| 1. |
- Calcagno, Giulio, 1990, et al.
(författare)
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Fast charging negative electrodes based on anatase titanium dioxide beads for highly stable Li-ion capacitors
- 2020
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Ingår i: Materials Today Energy. - : Elsevier BV. - 2468-6069. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Hybrid energy storage systems aim to achieve both high power and energy densities by combining supercapacitor-type and battery-type electrodes in tandem. The challenge is to find sustainable materials as fast charging negative electrodes, which are characterized by high capacity retention. In this study, mesoporous anatase beads are synthetized with tailored morphology to exploit fast surface redox reactions. The TiO2-based electrodes are properly paired with a commercial activated carbon cathode to form a Li-ion capacitor. The titania electrode exhibits high capacity and rate performance. The device shows extremely stable performance with an energy density of 27 mWh g-1 at a specific current of 2.5 A g−1 for 10,000 cycles. The remarkable stability is associated with a gradual shift of the potential during cycling as result of the formation of cubic LiTiO2 on the surface of the beads. This phenomenon renews the interest in using TiO2 as negative electrode for Li-ion capacitors.
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| 2. |
- Grieco, Rebecca, et al.
(författare)
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A significantly improved polymer||Ni(OH) 2 alkaline rechargeable battery using anthraquinone-based conjugated microporous polymer anode
- 2022
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Ingår i: Materials Today Energy. - : Elsevier BV. - 2468-6069. ; 27
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Tidskriftsartikel (refereegranskat)abstract
- Alkaline rechargeable batteries (ARBs) are predicted to be an attractive solution for large-scale electrochemical energy storage applications. However, their advancement is greatly hindered by the lack of high-performance and sustainable anode that can stably operate in less-corroding, low electrolyte concentration. Herein, we report the first example of polymer ARB able to operate in low concentrate electrolyte (1м potassium hydroxide [KOH]) due to the employment of a robust anthraquinone-based conjugated microporous polymer (IEP-11) as anode. The assembled IEP-11||Ni(OH)2 achieves high cell voltage (0.98 V), high gravimetric/areal capacities (150 mAh/g/7.2 mAh/cm2 at 3.5 and 65 mg/cm2, respectively), long cycle life (22,730 cycles, 960 h, 75% capacity retention at 20C), excellent rate performance (75 mAh/g at 50C) and low temperature operativity (75 mAh/g at −10 °C). Furthermore, rate capability, low-temperature performance and ability to prepare high mass loading anodes, along with low self-discharge is improved compared to conventional linear poly (anthraquinone sulfide) (PAQS) in commonly used 10 м KOH. This overall performance for IEP-11||Ni(OH)2 is not only far superior to that of PAQS||Ni(OH)2 owing to porous polymer's high specific surface area, combined micro-/mesoporosity and robust and mechanically stable three-dimensional (3D) architecture compared to the linear PAQS, but also surpass most of the reported organic||nickel [Ni]/cobalt [Co]/manganese [Mn] alkaline rechargeable batteries (ARBs).
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| 3. |
- Oliveira, Filipa M., et al.
(författare)
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Alkaline water electrolysis performance of mixed cation metal phosphorous trichalcogenides
- 2024
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Ingår i: Materials Today Energy. - 2468-6069. ; 39
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Tidskriftsartikel (refereegranskat)abstract
- A variety of mixed-cation metal phosphorus trichalcogenides (MnNiP2S6, FeCoP2S6, FeNiP2S6, CoNiP2S6, FeCoNiP2S6, and the high-entropy CrMnFeNiCoZnP2S6) are synthesized using chemical vapor transport and tested for water splitting under alkaline conditions. Among the materials synthesized, FeCoP2S6 demonstrates the most promising performance, acting as a catalyst with an overpotential of 409 mV and 325 mV for the hydrogen evolution reaction and oxygen evolution reaction (OER), respectively. To further enhance its catalytic activity, a combination of liquid-phase exfoliation techniques assisted by microwave and sonication is employed to FeCoP2S6 (exf-FeCoP2S6), thereby increasing the surface area and exposing more active sites. Promising results are obtained for the OER, with exf-FeCoP2S6 displaying an overpotential of 271 mV, a value very closely matching the best performances reported in the literature under alkaline conditions. Long-term stability tests show a stable profile over time, corroborated by the XPS analysis and computer modeling, which confirms minimal degradation of the catalyst.
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| 4. |
- Raza, Rizwan, 1980, et al.
