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Filate, T. T., Lee, S., Franco, L. R., Chen, Q., Genene, Z., Marchiori, C., . . . Wang, E. (2024). Aqueous Processed All-Polymer Solar Cells with High Open-Circuit Voltage Based on Low-Cost Thiophene-Quinoxaline Polymers. ACS Applied Materials and Interfaces, 16(10), 12886-12896
Open this publication in new window or tab >>Aqueous Processed All-Polymer Solar Cells with High Open-Circuit Voltage Based on Low-Cost Thiophene-Quinoxaline Polymers
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2024 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 16, no 10, p. 12886-12896Article in journal (Refereed) Published
Abstract [en]

Eco-friendly solution processing and the low-cost synthesis of photoactive materials are important requirements for the commercialization of organic solar cells (OSCs). Although varieties of aqueous-soluble acceptors have been developed, the availability of aqueous-processable polymer donors remains quite limited. In particular, the generally shallow highest occupied molecular orbital (HOMO) energy levels of existing polymer donors limit further increases in the power conversion efficiency (PCE). Here, we design and synthesize two water/alcohol-processable polymer donors, poly[(thiophene-2,5-diyl)-alt-(2-((13-(2,5,8,11-tetraoxadodecyl)-2,5,8,11-tetraoxatetradecan-14-yl)oxy)-6,7-difluoroquinoxaline-5,8-diyl)] (P(Qx8O-T)) and poly[(selenophene-2,5-diyl)-alt-(2-((13-(2,5,8,11-tetraoxadodecyl)-2,5,8,11-tetraoxatetradecan-14-yl)oxy)-6,7-difluoroquinoxaline-5,8-diyl)] (P(Qx8O-Se)) with oligo(ethylene glycol) (OEG) side chains, having deep HOMO energy levels (similar to-5.4 eV). The synthesis of the polymers is achieved in a few synthetic and purification steps at reduced cost. The theoretical calculations uncover that the dielectric environmental variations are responsible for the observed band gap lowering in OEG-based polymers compared to their alkylated counterparts. Notably, the aqueous-processed all-polymer solar cells (aq-APSCs) based on P(Qx8O-T) and poly[(N,N '-bis(3-(2-(2-(2-methoxyethoxy)-ethoxy)ethoxy)-2-((2-(2-(2-methoxyethoxy)ethoxy)ethoxy)-methyl)propyl)naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl)-alt-(2,5-thiophene)] (P(NDIDEG-T)) active layer exhibit a PCE of 2.27% and high open-circuit voltage (V-OC) approaching 0.8 V, which are among the highest values for aq-APSCs reported to date. This study provides important clues for the design of low-cost, aqueous-processable polymer donors and the fabrication of aqueous-processable OSCs with high V-OC.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2024
Keywords
oligo(ethylene glycol), low-cost, aqueous-processable, all-polymer solar cell, eco-compatibility, open-circuit voltage
National Category
Polymer Chemistry Textile, Rubber and Polymeric Materials
Research subject
Physics
Identifiers
urn:nbn:se:kau:diva-99027 (URN)10.1021/acsami.3c18994 (DOI)001179270000001 ()38425182 (PubMedID)2-s2.0-85186379387 (Scopus ID)
Funder
Swedish Research Council, (2019-04683, 2020-05223Swedish Energy Agency, 45420-1Swedish Research Council Formas, P2021-90067
Available from: 2024-03-26 Created: 2024-03-26 Last updated: 2024-04-04Bibliographically approved
Prasad, S., Genene, Z., Marchiori, C., Singh, S., Ericsson, L., Wang, E., . . . Moons, E. (2024). Effect of molecular structure on the photochemical stability of acceptor and donor polymers used in organic solar cells. Materials Advances, 5, 7708-7720
Open this publication in new window or tab >>Effect of molecular structure on the photochemical stability of acceptor and donor polymers used in organic solar cells
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2024 (English)In: Materials Advances, E-ISSN 2633-5409, Vol. 5, p. 7708-7720Article in journal (Refereed) Published
Abstract [en]

