Electrochemical Kinetics of Nanostructured Nb₂O₅Electrodes

Abstract

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Electrochemical Transport Phenomena in Hybrid Pseudocapacitors under Galvanostatic Cycling

“…A229-A243 (2016) to the positive activated carbon electrode. 8,12,14 This corresponds to Li + intercalation in the Nb 2 O 5 electrode during charging and deintercalation during discharging. It is interesting to note that the synthesis of Nb 2 O 5 described in Ref.…”

“…Indeed, several pseudocapacitor studies, featuring Figure 1a indicates that, for hybrid pseudocapacitors with Nb 2 O 5 , the cell potential ψ s (t) increased rapidly at the beginning of the charging step. 9,12,21 Then, the rate of change |dψ s /dt| abruptly decreased, resulting in a distinct "kink" in the potential evolution. The slope |dψ s /dt| also increased toward the end of the cycle, although it was not as large as at the beginning of the cycle.…”

“…The cell potential ψ s varied approximately linearly for the rest of the cycle, except for a very brief period of large slope |dψ s /dt| immediately after the charging/discharging transition. 9,12,21 Figure 1a also shows experimentally measured potential drops between each electrode and a reference electrode, denoted as ψ P (t) and ψ C (t) for the pseudocapacitive and carbon electrodes, respectively, and such that ψ s (t) = ψ C (t) − ψ P (t). It indicates that ψ C (t) for the carbon electrode varied linearly and that the variation of |dψ s /dt| was associated with the pseudocapacitive electrode.…”

Facile synthesis of T-Nb2O5 nanosheets/nitrogen and sulfur co-doped graphene for high performance lithium-ion hybrid supercapacitors

“…The CV curves (Fig. 5a) [2,15]. Generally, in CV tests the currents (i) are proportional to the scan rates (v):…”

“…Therefore, it is crucial to achieve advanced high power anode materials, narrowing the kinetics gap between anodes and cathodes. Recently, it has been proved that the orthorhombic niobium oxide (TNb 2 O 5 ) can deliver high power by a unique ion-intercalation pseudocapacitance occurring in the bulk of TNb 2 O 5 as well as on the surface [14,15]. In addition, the theoretical capacity (~200 mA h g −1 ) of T-Nb 2 O 5 is higher than that of TiO 2 and Li 4 Ti 5 O 12 (~170 mA h g suitable candidate as the anode materials of Li-HSCs.…”