| 1. |
- Liu, Jia, et al.
(författare)
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An Organic Catalyst for Li-O-2 Batteries : Dilithium Quinone-1,4-Dicarboxylate
- 2015
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Ingår i: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 8:13, s. 2198-2203
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Tidskriftsartikel (refereegranskat)abstract
- Solid organic electrocatalysts have hardly been tested in Li-O-2 batteries. Here, a new solid organic electrocatalyst, dilithium quinone-1,4-dicarboxylate (Li2C8H2O6) is presented, which is expected to overcome the shortcomings of inorganic catalysts. The function-oriented synthesis is low cost and low polluting. The electrocatalytic performance is evaluated by following the degradation of Li2O2 during the charge process in a Li-O-2 cell through insitu XRD and operando synchrotron radiation powder XRD (SR-PXD) measurements. The results indicate that the electrocatalytic activity of Li2C8H2O6 is similar to that of commercial Pt. The Li2O2 decomposition in a cell with Li2C8H2O6 catalyst follows a pseudo-zero-order reaction, virtually without any side reactions. These results provide an insight into the development of new organic catalysts for the oxygen evolution reaction (OER) in Li-O-2 batteries.
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| 2. |
- Mihali, Viorica Alina, et al.
(författare)
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Benzenediacrylates as organic battery electrode materials : Na versus Li
- 2014
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 4:72, s. 38004-38011
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Tidskriftsartikel (refereegranskat)abstract
- This paper discusses investigations of a novel Na-based organic battery electrode material, disodium benzenediacrylate (Na(2)BDA) in comparison with its Li-ion homologue. Li(2)BDA has previously shown promising battery properties, such as stable cycling and good capacity retention. Na(2)BDA and Li(2)BDA are here successfully synthesized and characterized, and investigated as anode materials in prototype Na- and Li-ion battery cells. Moreover, different electrolytes are screened for the Na-battery material, and a useful operating voltage window is explored. Na(2)BDA is shown to possess a higher initial coulombic efficiency (91%) than the Li-homologue, which is uncommon for sodiated organic electrode materials. The Na-compound shows an initial capacity of 177.7 mA h g(-1), which however decreases to ca. 50 mA h g(-1) after 20-100 cycles depending on the cycling rate; a significantly lower capacity retention then that observed for Li(2)BDA. The capacity loss can primarily be explained by a decomposition mechanism of the Na(2)BDA compound.
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| 3. |
- Oltean, Alina, 1987-
(författare)
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Building Sustainable Batteries : Organic electrodes based on Li- and Na-benzenediacrylate
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As possible alternatives to the conventional inorganic Li- or Na-ion battery electrode materials, organic compounds have recently drawn considerable attention. However, major challenges such as poor electronic conductivity, solubility in battery electrolyte or fast capacity decay of the resulting electrochemical cells are some of the reasons that hold these compounds back from becoming commercial solutions in the energy system.The goal of this thesis work was to investigate the background to these phenomena and find strategies for improvements. Two different compounds were studied: dilithium and disodium benzenediacrylate, in their respective cells. First, improving the performance of the dilithium compound was performed by applying different electrode fabrication strategies. A freeze-drying technique was combined with carbon coating in the liquid state, which rendered an improved electrode morphology. Moreover, when using the compound in pouch cell format instead of Swagelok® cells, a different technique was applied: calendaring. Successful results were obtained both in half-cells and in full-cells when the compound was cycled versus LiFePO4-based cathodes. Second, the sodium analogue was investigated, and while the synthesis of this compound is straightforward, the electrochemical performance in Na-ion battery cells displays an unexpected degree of complexity. The compound displays a considerably faster capacity decrease in comparison to the Li compound, and generally a poor chemical stability in the applied system. When cycled at higher currents (C-rates of C/4 or C/10, in comparison to C/40), the compound presents an capacity increase while the Li decreases, likely due to a chemical process more dependent on time than on the number of cycles for the Na compound.The fast capacity decay in the first cycles of these types of compounds is often considered to be related to the Solid Electrolyte Interphase (SEI) layer formation. Its study was also performed and it was concluded that the Na compound has a thicker SEI layer in comparison to the Li counterpart, and mostly consisted of inorganic species such as the electrolyte salt and its decomposition products. Finally, a concept for a sustainable manufacturing and recycling process of a hybrid full cell is also performed with positive results.Although the organic compounds cannot yet outperform the inorganic compounds used commercially in Li-ion batteries, important steps towards their employment in the energy system have been taken in this thesis work.
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| 4. |
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| 5. |
- Oltean, Viorica Alina, et al.
