Electrochemical Characterization of Carbon Anode Performance

Thorne, Rebecca Jayne; Sommerseth, Camilla; Sandnes, Espen; Kjos, Ole Sigmund; Aarhaug, Thor Anders; Lossius, Lorentz Petter; Linga, Hogne; Ratvik, Arne Petter

doi:10.1002/9781118663189.ch204

“…However, as the repeat variation was lower than the differences between materials, the overpotential trends were confirmed and were not experimental error. The order of the materials was also identical to that found in the previous paper [15]; Anode 4 had the lowest potential at 1 A cm -2 (and therefore the lowest overpotential), compared to graphite which had the highest potential. Polarisation curves additionally supported this trend, showing the same magnitude differences between anode materials at 1 A cm -2 .…”

Section: Overpotential Measurementssupporting

confidence: 68%

“…Immersed anode area was defined using boron nitride (BN) shielding. Thus, advantages over the previous anode design (from [15]) included a defined surface area to be immersed in the melt (1.5 cm 2 ), an even current distribution and a minimised bubble retention due to the vertical surface. The impact of anode geometry was directly compared by also including an unshielded graphite rod in the measurement series, as used in [15].…”

Section: Methodsmentioning

confidence: 99%

“…b. with dimensions (mm) Figure 2. The anode assembly used in [15], which was also used in this study to investigate the impact of anode geometry on electrochemical measurements. When immersed 1.5 cm in the melt, this had an approximate active anode surface area of 5.5 cm 2 .…”

Section: Methodsmentioning

confidence: 99%

“…Owing to the fact that all anodes had identical distribution of grain size and pitch type/level, these variations in potential must relate to differences in the coke properties. The effect of anode geometry was studied by comparing the new anode design with the defined vertical surface with an unshielded rod with both vertical and horizontal surfaces, as used in [15] ( Figures 1 and 2). Graphite was the anode material for both designs.…”

Section: Overpotential Measurementsmentioning

confidence: 99%

“…In a previous study that served as preliminary work on a new project, the total overpotential of a range of carbon anodes varying only in coke type was measured [15]. These anodes were labeled 1 to 4, and a distinct overpotential trend was found with anode 4 having a lower overpotential than anode 1 by approximately 200 mV at 1 A cm -2 .…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Understanding Anode Overpotential

Thorne¹,

Sommerseth²,

Svensson³

et al. 2014

Self Cite

View full text Add to dashboard Cite

In aluminium electrolysis cells the anodic process is associated with a substantial overpotential. Industrial carbon anodes are produced from a blend of coke materials, but the effect of coke type on anodic overpotential has not been well studied. In this work, lab-scale anodes were fabricated from single cokes and electrochemical methods were subsequently used to determine the overpotential trend of the anode materials. Attempts were then made to explain these trends in terms of both the physical and chemical characteristics of the baked anodes themselves and their raw materials. Routine coke and anode characterisation methods were used to measure properties such as impurity concentrations and reactivity (to air and CO 2 ), while non-routine characterisation methods were applied to study other surface and structural properties. It was found that the overpotential trend of the anodes correlated well with many of the properties studied, and explanations for these observed correlations are suggested. These findings offer exciting possibilities for reducing the energy demand of the anodic process.

show abstract

Off‐Gas Analysis of Laboratory‐Scale Electrolysis Experiments with Anodes of Various Compositions

Kjos¹,

Aarhaug²,

Skybakmoen³

et al. 2013

View full text Add to dashboard Cite

Understanding Anode Overpotential

Thorne

¹

,

Sommerseth

²

,

Svensson

³

et al. 2014

Self Cite

View full text Add to dashboard Cite

In aluminium electrolysis cells the anodic process is associated with a substantial overpotential. Industrial carbon anodes are produced from a blend of coke materials, but the effect of coke type on anodic overpotential has not been well studied. In this work, lab-scale anodes were fabricated from single cokes and electrochemical methods were subsequently used to determine the overpotential trend of the anode materials. Attempts were then made to explain these trends in terms of both the physical and chemical characteristics of the baked anodes themselves and their raw materials. Routine coke and anode characterisation methods were used to measure properties such as impurity concentrations and reactivity (to air and CO 2 ), while non-routine characterisation methods were applied to study other surface and structural properties. It was found that the overpotential trend of the anodes correlated well with many of the properties studied, and explanations for these observed correlations are suggested. These findings offer exciting possibilities for reducing the energy demand of the anodic process.

show abstract

Electrochemical Characterization of Carbon Anode Performance

Cited by 13 publications

References 7 publications

Understanding Anode Overpotential

Understanding Anode Overpotential

Off‐Gas Analysis of Laboratory‐Scale Electrolysis Experiments with Anodes of Various Compositions

Understanding Anode Overpotential

Contact Info

Product

Resources

About