Unveiling the Origin of Unusual Pseudocapacitance of RuO2·nH2O from Its Hierarchical Nanostructure by Small-Angle X-ray Scattering

Yoshida, Noboru; Yamada, Yuki; Nishimura, Shin Ichi; Oba, Yojiro; Ohnuma, Masato; Yamada, Atsuo

doi:10.1021/jp403402k

Cited by 65 publications

(48 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The thickness and AEF of the gold current collector, which can be easily modulated by the electrodeposition parameters, were ≈40 µm and 520, respectively. Pseudocapacitive hydrous ruthenium dioxide RuO 2 was afterward electrodeposited (using cyclic voltammetry at 50 mV s −1 from −0.3 to +0.95 V vs SCE for 400 cycles) on the resulting 3D conducting current collector and annealed at 150 °C for 1 h, i.e., just below its crystalline temperature . The pH value of the electrolytic bath was settled at 2.5 to achieve optimal RuO 2 deposition involving both chemical and electrochemical reactions.…”

Section: Resultsmentioning

confidence: 99%

3D Interdigitated Microsupercapacitors with Record Areal Cell Capacitance

Ferris

Bourrier

Garbarino

et al. 2019

Small

View full text Add to dashboard Cite

Due to their high‐power density and long lifetime, microsupercapacitors have been considered as an efficient energy supply/storage solution for the operation of small electronic devices. However, their fabrication remains confined to 2D thin‐film microdevices with limited areal energy. In this study, the integration of all‐solid‐state 3D interdigitated microsupercapacitors on 4 in. silicon wafers with record energy density is demonstrated. The device electrodes are composed of a pseudocapacitive hydrated ruthenium dioxide RuO2 deposited onto highly porous current collectors. The encapsulated devices exhibit cell capacitance of 812 mF cm−2 per footprint area at an energy density of 329 mJ cm−2, which is the highest value ever reported for planar configuration. These components achieve one of the highest surface energy/power density trade‐offs and address the issue of electrical energy storage of modern electronics.

show abstract

Section: Resultsmentioning

confidence: 99%

3D Interdigitated Microsupercapacitors with Record Areal Cell Capacitance

Ferris

Bourrier

Garbarino

et al. 2019

Small

View full text Add to dashboard Cite

show abstract

“…This particle size is in good agreement with the local structure derived by EXFAS 24 and SAXS. 25 The pseudocapacitance due to surface redox processes (C redox ) is calculated by subtracting C dl from the overall capacitance C at the respective scan rates and is shown in Fig. 1B.…”

Section: Methodsmentioning

confidence: 99%

Towards Implantable Bio-Supercapacitors: Pseudocapacitance of Ruthenium Oxide Nanoparticles and Nanosheets in Acids, Buffered Solutions, and Bioelectrolytes

Makino

Ban

Sugimoto

2015

J. Electrochem. Soc.

View full text Add to dashboard Cite

Metal oxides, in particular ruthenium-based oxides, are promising electrode materials for aqueous pseudocapacitors. Strong acids or bases are favored over neutral electrolytes owing to the higher capacitance. Here we explore the pseudocapacitive behavior of ruthenium oxide nanoparticles and nanosheets in near neutral pH as an environmentally benign electrolyte. The pseudocapacitive charge storage in poorly-crystalline hydrous RuO 2 nanoparticles, and highly-crystalline RuO 2 nanosheets were investigated in acetic acid-lithium acetate (AcOH-AcOLi) buffered solutions. It is shown that capacitance values as high as 1,038 F g −1 can be achieved in AcOH-AcOLi buffered solutions with RuO 2 nanosheets, which is 44% higher than the benchmark RuO 2 · nH 2 O in H 2 SO 4 electrolyte (720 F g −1 ). Furthermore, comparable performance was obtained in phosphate buffered saline and fetal bovine serum. The mechanism of the pseudocapacitive properties is discussed based on the difference in the surface redox behavior of different RuO 2 nanomaterials in acid, neutral, buffered solutions, and in weak acid. Electrochemical capacitors (also known as supercapacitors) are energy harvesting devices capable of charge and discharging within a few seconds, and cycle life in the order of thousands of cycles. Some metal-oxides are known to provide high capacitance in aqueous electrolytes, owing to the combination of the non-faradaic electrical double layer charging and the faradaic surface or near surface confined redox capacitance (psuedocapacitance).1 Pseudocapacitance is a phenomenon generally observed in aqueous electrolytes.2 Acidic or basic electrolytes such as H 2 SO 4 and KOH are favorable in terms of power density owing to the high conductivity. RuO 2 is one of the rare oxides that is stable in both acidic and basic conditions. Hydrous RuO 2 nanoparticles (RuO 2 · nH 2 O; where n is typically 0.5) offers capacitance of ∼700 F g −1 in H 2 SO 4 electrolyte and can be cycled for thousands of cycles with practically no decay, thus is often used for performance benchmarking of new electrode materials. Although studies on the asymmetric systems and applicability of non-aqueous electrolytes to oxide electrodes in order to widen the operating voltage window have recently been initiated, non-aqueous electrolytes have yet to surpass aqueous electrolytes in terms of specific capacitance. [3][4][5][6][7][8] Electrolytes near neutral pH are selected for materials that are not as corrosion-resistant in acids and base, for example manganese oxide.9-12 Neutral electrolytes are more environmentally benign and its low corrosiveness allows a wider range in choice for periphery material, such as current collectors and packaging.13 Despite the RuO 2 -based material being the model pseudocapacitive material, studies on the electrochemical capacitor behavior in neutral electrolytes are scarce compared to the more popular acidic or basic electrolytes. One of the reasons is that the capacitance of RuO 2 in neutral electrolytes is generally 1/2 of that in s...

show abstract

“…The results reveal that as‐synthesized RuO 2 ·0.4H 2 O was typical amorphous with partly rutile crystalline structure, which is an essential factor to simultaneously obtain high ion and electron conductivity, because electron conduction is supported by the rutile‐like nanocrystals and proton conduction is facilitated by the structural water, as shown in refs. and .…”

mentioning

confidence: 97%

A Flexible Fiber‐Based Supercapacitor–Triboelectric‐Nanogenerator Power System for Wearable Electronics

et al. 2015

View full text Add to dashboard Cite

A flexible self-charging power system is built by integrating a fiber-based supercapacitor with a fiber-based triboelectric nanogenerator for harvesting mechanical energy from human motion. The fiber-based supercapacitor exhibits outstanding electrochemical properties, owing to the excellent pseudocapacitance of well-prepared RuO2 ·xH2 O by a vapor-phase hydrothermal method as the active material. The approach is a step forward toward self-powered wearable electronics.

show abstract

Unveiling the Origin of Unusual Pseudocapacitance of RuO₂·nH₂O from Its Hierarchical Nanostructure by Small-Angle X-ray Scattering

Cited by 65 publications

References 39 publications

3D Interdigitated Microsupercapacitors with Record Areal Cell Capacitance

3D Interdigitated Microsupercapacitors with Record Areal Cell Capacitance

Towards Implantable Bio-Supercapacitors: Pseudocapacitance of Ruthenium Oxide Nanoparticles and Nanosheets in Acids, Buffered Solutions, and Bioelectrolytes

A Flexible Fiber‐Based Supercapacitor–Triboelectric‐Nanogenerator Power System for Wearable Electronics

Contact Info

Product

Resources

About