The limited operational lifetime of organic solar cells remains an obstacle to their commercial development and is largely due to the poor intrinsic photostability of the conjugated molecules that constitute the photoactive layer. Here, we selected a series of state-of-the-art donor and acceptor materials including PBDB-T, Y5, PF5-Y5, and PYT to study their photostability under AM1.5 simulated sunlight in ambient conditions. Their properties are monitored over time, using various spectroscopy techniques, including UV-Vis absorption, Fourier-transform infrared (FTIR), and X-ray and ultraviolet photoelectron spectroscopy (XPS and UPS). We found that the absorption spectra of Y5 and PYT films remain almost intact even after 30 hours of light exposure in air, while the PF5-Y5 and PBDB-T films undergo rapid photobleaching. The absorption losses observed in blend films of PBDB-T with Y5 and with PF5-Y5 can be understood as composed of contributions from the separate blend components that are similar to the absorption losses in neat films. The new peaks emerging in the FTIR spectra of PBDB-T, PF5-Y5, and their blend films witness the formation of new carbonyl groups, while these are absent in the spectra of the Y5 and PYT films. The XPS C 1s spectra of the PF5-Y5 and PBDB-T films confirm this carbonyl formation and the S 2p spectra reveal that sulphone groups are formed after 30 hours of exposure of these films. These results confirm that films of Y5 and the copolymer PYT are significantly more resistant to photooxidation, compared to the copolymer PF5-Y5. The comparison of these results suggests that the benzo[1,2-b:4,5-b ']dithiophene moiety with alkylated thiophenes as side chains (BDT-T) accelerates the photodegradation of PBDB-T and PF5-Y5. The replacement of the BDT-T unit by thiophene contributes to the enhanced stability of PYT, demonstrating that the nature of the co-monomer has a significant effect on the intrinsic photostability of Y5-based copolymers. These new insights are expected to stimulate the design of stable donors and acceptor polymers for the development of long-lived OPV devices. Absorption spectra show the photobleaching of acceptor copolymer PF5-Y5. The replacement of BDT-T by thiophene strongly improves the photostability.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2024
National Category
Physical Chemistry
Research subject
Physics
Identifiers
urn:nbn:se:kau:diva-101835 (URN)10.1039/d4ma00447g (DOI)001307979300001 ()2-s2.0-85203645363 (Scopus ID)
Funder
Swedish Research Council, 2018-07152; 2021-04798; 2022-06725; 2018-05973Vinnova, 2018-04969Swedish Research Council Formas, 2019-02496; 2020-01201Swedish Energy Agency, 48598-1; P2021-90067Wallenberg Foundations, 2016.0059
Available from: 2024-10-04 Created: 2024-10-04 Last updated: 2025-01-13Bibliographically approved
Pereira, C. F., Borges, B. G. A., Sousa, K. R. A., Holakoei, S., Roman, L. S., Araujo, M., . . . Rocco, M. L. (2024). Inducing molecular orientation in solution-processed thin films of fluorene-bithiophene-based copolymer: thermal annealing vs. solvent additive. RSC Advances, 14(13), 9051-9061
Open this publication in new window or tab >>Inducing molecular orientation in solution-processed thin films of fluorene-bithiophene-based copolymer: thermal annealing vs. solvent additive
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2024 (English)In: RSC Advances, E-ISSN 2046-2069, Vol. 14, no 13, p. 9051-9061Article in journal (Refereed) Published
Abstract [en]

