In situ investigation of pore clogging during discharge of a Li/O2 battery by electrochemical impedance spectroscopy
| Autor: | Olga Yezerska, Matthias Augustin, Daniela Fenske, Arne Wittstock, Ingo Bardenhagen, Marcus Bäumer |
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| Rok vydání: | 2015 |
| Předmět: |
Battery (electricity)
Materials science Renewable Energy Sustainability and the Environment Analytical chemistry Energy Engineering and Power Technology chemistry.chemical_element Electrochemistry Cathode Dielectric spectroscopy Anode law.invention chemistry law Electrode Lithium Electrical and Electronic Engineering Physical and Theoretical Chemistry Mesoporous material |
| Zdroj: | Journal of Power Sources. 278:255-264 |
| ISSN: | 0378-7753 |
| DOI: | 10.1016/j.jpowsour.2014.12.076 |
| Popis: | The behavior of three gas diffusion electrodes (GDE) with macro- and mesopores is investigated by in situ electrochemical impedance spectroscopy (EIS) in the Li/O2 battery system while discharging. Using a three electrode setup the current response from the anode (Li metal) and cathode (GDE) can be separated and the changes of the electrochemical processes at the GDE during discharge can be observed, exclusively. We identify up to four processes with different time constants which we assign to the lithium ion migration through a surface layer, the charge-transfer from the carbon surface to the molecular oxygen, the lithium ion and oxygen diffusion towards the cathode surface and, in case of the mesoporous materials, the lithium ion movement inside the pores, along the pore axis. The latter finding reflects that pore clogging of such is a limiting factor for the discharge of the Li/O2 battery. A large mesopore volume as in the xerogel electrode, however, allows for a high storage capability and a long and constant oxygen reduction. We demonstrate that the three electrode EIS proves to be a powerful in situ diagnostic tool to determine the state and, hence, the reversibility of the reactions at the cathode. |
| Databáze: | OpenAIRE |
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