| 1. |
- Chen, Cheng, et al.
(författare)
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Mass Transport Behaviors in Graphene and Polyaniline Heterostructure-Based Microsupercapacitors
- 2021
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Ingår i: Advanced energy and sustainability research. - : Wiley. - 2699-9412. ; 2:5
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Tidskriftsartikel (refereegranskat)abstract
- The development of miniaturized energy storage components with high areal performance for emerging electronics depends on scalable fabrication techniques for thick electrodes and an in-depth understanding of the intrinsic properties of materials. Based on the coprecipitation behavior of electrically exfoliated graphene and reduced graphene oxide–templated polyaniline (PANi) nanoflake, this work develops a simple, green, low-cost, and scalable drop-casted technique to easily fabricate uniform thick electrodes (up to 80 μm) on various substrates. Through using a direct laser writing process, planar microsupercapacitors can be readily attained. As-fabricated flexible all-solid-state microsupercapacitors exhibit an ultrahigh areal capacitance of 172 mF cm−2 at 0.1 A cm−2 and excellent cycling stability of 91% capacitance retention over 2000 cycles at a high current density of 1.0 A cm−2. Furthermore, based on the electrochemical quartz crystal microbalance research result, the pseudocapacitance contribution is mostly provided by the adsorption/desorption of SO42− anions during the protonation process of PANi. This work offers a simple strategy toward superior-performance micro-sized energy devices and a new perspective to understand the origin of the capacitance of composites and heterostructures.
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| 2. |
- Li, Jiantong, et al.
(författare)
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All-solid-state micro-supercapacitors based on inkjet printed graphene electrodes
- 2016
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Ingår i: Applied Physics Letters. - : American Institute of Physics (AIP). - 0003-6951 .- 1077-3118. ; 109:12
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Tidskriftsartikel (refereegranskat)abstract
- The all-solid-state graphene-based in-plane micro-supercapacitors are fabricated simply through reliable inkjet printing of pristine graphene in interdigitated structure on silicon wafers to serve as both electrodes and current collectors, and a following drop casting of polymer electrolytes (polyvinyl alcohol/H3PO4). Benefiting from the printing processing, an attractive porous electrode microstructure with a large number of vertically orientated graphene flakes is observed. The devices exhibit commendable areal capacitance over 0.1 mF/cm(2) and a long cycle life of over 1000 times. The simple and scalable fabrication technique for efficient micro-supercapacitors is promising for on-chip energy storage applications in emerging electronics.
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| 3. |
- Li, Zheng, et al.
(författare)
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Inkjet Printed Disposable High-Rate On-Paper Microsupercapacitors
- 2022
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 32:1, s. 2108773-
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Tidskriftsartikel (refereegranskat)abstract
- On-paper microsupercapacitors (MSCs) are a key energy storage component for disposable electronics that are anticipated to essentially address the increasing global concern of electronic waste. However, nearly none of the present on-paper MSCs combine eco-friendliness with high electrochemical performance (especially the rate capacity). In this work, highly reliable conductive inks based on the ternary composite of poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS), graphene quantum dots and graphene are developed for scalable inkjet printing of compact (footprint area ≈ 20 mm2) disposable MSCs on commercial paper substrates. Without any post treatment, the printed patterns attain a sheet resistance as low as 4 Ω ▫−1. The metal-free all-solid-state MSCs exhibit a maximum areal capacitance > 2 mF cm−2 at a high scan rate of 1000 mV s−1, long cycle life (>95% capacitance retention after 10 000 cycles), excellent flexibility, and long service time. Remarkably, the “totally metal-free” MSC arrays are fully inkjet printed on paper substrates and also exhibit high rate performance. The life cycle assessment indicates that these printed devices have much lower eco-toxicity and global warming potential than other on-paper MSCs.
