In situ dynamic Ohmic resistivity measurement of LiNi1−yCoyO2 cathodes as a function of the state of discharge
| Autor: | S. Vassilev, I. Bakalova, R.V. Moshtev, P. Zlatilova |
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| Rok vydání: | 2002 |
| Předmět: |
Yield (engineering)
Renewable Energy Sustainability and the Environment Chemistry Analytical chemistry Energy Engineering and Power Technology Reference electrode Cathode law.invention Electrical resistivity and conductivity law Electrode Electrical and Electronic Engineering Physical and Theoretical Chemistry Atomic physics Ohmic contact Voltage drop Voltage |
| Zdroj: | Journal of Power Sources. 111:39-42 |
| ISSN: | 0378-7753 |
| DOI: | 10.1016/s0378-7753(02)00226-4 |
| Popis: | A method for the in situ dynamic measurement of the Ohmic resistivity, Rc, of LiNi1−y CoyO2 cathodes as a function of the state of discharge, x, is developed. It follows the evolution of Rc with only a negligible interference of the discharge process by applying 6–10 short current interruptions and by recording the voltage transients between the cathode and a Li/Li+ reference electrode. It was established with several tens of different LiNi1−yCoyO2 cathodes that the area-specific Ohmic resistivity remains constant in a wide range of x, from 0 up to ca. 0.75, above which a steep linear rise of Rc is observed. This behaviour is in agreement with the expression of the redox potential of the Li insertion electrodes as a function of x proposed by Armand [1] and developed later by Ohzuku et al. [2] . In addition to the logarithmic Volmer–Tafel term this expression contains a linear one kx, which accounts for the close range in layer Li–Li interaction. The parameters of the Rc/x plots can yield valuable information for the effect of the cathode design as well of the cathode active material on the cyclig performance of the cathodes. |
| Databáze: | OpenAIRE |
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