microscope (SEM) combined with X-ray Photoemissio...Niobium capacitor uses electrolytic Nb2O5 as dielectric layer formed on surface of porous niobium anode through electrolytic reaction. Analysis of Scanning Electronics Microscope (SEM) combined with X-ray Photoemission Spectrum(XPS) shows that the formed niobium oxide dielectric consists of not only Nb2O5, but also two kinds of low valence niobium NbO2 and NbO oxide. When using different electrolytic reaction conditions, different valence niobium oxide shows different relative content. The fact provides an important basis for analyzing and improving performances of niobium capacitor.展开更多
Increasing the energy density, power density as well as widening the operation voltage are essential to electrochemical capacitors to meet the practical energy demands. Herein, a novel flexible quasi-solid-state dual-...Increasing the energy density, power density as well as widening the operation voltage are essential to electrochemical capacitors to meet the practical energy demands. Herein, a novel flexible quasi-solid-state dual-ion asymmetric supercapacitor(ASC) with Ni(OH)2 and Nb2O5 nanosheets directly grown on stainless steel mesh is developed. In the dual-ion ASC, Nb2O5 negative and Ni(OH)2 positive electrodes react with Li+ and OH- respectively in alkaline gel electrolyte to store energy, which is quite different from conventional alkali metal ion SCs and alkaline SCs. The as-assembled flexible device has an extended working voltage of 1.7 V and delivers a capacity of 5.37 mAh cm-2, a maximum energy density and power density of 0.52 mWh cm-3 and 170 mW cm-3 , respectively. The device maintains around 60% capacity retention after long cycling up to 1000 cycles. Moreover, our device can light up a LED light efficiently upon fast charging. The proposed quasi-solid-state dual-ion ASC has potential applications in future portable electronics and flexible energy storage devices.展开更多
文摘Niobium capacitor uses electrolytic Nb2O5 as dielectric layer formed on surface of porous niobium anode through electrolytic reaction. Analysis of Scanning Electronics Microscope (SEM) combined with X-ray Photoemission Spectrum(XPS) shows that the formed niobium oxide dielectric consists of not only Nb2O5, but also two kinds of low valence niobium NbO2 and NbO oxide. When using different electrolytic reaction conditions, different valence niobium oxide shows different relative content. The fact provides an important basis for analyzing and improving performances of niobium capacitor.
基金supported by the National Natural Science Foundation of China (Grant No. 51302079, 51705527 and 51672205)the National Key R&D Program of China (Grant No. 2016YFA0202602)+1 种基金the Natural Science Foundation of Hunan Province (Grant No. 2017JJ1008)the financial support by Queensland University of Technology Stratergic research grant
文摘Increasing the energy density, power density as well as widening the operation voltage are essential to electrochemical capacitors to meet the practical energy demands. Herein, a novel flexible quasi-solid-state dual-ion asymmetric supercapacitor(ASC) with Ni(OH)2 and Nb2O5 nanosheets directly grown on stainless steel mesh is developed. In the dual-ion ASC, Nb2O5 negative and Ni(OH)2 positive electrodes react with Li+ and OH- respectively in alkaline gel electrolyte to store energy, which is quite different from conventional alkali metal ion SCs and alkaline SCs. The as-assembled flexible device has an extended working voltage of 1.7 V and delivers a capacity of 5.37 mAh cm-2, a maximum energy density and power density of 0.52 mWh cm-3 and 170 mW cm-3 , respectively. The device maintains around 60% capacity retention after long cycling up to 1000 cycles. Moreover, our device can light up a LED light efficiently upon fast charging. The proposed quasi-solid-state dual-ion ASC has potential applications in future portable electronics and flexible energy storage devices.
