| 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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| 11. |
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| 12. |
- Hedbom, Daniel, 1983-, et al.
(författare)
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Influences of secondary building unit and linker functionalization on the surface properties of metal-organic framework materials: Gas sorption of SF6
- 2024
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Ingår i: ACS Spring 2024New Orleans, Louisiana & HybridMarch 17 - 21, 2024. - New Orleans, La : American Chemical Society (ACS).
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Konferensbidrag (refereegranskat)abstract
- Anthropogenic greenhouse gas emissions pose a serious threat to our environment. Therefore, the development of efficient systems to mitigate these issues is of utmost importance. In recent years, Sulphur hexafluoride (SF ) has garnered increasing attention due to its global warming potential, which greatly exceeds that of CO2 on a 100-year scale.These studies were undertaken to investigate SF6 sorption in novel metal-organic framework materials (MOFs)and how their components affect their function. First, the influence of secondary building units on coordination and sorption properties (SBUs) of SF6 on Ytterbium, Thulium, Cerium and Hafnium 1,3,6,8-tetrakis(4-carboxyphenyl) pyrene-based (TBAPy4−) MOFs was investigated. Secondly, the possibility of altering surface-chemical properties by pre-synthesis fluorination/amination of UIO-67/68 isostructures was studied.In the first case, the SF6 sorption properties of four novel, highly porous 1,3,6,8-tetrakis(4-carboxyphenyl)pyrene-based (TBAPy4−) MOFs containing either Ytterbium, Thulium or Cerium all in the +3-oxidation state, orHafnium (+4) was studied. Pore size effects, coordination-effects on structure, and gas sportive propertieswere investigated and found to change and in some cases improve in the case of SF6 adsorbate.In the second case, the structures remain the same throughout these different changes, maintaining the Fmmcrystallographic space group characteristic for UIO-MOFs, enabling investigation of the effect of fluorination in isolation from other possible changes. While adding one more novel material. These changes in turn cause changes in SF6 working capacity, uptake, selectivity in simulated binary mixtures and isothermal enthalpy of adsorption. The influence of specific surface area on the isosteric enthalpy of adsorption revealed differences between functionalities.There is a multi-faceted purpose in these studies. The creation of novel structures contributes to the basic science and understanding of MOFs in general. There is the proposed use of MOFs as swing adsorption adsorbents and in CCUS or more specifically, SF6 sorption. In addition to these purposes, the insight into these material properties can pave the road to more advanced interactions downstream, such as direct air capture of water, in-site catalysis or similar applications. These diverse applications each have intricacies that can be addressed within MOFs and the scientific groundwork surrounding them.
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| 13. |
- Huang, Hao, 1988-, et al.
(författare)
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Polaron Disproportionation Charge Transport in a Conducting Redox Polymer
- 2017
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Ingår i: The Journal of Physical Chemistry C. - : AMER CHEMICAL SOC. - 1932-7447 .- 1932-7455. ; 121:24, s. 13078-13083
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Tidskriftsartikel (refereegranskat)abstract
- Herein we report a mechanistic study of the charge transport in poly-3-((2,5-hydroquinone)vinyl)-1H-pyrrole by conductance measurements at various temperatures performed in situ during doping of the polypyrrole backbone in contact with an aqueous electrolyte. Charge transport was found to occur by electron hopping with associated electron transfer activation energies in the range of 0.08-0.2 eV. In situ electron paramagnetic resonance experiments indicated polarons as the dominant charge carriers and the charge transport was found to follow a second-order dependence with respect to the number of accumulated charges. Based on the findings, we present a polaron comproportionation/disproportionation model for electron conduction in poly-3-((2,5-hydroquinone)vinyl)-1H-pyrrole, thus, providing a complement to existing models for charge propagation in conducting polymers.
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| 14. |
- Huang, Hao, 1988-, et al.
