| 1. |
- 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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| 2. |
- Su, Yingchun, et al.
(författare)
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Monolithic Fabrication of Metal‐Free On‐Paper Self‐Charging Power Systems
- 2024
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028.
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Tidskriftsartikel (refereegranskat)abstract
- Self-charging power systems (SCPSs) are envisioned as promising solutions for emerging electronics to mitigate the increasing global concern about battery waste. However, present SCPSs suffer from large form factors, unscalable fabrication, and material complexity. Herein, a type of highly stable, eco-friendly conductive inks based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) are developed for direct ink writing of multiple components in the SCPSs, including electrodes for miniaturized spacer-free triboelectric nanogenerators (TENGs) and microsupercapacitors (MSCs), and interconnects. The principle of “one ink, multiple functions” enables to almost fully print the entire SCPSs on the same paper substrate in a monolithic manner without post-integration. The monolithic fabrication significantly improves the upscaling capability for manufacturing and reduces the form factor of the entire SCPSs (a small footprint area of ≈2 cm × 3 cm and thickness of ≈1 mm). After pressing/releasing the TENGs for ≈79000 cycles, the 3-cell series-connected MSC array can be charged to 1.6 V while the 6-cell array to 3.0 V. On-paper SCPSs are promising to serve as lightweight, thin, sustainable, and low-cost power supplies.
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| 3. |
- Chen, Shiqian, et al.
(författare)
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Ultrafast metal-free microsupercapacitor arrays directly store instantaneous high-voltage electricity from mechanical energy harvesters
- 2024
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Ingår i: Advanced Science. - : Wiley. - 2198-3844. ; 11:22
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Tidskriftsartikel (refereegranskat)abstract
- Harvesting renewable mechanical energy is envisioned as a promising and sustainable way for power generation. Many recent mechanical energy harvesters are able to produce instantaneous (pulsed) electricity with a high peak voltage of over 100 V. However, directly storing such irregular high-voltage pulse electricity remains a great challenge. The use of extra power management components can boost storage efficiency but increase system complexity. Here utilizing the conducting polymer PEDOT:PSS, high-rate metal-free micro-supercapacitor (MSC) arrays are successfully fabricated for direct high-efficiency storage of high-voltage pulse electricity. Within an area of 2.4 × 3.4 cm2 on various paper substrates, large-scale MSC arrays (comprising up to 100 cells) can be printed to deliver a working voltage window of 160 V at an ultrahigh scan rate up to 30 V s−1. The ultrahigh rate capability enables the MSC arrays to quickly capture and efficiently store the high-voltage (≈150 V) pulse electricity produced by a droplet-based electricity generator at a high efficiency of 62%, significantly higher than that (<2%) of the batteries or capacitors demonstrated in the literature. Moreover, the compact and metal-free features make these MSC arrays excellent candidates for sustainable high-performance energy storage in self-charging power systems.
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| 4. |
- Hu, Xiangzhao, et al.
(författare)
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Boosting Industrial-Level CO2 Electroreduction of N-Doped Carbon Nanofibers with Confined Tin-Nitrogen Active Sites via Accelerating Proton Transport Kinetics
- 2023
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Ingår i: Advanced Functional Materials. - : John Wiley and Sons Inc. - 1616-301X .- 1616-3028. ; 33:4
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Tidskriftsartikel (refereegranskat)abstract
- The development of highly efficient robust electrocatalysts with low overpotential and industrial-level current density is of great significance for CO2 electroreduction (CO2ER), however the low proton transport rate during the CO2ER remains a challenge. Herein, a porous N-doped carbon nanofiber confined with tin-nitrogen sites (Sn/NCNFs) catalyst is developed, which is prepared through an integrated electrospinning and pyrolysis strategy. The optimized Sn/NCNFs catalyst exhibits an outstanding CO2ER activity with the maximum CO FE of 96.5%, low onset potential of −0.3 V, and small Tafel slope of 68.8 mV dec−1. In a flow cell, an industrial-level CO partial current density of 100.6 mA cm−2 is achieved. In situ spectroscopic analysis unveil the isolated Sn-N site acted as active center for accelerating water dissociation and subsequent proton transport process, thus promoting the formation of intermediate *COOH in the rate-determining step for CO2ER. Theoretical calculations validate pyrrolic N atom adjacent to the Sn-N active species assisted reducing the energy barrier for *COOH formation, thus boosting the CO2ER kinetics. A Zn-CO2 battery is designed with the cathode of Sn/NCNFs, which delivers a maximum power density of 1.38 mW cm−2 and long-term stability.
