| 1. |
- Belaineh Yilma, Dagmawi, et al.
(författare)
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Printable carbon-based supercapacitors reinforced with cellulose and conductive polymers
- 2022
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Ingår i: Journal of Energy Storage. - : Elsevier Ltd. - 2352-152X .- 2352-1538. ; 50
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Tidskriftsartikel (refereegranskat)abstract
- Sustainable electrical energy storage is one of the most important scientific endeavors of this century. Battery and supercapacitor technologies are here crucial, but typically the current state of the art suffers from either lack of large-scale production possibilities, sustainability or insufficient performance and hence cannot match growing demands in society. Paper and cellulosic materials are mature scalable templates for industrial roll-to-roll production. Organic materials, such as conducting polymers, and carbon derivatives are materials that can be synthesized or derived from abundant sources. Here, we report the combination of cellulose, PEDOT:PSS and carbon derivatives for bulk supercapacitor electrodes adapted for printed electronics. Cellulose provides a mesoscopic mesh for the organization of the active ingredients. Furthermore, the PEDOT:PSS in combination with carbon provides superior device characteristics when comparing to the previously standard combination of activated carbon and carbon black. PEDOT:PSS acts as a mixed ion-electron conducting glue, which physically binds activated carbon particles together, while at the same time facilitating swift transport of both electrons and ions. A surprisingly small amount (10%) of PEDOT:PSS is needed to achieve an optimal performance. This work shows that cellulose added to PEDOT:PSS-carbon enables high-performing, mechanically stable, printed supercapacitor electrodes using a combination of printing methods.
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| 2. |
- Brooke, Robert, 1989-, et al.
(författare)
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Nanocellulose and PEDOT:PSS composites and their applications
- 2023
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Ingår i: Polymer Reviews. - : Taylor and Francis Ltd.. - 1558-3724 .- 1558-3716. ; :2, s. 437-
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Tidskriftsartikel (refereegranskat)abstract
- The need for achieving sustainable technologies has encouraged research on renewable and biodegradable materials for novel products that are clean, green, and environmentally friendly. Nanocellulose (NC) has many attractive properties such as high mechanical strength and flexibility, large specific surface area, in addition to possessing good wet stability and resistance to tough chemical environments. NC has also been shown to easily integrate with other materials to form composites. By combining it with conductive and electroactive materials, many of the advantageous properties of NC can be transferred to the resulting composites. Conductive polymers, in particular poly(3,4-ethylenedioxythiophene:poly(styrene sulfonate) (PEDOT:PSS), have been successfully combined with cellulose derivatives where suspensions of NC particles and colloids of PEDOT:PSS are made to interact at a molecular level. Alternatively, different polymerization techniques have been used to coat the cellulose fibrils. When processed in liquid form, the resulting mixture can be used as a conductive ink. This review outlines the preparation of NC/PEDOT:PSS composites and their fabrication in the form of electronic nanopapers, filaments, and conductive aerogels. We also discuss the molecular interaction between NC and PEDOT:PSS and the factors that affect the bonding properties. Finally, we address their potential applications in energy storage and harvesting, sensors, actuators, and bioelectronics. © 2022 The Author(s).
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| 3. |
- Chen, Shangzhi, et al.
(författare)
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Tunable Structural Color Images by UV-Patterned Conducting Polymer Nanofilms on Metal Surfaces.
- 2021
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Ingår i: Advanced Materials. - : Wiley. - 0935-9648 .- 1521-4095. ; 33:33
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Tidskriftsartikel (refereegranskat)abstract
- Precise manipulation of light-matter interactions has enabled a wide variety of approaches to create bright and vivid structural colors. Techniques utilizing photonic crystals, Fabry-Pérot cavities, plasmonics, or high-refractive-index dielectric metasurfaces have been studied for applications ranging from optical coatings to reflective displays. However, complicated fabrication procedures for sub-wavelength nanostructures, limited active areas, and inherent absence of tunability of these approaches impede their further development toward flexible, large-scale, and switchable devices compatible with facile and cost-effective production. Here, a novel method is presented to generate structural color images based on monochromic conducting polymer films prepared on metallic surfaces via vapor phase polymerization and ultraviolet (UV) light patterning. Varying the UV dose enables synergistic control of both nanoscale film thickness and polymer permittivity, which generates controllable structural colors from violet to red. Together with grayscale photomasks this enables facile fabrication of high-resolution structural color images. Dynamic tuning of colored surfaces and images via electrochemical modulation of the polymer redox state is further demonstrated. The simple structure, facile fabrication, wide color gamut, and dynamic color tuning make this concept competitive for applications like multifunctional displays.