(författare)
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Potential-tuning in quinone-pyrrole dyad-based conducting redox polymers
- 2021
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Ingår i: Electrochimica Acta. - : Elsevier. - 0013-4686 .- 1873-3859. ; 389, s. 19099-19108
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Tidskriftsartikel (refereegranskat)abstract
- In this study, conducting redox polymers (CRPs), which consist of a polypyrrole conducting polymer backbone with attached quinone pendant groups, have been explored as electrode materials for organic batteries. A modular organic synthetic approach is presented that allows the assembly of pyrrole and quinone units into quinone-pyrrole dyads and modifying the dyads by varying the substitution pattern on the quinone moiety. These dyad monomers were copolymerized electrochemically with pyrrole to yield the CRPs with quinone formal potentials varying within a 0.6 V range. With access to CRP materials with tunable quinone formal potentials an all-organic water-based battery was constructed by choosing CRPs with different quinone potentials as anode and cathode material. Galvanostatic charge-discharge of the cell showed that the cell potentials coincided well with the difference in redox potential between the quinone substituents used in the anode and cathode CRP.
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| 15. |
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| 16. |
- Huang, Hao, et al.
(författare)
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Quinone Based Conducting Redox Polymers for Electric Energy Storage
- 2016
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Ingår i: ECS Meeting Abstracts 2016. ; , s. 637-637
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Konferensbidrag (refereegranskat)abstract
- Conducting redox polymers (CRP), consisting of conducing polymer (CP) and a redox active pendant group (PG) covalently linked to the CP backbone, have been suggested as electrode materials for secondary batteries. This type of material could provide an alternative to inorganic electrode materials and is favorable because of its renewability and sustainability (figure 1). Redox active organic compounds have previously been used as electrode materials for secondary batteries. However, due to the dissolution of many interesting compounds in common battery electrolytes, they suffer from poor recyclability and, in addition, the limited conductivity in these materials requires addition of substantial amounts of conductivity additives in the electrode formulation. By introducing a CP as backbone, not only the dissolution issue is solved, but also the conductivity will be greatly improved.In our studies, we choose polypyrrole as CP, and p-benzoquinone as PG. Polypyrrole has been extensively studied and the electrochemistry and charge transport in this system is well understood. The corresponding knowledge of charge transport in CRPs is however to a large extent lacking. With the aid of temperature dependent in-situ conductivity measurements during the polymer doping process, mechanistic information on the charge transfer in quinone-based CRPs was investigated. Additionally, by varying the link between the two subunits the effect of linker on the performance of the materials was studied. With assistance of various in situ techniques, such as in situ conductivity measurement, in situ ATR-FTIR, EQCM, the interaction between the CP and PG was probed. It was found that the choice of linker has a substantial impact on the charge transport properties of the material. The insight gained from investigating the interaction between these two subunits will benefit further molecular variation of quinone-based electrode materials for secondary batteries.
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| 17. |
- Huang, Hao, 1988-, et al.
(författare)
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Synthesis and Characterization of Poly-3-((2,5-hydroquinone)vinyl)-1H-pyrrole : investigation on Backbone/Pendant Interactions in a Conducting Redox Polymer
- 2017
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 19:16, s. 10427-10435
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Tidskriftsartikel (refereegranskat)abstract
- We herein report the synthesis and electrochemical characterization of poly-3-((2,5-hydroquinone)vinyl)-1H-pyrrole, consisting of a polypyrrole backbone derivatized at the beta position by a vinyl-hydroquinone pendant group. The structure of the polymer was characterized by solid state NMR spectroscopy. The interactions between the polypyrrole backbone and the oxidized quinone or reduced hydroquinone pendant groups are probed by several in situ methods. In situ attenuated total reflectance-Fourier transform infrared spectroscopy shows spectroscopic response from both the doping of the polymer backbone and the redox activity of the pendant groups. Using an in situ Electrochemical Quartz Crystal Microbalance we reveal that the polymer doping is unaffected by the pendant group redox chemistry, as opposed to previous reports. Despite the continuous doping the electrochemical conversion from the hydroquinone state to the quinone state results in a significant conductance drop, as observed by in situ conductivity measurements using an InterDigitated Array electrode set-up. Twisting of the conducting polymer backbone as a result of a decreased separation between pendant groups due to π-π stacking in the oxidized state is suggested as the cause of this conductance drop.