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| 5. |
- Li, Gui, et al.
(författare)
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In operando study of microsupercapacitors with gel electrolytes using nano-beam synchrotron X-ray diffraction
- 2024
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Ingår i: Batteries & Supercaps. - : Wiley-VCH Verlagsgesellschaft. - 2566-6223. ; 7:8
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Tidskriftsartikel (refereegranskat)abstract
- Synchrotron radiation X-ray diffraction (XRD) with nanoscale beam size was used here for in situ and in operando study of micro-supercapacitors (MSC) with gel electrolyte and MXene Ti3C2Tx electrodes. The electrode structure was characterized as a function of applied voltage and distance from the gap separating electrodes using microscopic cells with cylindrical shape designed for transmission mode XRD. The devices with gel electrolytes based on H2SO4 (with H2O/PVA and DMSO/PVA) showed stable performance with no changes in MXene structure under voltage swaps between positive and negative values. Experiments with KI-based electrolytes demonstrated changes of MXene structure correlated with decrease of energy storage parameters under conditions of increased operation voltage starting from 0.8 V. The optimal performance of the MSCs was observed when the MXene structure remained unchanged upon switching the applied voltage polarity. The changes of inter-layer distance of MXene upon swap of applied voltage correlate with decrease of device performance and are undesirable for stable operation of MSC's. We also tested feasibility of X-ray fluorescence (XRF) for characterization of electrolyte ion migration in MSCs using 2D element mapping. Irreversible sorption of iodine by MXene was found using XRF mapping of charged electrodes using standard in-plane MSC device and KI electrolyte.
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| 6. |
- Su, Yingchun, et al.
(författare)
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Monolithic Fabrication of On-Paper Self-Charging Power Systems Through Direct Ink Writing
- 2024
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Ingår i: NordPac 2024 - 60th Annual Microelectronics and Packaging Conference and Exhibition. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- The rapid development of emerging electronics requires power sources with the advantages of lightweight, high efficiency, and portability. Considering the use of critical raw materials (such as Li, Co, etc.) and the increasing global concern of battery waste, self-charging power systems (SCPSs) integrating energy harvesting, power management, and energy storage devices have been envisioned as promising solutions to replace traditional batteries to avoid the use of toxic materials and the need of frequent recharging/replacement. Up to date, the reported SCPSs still hold the problem of large form factor, unscalable fabrication, noble materials, and material complexity. In our work, a highly stable and eco-friendly organic conductive ink based on poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) has been developed for monolithic fabrication on-paper SCPSs almost fully through a simple direct ink writing (DIW) process. The ink possesses multiple functions and enables to directly print almost all the key components in the SCPSs, including electrodes for triboelectric nanogenerators (TENGs, mechanical energy harvesters), electrodes for micro-supercapacitors (MSCs, energy storage devices), and interconnects, on the same paper substrate in a monolithic manner without the need for “post-integration”. The monolithic printing process exhibits excellent upscaling capability for manufacturing. In particular, the direct patterning merit of the DIW process offers great flexibility in optimizing the system performance through adjusting the cell number, electrode dimension, and thickness of the MSC arrays. By adjusting the cell numbers, the MSC arrays attain high-rate capability up to 50 V/s to match the pulsing electricity produced from the TENGs. For small-size printed SCPSs (~ 2 cm × 3 cm ×1 mm), after continuous press and release of the TENGs for ~79000 cycles, the 3-cell series-connected MSC array can be charged to 1.6 V while 6-cell array to 3.0 V. For a larger-size printed SCPS with 30 MSC cells (~ 7.5 cm × 5 cm ×0.5 mm), after charging through pressing/releasing for 10 min (nearly 1200 cycles), it can light up a LED (~ 4 W) for 5 s. The demo of successfully powering an LED device exhibited its great potential for powering various electronics. The monolithically fabricated on-paper SCPSs have great potential to serve as lightweight, thin, sustainable, eco-friendly, and low-cost power supplies for emerging electronics.
