Asymmetric capacitance response from the chemical characteristics of activated carbons in KOH electrolyte

Sun, Gongquan; Long, Donghui; Liu, Xiaojun; Qiao, Wenming; Zhan, Lin; Liang, Xia; Ling, Licheng

doi:10.1016/j.jelechem.2011.05.017

Cited by 24 publications

(12 citation statements)

References 35 publications

(42 reference statements)

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“…As for the CV curves in KOH electrolyte, although there is no obvious redox peaks, RGOA also exhibits pseudocapacitance besides electric double-layer capacitance at the potential window of −1.0 ~ −0.3 V because the current density severely changes as the potential varies within this potential window [21]. An equilibrium redox reaction probably occurs as follows within this potential window [37]:…”

Section: Resultsmentioning

confidence: 99%

Reduced graphene oxide aerogel with high-rate supercapacitive performance in aqueous electrolytes

Zhou

et al. 2013

Nanoscale Res Lett

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Reduced graphene oxide aerogel (RGOA) is synthesized successfully through a simultaneous self-assembly and reduction process using hypophosphorous acid and I2 as reductant. Nitrogen sorption analysis shows that the Brunauer-Emmett-Teller surface area of RGOA could reach as high as 830 m2 g−1, which is the largest value ever reported for graphene-based aerogels obtained through the simultaneous self-assembly and reduction strategy. The as-prepared RGOA is characterized by a variety of means such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Electrochemical tests show that RGOA exhibits a high-rate supercapacitive performance in aqueous electrolytes. The specific capacitance of RGOA is calculated to be 211.8 and 278.6 F g−1 in KOH and H2SO4 electrolytes, respectively. The perfect supercapacitive performance of RGOA is ascribed to its three-dimensional structure and the existence of oxygen-containing groups.

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Section: Resultsmentioning

confidence: 99%

Reduced graphene oxide aerogel with high-rate supercapacitive performance in aqueous electrolytes

Zhou

et al. 2013

Nanoscale Res Lett

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“…Additionally, these heteroatoms usually introduce pseudo-capacitance via fast redox reaction of specic electro-active groups, such as C]O, C-OH, etc. 42,43…”

Section: Resultsmentioning

confidence: 99%

“…It is widely known that the oxygen-containing groups could introduce additional pseudocapacitance into the whole capacitance of carbon materials. In the case of KOH electrolyte, a redox mechanism for a carbonyl or quinone-type group has been proposed as 42 -C x O + e À + K + 5 -C x -OK (4) In the case of H 2 SO 4 , the redox mechanism could be expressed as: 43 -C]O + H + + e 5 -C-OH (5) However, in the case of Na 2 SO 4 , Young Joon Oh reported that the oxygenated groups are not involved in the pseudocapacitive faradaic reaction. 43 Moreover, the hydrophilic oxygen species could promote the wettability of carbon pore surface to the aqueous electrolytes, facilitating the diffusion of electrolyte ions.…”

Section: Electrochemical Performance In Aqueous Electrolytesmentioning

confidence: 99%

Porous carbons derived from waste printing paper for high rate performance supercapacitors in alkaline, acidic and neutral electrolytes

et al. 2018

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“…In the pulsed charging mode, the duty cycle was 50%, and the frequency range was 5GHz-10THz. Although many studies are about the asymmetric capacitance behavior of anions and cations in capacitors [22], we just intended to compare the DC-CDI and the pulsed-CDI, so only Na + were set in the system, the anions were not set.…”

Section: Molecular Dynamics Simulationmentioning

confidence: 99%

Capacitive deionization using a pulsed power supply for water treatment

Jin¹,

Hu²,

Sun³

et al. 2019

Desalination and Water Treatment

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A capacitive deionization system utilizing a pulsed power supply was designed and investigated for desalination. In most studies on capacitive deionization, direct current power supply is the most common power source. Compared with traditional direct-current capacitive deionization, pulsed-capacitive deionization exhibits some excellent properties in desalination: lower power consumption, higher removal rate. The optimal operational conditions of a pulsed power supply in capacitive deionization were discussed in this study. From the experiment results, as for NO 3 of initial concentration 40 mg/L, a duty cycle of 50% and a frequency of 1000 Hz were optimal. From the theory of electrolyte solution, the optimal frequency is related to properties of ion, such as: ionic radius, valence, ion mobility, and also related to the concentration of ion. The results of molecular dynamics simulation were consistent with the experimental results. the reasons for excellent performances of pulsed-capacitive deionization in desalination may be that: the effect of concentration polarization and the migration resistance from solution to the EDL were reduced. Pulsed-capacitive deionization could be used for low concentration water desalination and it provides a new idea for the preparation of ultra pure water and the advanced treatment of wastewater.

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Asymmetric capacitance response from the chemical characteristics of activated carbons in KOH electrolyte

Cited by 24 publications

References 35 publications

Reduced graphene oxide aerogel with high-rate supercapacitive performance in aqueous electrolytes

Reduced graphene oxide aerogel with high-rate supercapacitive performance in aqueous electrolytes

Porous carbons derived from waste printing paper for high rate performance supercapacitors in alkaline, acidic and neutral electrolytes

Capacitive deionization using a pulsed power supply for water treatment

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