Electrochemical characteristics of activated carbon/Ppy electrode combined with P(VdF-co-HFP)/PVP for EDLC

Kim, Kyong-Min; Hur, Jun; Jung, Se-il; Kang, An-Soo

doi:10.1016/j.electacta.2004.02.059

Cited by 34 publications

(20 citation statements)

References 11 publications

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“…Recently, few studies also reported about the use of derivatives of those two binders, e.g. PVdF-hexafluoropropylene (PVdF-HFP) [12] and Nafion [13,14], a perfluorosulfonated ionomer derived from PTFE. These binders can be advantageously used for the realization of composite electrodes to be combined with all types of electrolytes commonly used in EDLCs (see Table 1).…”

Section: Introductionmentioning

confidence: 99%

Natural, cheap and environmentally friendly binder for supercapacitors

Böckenfeld

Jeong

Winter

et al. 2013

Journal of Power Sources

104

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Section: Introductionmentioning

confidence: 99%

Natural, cheap and environmentally friendly binder for supercapacitors

Böckenfeld

Jeong

Winter

et al. 2013

Journal of Power Sources

104

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“…33 Polytetrafluoroethylene (PTFE) 28,30,33,34 and polyvinylidene difluoride (PVdF) 27,31,32 are the most widely used binders for EDLC electrodes. Some studies used derivatives of these two binders, such as polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP) 41 and Nafion. 42 Recently, cellulose and its derivatives have also been employed in electrochemical energy storage devices as substrate, separator, and electrode binder for their low cost, environmental friendliness, and easy processability.…”

Section: Introductionmentioning

confidence: 99%

Effects of Constituent Materials on Heat Generation in Individual EDLC Electrodes

Munteshari

Lau

Ashby

et al. 2018

J. Electrochem. Soc.

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This study aims to investigate the effect of electrode composition on heat generation in electric double layer capacitor (EDLC) electrodes under galvanostatic cycling. EDLCs consist of two identical electrodes usually made of a mixture of (i) carbon-based material, (ii) binder, and (iii) other conductive additives. These constituents were found to influence the capacitance and internal resistance of the device and the heat generation rate in the positive and negative electrodes. Indeed, the heat generation rate was measured using an isothermal calorimeter in both electrodes of five EDLC devices with different electrode compositions but the same electrolyte consisting of 1 M LiPF 6 in EC:DMC. The reversible heat generation rates at the positive and negative electrodes were nearly identical in absence of CMC. However, in devices containing CMC, the reversible heat generation rate in the positive electrode was significantly larger than that in the negative electrode. Such asymmetric heating was attributed to asymmetry in the charging mechanism due to the overscreening effect caused by interactions between the anionic functional groups of CMC and the cations at the negative electrode. Electric double layer capacitors (EDLCs) have received significant attention in recent years for electrical energy storage applications in particular those requiring rapid charging/discharging, such as regenerative braking in electric vehicles, 1 smart grids, 2 and renewable energy harvesting systems.3-5 Indeed, EDLCs can provide higher power density, higher cycle efficiency, and longer lifetime than batteries. 4,6 EDLC devices consist typically of two carbon-based electrodes partitioned by a separator immersed in aqueous or organic electrolytes. EDLCs store electrical energy in the electrical double layer of ions forming at electrode/electrolyte interface.Heat generation in EDLC is a major concern since these devices are usually cycled under high current density resulting in excessive temperature rise.7 This, in turn, can lead to (i) accelerated cell aging, [8][9][10] (ii) increased self-discharge rates, 9,11 and possibly (iii) electrolyte decomposition and evaporation. 9,12 Heat generation in EDLCs can be classified into irreversible and reversible heat generation rates. 7,[13][14][15][16][17] Irreversible heat generation has been attributed, both theoretically and experimentally, to Joule heating. 7,9,11,[13][14][15][16][17][18][19][20] It is constant throughout the EDLC cell and equal to the product of the EDLC internal resistance and the square of the imposed current. 7,[14][15][16] On the other hand, reversible heat generation rate in the entire device was theoretically and experimentally found to be exothermic during charging and endothermic during discharging.7,14-16 The time-averaged reversible heat generation over a charging step was shown to be proportional to the imposed current under galvanostatic cycling.7,14-16 Experimentally, reversible heat generation has been assumed to be identical in both the positive and negative e...

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“…The high frequency one is strongly flattened, which can be interpreted as the signature of the porous structure of the composite electrode. The low frequency loop is governed by the large interfacial capacitance of the electrolyte/electrode interface in parallel with a finite transfer resistance [11,17,22]. The value of the interfacial capacitance can be more clearly evidenced by plotting the complex capacitance C Ã ¼ C 0 À jC 00 , defined by C Ã ¼ ðjxZÞ À1 , as shown in Fig.…”

Section: Electrochemical Impedance Spectroscopy Measurementsmentioning

confidence: 99%

Usefulness of a composite electrode with a carbon surface modified by electrosynthesized polypyrrole for supercapacitor applications

et al. 2010

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Thin polypyrrole (PPy) films (thickness = 5-10 nm) were electrochemically deposited in situ on a carbon paste (97% of graphite plus 3% of Teflon) by means of cyclic voltammetry (CV), from an acetonitrile solution of pyrrole (0.2 M) and NaClO 4 (0.1 M). The obtained PPy/ graphite composite electrode was investigated by CV and chronopotentiometry in 0.3 M NaClO 4 aqueous electrolytic solution. The capacitance of a composite electrode, calculated by CV, was about 10 F g -1 . The capacitance value of the composite electrode was approximately nine times larger than that of pure graphite. The massic charge and discharge capacity (Q) values, calculated by chronopotentiometry, were considerably higher for the composite electrode-by more than 60 times-than for the pure graphite electrode. Electrochemical impedance spectroscopy (EIS) measurements, performed under stationary conditions, led to an interfacial capacitance value intermediate between that of pure graphite and that of the composite electrode.

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Electrochemical characteristics of activated carbon/Ppy electrode combined with P(VdF-co-HFP)/PVP for EDLC

Cited by 34 publications

References 11 publications

Natural, cheap and environmentally friendly binder for supercapacitors

Natural, cheap and environmentally friendly binder for supercapacitors

Effects of Constituent Materials on Heat Generation in Individual EDLC Electrodes

Usefulness of a composite electrode with a carbon surface modified by electrosynthesized polypyrrole for supercapacitor applications

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