Preparation and Surface Area Measurements of Platinized-Platinum Electrodes

Joncich, M. J.; Hackerman, Norman

doi:10.1149/1.2425981

Cited by 12 publications

(5 citation statements)

References 13 publications

(28 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Platinization effects reported in the literature for the normalized hydrogen electroactivity on platinized platinum surfaces vary over a wide range. Although extreme values of 3900, or even 20 000, have been reported, high values are generally in the range of 200−800. − Discrepancies in normalized electroactivity can be attributed to surface morphologies obtained under different experimental conditions as well as differences in the methodology of estimation. In many cases, a comparison with reported effective surface area values cannot be made, as the amount of Pt loading was not reported.…”

Section: Resultsmentioning

confidence: 99%

Conductive-Matrix-Mediated Alkaline Fe(III/VI) Charge Transfer: Three-Electron Storage, Reversible Super-Iron Thin Film Cathodes

Licht

Alwis

2006

J. Phys. Chem. B

View full text Add to dashboard Cite

An extended conductive matrix facilitates a 100-fold enhancement in charge storage for reversible Fe(III/VI) super-iron thin films. These films were deposited, by electrochemical reduction of Na2FeO4, with an intrinsic high capacity 3 e- cathodic storage of 485 mAh g(-1). Whereas 3 nm Fe(III/VI) films exhibited a high degree of reversibility (throughout 100 charge/discharge cycles), thicker films had been increasingly passive toward the Fe(VI) charge transfer. Films were alternatively deposited on either smooth or on extended conductive matrixes composed of high-surface-area Pt, Ti, and Au and probed galvanostatically and via cyclic voltammetry. A 100 nm Fe(VI) cathode, on the extended conductive matrixes, sustained 100-200 reversible three-electrode charge/discharge cycles, and a 19 nm thin film cathode sustained 500 such cycles. With a metal hydride anode, full cell storage was probed, and a 250 nm super-iron film cathode film sustained 40 charge/discharge cycles, and a 25 nm film was reversible throughout 300 cycles. Fe(VI) salts exhibit higher cathodic capacity and environmental advantages, and the films are of relevance toward the next generation charge storage chemistry for reversible cathodes.

show abstract

Section: Resultsmentioning

confidence: 99%

Conductive-Matrix-Mediated Alkaline Fe(III/VI) Charge Transfer: Three-Electron Storage, Reversible Super-Iron Thin Film Cathodes

Licht

Alwis

2006

J. Phys. Chem. B

View full text Add to dashboard Cite

show abstract

“…A linear trend for the variation of this electroactivity with the amount of Pt deposited was observed in accordance with normalized electroactivity ) 96 × (Pt loading, mg cm -2 ) + 2.7 (14) Platinization effects reported in the literature for the normalized hydrogen electroactivity on platinized platinum surfaces vary over a wide range. [35][36][37][38] Greater levels of platinization lead to greater surface activity, but beyond a certain level these films will exhibit diminished mechanical and structural integrity. Discrepancies in normalized electroactivity can be attributed to surface morphologies obtained under different experimental conditions, as well as differences in the methodology of estimation.…”

Section: Optimization Of Fe(iii/vi) Film Formation By Alkalinementioning

confidence: 99%

Enhancement of Reversible Nonaqueous Fe(III/VI) Cathodic Charge Transfer

2009

View full text Add to dashboard Cite

The electrochemical preparation of Fe(III/VI) super-iron thin films cathodes on an extended conductive matrix significantly facilitates such film’s nonaqueous, reversible charge transfer. Fe(VI) salts can exhibit higher cathodic capacity and environmental advantages, and the films are of relevance toward the next generation charge storage chemistry for reversible cathodes. These films were electrochemically deposited on either smooth or platinized platinum by electrochemical reduction of Na2FeO4, which retains an intrinsic 3 e− cathodic charge storage capacity of 485 mAh g−1. The influence on cathode reversibility, capacity, and charge retention was probed as function of film deposition conditions (including the deposition potential and stirring rate, and the concentration of NaOH and K2FeO4, in the deposition electrolyte). The highest storage capacity films were formed from an 8.0 M NaOH electrolyte containing 50.0 mM of K2FeO4 and examined by FTIR. Those “super-iron” cathode films, which are up to 191 nm thick and electrodeposited on smooth platinum, sustained up to 300 reversible three-electron galvanostatic charge/discharge cycles to a high depth of discharge in 1 M LiPF6 in PC:DME electrolyte lithium cells. Thicker (greater than 500 nm thick) films deposited on smooth platinum evidence increasing passivity to Fe(VI) charge transfer and charge storage. Films deposited on platinized platinum overcome this passivity, permitting sustained nonaqueous charge/discharge cycling with a thicker (571 nm) Fe(VI) film cathode, and provide a first demonstration of significant Fe(VI)/lithium thin-film secondary cell behavior.

show abstract

“…This ceases to be the case, however, when treating the problem of whole, porous, electrodes. Salkind et al (1) reported on a nondestructive method [based on BET (14) gas adsorption measurements] for the determination of surface areas and pore size distributions of porous electrodes; a similar approach was used to study the preparation of platinized-platinum electrodes (2) and to check electrode surface area data obtained also by an electrochemical method (3). Others tried radiographic (4)(5)(6), electron microscopic (7), and polarized light microscopy (8) techniques for determination of porous electrode structure and operational parameters.…”

mentioning

confidence: 99%

Structural Studies of Porous Electrodes

Weissman

1967

J. Electrochem. Soc.

View full text Add to dashboard Cite

Nondestructive techniques are described for the measurement of total electrode surface area, microporosity and pore size distribution, total porosity, and fraction of total porosity consisting of open pores. These measurements have been applied to a class of composite porous electrode structures based on platinum black, Teflon, and a metal screen current collector. They have been shown to correlate with electrochemical performance on the basis of exponential relationships of the type i=aexp)(normalbS or bσV where i is the current or limiting current density based on the geometric electrode area, S is the total (BET) surface area, σV is the cumulative micropore volume, and a and b are constants depending on the type of electrode and experimental conditions. The electrochemical performance of the electrodes was shown to increase with an increase in the percentage of total open (i.e., accessible) porosity consisting of micropores. It is not clear, at present, whether the relative importance of the micro‐ and macro‐pore structures is actually conducive to maximum or asymptote‐type of optimum structure, since no macropore size distribution data are now available. Within the micro‐ pore range of 25–350Aå pore radius it was shown that the range 25–200 is performance‐determining for the class of composite electrode that was studied.

show abstract

Preparation and Surface Area Measurements of Platinized-Platinum Electrodes

Cited by 12 publications

References 13 publications

Conductive-Matrix-Mediated Alkaline Fe(III/VI) Charge Transfer: Three-Electron Storage, Reversible Super-Iron Thin Film Cathodes

Conductive-Matrix-Mediated Alkaline Fe(III/VI) Charge Transfer: Three-Electron Storage, Reversible Super-Iron Thin Film Cathodes

Enhancement of Reversible Nonaqueous Fe(III/VI) Cathodic Charge Transfer

Structural Studies of Porous Electrodes

Contact Info

Product

Resources

About