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| 18. |
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| 19. |
- Huang, Xiao, et al.
(författare)
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A versatile route to polythiophenes with functional pendant groups using alkyne chemistry
- 2016
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Ingår i: Beilstein Journal of Organic Chemistry. - : Beilstein Institut. - 2195-951X .- 1860-5397. ; 12, s. 2682-2688
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Tidskriftsartikel (refereegranskat)abstract
- A new versatile polythiophene building block, 3-(3,4-ethylenedioxythiophene)prop-1-yne (pyEDOT) (3), is prepared from glycidol in four steps in 28% overall yield. pyEDOT features an ethynyl group on its ethylenedioxy bridge, allowing further functionalization by alkyne chemistry. Its usefulness is demonstrated by a series of functionalized polythiophene derivatives that were obtained by pre- and post-electropolymerization transformations, provided by the synthetic ease of the Sonogashira coupling and click chemistry.
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| 20. |
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| 21. |
- Huang, Xiao, et al.
(författare)
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Synthesis and Redox Properties of Thiophene Terephthalate Building Blocks for Low-Potential Conducting Redox Polymers
- 2015
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 119:49, s. 27247-27254
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Tidskriftsartikel (refereegranskat)abstract
- Terephthalate-substituted thiophene derivatives are promising redox-active components for anode materials in lithium-ion batteries. In this study, we present the synthesis of substituted 2-(thiophen-3-yl)terephthalate derivatives (TTDs) as suitable monomers for thiophene-based conducting redox polymers, along with their characterization by electrochemical and spectroscopic techniques. Density functional theory (DFT) calculations, utilizing the universal solvation model based on solute electron density (SMD), were used to predict both the first and the second reduction potentials of these TTDs. The computational results showed good agreement with the experimental data in nonaqueous acetonitrile solvent, with mean absolute errors of 30 and 40 mV for the first and second reduction steps, respectively. Time-dependent (TD) DFT calculations on TTDs indicated terephthalate local transitions at both 200 and 240 nm and charge-transfer transitions above 300 nm by examination of the involved molecular orbitals.
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| 22. |
- Ivanko, Iryna, et al.
(författare)
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Conjugated redox polymer with poly(3,4-ethylenedioxythiophene) backbone and hydroquinone pendant groups as the solid contact in potassium-selective electrodes
- 2021
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 329
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Tidskriftsartikel (refereegranskat)abstract
- We have used for the first time a conjugated redox polymer with hydroquinone (HQ) pendant groups covalently attached to the poly(3,4-ethylenedioxythiophene) (PEDOT) backbone as the solid contact (SC) in plasticized poly(vinyl chloride) (PVC) based K+-selective electrodes (K-SCISE). Redox couples are one of the simplest ways to precisely adjust the standard potential (E°) of the SCISEs, but usually the initially high E° reproducibility is lost quite quickly due to leaching out of non-covalently bound redox molecules from the SCISE. In PEDOT-HQ, the covalently attached HQ groups prevent the leaching and simultaneously allow additional charge storage in PEDOT-HQ that is ca. 25–30 times higher than for unsubstituted PEDOT. Before the ion-selective membrane (ISM) deposition, we controlled the potential of the SC with high reproducibility (±0.4 mV, n = 5) by pre-polarization in a mixture of acetonitrile containing potassium tetrakis(pentafluorophenyl)borate and perchloric acid as proton source. Pre-polarization of the SC close to the formal potential where the redox buffer capacity is highest gave the best potential reproducibility. However, after the ISM deposition, the K-SCISEs showed in the best case an E° reproducibility of ±2.8 mV (n = 5). Chronopotentiometric measurements reveal that only a minor fraction of the very high redox capacitance of PEDOT-HQ can be utilized for the ion-to-electron transduction beneath the ISM. The influence of this shortcoming on the E° reproducibility of the SCISEs has been underestimated for most SC materials. Modification of the commonly used PVC-ISM formulations to allow faster ion transfer at the SC/ISM interface could be one way of overcoming the disadvantage.
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| 23. |
- Karlsson, Christoffer, et al.
