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- 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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| 2. |
- Say, Mehmet Girayhan, 1992-
(författare)
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Hybrid Materials for Wearable Electronics and Electrochemical Systems
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Flexible electronic systems such as wearable devices, sensors and electronic skin require power sources and sensing units that are mechanically robust, operational at low bending radius, and environmentally friendly. Recently, there has been an enormous interest in active materials such as thin film semiconductors, conductive polymers, and ion-electron conductors. These materials can be deposited with both printing and microfabrication techniques onto the flexible substrates such as plastics and paper. In addition, paper-based composites with nanofibrillated cellulose are favorable due to their mechanical strength, porosity, and solution-processability. Printing of such systems enables mass-production of large area electrochemical devices i.e., batteries, supercapacitors and fuel cells. Moreover, designing ultrathin devices for such concepts are promising for implantable and skin-like conformable electronics.The aim of this thesis is the development of flexible electronic devices where, both organic and inorganic materials are explored, and examples of smart packaging and wearable electronics are demonstrated. Within the thesis, two different fabrication approaches are presented to achieve flexible electronics: (1) fabrication of porous paper electrodes for printable, wearable supercapacitor applications, where our efforts towards sustainable solutions for energy storage and (2) development of ultraflexible devices for electronic skin and implantable electronics to attain miniaturized, ultrathin device concepts. Overall, high performance electronic devices and demonstrators shown here have a significant impact on portable hybrid systems and flexible electronics applications.
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| 3. |
- Say, Mehmet Girayhan, 1992-, et al.
(författare)
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Ultrathin Paper Microsupercapacitors for Electronic Skin Applications
- 2022
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Ingår i: Advanced Materials Technologies. - : John Wiley and Sons Inc. - 2365-709X. ; 7:8
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Tidskriftsartikel (refereegranskat)abstract
- Ultrathin devices are rapidly developing for skin-compatible medical applications and wearable electronics. Powering skin-interfaced electronics requires thin and lightweight energy storage devices, where solution-processing enables scalable fabrication. To attain such devices, a sequential deposition is employed to achieve all spray-coated symmetric microsupercapacitors (μSCs) on ultrathin parylene C substrates, where both electrode and gel electrolyte are based on the cheap and abundant biopolymer, cellulose. The optimized spraying procedure allows an overall device thickness of ≈11 µm to be obtained with a 40% active material volume fraction and a resulting volumetric capacitance of 7 F cm−3. Long-term operation capability (90% of capacitance retention after 104 cycles) and mechanical robustness are achieved (1000 cycles, capacitance retention of 98%) under extreme bending (rolling) conditions. Finite element analysis is utilized to simulate stresses and strains in real-sized μSCs under different bending conditions. Moreover, an organic electrochromic display is printed and powered with two serially connected μ-SCs as an example of a wearable, skin-integrated, fully organic electronic application. © 2022 The Authors.
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| 4. |
- Wang, Xin, et al.
(författare)
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Upscalable ultra thick rayon carbon felt based hybrid organic-inorganic electrodes for high energy density supercapacitors
- 2022
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Ingår i: Energy Storage. - : John Wiley and Sons Inc. - 2578-4862. ; 4:5
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Tidskriftsartikel (refereegranskat)abstract
- Low weight, small footprint, and high performances are essential requisites for the implementation of energy storage devices within consumer electronics. One way to achieve these goals is to increase the thickness of the active material layer. In this work, carbonized and graphitized rayon felt, a cellulose-derived material, is used as a three-dimensional current collector scaffold to enable the incorporation of large amount of active energy storage materials and ionic liquid-based gel electrolyte in the supercapacitor devices. PEDOT:PSS, alone or in combination with active carbon, has been used as the active material. Three-dimensional supercapacitors with high per unit area capacitance (more than 1.1 F/cm2) have been achieved owing to the loading of large amount of active material in the felt matrix. Areal energy density of more than 101 μWh/cm2 and areal power density of more than 5.9 mW/cm2 have been achieved for 0.8 V operating voltage at a current density of 1 mA/cm2. A nanographite material was found to be beneficial in reducing the internal serial resistance of the supercapacitor to lower than 1.7 Ω. Furthermore, it was shown that even after 2000 times cycling test, the devices could still retain its performance with at least 88% coulombic efficiency for all the devices. All the materials are readily available commercially, environmentally sustainable and the process can potentially be upscaled with industrial process. © 2022 The Authors.
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