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| 4. |
- Mishukova, Viktoriia
(författare)
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Direct patterning processes for high-performance microsupercapacitors
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The surge in miniaturized electronic components driven by the Internet of Things (IoT) has prompted an interest in non-traditional energy storage solutions. For these applications, reduction of size while preserving power and energy densities are of great importance. Within this context, planar microsupercapacitors (MSCs) have emerged as strong candidates for energy storage. Their unique two-dimensional structure, rapid charge-discharge capabilities, high power density, and enduring stability make them highly appealing as power units for on-chip integration.However, the intricate nature of MSC fabrication remains a substantial challenge. Conventionally used indirect patterning processes, such as photolithography, are limiting the implementation of novel functional nanomaterials with high charge storing capacities. As a result, other kinds of direct patterning processes can be used to fabricate state-of-the-art MSCs. Recent studies mainly focused on improving the patterning geometry, minimizing electrode dimensions and narrowing the electrode gap to maintain high resolution of MSCs. However, these efforts were made at the expense of process scalability potential and degree of complexity of the fabrication processes. This thesis aims to develop fabrication process flows with emphasis on simplicity and versatility without sacrificing the possibility for large-scale fabrication of MSCs with high-performance.The first part of this thesis describes the implementation of highly scalable inkjet printing process for fabrication of high-performance MSCs. Typically, inkjet printing can be used to deposit thin films of materials. However, to fabricate MSCs with high-performance, the thickness is a crucial parameter that requires scaling up. The contribution of the first work is dealing with overcoming printing limitations by describing a step-like fabrication process that was developed to overcome the limitations of inkjet printing to increase the thickness of the electrode material, and, therefore its electrochemical performance. The outcome graphene-based solid-state MSCs free from metallic current collector exhibit high areal capacitance of 0.1mF cm−2 and hold promise for on-chip fabrication. In the second work, a facile integration of inkjet printing with an electrodeposition technique is used to fabricate hybrid flexible MSCs based on graphene, Fe2O3, and MnO2 nanomaterials with∼90% capacitance retention after 10 000 charge-discharge cycles.In the second part of this thesis, direct laser writing process is implemented as a viable alternative to fabrication of planar MSCs, based on a variety of highly electrochemically active nanomaterials that are not compatible with inkjet printing. In the third, fourth, and fifth works binder-free ink formulation approaches were developed to fabricate composite nanomaterial films based on graphene, graphene oxide, carbon nanotubes (CNTs), and polyaniline (PANI). Efficient patterning of these films, thanks to the wide range of controls over the laser beam, was realized highlighting the simplicity of the developed fabrication processes for MSCs with high areal capacitance of 172 mF cm−2. Furthermore, it enabled the fabrication of MSCs that can operate in a wide temperature range from 25 to 250 °C.In summary, this thesis reshapes the MSC fabrication process by considering performance, scalability, and process adaptability towards novel functional nanomaterials. These proposed methods are further strengthened by innovative ink formulation strategies using these materials, highlighting their potential applicability in emergent energy storage devices.
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| 5. |
- Mishukova, Viktoriia, et al.
(författare)
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Facile fabrication of graphene-based high-performance microsupercapacitors operating at a high temperature of 150 °C
- 2021
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Ingår i: Nanoscale Advances. - : Royal Society of Chemistry (RSC). - 2516-0230. ; 3:16, s. 4674-4679
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Tidskriftsartikel (refereegranskat)abstract
- Many industry applications require electronic circuits and systems to operate at high temperatures over 150 °C. Although planar microsupercapacitors (MSCs) have great potential for miniaturized on-chip integrated energy storage components, most of the present devices can only operate at low temperatures (<100 °C). In this work, we have demonstrated a facile process to fabricate activated graphene-based MSCs that can work at temperatures as high as 150 °C with high areal capacitance over 10 mF cm−2and good cycling performance. Remarkably, the devices exhibit no capacitance degradation during temperature cycling between 25 °C and 150 °C, thanks to the thermal stability of the active components.
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| 6. |
- Mishukova, Viktoriia, et al.
(författare)
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Microsupercapacitors Working at 250 °C
- 2023
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Ingår i: Batteries & Supercaps. - : Wiley-VCH Verlagsgesellschaft. - 2566-6223.
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Tidskriftsartikel (refereegranskat)abstract
- The raised demand for portable electronics in high-temperature environments (>150 °C) stimulates the search for solutions to release the temperature constraints of power supply. All-solid-state microsupercapacitors (MSCs) are envisioned as promising on-chip power supply components, but at present, nearly none of them can work at temperature over 200 °C, mainly restricted by the electrolytes which possess either low thermal stability or incompatible fabrication process with on-chip integration. In this work, we have developed a novel process to fabricate highly thermally stable ionic liquid/ceramic composite electrolytes for on-chip integrated MSCs. Remarkably, the electrolytes enable MSCs with graphene-based electrodes to operate at temperatures as high as 250 °C with a high areal capacitance (~72 mF cm−2 at 5 mV s−1) and good cycling stability (70 % capacitance retention after 1000 cycles at 1.4 mA cm−2).