(författare)
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Functional ceria-based nanocomposites for advanced low-temperature (300–600 °C) solid oxide fuel cell: A comprehensive review
- 2020
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Ingår i: Materials Today Energy. - : Elsevier BV. - 2468-6069. ; 15
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Forskningsöversikt (refereegranskat)abstract
- There is world tendency to develop SOFC to lower temperatures and two technical routes and approaches are going in parallel. One is to use thin film technology, focussing on reducing the electrolyte thickness on conventional electrolyte, e.g. YSZ (yttria-stabilized zirconia) and SDC (samaria-doped ceria) to reduce the cell resistance i.e. to lower the operational temperatures. Another technique is to develop new materials, e.g. functional nanocomposites. This paper presents a state-of-the-art of nanocomposite electrolytes-based advanced fuel cell technology, i.e. low-temperature (300–600 °C) ceria-based fuel cells, a new scenario for fuel cell R&D with an overview of important aspects and frontier subjects. A typical nanocomposite has a core–shell type structure in nano-scale, in which ceria forms a core and a salt, e.g. carbonate or another oxide develops a shell layer covering the core. The functionality of nanocomposites is determined by the interfaces between the constituent phases, which can lead to super or fast ions transport (H+ and O2−) at interfaces. Ionic conductivities >0.1 S cm−1 already at ~300 °C have been reported. Five major characteristics of nanocomposites have been identified as important to their properties and applications in fuel cells: i) advanced materials design based on non-structure or interfacial properties/mechanisms; ii) dual or hybrid H+ and O2− conduction; iii) interfacial super-ionic conduction; iv) transition from non-functional to functional materials; v) use of interfacial and surface redox agents and reactions. In the fuel cell context, it is refer to these functional nano-composites as NANOCOFC (Nanocomposites for Advanced Fuel Cells) to distinguish them from the traditional SOFCs and to be oriented to a new fuel cell R&D strategy.
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| 5. |
- Xiong, Shizhao, 1985, et al.
(författare)
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Lithium electrodeposition for energy storage: filling the gap between theory and experiment
- 2022
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Ingår i: Materials Today Energy. - : Elsevier BV. - 2468-6069. ; 28
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Lithium (Li) metal has been considered a promising anode material for high-energy-density rechargeable batteries, but its utilization is impeded by the nonuniform electrodeposition during the charging process which leads to poor cycling life and safety concerns. Thus, understanding the electrodeposition mechanism of Li-metal anode is of great importance to develop practical engineering strategies for rechargeable Li-metal batteries. The electrodeposition of Li is controlled by both thermodynamic and kinetic factors, such as the solvation free energy of Li-ions, the Li nucleation, the surface diffusion of Li atom, and the strength of the interaction between Li-ion and the electrolyte anion. The scale of the whole process from the Li-ion reduction to the growth of a Li nucleus goes from sub-nanometer up to a few micrometers, which poses an outstanding challenge to both experiments and simulation. In this perspective, we discuss the top-down, the bottom-up, and the middle-way approaches to this challenge and the possible synergies between them.
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| 6. |
- Zahra, M., et al.
(författare)
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Tailoring the ions and bandgaps in a novel semi-ionic energy conversion device for electrochemical performance
- 2020
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Ingår i: Materials Today Energy. - : Elsevier BV. - 2468-6069. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- The new semi-ionic energy conversion (SIEC) device has attracted remarkable attention owing to its clean and environmentally friendly applications. In this device, novel materials and mechanisms have been explored using electronic and ionic conductor materials. The tuning effect of the ions and bandgap has been studied to investigate the structural, optical, and electrochemical performance of the material. Composite materials, gadolinium-doped ceria-cadmium-doped ZnO (GDC-ZnCdO), based on ionic gadolinium-doped ceria (GDC) and semiconductor (ZnCdO) in molar ratios of 1:4, 2:3, 3:2, and 4:1 have been prepared by a wet chemical route. The crystalline structure of the GDC-ZnCdO was studied and found to have cubic and hexagonal wurtzite phases with an average crystallite size of 30–40 nm. The morphology of the prepared composite materials is a homogenous and porous structure. It was found that the addition of GDC increases the transmittance and shows a red shift in the bandgap from 2.70 eV to 2.46 eV. The maximum conductivity of 2.0 S/cm1 was achieved for the sample 4GDC-1ZnCdO at 700°C. Electrochemical impedance spectra and X-ray photoelectron spectroscopy analysis were performed to investigate the electrochemical properties of the prepared semi-ionic composite materials. The SIEC device showed a much better performance than a conventional solid oxide fuel cell. The maximum open-circuit voltage (OCV) of about 1.013 Vand power density of 0.65 W/cm2 were obtained using hydrogen fuel at 600°C, as compared with a conventional fuel cell with 0.72 V and 0.27 W/cm2, respectively. Hence, the results reveal that the ions and bandgap tuning play a crucial role in fuel cell functions. Therefore, it has been determined that the bandgap can be tuned to obtain a better and more stable performance of the SIEC device. This study presents a novel approach to enhance the electrochemical performance with the tailoring of the new semi-ionic materials.
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