(författare)
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Ion- and Electron Transport in Pyrrole/Quinone Conducting Redox Polymers Investigated by In Situ Conductivity Methods
- 2015
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Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 179, s. 336-342
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Tidskriftsartikel (refereegranskat)abstract
- Polypyrrole functionalized with redox active pendant groups constitutes a so called conducting redox polymer, and functions both as a conducting polymer and as a redox polymer. The electrochemical response reveals capacitive charging of the conducting backbone as well as redox cycling of the pendant groups. While the backbone provides an electrically conducting matrix for fast electron transport through the material, the pendant groups offer a large charge storage capacity, much greater than that of polypyrrole itself. We have investigated such polypyrrole-hydroquinone conducting redox polymers, with focus on their in situ conductivity during electrochemical cycling, in order to understand the charge transport mechanisms in this type of system. The most notable feature is that oxidation of the pendant groups leads to a large decrease in the polymer conductivity. The causes of this phenomenon are discussed, as well as the rate limitations of fast redox cycling of the polymer, which are investigated through a combination of bipotentiostat cyclic voltammetry and potential steps of polymer films on interdigitated array electrodes.
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| 24. |
- Karlsson, Christoffer, 1986-, et al.
(författare)
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Nonstoichiometric Triazolium Protic Ionic Liquids for All-Organic Batteries
- 2018
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Ingår i: ACS Applied Energy Materials. - : American Chemical Society. - 2574-0962. ; :11, s. 6451-6462
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Tidskriftsartikel (refereegranskat)abstract
- Nonstoichiometric protic ionic liquids (NSPILs) are efficient electrolytes for protic electrochemical devices such as the all-organic proton battery, which has been suggested as a sustainable approach to energy storage. NSPILs contain a mixture of proton donors and acceptors and are ideal for this purpose due to their high proton conductivity, high electrochemical stability, low cost, and ease of synthesis. However, the electrolyte proton activity must be controlled carefully in these devices since it greatly influences the kinetics and energetics of the electrode redox reactions and, hence, also impacts battery device performance. In this study, specific NSPILs were designed and evaluated as electrolytes for the all-organic proton battery. The NSPILs were based on either 1,2,4-triazole or 1-methyl-1,2,4-triazole partially protonated with bis(trifluoromethylsulfonyl)imide (TFSI) to produce a range of NSPILs with different degrees of protonation. Both types of NSPIL investigated here exhibited a maximum conductivity of 1.2 S/cm (at 120 and 70 °C, respectively), and the eutectic composition of 1-methyl-1,2,4-triazolium TFSI also had high conductivity at 25 °C (24.9 mS/cm), superior to, e.g., imidazolium TFSI NSPILs. Pulsed field gradient NMR in conjunction with electrochemical impedance spectroscopy showed that the conductivity originated mainly from vehicle diffusion and proton hopping. Quinone functionalized poly(3,4-ethylenedioxythiophene) (PEDOT) electrodes exhibited reversible, fast, and stable redox conversion in these electrolytes, and a model is suggested to determine proton activities of NSPILs based on the quinone formal potential. An all-organic proton battery cell was assembled to demonstrate the usefulness of these electrolytes in devices. Fast and complete redox conversion with a cell potential of 0.45 V was demonstrated, even up to scan rates corresponding to 140 C. Compared to the pyridine based electrolytes used for the all-organic proton battery up until now, the present electrolytes display several advantages including lower melting point, lower toxicity, and compatibility with plastic materials.
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| 25. |
- Karlsson, Christoffer, et al.
(författare)
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Stable Deep Doping of Vapor-Phase Polymerized Poly(3,4-ethylenedioxythiophene)/Ionic Liquid Supercapacitors.