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| 4. |
- Engquist, Isak, et al.
(författare)
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Highly conducting nanographite-filled paper fabricated via standard papermaking techniques
- 2020
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society. - 1944-8244 .- 1944-8252. ; 12:43, s. 48828-48835
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Tidskriftsartikel (refereegranskat)abstract
- Eco-friendly and cost-effective materials and processes to manufacture functional substrates are crucial to further advance the area of printed electronics. One potential key component in the printed electronics platform is an electrically functionalized paper, produced by simply mixing common cellulosic pulp fibers with high-performance electroactive materials. Herein, an electronic paper including nanographite has been prepared using a standardized and scalable papermaking technique. No retention aid was needed to achieve a conducting nanographite loading as high as 50 wt %. The spontaneous retention that provides the integrity and stability of the nanographite paper, likely originates partially from an observed water-stable adhesion of nanographite flakes onto the fiber surfaces. The resulting paper exhibits excellent electrical characteristics, such as an in-plane conductivity of 107 S/cm and an areal capacitance of 9.2 mF/cm2, and was explored as the back-electrode in printed electrochromic displays.
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| 5. |
- Isacsson, Patrik Anders Gustav, et al.
(författare)
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Electrochemical characteristics of lignin in CTMP for paper battery electrodes.
- 2024
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Ingår i: ChemSusChem. - 1864-5631 .- 1864-564X.
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Tidskriftsartikel (refereegranskat)abstract
- Lignin has been extensively researched as a cathode active material in secondary batteries. In the present work, the energy storage potential of lignin naturally present in papers made of chemi-thermomechanical pulp (CTMP) is explored. More specifically, effects from CTMP fines on the electrochemical characteristics have been studied. Compared to pulp fibers, fines are higher in lignin content and have higher specific surface area. It was expected that this would be positive for the electrode performance; however, the result points to the opposite. The fines do not significantly contribute to a higher lignin specific capacity, and they deteriorate the cycling stability. Higher fines content was found to result in a higher oxidative activity as well as more abundant competing reactions. These competing reactions are believed to be linked to the cycle stability. Therefore, we hypothesize that the electrochemical stability of lignin can be better understood by studying differences between fines and fiber lignin. As the theoretical specific capacity of this material is about 20 times larger than obtained here, identification of the reasons for this capacity discrepancy is needed to realize the full potential of lignin-based paper batteries.