A deep understanding of the factors influencing the morphology of thin films based on conjugated polymers is essential to boost their performance in optoelectronic devices. Herein, we investigated the electronic structure and morphology of thin films of the copolymer poly(9,9-dioctyl-fluorenyl-co-bithiophene) (F8T2) in its pristine form as well as samples processed with the solvent additive 1,8-diiodooctane (DIO) or post-processed through thermal annealing treatment. Measurements were carried out using angle-resolved S K-edge NEXAFS (near-edge X-ray absorption fine structure) in total electron yield (TEY) and fluorescence yield (FY) detection modes. Two main transitions were observed at the S 1s NEXAFS spectra: S 1s -> pi* and S 1s -> sigma* (S-C). The observed dichroism pointed to a face-on orientation of the conjugated backbone, which was significantly increased for F8T2 films processed with DIO. Resonant Auger decay spectra were obtained and analyzed using the core-hole clock (CHC) method. An enhancement in the charge transfer process was observed for thermally annealed films, especially for samples processed with DIO, corresponding to an increase in film ordering. Furthermore, the investigated films were characterized using X-ray photoelectron spectroscopy, attesting to the presence of the thiophene unit in the samples and demonstrating that some of its sulfur atoms were positively polarized in the F8T2 films. All these experimental findings were compared with molecular dynamics (MD) simulations of film evaporation with and without DIO. The use of MD, together with mathematical modeling, was able to explain the major effects found in the experiments, including the polarization of sulfur atoms. The simultaneous use of powerful spectroscopic techniques and theoretical methods shed light on key aspects linking film morphology with fabrication procedures.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2024
Keywords
stimulated ion desorption, x-ray photoelectron, polymer solar-cells, electronic-structure, transfer dynamics, charge-transfer, thiophene, poly(thiophene), femtosecond, performance
National Category
Atom and Molecular Physics and Optics
Research subject
Physics
Identifiers
urn:nbn:se:kau:diva-99235 (URN)10.1039/d3ra08066h (DOI)001186433600001 ()38500615 (PubMedID)2-s2.0-85188139932 (Scopus ID)
Available from: 2024-04-08 Created: 2024-04-08 Last updated: 2024-04-09Bibliographically approved
Christopholi, L., Marchiori, C., Jalan, I., Opitz, A., Muntean, S. A. & Moons, E. (2024). Role of the Solvent on the Orientation of Y-Type Acceptor Molecules in Spin-Coated Films. The Journal of Physical Chemistry C, 128, 17825-17835
Open this publication in new window or tab >>Role of the Solvent on the Orientation of Y-Type Acceptor Molecules in Spin-Coated Films
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2024 (English)In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 128, p. 17825-17835Article in journal (Refereed) Published
Abstract [en]

In this study, a rational processing strategy is presented, aiming to achieve well-ordered thin films of the molecular electron acceptors Y5 and Y6 by the choice of solvent as a key parameter. The thin films were spin-coated from chlorobenzene (CB), chloroform (CF), and ortho-xylene (o-XYL) solutions. The film morphology and molecular orientation were investigated by atomic force microscopy (AFM) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy, respectively. A homogeneous and smooth morphology was achieved when CF was used as the processing solvent. However, using CB and o-XYL resulted in significantly rougher films with larger structures. The dichroism observed in NEXAFS spectra using a linearly polarized incident X-ray beam and recorded in total electron yield (TEY) mode is indicative of a preferential face-on molecular orientation at the surface of Y5 and Y6 thin films processed from CF solution. In contrast, NEXAFS spectra of thin films processed from CB and o-XYL do not show any dependence on the electric field polarization direction of the incident X-ray beam, implying the absence of molecular orientation in those films. To understand the nature of the electronic transitions responsible for the absorption resonances in the NEXAFS spectra at the N and C K-edges, the natural transition orbitals corresponding to these electronic transitions were determined by time-dependent density functional theory (TD-DFT) calculations, confirming the face-on orientation of the molecules in the films processed from the CF solution. The fact that face-on oriented films are only achieved using CF is attributed to the superior solubility of Y5 and Y6 in this solvent and the lower degree of preaggregation in solution.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2024
National Category
Physical Chemistry
Research subject
Chemistry; Physics
Identifiers
urn:nbn:se:kau:diva-102096 (URN)10.1021/acs.jpcc.4c04176 (DOI)001333437300001 ()2-s2.0-85206551866 (Scopus ID)
Funder
Swedish Research Council, 2021-04798; 2022-06725; 2018-05973Swedish National Space Board, 2021-137; 2022-197German Research Foundation (DFG), 239543752
Available from: 2024-10-29 Created: 2024-10-29 Last updated: 2025-01-09Bibliographically approved
Zhang, C., Cheng, J., Chen, Y., Chan, M. K. Y., Cai, Q., Carvalho, R. P., . . . Sundararaman, R. (2023). 2023 Roadmap on molecular modelling of electrochemical energy materials. Journal of Physics: Energy, 5(4), Article ID 041501.
Open this publication in new window or tab >>2023 Roadmap on molecular modelling of electrochemical energy materials
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2023 (English)In: Journal of Physics: Energy, E-ISSN 2515-7655, Vol. 5, no 4, article id 041501Article, review/survey (Refereed) Published
Abstract [en]