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| 7. |
- Zhou, Y., et al.
(författare)
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Versatile Functionalization of Carbon Nanomaterials by Ferrate(VI)
- 2020
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Ingår i: Nano-Micro Letters. - : Springer. - 2311-6706 .- 2150-5551. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- As a high-valent iron compound with Fe in the highest accessible oxidation state, ferrate(VI) brings unique opportunities for a number of areas where chemical oxidation is essential. Recently, it is emerging as a novel oxidizing agent for materials chemistry, especially for the oxidation of carbon materials. However, the reported reactivity in liquid phase (H2SO4 medium) is confusing, which ranges from aggressive to moderate, and even incompetent. Meanwhile, the solid-state reactivity underlying the “dry” chemistry of ferrate(VI) remains poorly understood. Herein, we scrutinize the reactivity of K2FeO4 using fullerene C60 and various nanocarbons as substrates. The results unravel a modest reactivity in liquid phase that only oxidizes the active defects on carbon surface and a powerful oxidizing ability in solid state that can open the inert C=C bonds in carbon lattice. We also discuss respective benefit and limitation of the wet and dry approaches. Our work provides a rational understanding on the oxidizing ability of ferrate(VI) and can guide its application in functionalization/transformation of carbons and also other kinds of materials.[Figure not available: see fulltext.].
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| 8. |
- 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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| 9. |
- Delekta, Szymon Sollami, et al.
(författare)
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Drying-Mediated Self-Assembly of Graphene for Inkjet Printing of High-Rate Micro-supercapacitors
- 2020
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Ingår i: Nano-Micro Letters. - : Springer. - 2311-6706 .- 2150-5551. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Scalable fabrication of high-rate micro-supercapacitors (MSCs) is highly desired for on-chip integration of energy storage components. By virtue of the special self-assembly behavior of 2D materials during drying thin films of their liquid dispersion, a new inkjet printing technique of passivated graphene micro-flakes is developed to directly print MSCs with 3D networked porous microstructure. The presence of macroscale through-thickness pores provides fast ion transport pathways and improves the rate capability of the devices even with solid-state electrolytes. During multiple-pass printing, the porous microstructure effectively absorbs the successively printed inks, allowing full printing of 3D structured MSCs comprising multiple vertically stacked cycles of current collectors, electrodes, and sold-state electrolytes. The all-solid-state heterogeneous 3D MSCs exhibit excellent vertical scalability and high areal energy density and power density, evidently outperforming the MSCs fabricated through general printing techniques.[Figure not available: see fulltext.].
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| 10. |
- Huang, J., et al.
(författare)
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Perovskite oxide and polyazulene–based heterostructure for high–performance supercapacitors
- 2021
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Ingår i: Journal of Applied Polymer Science. - : John Wiley and Sons Inc. - 0021-8995 .- 1097-4628. ; 138:41
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Tidskriftsartikel (refereegranskat)abstract
- Several types of electrode materials have been developed for high–performance supercapacitors. Most of the relevant studies have focused on the discovery of new atomic structures and paid limited attention to the effect of heterostructures in supercapacitor electrodes, which has long hindered the fundamental understanding of the use of hybrid materials in supercapacitors. In this study, a novel heterostructure based on perovskite oxide (LaNiO3) nanosheets and polyazulene was synthesized. The as–prepared heterostructure–based supercapacitor exhibited a specific capacitance of up to 464 F g−1 at a high current density of 2 A g−1 in 1–ethyl–3–methylimidazolium tetrafluoroborate. In a symmetric supercapacitor, this heterostructure delivered an energy density of up to 56.4 Wh kg−1 at a power density of 1100 W kg−1. Both LaNiO3 and polyazulene contributed pseudocapacitance and dominated the performance. Unexpectedly, electric double–layer capacitance was found to contribute in this system. Density functional theory calculations indicated that the advantage of the high electrical conductivity of the heterostructure benefited the supercapacitor operation. Electrochemical quartz crystal microbalance analysis revealed that the fast ion flux and adsorption boosted performance. The high intrinsic electrical conductivity and improved stability make this heterostructure a promising electrode material candidate for supercapacitors.
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