| 1. |
- Araujo, Rafael B., et al.
(författare)
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Assessing Electrochemical Properties of Polypyridine and Polythiophene for Prospective Application in Sustainable Organic Batteries
- 2017
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - 1463-9076 .- 1463-9084. ; 19:4, s. 3307-3314
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Tidskriftsartikel (refereegranskat)abstract
- Conducting polymers are being considered promising candidates for sustainable organic batteries mainly due to their fast electron transport properties and high recyclability. In this work, key properties of polythiophene and polypyridine have been assessed through a combined theoretical and experimental study focusing on such applications. A theoretical protocol has been developed to calculate redox potentials in solution within the framework of the density functional theory and using continuous solvation models. Here, the evolution of the electrochemical properties of solvated oligomers as a function of the length of the chain is analyzed and then the polymer properties are estimated via linear regressions using ordinary least square. The predicted values were verified against our electrochemical experiments. This protocol can now be employed to screen a large database of compounds in order to identify organic electrodes with superior properties.
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| 2. |
- Araujo, Rafael B., et al.
(författare)
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Designing strategies to tune reduction potential of organic molecules for sustainable high capacity batteries application
- 2017
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Ingår i: Journal of Materials Chemistry A. - 2050-7488 .- 2050-7496. ; 5:9, s. 4430-4454
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Tidskriftsartikel (refereegranskat)abstract
- Organic compounds evolve as a promising alternative to the currently used inorganic materials in rechargeable batteries due to their low-cost, environmentally friendliness and flexibility. One of the strategies to reach acceptable energy densities and to deal with the high solubility of known organic compounds is to combine small redox active molecules, acting as capacity carrying centres, with conducting polymers. Following this strategy, it is important to achieve redox matching between the chosen molecule and the polymer backbone. Here, a synergetic approach combining theory and experiment has been employed to investigate this strategy. The framework of density functional theory connected with the reaction field method has been applied to predict the formal potential of 137 molecules and identify promising candidates for the referent application. The effects of including different ring types, e.g. fused rings or bonded rings, heteroatoms, [small pi] bonds, as well as carboxyl groups on the formal potential, has been rationalized. Finally, we have identified a number of molecules with acceptable theoretical capacities that show redox matching with thiophene-based conducting polymers which, hence, are suggested as pendent groups for the development of conducting redox polymer based electrode materials.
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| 3. |
- Banerjee, Amitava, et al.
(författare)
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Identifying the tuning key of disproportionation redox reaction in terephthalate : A Li-based anode for sustainable organic batteries
- 2018
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Ingår i: Nano Energy. - : Elsevier BV. - 2211-2855 .- 2211-3282. ; 47, s. 301-308
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Tidskriftsartikel (refereegranskat)abstract
- The ever-increasing consumption of energy storage devices has pushed the scientific community to realize strategies toward organic electrodes with superior properties. This is owed to advantages such as economic viability and eco-friendliness. In this context, the family of conjugated dicarboxylates has emerged as an interesting candidate for the application as negative electrodes in advanced Li-ion batteries due to the revealed thermal stability, rate capability, high capacity and high cyclability. This work aims to rationalize the effects of small molecular modifications on the electrochemical properties of the terephthalate anode by means of first principles calculations. The crystal structure prediction of the investigated host compounds dilithium terephthalate (Li2TP) and diethyl terephthalate (Et2Li0TP) together with their crystal modification upon battery cycling enable us to calculate the potential profile of these materials. Distinct underlying mechanisms of the redox reactions were obtained where Li2TP comes with a disproportionation reaction while Et2Li0TP displays sequential redox reactions. This effect proved to be strongly correlated to the Li coordination number evolution upon the Li insertion into the host structures. Finally, the calculations of sublimation enthalpy inferred that polymerization techniques could easily be employed in Et2Li0TP as compared to Li2TP. Similar results are observed with methyl, propyl, and vinyl capped groups. That could be a strategy to enhance the properties of this compound placing it into the gallery of the new anode materials for state of art Li-batteries.
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| 4. |
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| 5. |
- Emanuelsson, Rikard, et al.
(författare)
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An All-Organic Proton Battery
- 2017
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 139:13, s. 4828-4834
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Tidskriftsartikel (refereegranskat)abstract
- Rechargeable batteries that use organic matter as. the capacity-carrying material have previously been considered a technology for the future. Earlier batteries in which both the anode and cathode consisted of organic material required significant amounts of conductive additives and were often based on metal-ion electrolytes containing Li+ or Na+. However, we have used conducting poly(3,4-ethylenedioxythiophene) (PEDOT), functionalized with anthraquinone (PEDQT-AQ) or, benzonquinone (PEDOT-BQ) pendant groups as the negative and positive electrode materials, respectively, to make an all-organic proton battery devoid of metals. The electrolyte consists of a proton donor and acceptor slurry containing substituted pyridinium triflates and the corresponding pyridine base. This slurry allows the 2e(-)/2H(+) quinone/hydroquinone redox reactions while suppressing proton reduction in the battery cell. By using strong (acidic) proton donors, the formal potential of the quinone redox reactions is tuned into the potential region in which the PEDOT backbone is conductive, thus eliminating the need for conducting additives. In this all-organic proton battery cell, PEDOT-AQ and PEDOT-BQ deliver 103 and 120 mAh g(-1), which correspond to 78% and 75%, respectively, of the theoretical specific capacity of the materials at an average cell potential of 0.5 V. We show that PEDOT-BQ determines the cycling stability of the device while PEDOT-AQ provides excellent reversibility for at least 1000 cycles. This proof-of-concept shows the feasibility of assembling all organic proton batteries which require no conductive additives and also reveals where the challenges and opportunities lie on the path to producing plastic batteries.