New materials for electrochemical energy storage and conversion are the key to the electrification and sustainable development of our modern societies. Molecular modelling based on the principles of quantum mechanics and statistical mechanics as well as empowered by machine learning techniques can help us to understand, control and design electrochemical energy materials at atomistic precision. Therefore, this roadmap, which is a collection of authoritative opinions, serves as a gateway for both the experts and the beginners to have a quick overview of the current status and corresponding challenges in molecular modelling of electrochemical energy materials for batteries, supercapacitors, CO2 reduction reaction, and fuel cell applications.

Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP), 2023
Keywords
electrochemical interfaces, density-functional theory, molecular dynamics simulation, electrochemical energy storage, machine learning, electrocatalysis
National Category
Energy Engineering
Research subject
Materials Science
Identifiers
urn:nbn:se:kau:diva-97389 (URN)10.1088/2515-7655/acfe9b (DOI)001090149100001 ()2-s2.0-85177181901 (Scopus ID)
Funder
Swedish Energy Agency, P50638-1EU, Horizon 2020, 771294, 851441, 957189, 949012VinnovaKnut and Alice Wallenberg FoundationAcademy of Finland, 338228
Available from: 2023-11-16 Created: 2023-11-16 Last updated: 2023-12-04Bibliographically approved
Jalan, I., Marchiori, C., Genene, Z., Johansson, A., Araujo, M., Wang, E., . . . Moons, E. (2023). Donor-acceptor polymer complex formation in solution confirmed by spectroscopy and atomic-scale modelling. Journal of Materials Chemistry C, 11(27), 9316-9326
Open this publication in new window or tab >>Donor-acceptor polymer complex formation in solution confirmed by spectroscopy and atomic-scale modelling
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2023 (English)In: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 11, no 27, p. 9316-9326Article in journal (Refereed) Published
Abstract [en]

In all-polymer solar cells, high performance is attributed to the fine-grained morphology of the film in the active layer. However, the mechanism by which this fine-grained morphology is achieved remains unknown. Polymeric non-fullerene acceptors have the potential to restrict the self-aggregation, typical of non-fullerene small molecule acceptors. Here we employed a blend of the polymeric acceptor PF5-Y5 and the donor polymer PBDB-T to investigate the balance between molecular interactions in solution. Temperature-dependent absorption spectra show evidence of temperature-induced disaggregation of both donor and acceptor polymers, where the donor polymer disaggregation depends on the solvent polarity. Concentration-dependent fluorescence spectra of blend solutions display blue-shifted acceptor emission upon dilution, similar to that observed in acceptor solutions, and a decreased tendency for charge transfer from donor to acceptor upon dilution. Excitation spectra of dilute blend solutions contain an increased contribution to the long-wavelength acceptor emission, as compared to pure acceptor solutions, from a chromophore that absorbs in a region where the donor does not absorb. These observations can be explained by donor-acceptor complexation in dilute blend solutions, that is stabilized in more polar solvents. Moreover, the near IR-region of the absorption spectrum could be matched with the calculated electronic excitations of donor-acceptor complexes of PBDB-T and PF5-Y5 oligomers. The results corroborate that the interaction between segments of the donor and acceptor polymer chains favours the formation of donor-acceptor charge transfer complexes, stabilized by hybridization of the molecular orbitals, which reduces the electronic energy. The proposed donor-acceptor complex formation competes with the donor and acceptor self-aggregation and is influenced by the solvent environment. These pre-formed donor-acceptor complexes in low-concentration solutions can be expected to have important consequences on the film morphology of all-polymer blends. The results from this joint experimental-theoretical spectroscopy study provide insights that can guide the design of compatible donor and acceptor polymers for future high-performance organic solar cells.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2023
National Category
Polymer Chemistry Theoretical Chemistry
Research subject
Chemistry; Materials Science
Identifiers
urn:nbn:se:kau:diva-94224 (URN)10.1039/d1tc03853b (DOI)001019691000001 ()2-s2.0-85164140693 (Scopus ID)
Funder
Knut and Alice Wallenberg Foundation, 2016.0059Swedish Energy Agency, 48598-1Swedish National Space Board, 174/19 and 137/21Swedish Research Council, 2014-05984
Note