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| 6. |
- Isacsson, Patrik, 1991-
(författare)
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Materials Design for Paper Electrodes : A Papermaking Perspective on Electrode Fabrication
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The electrification and digitalization of our society has propelled the demand for energy storage solutions. High-end technologies have been developed to satisfy the requirements of demanding applications, such as electromobility and portable consumer electronics, which also increasingly find markets for less demanding applications. These markets include grid and domestic energy storage, as well as Internet of Things (IoT). However, using high-end technologies for low-end applications is a waste of resources that puts unnecessary stress on the supply lines. Thus, more low-cost cost and environmentally friendly alternative technologies are sought, among which renewable biobased materials derived from agriculture and forestry play a prominent role.The dominant chemical constituents in plants, cellulose and lignin, exhibit some intriguing electrochemical and colloidal properties. Cellulose has been found to efficiently stabilize various electronic materials, whereas lignin can be used as an electronic material itself. Lignocellulosic materials also open for papermaking as an alternative manufacturing approach. Taking the step to using papermaking methods is, however, a bit far from the technology readiness level, as the vast majority of the research on paper electrodes is based on nanocellulose. The material properties of such nanopapers are indeed extraordinary, but the lack of large-scale production methods for nanopapers is a serious challenge.To circumvent this obstacle and find a shortcut to the realization of paper electrodes, this thesis has turned to conventional papermaking techniques. Fibres are essentially different to nanofibrils by their difference in size, and the papermaking process requires careful composition of the formulations. Thus, as the research on nanopaper electrodes cannot be directly translated into conventional papermaking techniques, this calls for separate studies on fibre-based systems.This thesis is based on four separate works carried out by an explorative approach, where different kinds of paper electrodes have been investigated with touchdowns in example applications. Based on these studies, general knowledge has been concluded. This has been summarized by four important aspects for materials design of paper electrodes:Colloidal Systems. The paper electrode formulations exhibit both familiar and unfamiliar colloidal interactions. Established wet-end chemistry including charge balance control and electrostatic interactions remain important in parallel with unconventional behaviours. Exfoliated graphite forms water-stable coatings around pulp fibres and exhibit auto-retention mechanism(s). The conducting polymer system PEDOT:PSS, which can adsorb to chemical pulp fibres, does not exhibit affinity to chemi-thermomechanical pulp.Percolating Networks. Cellulosic fibres constitute an insulative matrix, in which efficient percolating conductive networks must be formed. The way a conducting additive is introduced, as well as the morphology of the additive, is important. Combining conducting polymers with nanocarbons is a promising concept for material-efficient networks. For a filler used as an electrode active material, it is important to acknowledge whether it is electronically conductive or not. A higher amount of conductive additives is required for insulative electrode active materials than for those with internal conductivity.Lignin Electrochemistry. Residual lignin present in softwood pulps, in both mechanical and chemical pulps, is electrochemically active. This can either be wanted or unwanted depending on application. Fines differ from fibres in terms of electrochemical stability and oxidative activity. Substantial competing electrochemical reactions occur, which might be related to the electrochemical stability.Mechanical Properties. Percolating conductive networks require high interconnectivity, which entails a cross-linked structure. This brings increased stiffness to the papers, which can be observed both for exfoliated graphite as a filler as well as for papers impregnated with PEDOT:PSS.Based on the four aspects described above, prospects for a few paper electrode applications have been reviewed. The prospects are mixed, each with their own challenges and opportunities which requires further research and development. While this thesis can conclude that we have not yet reached the point where paper electrodes can be realized, it certainly paves the way to get there.
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| 7. |
- Isacsson, Patrik, et al.
(författare)
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Production of energy-storage paper electrodes using a pilot-scale paper machine
- 2022
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry. - 2050-7488 .- 2050-7496. ; 10:40, s. 21579-21589
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Tidskriftsartikel (refereegranskat)abstract
- The global efforts in electrifying our society drive the demand for low-cost and sustainable energy storage solutions. In the present work, a novel material concept was investigated to enable fabrication of several 10 meter-long rolls of supercapacitor paper electrodes on a pilot-scale paper machine. The material concept was based on cationized, cellulose-rich wood-derived fibres, conducting polymer PEDOT:PSS, and activated carbon filler particles. Cationic fibres saturated with anionic PEDOT:PSS provide a conducting scaffold hosting the activated carbon, which functions as the active charge-storage material. The response from further additives was systematically investigated for several critical paper properties. Cellulose nanofibrils were found to improve mechanical properties, while carbon black enhanced both the conductivity and the storage capacity of the activated carbon, reaching a specific capacitance of 67 F g−1. This pilot trial shows that “classical” papermaking methods are fit for the purpose and provides valuable insights on how to further advance bio-based energy storage solutions for large-scale applications.
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| 8. |
- Lay, Makara, et al.
