| 1. |
- Liu, Tao, et al.
(author)
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Understanding LiOH Formation in a Li-O2 Battery with LiI and H2O Additives
- 2019
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In: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 9:1, s. 66-77
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Journal article (peer-reviewed)abstract
- LiI-promoted LiOH formation in Li-O2 batteries with wet ether electrolytes has been investigated by Raman, nuclear magnetic resonance spectroscopy, operando pressure tests, and molecular dynamics simulations. We find that LiOH formation is a synergistic effect involving both H2O and LiI additives, whereas with either alone Li2O2 forms. LiOH is generated via a nominal four-electron oxygen reduction reaction, the hydrogen coming from H2O and the oxygen from both O2 and H2O, and with fewer side reactions than typically associated with Li2O2 formation; the presence of fewer parasitic reactions is attributed to the proton donor role of water, which can coordinate to O2- and the higher chemical stability of LiOH. Iodide plays a catalytic role in decomposing H2O2/HO2- and thereby promoting LiOH formation, its efficacy being highly dependent on the water concentration. This iodide catalysis becomes retarded at high water contents due to the formation of large water-solvated clusters, and Li2O2 forms again.
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| 2. |
- Quesnel, Etienne, et al.
(author)
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Graphene-based technologies for energy applications, challenges and perspectives
- 2015
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In: Current Opinion in Chemical Engineering. - : IOP Publishing. - 2211-3398. ; 2:3, s. 1-16
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Journal article (peer-reviewed)abstract
- Here we report on technology developments implemented into the Graphene Flagship European project for the integration of graphene and graphene-related materials (GRMs) into energy application devices. Many of the technologies investigated so far aim at producing composite materials associating graphene or GRMs with either metal or semiconducting nanocrystals or other carbon nanostructures (e.g., CNT, graphite). These composites can be used favourably as hydrogen storage materials or solar cell absorbers. They can also provide better performing electrodes for fuel cells, batteries, or supercapacitors. For photovoltaic (PV) electrodes, where thin layers and interface engineering are required, surface technologies are preferred. We are using conventional vacuum processes to integrate graphene as well as radically new approaches based on laser irradiation strategies. For each application, the potential of implemented technologies is then presented on the basis of selected experimental and modelling results. It is shown in particular how some of these technologies can maximize the benefit taken from GRM integration. The technical challenges still to be addressed are highlighted and perspectives derived from the running works emphasized.
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| 3. |
- Temprano, Israel, et al.
(author)
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Toward Reversible and Moisture-Tolerant Aprotic Lithium-Air Batteries
- 2020
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In: Joule. - : Elsevier BV. - 2542-4351. ; 4:11, s. 2501-2520
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Journal article (peer-reviewed)abstract
- The development of moisture-tolerant, LiOH-based non-aqueous Li-O2 batteries is a promising route to bypass the inherent limitations caused by the instability of their typical discharge products, LiO2 and Li2O2. The use of the I−/I3− redox couple to mediate the LiOH-based oxygen reduction and oxidation reactions has proven challenging due to the multiple reaction paths induced by the oxidation of I− on cell charging. In this work, we introduce an ionic liquid to a glyme-based electrolyte containing LiI and water and demonstrate a reversible LiOH-based Li-O2 battery cycling that operates via a 4 e−/O2 process with a low charging overpotential (below 3.5 V versus Li/Li+). The addition of the ionic liquid increases the oxidizing power of I3−, shifting the charging mechanism from IO−/IO3− formation to O2 evolution.
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