dc.contributor.author | Richter, Frank | |
dc.contributor.author | Gunnarshaug, Astrid Fagertun | |
dc.contributor.author | Burheim, Odne Stokke | |
dc.contributor.author | Vie, Preben Joakim Svela | |
dc.contributor.author | Kjelstrup, Signe Helene | |
dc.date.accessioned | 2018-01-02T08:42:56Z | |
dc.date.available | 2018-01-02T08:42:56Z | |
dc.date.created | 2018-01-01T14:11:57Z | |
dc.date.issued | 2017 | |
dc.identifier.citation | ECS Transactions. 2017, 80 219-238. | nb_NO |
dc.identifier.issn | 1938-5862 | |
dc.identifier.uri | http://hdl.handle.net/11250/2473888 | |
dc.description.abstract | Heat effects are known to be crucial for the performance of the Li-battery. In addition to the irreversible effects (e.g. Joule heat), reversible heat effects may play a role. These effects, i.e. the Soret and Seebeck effects, are however scarcely investigated. We report the initial and stationary state thermoelectric potentials of a pouch cell having electrodes where Li is intercalated in CoO2. The electrolyte consists of 1.0 M lithium hexafluoro phosphate dissolved in a mixture of equal volumes of ethylene carbonate and diethyl carbonate.The two identical electrodes were thermostatted at different temperatures, the average being always 298 K and the potential was measured over several days. We observe two time-dependent phenomena with characteristic times of 4.5 and 21.3 hours. We explain them by thermal diffusion of salt and esters. The Seebeck coefficient varies from -2.8 mV/K in the initial state to 1.5 mV/K in the state characterized by partial Soret equilibrium. The time-variation of the signal is used to compute Seebeck coefficients, the contributions to the heats of transfer, and the reversible heat effect at the LiCoO2-and carbon electrodes. The electrode heat effects in a Li-battery is surprisingly asymmetric, given the small entropy of the total reaction.The LiCoO2 electrode heat varies from 51 to - 46 kJ/mol, while the carbon electrode will vary from -73 to 56 kJ/mol. Uncertainties in computations are within 15%. This may explain why the reaction entropy depends largely on the state of charge. It may also be important for thermal modeling of the battery. | nb_NO |
dc.language.iso | eng | nb_NO |
dc.publisher | Electrochemical Society | nb_NO |
dc.title | Single Electrode Entropy Change for LiCoO2 Electrodes | nb_NO |
dc.type | Journal article | nb_NO |
dc.description.version | submittedVersion | nb_NO |
dc.source.pagenumber | 219-238 | nb_NO |
dc.source.volume | 80 | nb_NO |
dc.source.journal | ECS Transactions | nb_NO |
dc.identifier.doi | 10.1149/08010.0219ecst | |
dc.identifier.cristin | 1533265 | |
dc.relation.project | Norges forskningsråd: 228739 | nb_NO |
dc.description.localcode | This is a submitted manuscript of an article published by The Electrochemical Society in ECS Transactions, Oct 4 2017 | nb_NO |
cristin.unitcode | 194,66,25,0 | |
cristin.unitcode | 194,64,25,0 | |
cristin.unitname | Institutt for kjemi | |
cristin.unitname | Institutt for energi- og prosessteknikk | |
cristin.ispublished | true | |
cristin.fulltext | preprint | |
cristin.qualitycode | 1 | |