This paper was included as a manuscript in Ishita Jalan's PhD thesis entitled "Solution Chemistry and Morphological Properties for Organic Solar Cells: Exploring Alternative Solvents Using Microgravity and Modelling as Tools", 2023:13.

Available from: 2023-04-10 Created: 2023-04-10 Last updated: 2023-08-09Bibliographically approved
Wu, J., Ling, Z., Franco, L. R., Jeong, S. Y., Genene, Z., Mena, J., . . . Wang, E. (2023). On the Conformation of Dimeric Acceptors and Their Polymer Solar Cells with Efficiency over 18 %. Angewandte Chemie International Edition, 62(45), Article ID e202302888.
Open this publication in new window or tab >>On the Conformation of Dimeric Acceptors and Their Polymer Solar Cells with Efficiency over 18 %
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2023 (English)In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 62, no 45, article id e202302888Article in journal (Refereed) Published
Abstract [en]

The determination of molecular conformations of oligomeric acceptors (OAs) and their impact on molecular packing are crucial for understanding the photovoltaic performance of their resulting polymer solar cells (PSCs) but have not been well studied yet. Herein, we synthesized two dimeric acceptor materials, DIBP3F-Se and DIBP3F-S, which bridged two segments of Y6-derivatives by selenophene and thiophene, respectively. Theoretical simulation and experimental 1D and 2D NMR spectroscopic studies prove that both dimers exhibit O-shaped conformations other than S- or U-shaped counter-ones. Notably, this O-shaped conformation is likely governed by a distinctive "conformational lock" mechanism, arising from the intensified intramolecular & pi;-& pi; interactions among their two terminal groups within the dimers. PSCs based on DIBP3F-Se deliver a maximum efficiency of 18.09 %, outperforming DIBP3F-S-based cells (16.11 %) and ranking among the highest efficiencies for OA-based PSCs. This work demonstrates a facile method to obtain OA conformations and highlights the potential of dimeric acceptors for high-performance PSCs.

Place, publisher, year, edition, pages
John Wiley & Sons, 2023
Keywords
Acceptor, Molecular Conformation, Oligomer, Selenophene, Solar Cells
National Category
Organic Chemistry Biophysics
Research subject
Physics
Identifiers
urn:nbn:se:kau:diva-96239 (URN)10.1002/anie.202302888 (DOI)001030527700001 ()37380618 (PubMedID)2-s2.0-85165198230 (Scopus ID)
Funder
Swedish Research Council, 2016-06146; 2019-04683; 2020-05233Swedish Research Council Formas, 2017.0186Knut and Alice Wallenberg Foundation, 2016.0059Swedish Energy Agency, P2021-90067
Available from: 2023-08-08 Created: 2023-08-08 Last updated: 2024-07-23Bibliographically approved
Prasad, S., Marchiori, C., Genene, Z., Ericsson, L., Araujo, M., Wang, E. & Moons, E. (2023). Photostability of Y-type electron acceptor molecules and related copolymer. In: Gang Li, Natalie Stingelin, Ana Flávia Nogueira, Thuc-Quyen Nguyen, Ellen Moons, Barry P. Rand (Ed.), Proceedings Volume 12660, Organic, Hybrid, and Perovskite Photovoltaics XXIV;: . Paper presented at SPIE Optics + Photonics, San Diego, United States, August 20-24, 2023.. SPIE - The International Society for Optics and Photonics, 12660
Open this publication in new window or tab >>Photostability of Y-type electron acceptor molecules and related copolymer
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2023 (English)In: Proceedings Volume 12660, Organic, Hybrid, and Perovskite Photovoltaics XXIV; / [ed] Gang Li, Natalie Stingelin, Ana Flávia Nogueira, Thuc-Quyen Nguyen, Ellen Moons, Barry P. Rand, SPIE - The International Society for Optics and Photonics, 2023, Vol. 12660Conference paper, Published paper (Refereed)
Abstract [en]