(författare)
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Enhanced performance of organic materials for lithium-ion batteries using facile electrode calendaring techniques
- 2016
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Ingår i: Electrochemistry communications. - : Elsevier BV. - 1388-2481 .- 1873-1902. ; 68, s. 45-48
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Tidskriftsartikel (refereegranskat)abstract
- A simple and convenient strategy for achieving higher capacities in organic electrode materials used in pouch-cell format is presented here. By calendaring of the electrodes, the resulting electrode porosity can be tailored. It is shown for carboxylate electrodes of dilithium benzenediacrylate that a 30% porosity constitutes the best compromise between electronic wiring, particle contact and electrolyte infiltration into the electrodes, displaying higher capacities than in Swagelock cells.
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| 6. |
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| 7. |
- Oltean, Viorica Alina, et al.
(författare)
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Investigating the Interfacial Chemistry of Organic Electrodes in Li- and Na-Ion Batteries
- 2016
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Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 28:23, s. 8742-8751
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Tidskriftsartikel (refereegranskat)abstract
- Organic compounds are increasingly being investigated as electrode materials for Li- or Na-ion batteries. Even though their gravimetric capacity can challenge that of their inorganic counterparts, a number of problems need further attention, not least their chemical and electrochemical stability toward the electrolyte systems. There has been speculation that several of these issues have their origin in the formation of a less stable solid electrolyte interphase (SEI) layer and its evolution during battery cycling. We here present the very first thorough characterization of the organic electrode material SEI layer using hard X-ray photoelectron spectroscopy (HAXPES), for both Li- and Na-based electrodes. Dilithium and disodium benzenediacrylates have been used for battery construction and investigated electrochemically followed by HAXPES measurements electrolyte and after cycling. The Na-based electrodes react spontaneously with the electrolyte, and the SEI layer is dominated by inorganic species with continuous salt degradation during cycling. The Li-based electrodes display an SEI layer with primarily organic species from solvent degradation products appearing only after cycling and increasing in amount with the number of electrochemical cycles.
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| 8. |
- Oltean, Viorica-Alina, et al.
(författare)
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Sustainable Materials for Sustainable Energy Storage : Organic Na Electrodes
- 2016
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Ingår i: Materials. - : MDPI AG. - 1996-1944 .- 1996-1944. ; 9:3
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Forskningsöversikt (refereegranskat)abstract
- In this review, we summarize research efforts to realize Na-based organic materials for novel battery chemistries. Na is a more abundant element than Li, thereby contributing to less costly materials with limited to no geopolitical constraints while organic electrode materials harvested from biomass resources provide the possibility of achieving renewable battery components with low environmental impact during processing and recycling. Together, this can form the basis for truly sustainable electrochemical energy storage. We explore the efforts made on electrode materials of organic salts, primarily carbonyl compounds but also Schiff bases, unsaturated compounds, nitroxides and polymers. Moreover, sodiated carbonaceous materials derived from biomasses and waste products are surveyed. As a conclusion to the review, some shortcomings of the currently investigated materials are highlighted together with the major limitations for future development in this field. Finally, routes to move forward in this direction are suggested.
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| 9. |
- Pereira de Carvalho, Rodrigo, et al.
(författare)
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Structure-property relationships in organic battery anode materials : exploring redox reactions in crystalline Na- and Li-benzene diacrylate using combined crystallography and density functional theory calculations
- 2021
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Ingår i: Materials Advances. - : Royal Society of Chemistry. - 2633-5409. ; 2:3, s. 1024-1034
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Tidskriftsartikel (refereegranskat)abstract
- Organic-based materials are potential candidates for a new generation of sustainable and environmentally friendly battery technologies, but insights into the structural, kinetic and thermodynamic properties of how these compounds lithiate or sodiate are currently missing. In this regard, benzenediacrylates (BDAs) are here investigated for application as low-potential electrodes in Na-ion and Li-ion batteries. Aided by a joint effort of theoretical and experimental frameworks, we unveil the structural, electronic and electrochemical properties of the Na(2)BDA and Li(2)BDA compounds. The crystal structure of these systems in their different sodiated and lithiated phases have been predicted by an evolutionary algorithm interplayed with density functional theory calculations. Due to difficulties in obtaining useful single crystals for the BDA salts, other methods have been explored in combination with the computational approach. While the predicted structure of the pristine Na(2)BDA compound has been experimentally confirmed through the 3D Electron Diffraction (3DED) technique, the hydrated version of Li(2)BDA is analysed through single crystal X-ray diffraction. The calculated cell voltages for the sodiation (0.63 V vs. Na/Na+) and lithiation (1.12 V vs. Li/Li+) processes display excellent quantitative agreement with experimental findings. These results validate the developed theoretical methodology. Moreover, fundamental aspects of the electronic structures and their relationship with the reaction thermodynamics are discussed. The results suggest a possible disproportionation between the sodiated phases of Na(2)BDA, supporting a two-electron process, and also unveil major differences for the two employed cations: Na+ and Li+.
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| 10. |
- Poizot, Philippe, et al.
(författare)
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Perspectives in Lithium Batteries
- 2015
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Ingår i: Lithium Process Chemistry. - : Elsevier. - 9780128014172 ; , s. 233-268
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Bokkapitel (refereegranskat)
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