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| 7. |
- Xia, Zhenyuan, 1983, et al.
(författare)
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Selective deposition of metal oxide nanoflakes on graphene electrodes to obtain high-performance asymmetric micro-supercapacitors
- 2021
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Ingår i: Nanoscale. - 2040-3372 .- 2040-3364. ; 13:5, s. 3285-3294
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Tidskriftsartikel (refereegranskat)abstract
- To meet the charging market demands of portable microelectronics, there has been a growing interest in high performance and low-cost microscale energy storage devices with excellent flexibility and cycling durability. Herein, interdigitated all-solid-state flexible asymmetric micro-supercapacitors (A-MSCs) were fabricated by a facile pulse current deposition (PCD) approach. Mesoporous Fe2O3 and MnO2 nanoflakes were functionally coated by electrodeposition on inkjet-printed graphene patterns as negative and positive electrodes, respectively. Our PCD approach shows significantly improved adhesion of nanostructured metal oxide with crack-free and homogeneous features, as compared with other reported electrodeposition approaches. The as-fabricated Fe2O3/MnO2 A-MSCs deliver a high volumetric capacitance of 110.6 F cm(-3) at 5 mu A cm(-2) with a broad operation potential range of 1.6 V in neutral LiCl/PVA solid electrolyte. Furthermore, our A-MSC devices show a long cycle life with a high capacitance retention of 95.7% after 10 000 cycles at 100 mu A cm(-2). Considering its low cost and potential scalability to industrial levels, our PCD technique could be an efficient approach for the fabrication of high-performance MSC devices in the future.
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| 8. |
- Xia, Zhenyuan, et al.
(författare)
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Selective deposition of metal oxide nanoflakes on graphene electrodes to obtain high-performance asymmetric micro-supercapacitors
- 2021
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Ingår i: Nanoscale. - : Royal Society of Chemistry (RSC). - 2040-3364 .- 2040-3372. ; 13:5, s. 3285-3294
-
Tidskriftsartikel (refereegranskat)abstract
- To meet the charging market demands of portable microelectronics, there has been a growing interest in high performance and low-cost microscale energy storage devices with excellent flexibility and cycling durability. Herein, interdigitated all-solid-state flexible asymmetric micro-supercapacitors (A-MSCs) were fabricated by a facile pulse current deposition (PCD) approach. Mesoporous Fe2O3 and MnO2 nanoflakes were functionally coated by electrodeposition on inkjet-printed graphene patterns as negative and positive electrodes, respectively. Our PCD approach shows significantly improved adhesion of nanostructured metal oxide with crack-free and homogeneous features, as compared with other reported electrodeposition approaches. The as-fabricated Fe2O3/MnO2 A-MSCs deliver a high volumetric capacitance of 110.6 F cm(-3) at 5 mu A cm(-2) with a broad operation potential range of 1.6 V in neutral LiCl/PVA solid electrolyte. Furthermore, our A-MSC devices show a long cycle life with a high capacitance retention of 95.7% after 10 000 cycles at 100 mu A cm(-2). Considering its low cost and potential scalability to industrial levels, our PCD technique could be an efficient approach for the fabrication of high-performance MSC devices in the future.
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| 9. |
- Xue, Han, et al.
(författare)
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Ocean wave energy generator based on graphene/TiO2 nanoparticle composite films†
- 2022
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Ingår i: Nanoscale Advances. - : Royal Society of Chemistry (RSC). - 2516-0230. ; 4:6, s. 1533-1537
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Tidskriftsartikel (refereegranskat)abstract
- Harvesting ocean wave energy through carbon-based materials, particularly graphene, is receiving increasing attention. However, the complicated fabrication process and the low output power of the present monolayer graphene-based wave energy generators limit their further application. Here, we demonstrate the facile fabrication of a new type of wave energy generator based on graphene/TiO2 nanoparticle composite films using the doctor-blading method. The developed wave energy harvesting device exhibits a high open-circuit voltage of up to 75 millivolts and a high output power up to 1.8 microwatts. A systematic study was conducted to explore the optimal conditions for the energy harvesting performance.
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