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| 6. |
- Emanuelsson, Rikard, et al.
(författare)
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Quinone based conducting redox polymers for electrical energy storage
- 2017
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Ingår i: Russian journal of electrochemistry. - : MAIK NAUKA/INTERPERIODICA/SPRINGER. - 1023-1935 .- 1608-3342. ; 53:1, s. 8-15
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Tidskriftsartikel (refereegranskat)abstract
- Conducting redox polymers (CRPs) constitute a promising class of materials for the development of organic matter based batteries with the potential to overcome the main limitations connected to this type of rechargeable battery systems including low conductivity and dissolution problems. In this report we show that the potential of quinones can be effectively tuned into the conducting region of polypyrrole (PPy), both in water based solutions and in acetonitrile, which is a prerequisite for profitable combination of the two units. We also present a device where both anode and cathode are made from PPy substituted with different quinone pendant groups and where good rate performance is achieved without any conductivity additives thus providing support for the hypothesized synergetic effect of a conducting polymer backbone and a covalently attached redox active pendant group. This device constitutes, to the best of our knowledge, the first all-CRP based battery reported to date.
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| 7. |
- Emanuelsson, Rikard, et al.
(författare)
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Quinone based conducting redox polymers for electrical energy storage
- 2017
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Ingår i: Elektrokhimiya. - : MAIK NAUKA/INTERPERIODICA. - 0424-8570. ; 53:1, s. 11-20
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Tidskriftsartikel (refereegranskat)abstract
- Conducting redox polymers (CRPs) constitute a promising class of materials for the development of organic matter based batteries with the potential to overcome the main limitations connected to this type of rechargeable battery systems including low conductivity and dissolution problems. In this report we show that the potential of quinones can be effectively tuned into the conducting region of polypyrrole (PPy), both in water based solutions and in acetonitrile, which is a prerequisite for profitable combination of the two units. We also present a device where both anode and cathode are made from PPy substituted with different quinone pendant groups and where good rate performance is achieved without any conductivity additives thus providing support for the hypothesized synergetic effect of a conducting polymer backbone and a covalently attached redox active pendant group. This device constitutes, to the best of our knowledge, the first all-CRP based battery reported to date.
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| 8. |
- Fernández-Benito, A., et al.
(författare)
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Multifunctional metal-free rechargeable polymer composite nanoparticles boosted by CO2
- 2020
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Ingår i: Materials Today Sustainability. - : Elsevier BV. - 2589-2347. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we present a multigram scale-up route for the preparation of novel polymer composite nanoparticles as potential multifunctional rechargeable material for future, sustainable batteries. The nanoparticles (20 nm) comprise three innocuous yet functional interpenetrated macromolecular networks: polypyrrole, methylcellulose, and lignin. They are uniquely assembled in strands or chains (∌200 nm) such as necklace beads and show long-term stability as water dispersion. We find that an aqueous suspension of this hierarchical nanomaterial shows two sets of reversible redox peaks, separated by ∌600 mV, originating from the catechol moieties present in the lignin biopolymer. Remarkably, the addition of carbon dioxide increased the capacity of one of the redox processes by 500%. Importantly, the three redox stages occur in the presence of the same nanostructured polymer so being a potentially bifunctional material to be used in advanced electrochemical systems. The new properties are attributed to an intrinsic chemical and electronic coupling at the nanoscale among the different building blocks of the metal-free polymer composite and the structural rearrangement of the interpenetrated polymer network by the incorporation of CO2. We have provided both a new electrochemically multifunctional hierarchically structured material and a facile route that could lead to novel sustainable energy applications.
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| 9. |
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| 10. |
- Gaiser, Philipp, 1994-, et al.
(författare)
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Surface immobilization of molecular catalysts using conducting redox polymers
- 2022
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Konferensbidrag (refereegranskat)abstract
- Electrocatalysts play an essential role in converting electrical energy into fuel and vice versa. A wide variety of well defined molecular catalysts have been developed to catalyze key reactions like water oxidation, proton reduction, carbon dioxide reduction etc..[1] Immobilizing molecular catalyst on electrode surface combines the benefits of having a well defined catalytic center with the benefits of heterogeneous catalysts such as efficient electronic connection between the electrode and the catalytic center.[1]Having surface constrained catalytic sites and using electrochemical methods enables the investigation of catalytic reactions at various potentials and the determination of kinetic thermodynamic parameters without mass transport limitations.[1]The immobilization of molecular catalysts on an electrode surface can be achieved by incorporating them in a conducting redox polymer.[1-3] These polymers consist of a conducting polymer backbone, such as polythiophene, and covalently bound redox active pendant groups. In this poster we present the synthesis and electrochemical characterization of conducting redox polymers bearing molecular catalysts as pendant groups. Functionalized derivatives of molecular catalysts are coupled with monomeric or trimeric units of 3,4-ethylenedioxythiophene (EDOT) or 3,4-propylenedioxythiophene (ProDOT). Subsequent electro polymerization yields functionalized electrodes which are investigated by cyclic voltammetry as well as a variety of in situ methods such as UV-vis spectroscopy, and conductance measurements.[4]References [1] R. M. Bullock et al., Chem. Eur. J. 23 (2017) 7626–7641.[2] L. Wang et al. Chem., Commun. 51 (2015) 7883–7886.[3] D. Curran et al., Chem. Soc. Rev. 20 (1991) 391.[4] M. Sterby et al., Electrochimica Acta 308 (2019) 277–284.
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