- 2016
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Ingår i: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 9:16, s. 2112-2121
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Tidskriftsartikel (refereegranskat)abstract
- Liquid-solution polymerization and vapor-phase polymerization (VPP) have been used to manufacture a series of chloride- and tosylate-doped poly(3,4-ethylenedioxythiophene) (PEDOT) carbon paper electrodes. The electrochemistry, specific capacitance, and specific charge were determined for single electrodes in 1-ethyl-3-methylimidazolium dicyanamide (emim dca) ionic liquid electrolyte. VPP-PEDOT exhibits outstanding properties with a specific capacitance higher than 300 F g(-1) , the highest value reported for a PEDOT-based conducting polymer, and doping levels as high as 0.7 charges per monomer were achieved. Furthermore, symmetric PEDOT supercapacitor cells with the emim dca electrolyte exhibited a high specific capacitance (76.4 F g(-1) ) and high specific energy (19.8 Wh kg(-1) ). A Ragone plot shows that the VPP-PEDOT cells combine the high specific power of conventional ("pure") capacitors with the high specific energy of batteries, a highly sought-after target for energy storage.
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| 26. |
- Keskinen, Jari, et al.
(författare)
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Asymmetric and symmetric supercapacitors based on polypyrrole and activated carbon electrodes
- 2015
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Ingår i: Synthetic metals. - : Elsevier BV. - 0379-6779 .- 1879-3290. ; 203, s. 192-199
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Supercapacitors were prepared using either two polypyrrole (PPy) composite electrodes or one PPy composite and one activated carbon electrode. The PPy composite electrodes were either freestanding paper-like sheets or PPy films printed on graphite ink coated aluminium/PET laminate substrates, using Cladophora algae derived cellulose as the substrate or binder, respectively. The specific capacitance of the PPy electrodes was found to be about 200 F g−1 depending on the manufacturing method, yielding supercapacitors with capacitances between 0.45 and 3.8 F and energy efficiencies of over 90%. For an asymmetric device with activated carbon positive electrode and PPy negative electrode a capacitance loss of 5% was seen after 14300 cycles.
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| 27. |
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| 28. |
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| 29. |
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| 30. |
- Oka, Kouki, et al.
(författare)
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Characterization of PEDOT-Quinone conducting redox polymers in water-in-salt electrolytes for safe and high-energy Li-ion batteries
- 2019
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Ingår i: Electrochemistry communications. - : Elsevier. - 1388-2481 .- 1873-1902. ; 105
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Tidskriftsartikel (refereegranskat)abstract
- Li-ion batteries (LIBs) raise safety and environmental concerns, which mostly arise from their toxic and flammable electrolytes and the extraction of limited material resources by mining. Recently, water-in-salt electrolytes (WiSEs), in which a large amount of lithium salt is dissolved in water, have been proposed to allow for assembling safe and high-voltage (>3.0 V) aqueous LIBs. In addition, organic materials derived from abundant building blocks and their tunable properties could provide safe and sustainable replacements for inorganic cathode materials. In the current work, the electrochemical properties of a conducting redox polymer based on poly(3,4-ethylenedioxythiophene) (PEDOT) with hydroquinone (HQ) pendant groups have been characterized in WiSEs. The quinone redox reaction occurs within the potential region where the polymer is conducting, and fast redox conversion that involves lithium cycling during pendant group redox conversion was observed. These properties make conducting redox polymers promising candidates as cathode-active materials for safe and high-energy aqueous LIBs. An organic-based aqueous LIB, with a HQ-PEDOT as a cathode, Li4Ti5O12 (LTO) as an anode, and ca. 15 m lithium bis(trifluoromethanesulfonyl)imide water/dimethyl carbonate (DMC) as electrolyte, yielded an output voltage of 1.35 V and high rate capabilities up to 500C.
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| 31. |
- Oka, Kouki, et al.
(författare)
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Conducting Redox Polymer as Organic Anode Material for Polymer-Manganese Secondary Batteries
- 2020
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Ingår i: ChemElectroChem. - : Wiley. - 2196-0216. ; 7:15, s. 3336-3340
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Tidskriftsartikel (refereegranskat)abstract
- Manganese-based aqueous batteries have attracted significant attention due to their earth-abundant components and low environmental burden. However, state-of-the-art manganese-zinc batteries are poorly rechargeable, owing to dendrite formation on the zinc anode. Organic materials could provide a safe and sustainable replacement. In the present work, a conducting redox polymer (CRP) based on a trimer of EPE (E=3,4-ethylenedioxythiophene; P=3,4-propylenedioxythiophene) and a naphthoquinone (NQ) pendant group is used as anode in polymer-manganese secondary batteries. The polymer shows stable redox conversion around+0.05 V vs. Ag/AgCl, and fast kinetics that involves proton cycling during pendant group redox conversion. For the first time, a CRP-manganese secondary battery was fabricated with pEP(NQ)E as the anode, manganese oxide as the cathode, and manganese-containing acidic aqueous solution as the electrolyte. This battery yielded a discharge voltage of 1.0 V and a discharging capacity of 76 mAh/ganode over >50 cycles and high rate capabilities (up to 10C).
