J. Geiser, H. Natter, R. Hempelmann, B. Morgenstern, K. Hegetschweiler
{"title":"钒氧化还原液流电池中电荷状态的光度法测定第一部分:与电位滴定法的结合","authors":"J. Geiser, H. Natter, R. Hempelmann, B. Morgenstern, K. Hegetschweiler","doi":"10.1515/zpch-2019-1379","DOIUrl":null,"url":null,"abstract":"Abstract The stepwise oxidation of vanadium ions in electrolytes, as used in all vanadium redox flow batteries (VRFB), is studied offline by a combination of potentiometric titration and simultaneous UV/Vis/NIR spectroscopy. Eight different total vanadium concentrations between 0.2 mol L−1 and 1.6 mol L−1 have been investigated. The analyte (titrand, V2+ solution) is the anolyte (V2+/V3+ side) of a fully charged laboratory vanadium redox flow battery (VRFB). Absorption maxima are observed at λ = 850 nm for V2+ and at λ = 400 nm for V3+, the corresponding absorption coefficients are determined. In the former case an extrapolation procedure is necessary because during transfer from the VRFB to the titration cell, oxidation to V3+ by ambient oxygen cannot completely be avoided. Based on the knowledge of the absorption coefficients, via simultaneous photometry of V2+ and V3+, the state-of-charge of the anolyte of a VRFB can be determined. In the catholyte (V4+/V5+ side) of a VRFB the formation of an intermediate mixed valence VIV–VV complex at large vanadium concentration prevents a simple photometric SOC determination.","PeriodicalId":23847,"journal":{"name":"Zeitschrift für Physikalische Chemie","volume":"134 7 1","pages":"1683 - 1694"},"PeriodicalIF":0.0000,"publicationDate":"2019-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"15","resultStr":"{\"title\":\"Photometrical Determination of the State-of-Charge in Vanadium Redox Flow Batteries Part I: In Combination with Potentiometric Titration\",\"authors\":\"J. Geiser, H. Natter, R. Hempelmann, B. Morgenstern, K. Hegetschweiler\",\"doi\":\"10.1515/zpch-2019-1379\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Abstract The stepwise oxidation of vanadium ions in electrolytes, as used in all vanadium redox flow batteries (VRFB), is studied offline by a combination of potentiometric titration and simultaneous UV/Vis/NIR spectroscopy. Eight different total vanadium concentrations between 0.2 mol L−1 and 1.6 mol L−1 have been investigated. The analyte (titrand, V2+ solution) is the anolyte (V2+/V3+ side) of a fully charged laboratory vanadium redox flow battery (VRFB). Absorption maxima are observed at λ = 850 nm for V2+ and at λ = 400 nm for V3+, the corresponding absorption coefficients are determined. In the former case an extrapolation procedure is necessary because during transfer from the VRFB to the titration cell, oxidation to V3+ by ambient oxygen cannot completely be avoided. Based on the knowledge of the absorption coefficients, via simultaneous photometry of V2+ and V3+, the state-of-charge of the anolyte of a VRFB can be determined. In the catholyte (V4+/V5+ side) of a VRFB the formation of an intermediate mixed valence VIV–VV complex at large vanadium concentration prevents a simple photometric SOC determination.\",\"PeriodicalId\":23847,\"journal\":{\"name\":\"Zeitschrift für Physikalische Chemie\",\"volume\":\"134 7 1\",\"pages\":\"1683 - 1694\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2019-03-09\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"15\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Zeitschrift für Physikalische Chemie\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1515/zpch-2019-1379\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Zeitschrift für Physikalische Chemie","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1515/zpch-2019-1379","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Photometrical Determination of the State-of-Charge in Vanadium Redox Flow Batteries Part I: In Combination with Potentiometric Titration
Abstract The stepwise oxidation of vanadium ions in electrolytes, as used in all vanadium redox flow batteries (VRFB), is studied offline by a combination of potentiometric titration and simultaneous UV/Vis/NIR spectroscopy. Eight different total vanadium concentrations between 0.2 mol L−1 and 1.6 mol L−1 have been investigated. The analyte (titrand, V2+ solution) is the anolyte (V2+/V3+ side) of a fully charged laboratory vanadium redox flow battery (VRFB). Absorption maxima are observed at λ = 850 nm for V2+ and at λ = 400 nm for V3+, the corresponding absorption coefficients are determined. In the former case an extrapolation procedure is necessary because during transfer from the VRFB to the titration cell, oxidation to V3+ by ambient oxygen cannot completely be avoided. Based on the knowledge of the absorption coefficients, via simultaneous photometry of V2+ and V3+, the state-of-charge of the anolyte of a VRFB can be determined. In the catholyte (V4+/V5+ side) of a VRFB the formation of an intermediate mixed valence VIV–VV complex at large vanadium concentration prevents a simple photometric SOC determination.