The lifetime of organic solar cells critically depends on the photochemical stability of the materials. To shed light on the photostability of novel Y-series electron acceptors, we investigate the evolution of optical properties and composition during one-sun illumination in ambient atmosphere of thin films of the small-molecule acceptor Y5 and its copolymers PF5-Y5 and PYT. We employ UV-vis, Fourier-transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS), to assess changes in these properties as a function of illumination time. UV-Vis spectra show that PF5-Y5 undergoes rapid photobleaching, while the Y5 spectrum remains essentially unaffected even after 30 hours of exposure. The absorption spectrum of PYT, which contains a different co-mer than PF5-Y5, is only weakly affected. XPS C1s spectra of the PF5- Y5 film show a decreasing main peak and the development of a new component after 30 hours exposure, while the Y5 film surface composition remained intact. The photodegradation products of PF5-Y5 are characterized by the presence of new carbonyl groups, emerging as absorption bands in the FTIR spectra, while such spectral changes are absent for the Y5 film, indicating that Y5 is resistant to photooxidation, while PF5-Y5 undergoes photochemical reactions. The faster photodegradation of PF5-Y5 compared to Y5 and PYT raises the question about the role of the copolymer’s BDT moiety in the photooxidation. These new insights on the dependence of the photostability of acceptor molecules on their molecular structure are expected to contribute to the design of stable acceptor copolymers for organic solar cells with long operational lifetimes. 

Place, publisher, year, edition, pages
SPIE - The International Society for Optics and Photonics, 2023
Keywords
co-polymer, non-fullerene acceptor, organic photovoltaics, photooxidation
National Category
Other Physics Topics
Research subject
Physics
Identifiers
urn:nbn:se:kau:diva-97578 (URN)10.1117/12.2679517 (DOI)2-s2.0-85176501822 (Scopus ID)
Conference
SPIE Optics + Photonics, San Diego, United States, August 20-24, 2023.
Available from: 2023-11-30 Created: 2023-11-30 Last updated: 2023-11-30Bibliographically approved
Franco, L. R., Marchiori, C. & Araujo, M. (2023). Unveiling the impact of exchange-correlation functionals on the description of key electronic properties of non-fullerene acceptors in organic photovoltaics. Journal of Chemical Physics, 159(20), Article ID 204110.
Open this publication in new window or tab >>Unveiling the impact of exchange-correlation functionals on the description of key electronic properties of non-fullerene acceptors in organic photovoltaics
2023 (English)In: Journal of Chemical Physics, ISSN 0021-9606, E-ISSN 1089-7690, Vol. 159, no 20, article id 204110Article in journal (Refereed) Published
Abstract [en]

