Parameters influencing the ratio between electrochemically formed α- and β-PbO2
| Autor: | Elisabet Ahlberg, Bo Berghult, Ingela Petersson |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Renewable Energy
Sustainability and the Environment Scanning electron microscope Inorganic chemistry Active surface area Energy Engineering and Power Technology Lead dioxide Crystal structure Perchlorate chemistry.chemical_compound chemistry Electrode Electrical and Electronic Engineering Physical and Theoretical Chemistry Porosity Powder diffraction |
| Zdroj: | Journal of Power Sources. 76:98-105 |
| ISSN: | 0378-7753 |
| DOI: | 10.1016/s0378-7753(98)00145-1 |
| Popis: | The interparticle contact is an important aspect for the capacity of all lead dioxide electrodes. It can be discussed with respect to the ratio of the two lead dioxide phases, α- and β-PbO 2 . Of the two phases the α-PbO 2 has a more compact structure compared to the more porous β-PbO 2 , resulting in a better contact between the particles. It has previously been shown that different perchlorate salts have an influence on the discharge properties, the self discharge and the active surface area of formed PbO 2 . The results were attributed to crystal structure defects caused by the cations and it was suggested that different cations may influence the ratio between α- and β-PbO 2 resulting in different discharge properties. In the present study, structural changes of electrochemically formed lead dioxide were studied as a function of formation time, current, porosity, interparticle contact, and electrolyte cation by X-ray powder diffraction and scanning electron microscopy (SEM). Three different electrode thicknesses 100, 200 and 400 μm were investigated at two current densities and with four perchlorate salts, KClO 4 , NaClO 4 , LiClO 4 and HClO 4 . The initial results indicate that the ratio of α/(α+β) increased when a larger cation was used in the order H + + + + . The ratio of lead sulfate PbSO 4 /(α+β) in the sample seems to decrease both with a decreased cation and with an increased electrode thickness. |
| Databáze: | OpenAIRE |
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