PDF Publication Title:
Text from PDF Page: 041
3 Electrode modifications The effectiveness of bismuth deposition was improved by etching carbon felt with KOH before depositing bismuth nanoparticles. The etching produced micropores and oxygen-containing surface groups that increased bismuth deposition. The KOH etched and bismuth deposited electrodes returned smaller peak separations in cyclic voltammograms (CVs) and reduced charge transfer resistance as measured by EIS. An energy efficiency of 79.3% was achieved at a current density of 160 mAcm−2, which was 36.2% higher than with an unmodified carbon felt electrode [106]. Another group electrodeposited bismuth nanoparticles onto graphite felt and observed improved kinetics from cyclic voltammetry. They proposed that Bi nanoparticles form an intermediate BiHx, which in turn reduces V3+ to V2+, subsequently inhibiting the formation of hydrogen and improving coulombic efficiency [101]. In addition to bismuth, tin was deposited in-situ by dissolving 0.02 M or less into the negative vanadium electrolyte. As the tin is deposited a clear increase in kinetics was observed during cyclic voltammetry [98]. Using a similar in-situ electrodeposition method, antimony (Sb3+ ions) were added to the vanadium electrolyte solution. An optimal concentration of 5 mM was found and as the Sb3+ ions were reduced onto the negative electrode, a decrease in the charge transfer resistance was measured by EIS. The energy efficiency of the cell was increased to 67.1% from 57.5% at a current density of 120 mAcm−2 to 67.1% [107]. Surface Area and Roughness Effects Bismuth nanoparticles 35-50 nm in diameter were attached to graphite felt by immersion in a Bi2O3 solution, with a 1% loading by weight achieved after immersion. The felt was then treated thermally at 450 oC in air for 3 hours and the surface area increased from 0.92 m2g−1 for a thermally treated graphite felt, to 3.36 m2g−1 for the felt that was immersed in bismuth and then thermally treated. It was hypothesized that the bismuth nanoparticles catalysed the oxidation of the graphite felt. An increase in electrode conductivity was also observed, contributing to the improved performance [103]. 29PDF Image | Electron Transfer Kinetics in Redox Flow Batteries
PDF Search Title:
Electron Transfer Kinetics in Redox Flow BatteriesOriginal File Name Searched:
electron-transfer-flow-batteries-thesis.pdfDIY PDF Search: Google It | Yahoo | Bing
Salgenx Redox Flow Battery Technology: Salt water flow battery technology with low cost and great energy density that can be used for power storage and thermal storage. Let us de-risk your production using our license. Our aqueous flow battery is less cost than Tesla Megapack and available faster. Redox flow battery. No membrane needed like with Vanadium, or Bromine. Salgenx flow battery
| CONTACT TEL: 608-238-6001 Email: greg@salgenx.com | RSS | AMP |