Non-fullerene electron acceptors have emerged as promising alternatives to traditional electron-acceptors in the active layers of organic photovoltaics. This is due to their tunable energy levels, optical response in the visible light spectrum, high electron mobility, and photochemical stability. In this study, the electronic properties of two representative non-fullerene acceptors, ITIC and Y5, have been calculated within the framework of density functional theory using a range of hybrid and non-hybrid density functionals. Screened range-separated hybrid (SRSH) approaches were also tested. The results are analyzed in light of the previously reported experimental outcomes. Specifically, we have calculated the oxidation and reduction potentials, fundamental and optical gaps, the highest occupied molecular orbital and lowest unoccupied molecular orbital energies, and exciton binding energies. Additionally, we have investigated the effects of the medium dielectric constant on these properties employing a universal implicit solvent model. It was found that hybrid functionals generally perform poorly in predicting oxidation potentials, while non-hybrid functionals tend to overestimate reduction potentials. The inclusion of a large Hartree-Fock contribution to the global or long range was identified as the source of inaccuracy for many hybrid functionals in predicting both redox potentials and the fundamental and optical gaps. Corroborating with the available literature, ∼50% of all tested functionals predicted very small exciton binding energies, within the range of ±0.1 eV, that become even smaller by increasing the dielectric constant of the material. Finally, the OHSE2PBE and tHCTHhyb functionals and the optimal tuning SRSH approach emerged as the best-performing methods, with good accuracy in the description of the electronic properties of interest. 

Place, publisher, year, edition, pages
American Institute of Physics (AIP), 2023
Keywords
Binding energy; Density functional theory; Electronic properties; Excitons; Molecular orbitals; Redox reactions; fullerene; solvent; Electron-acceptor; Exciton-binding energy; Functionals; Fundamental gaps; Hybrid approach; Hybrid functionals; Optical-gap; Organic photovoltaics; Oxidation potentials; Reduction potential; article; controlled study; density functional theory; dielectric constant; electron; oxidation; oxidation reduction potential; Fullerenes
National Category
Condensed Matter Physics Atom and Molecular Physics and Optics Theoretical Chemistry
Research subject
Physics
Identifiers
urn:nbn:se:kau:diva-97689 (URN)10.1063/5.0163180 (DOI)001110536100006 ()38018752 (PubMedID)2-s2.0-85178180700 (Scopus ID)
Funder
Swedish Research Council, 2020-05223Swedish Energy Agency, 45420-1Linköpings universitet, 2018-05973, 2022-06725
Available from: 2023-12-11 Created: 2023-12-11 Last updated: 2023-12-22Bibliographically approved
Carvalho, R. P., Marchiori, C., Brandell, D. & Araujo, M. (2022). Artificial intelligence driven in-silico discovery of novel organic lithium-ion battery cathodes. Energy Storage Materials, 44, 313-325
Open this publication in new window or tab >>Artificial intelligence driven in-silico discovery of novel organic lithium-ion battery cathodes
2022 (English)In: Energy Storage Materials, ISSN 2405-8289, E-ISSN 2405-8297, Vol. 44, p. 313-325Article in journal (Refereed) Published
Abstract [en]

Organic electrode materials (OEMs) combine key sustainability and versatility properties with the potential to enable the realisation of the next generation of truly green battery technologies. However, for OEMs to become a competitive alternative, challenging issues related to energy density, rate capability and cycling stability need to be overcome. In this work, we have developed and applied an alternative yet systematic methodology to accelerate the discovery of suitable cathode-active OEMs by interplaying artificial intelligence (AI) and quantum mechanics. This AI-kernel has allowed a high-throughput screening of a huge library of organic molecules, leading to the discovery of 459 novel promising OEMs with candidates offering the potential to achieve theoretical energy densities superior to 1000 W h kg(1). Moreover, the machinery accurately identified common molecular functionalities that lead to such higher-voltage electrodes and pointed out an interesting donor-accepter-like effect that may drive the future design of cathode-active OEMs.

Keywords
Battery materials; Organic electrode; Li-ion battery; Artificial intelligence; Machine learning; Materials discovery
National Category
Condensed Matter Physics
Research subject
Materials Science
Identifiers
urn:nbn:se:kau:diva-87392 (URN)10.1016/j.ensm.2021.10.029 (DOI)
Available from: 2021-11-25 Created: 2021-11-25 Last updated: 2022-05-11Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-0377-3669

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