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| 32. |
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| 33. |
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| 34. |
- Olsson, Henrik, 1968-, et al.
(författare)
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Parallel mechanisms of polypyrrole self-discharge in aqueous media
- 2015
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Ingår i: Physical Chemistry, Chemical Physics - PCCP. - 1463-9076 .- 1463-9084. ; 17, s. 11014-11019
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Tidskriftsartikel (refereegranskat)abstract
- In this report we investigate the self-discharge in a positively charged polypyrrole-cellulose composite material in water solution. Rate constants for the self-discharge reaction are determined by potential step methods and their dependence on pH, temperature and applied potential are reported. Based on the results, we propose that two fundamentally different self-discharge mechanisms operate in parallel; one of faradaic origin with a rate constant increasing exponentially with applied potential and one mechanism comprising an initial reaction of the charged polymer with hydroxide ions. The second mechanism dominates at high pH as the rate constant for this reaction increases exponentially with pH whilst the faradaic reaction dominates at low pH. With this report we hope to shed light on the complex and elusive nature of self-discharge in conducting polymers to serve as guidance for the construction of electrical energy storage devices with conducting polymer components.
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| 35. |
- Olsson, Henrik, et al.
(författare)
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Self-discharge Reactions in Energy Storage Devices Based on Polypyrrole-cellulose Composite Electrodes
- 2014
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Ingår i: Green. - : Walter de Gruyter GmbH. - 1869-8778 .- 1869-876X. ; 4:1-6, s. 27-39
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Tidskriftsartikel (refereegranskat)abstract
- The self-discharge behavior of organic electrodes and symmetric devices for sustainable energy storage, composed of electrodes containing a thin layer of polypyrrole coated onto a high surface area cellulose matrix, has been studied for the first time using different electrode sizes and electrolytes. Experimental data from open circuit measurements of the individual electrode potentials of charged symmetrical two-electrode energy storage devices as a function of time were evaluated based on three different self-discharge models. This evaluation clearly showed that the self-discharge process of the positive electrode is governed by a previously undetected activation-controlled faradaic reaction while the self-discharge of the negative electrode is due to diffusion controlled oxidation involving oxygen dissolved in the electrolyte. Potentiostatic three-electrode measurements and spectroelectrochemical experiments also showed that protons as well as maleimide were released from positively polarized polypyrrole electrodes. These new findings clearly show that the self-discharge of the cells originate from two different types of reactions on the positive and negative electrodes and that the main contribution to the self-discharge of the cells comes from an activation controlled reaction involving the positive electrode. These results provide an improved understanding of polypyrrole based devices and also yield new possibilities for the development of stable conducting polymer system for energy storage applications.
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| 36. |
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| 37. |
- Sjödin, Martin, 1974-, et al.
(författare)
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Conducting redox oligomers
- 2022
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Patent (populärvet., debatt m.m.)abstract
- The present disclosure relates to compounds of formula IVa or IVb, or salts thereof, as intermediates in the manufacture of conducting redox polymers. L is a covalent linker moiety and R is a reversible redox group.The disclosure further relates to conducting redox polymers produced from such compounds, as well as substrates coated with such conducting redox polymers, and organic batteries comprising such conducting redox polymers.
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| 38. |
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| 39. |
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| 40. |
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| 41. |
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| 42. |
- Sjödin, Martin, 1974-, et al.