(författare)
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Direct Ink Writing of Nanocellulose and PEDOT:PSS for Flexible Electronic Patterned and Supercapacitor Papers
- 2023
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Ingår i: Advanced Materials Technologies. - : WILEY. - 2365-709X. ; 8:18
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Tidskriftsartikel (refereegranskat)abstract
- Printed electronic paper identifies its interest in flexible organic electronics and sustainable and clean energy applications because of its straightforward production method, cost-effectiveness, and positive environmental impact. However, current limitations include restricted material thickness and the use of supporting substrate for printing. Here, 2D and 3D electronic patterned paper are fabricated from direct ink writing (DIW) nanocellulose and PEDOT:PSS-based materials using syringe deposition and 3D printing. The conductor patterns are integrated in the bulk of the paper, while non-conductive sections are used as support to form free-standing paper. The strong interface between the patterns of electronic patterned paper gives mechanical stability for practical handling. The conductive paper-based electrode has 202 S cm(-1) and is capable of handling electric current up to 0.7 A, which can be used for high-power devices. Printed supercapacitor papers show high specific energy of 4.05 Wh kg(-1), specific power of 4615 W kg(-1) at 0.06 A g(-1), and capacitance retention above 95% after 2000 cycles. The new design structure of electronic patterned papers presents a solution for additive manufacturing of paper-based composites for supercapacitors, wearable electronics, or sensors for smart packaging.
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| 9. |
- Mastantuoni, Gabriella G., et al.
(författare)
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In Situ Lignin Sulfonation for Highly Conductive Wood/Polypyrrole Porous Composites
- 2023
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Ingår i: Advanced Materials Interfaces. - : Wiley. - 2196-7350. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- To address the rising need of sustainable solutions in electronic devices, the development of electronically conductive composites based on lightweight but mechanically strong wood structures is highly desirable. Here, a facile approach for the fabrication of highly conductive wood/polypyrrole composites through top-down modification of native lignin followed by polymerization of pyrrole in wood cell wall. By sodium sulfite treatment under neutral condition, sulfonated wood veneers with increased porosity but well-preserved cell wall structure containing native lignin and lignosulfonates are obtained. The wood structure has a content of sulfonic groups up to 343 µmol g−1 owing to in situ sulfonated lignin which facilitates subsequent oxidative polymerization of pyrrole, achieving a weight gain of polypyrrole as high as 35 wt%. The lignosulfonates in the wood structure act as dopant and stabilizer for the synthesized polypyrrole. The composite reaches a high conductivity of 186 S m−1 and a specific pseudocapacitance of 1.71 F cm−2 at the current density of 8.0 mA cm−2. These results indicate that tailoring the wood/polymer interface in the cell wall and activating the redox activity of native lignin by sulfonation are important strategies for the fabrication of porous and lightweight wood/conductive polymer composites with potential for sustainable energy applications.
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| 10. |
- Mastantuoni, Gabriella G., et al.
(författare)
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Rationally designed conductive wood with mechanoresponsive electrical resistance
- 2024
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Ingår i: Composites. Part A, Applied science and manufacturing. - : Elsevier BV. - 1359-835X .- 1878-5840. ; 178
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Tidskriftsartikel (refereegranskat)abstract
- Porous cellular foams, combining lightweight, high strength, and compressibility, hold great promise in a wide range of advanced applications. Here, the native structure of pine wood was modified by in-situ lignin sulfonation and unidirectional freezing, resulting in an alveolate structure inside the wood cell wall with arrays of sub-100 nm channels. The obtained wood foam exhibited highly enhanced permeability while retaining the native cellular arrangement and high lignin and hemicellulose content. Such engineered cellular foam contributed to superior mechanical performance with compressive strength of 9 MPa and Young's modulus of 344 MPa in the longitudinal direction. The high porosity allowed homogeneous infiltration of conductive polymer PEDOT:PSS inside the wood cell wall. The resulting composite exhibited high conductivity, sponge-like compressibility and the ability to modulate electrical resistance in a reversible manner in the radial direction. This rationally designed conductive wood demonstrated potential in durable and ultrasensitive pressure-responsive devices and strain sensors.
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