Self-discharge mechanism of high-voltage KVPO4F for K-ion batteries
| Autor: | Romain Wernert, Long H.B. Nguyen, Antonella Iadecola, François Weill, François Fauth, Laure Monconduit, Dany Carlier, Laurence Croguennec |
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| Přispěvatelé: | Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut Charles Gerhardt Montpellier - Institut de Chimie Moléculaire et des Matériaux de Montpellier (ICGM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Université de Montpellier (UM), Réseau sur le stockage électrochimique de l'énergie (RS2E), Aix Marseille Université (AMU)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Collège de France (CdF (institution))-Université de Picardie Jules Verne (UPJV)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Pau et des Pays de l'Adour (UPPA)-Institut de Chimie du CNRS (INC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Université Grenoble Alpes (UGA)-Nantes Université (Nantes Univ)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM), Advanced Lithium Energy Storage Systems - ALISTORE-ERI (ALISTORE-ERI), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), ALBA-CELLS, This work was part of the TROPIC project supported by the Agence Nationale de la Recherche (ANR) under the grant ANR-19-CE05-0026. ANR is also acknowledged for funding the RS2E network through the STORE-EX Labex Project ANR-10-LABX-76-01. Synchrotron Soleil (France) is acknowledged for providing in-house beamtime at the beamline ROCK, which also benefits from an ANR grant as part of the 'Investissements d’Avenir' program ANR-10-EQPX-45., ANR-19-CE05-0026,TROPIC,Vers des batteries innovantes K-ion(2019), ANR-10-LABX-0076,STORE-EX,Laboratory of excellency for electrochemical energy storage(2010) |
| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: |
Chemical deintercalation
Vanadium phosphate fluoride Potassium-ion battery Materials Chemistry Electrochemistry Energy Engineering and Power Technology Chemical Engineering (miscellaneous) [CHIM.MATE]Chemical Sciences/Material chemistry Electrical and Electronic Engineering Self-discharge mechanism Side reactions |
| Zdroj: | ACS Applied Energy Materials ACS Applied Energy Materials, 2022, 5 (12), pp.14913-14921. ⟨10.1021/acsaem.2c02379⟩ |
| ISSN: | 2574-0962 |
| Popis: | International audience; Current performances of Li-, Na-, or K-ion batteries are mainly limited by the specific capacity of the positive electrode. Therefore, it is important to reach the highest capacity possible for a given electrode material. Here, we investigate the performance limitation of KVPO4F, a prospective material for K-ion batteries, which can deliver only 80% of its theoretical capacity. We discover that the capacity limitation of KVPO4F is related to a kinetic competition between K+ deinsertion and side reactions ascribed to the electrolyte degradation at high potentials. Homeotypic VPO4F can be obtained from KVPO4F through a chemical deintercalation process, which disproves a possible structural limitation or instability. The deintercalated compound was characterized by electron and X-ray diffraction, X-ray absorption spectroscopy, and nuclear magnetic resonance spectroscopy. Despite the structural stability, a spontaneous reaction occurs between the deintercalated KxVPO4F (x < 0.5) and the electrolyte (0.8 M KPF6 in ethylene carbonate/diethylene carbonate), with an electron transfer to vanadium compensated by K+ intercalation. This reaction leads to self-discharge until the open circuit potential is lower than 4.7 V versus K+/K, corresponding to the K0.5VPO4F composition. |
| Databáze: | OpenAIRE |
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