(författare)
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Conducting Redox Polymers as Electrical Energy Storage Materials
- 2019
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Konferensbidrag (refereegranskat)abstract
- Conducting redox polymers (CRPs) is an attractive alternative as organic matter based electrical energy storage materials as they provide means of combining the favorable charge transport properties of conducting polymers with the high capacity and well defined redox chemistry of small redox active groups. In general CRPs are composed of a conducting polymer backbone where each or some of the monomers building up the polymer is bearing a redox active functional group. Although the working principle of CRPs is straightforward several key criteria need to be met in the CRP design in order to benefit from synergetic effects of the conducting polymer backbone and the pendent group in CRPs that will be outlined in this presentation: 1) As conducting polymers are only conducting in their charged state successful polymer-pendent group combinations rely on that the pendant group has a redox potential within the conducting region of the polymer backbone. This condition is referred to as redox matching and the requirement in the CRP design will be explicitly proven.[1] 2) The purpose of the polymer backbone is to provide efficient electron transport through the material. We have previously shown the polymer conductivity can be severely compromised by the pendant group.[2] This could be overcome by judicious choice of polymer backbone and results will be presented that show that non-activated (semi-metallic) electron transport can be achieved in CRPs.[3-4] 3) A final design principle that will be discussed is related to the polymerizability and how it is affected by the nature of the link between the polymer backbone and the pendent.[5] In addition a novel polymerization method for CRP monomers will be presented that allow bulk processing even for insoluble CRPmaterials.
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| 43. |
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| 44. |
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| 45. |
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| 46. |
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| 47. |
- Sjödin, Martin, 1974-, et al.
(författare)
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Designing Quinone-based Conducting Redox Polymers specifically for Aqueous Proton Batteries and for Lithium Ion Battery Cathodes
- 2020
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Konferensbidrag (refereegranskat)abstract
- Conducting redox polymers (CRPs) are conducting polymers that have been decorated with redox active functional groups and they provide an attractive alternative as organic matter based electrical energy storage materials. The purpose of the polymer backbone is two-fold, 1) it prevents dissolution of the redox group and, 2) it renders the material conductive. The redox active pendant groups, on the other hand, provide the material with a well-defined redox reaction as well as a high charge storage capacity. CRPs thus provide a solution to two of the most significant obstacles in achieving powerful and stable battery materials from organic compounds, i.e. materials dissolution and limited electronic conductivity while simultaneously providing a high charge storage capacity. For battery applications it is thus essential that the individual properties of the conducting polymer backbone and the redox group can be preserved and that they operate in synergy in the CRP. One prerequisite for synergetic polymer-pendant combinations is redox matching. As conducting polymers are only conducting in their charged state successful combinations rely on that the pendant group has a redox potential within the conducting region of the polymer backbone. In addition, the CRP must allow mass transport of ions, not only related to the cycling chemistry of the pendant group but also ions related to the doping of the polymer backbone. These requirements put significantly different demands on the polymer design for the development of aqueous proton batteries and for CRPs for lithium cycling cathodes. In this presentation specific CRP design-solutions will be presented that allow for the development of all-organic proton batteries 1,2 and for lithium ion CRP-battery cathodes 3. In addition, a solution-processing method, termed Post Deposition Polymerization (PDP), for CRP-materials and the underlying principles and requirements for PDP will be presented. Importantly, in PDP the processing step occurs prior to polymerization. After depositing and drying of the repeat-unit precursor onto a substrate polymerization is achieved by oxidative polymerization of the precursor. The PDP-method opens up for a scalable method for the coating of CRP materials onto any substrate and can, for instance, be used to make nanostructured CRP materials.1 Emanuelsson, R., Sterby, M., Strømme, M. & Sjödin, M. An All-Organic Proton Battery. J. Am. Chem. Soc. 139, 4828-4834, doi:10.1021/jacs.7b00159 (2017).2 Strietzel, C. et al. Accepted in Angewandte Chemie doi:10.1002/anie.202001191 (2020).3 Wang, H. et al. Redox-State-Dependent Interplay between Pendant Group and Conducting Polymer Backbone in Quinone-Based Conducting Redox Polymers for Lithium Ion Batteries. ACS Applied Energy Materials 2, 7162-7170, doi:10.1021/acsaem.9b01130 (2019).
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