| 1. |
- Bombarda, F., et al.
(author)
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Runaway electron beam control
- 2019
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In: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 1361-6587 .- 0741-3335. ; 61:1
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Journal article (peer-reviewed)
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| 2. |
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- 2018
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In: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 58:1
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Research review (peer-reviewed)
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Cavallo, Carmen, 1986, et al.
(author)
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A free-standing reduced graphene oxide aerogel as supporting electrode in a fluorine-free Li2S8 catholyte Li-S battery
- 2019
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In: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 416, s. 111-117
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Journal article (peer-reviewed)abstract
- We report on a novel, simple, and environmentally benign synthesis route for a free-standing reduced graphene oxide (r-GO) aerogel and its application as supporting electrode for the electrochemical redox reaction of sulphur in a catholyte-based lithium-sulphur battery. A mesoporous matrix is formed by a layers of r-GO, providing sites for electrochemical reactions and a highly conducting pathway for electrons. The highly porous structure is easily infiltrated by a catholyte solution providing a homogeneous distribution of the sulphur active material in the conductive graphene matrix and ensuring efficient electrochemical reactions. This is demonstrated by a high capacity, 3.4 mAh cm−2, at high mass loading, 3.2 mg cm−2 of sulphur in the cathode and in total the sulphur loading in the Li-S cell is even double (6.4 mg cm−2). Additionally, the presence of oxygen groups in the r-GO aerogel structure stabilizes the cycling performance and the Li-S cell with the fluorine free catholyte shows a capacity retention of 85% after 350 cycles.
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| 7. |
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| 8. |
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| 9. |
- Fretz, Samuel Joseph, 1987, et al.
(author)
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Amine- and Amide-Functionalized Mesoporous Carbons: A Strategy for Improving Sulfur/Host Interactions in Li-S Batteries
- 2020
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In: Batteries and Supercaps. - : Wiley. - 2566-6223. ; 3:8, s. 757-765
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Journal article (peer-reviewed)abstract
- Lithium-sulfur (Li-S) batteries are of great interest due to their potentially high energy density, but the low electronic conductivity of both the sulfur (S-8) cathode active material and the final discharge product lithium sulfide (Li2S) require the use of a conductive host. Usually made of relatively hydrophobic carbon, such hosts are typically ill-suited to retain polar discharge products such as the intermediate lithium polysulfides (LiPs) and the final Li2S. Herein, we propose a route to increase the sulfur utilization by functionalizing the surface of ordered mesoporous carbon CMK3 with polar groups. These derivatized CMK3 materials are made using a simple two-step procedure of bromomethylation and subsequent nucleophilic substitution with amine or amide nucleophiles. We demonstrate that, compared to the unfunctionalized control, these modified CMK3 surfaces have considerably larger binding energies with LiPs and Li2S, which are proposed to aid the electrochemical conversion between S-8 and Li2S by keeping the LiPs species in close proximity to the carbon surface during Li-S battery cycling. As a result, the functionalized cathodes exhibit significantly improved specific capacities relative to their unmodified precursor.
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| 10. |
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| 11. |
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| 12. |
- Jia, Pan, et al.
(author)
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The combination of 2d layered graphene oxide and 3d porous cellulose heterogeneous membranes for nanofluidic osmotic power generation
- 2021
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In: Molecules. - : MDPI AG. - 1420-3049 .- 1420-3049 .- 1431-5157. ; 26:17
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Journal article (peer-reviewed)abstract
- Salinity gradient energy, as a type of blue energy, is a promising sustainable energy source. Its energy conversion efficiency is significantly determined by the selective membranes. Recently, nanofluidic membrane made by two-dimensional (2D) nanomaterials (e.g., graphene) with densely packed nanochannels has been considered as a high-efficient membrane in the osmotic power generation research field. Herein, the graphene oxide-cellulose acetate (GO–CA) heterogeneous membrane was assembled by combining a porous CA membrane and a layered GO membrane; the combination of 2D nanochannels and 3D porous structures make it show high surface-charge-governed property and excellent ion transport stability, resulting in an efficient osmotic power harvesting. A power density of about 0.13 W/m2 is achieved for the sea–river mimicking system and up to 0.55 W/m2 at a 500-fold salinity gradient. With different functions, the CA and GO membranes served as ion storage layer and ion selection layer, respectively. The GO–CA heterogeneous membrane open a promising avenue for fabrication of porous and layered platform for wide potential applications, such as sustainable power generation, water purification, and seawater desalination.
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| 13. |
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| 14. |
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Sun, Jinhua, 1987, et al.
(author)
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Critical Role of Functional Groups Containing N, S, and O on Graphene Surface for Stable and Fast Charging Li-S Batteries
- 2021
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In: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 17:17
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Journal article (peer-reviewed)abstract
- Lithium‐sulfur (Li‐S) batteries are considered one of the most promising energy storage technologies, possibly replacing the state‐of‐the‐art lithium‐ion (Li‐ion) batteries owing to their high energy density, low cost, and eco‐compatibility. However, the migration of high‐order lithium polysulfides (LiPs) to the lithium surface and the sluggish electrochemical kinetics pose challenges to their commercialization. The interactions between the cathode and LiPs can be enhanced by the doping of the carbon host with heteroatoms, however with relatively low doping content (<10%) in the bulk of the carbon, which can hardly interact with LiPs at the host surface. In this study, the grafting of versatile functional groups with designable properties (e.g., catalytic effects) directly on the surface of the carbon host is proposed to enhance interactions with LiPs. As model systems, benzene groups containing N/O and S/O atoms are vertically grafted and uniformly distributed on the surface of expanded reduced graphene oxide, fostering a stable interface between the cathode and LiPs. The combination of experiments and density functional theory calculations demonstrate improvements in chemical interactions between graphene and LiPs, with an enhancement in the electrochemical kinetics, power, and energy densities.
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| 19. |
- Agostini, Marco, 1987, et al.
(author)
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A high-power and fast charging Li-ion battery with outstanding cycle-life
- 2017
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 7:1
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Journal article (peer-reviewed)abstract
- Electrochemical energy storage devices based on Li-ion cells currently power almost all electronic devices and power tools. The development of new Li-ion cell configurations by incorporating innovative functional components (electrode materials and electrolyte formulations) will allow to bring this technology beyond mobile electronics and to boost performance largely beyond the state-of-theart. Here we demonstrate a new full Li-ion cell constituted by a high-potential cathode material, i.e. LiNi0.5Mn1.5O4, a safe nanostructured anode material, i.e. TiO2, and a composite electrolyte made by a mixture of an ionic liquid suitable for high potential applications, i.e. Pyr(1),4PF6, a lithium salt, i.e. LiPF6, and standard organic carbonates. The final cell configuration is able to reversibly cycle lithium for thousands of cycles at 1000 mAg(-1) and a capacity retention of 65% at cycle 2000.
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| 20. |
- Agostini, Marco, 1987, et al.
(author)
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A mixed mechanochemical-ceramic solid-state synthesis as simple and cost effective route to high-performance LiNi0.5Mn1.5O4 spinels
- 2017
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In: Electrochimica Acta. - : Elsevier BV. - 0013-4686. ; 235, s. 262-269
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Journal article (peer-reviewed)abstract
- The implementation of high potential materials as positive electrodes in high energy Li-ion batteries requires to develop scalable and smart synthetic routes. In the case of the LiNi0.5Mn1.5O4 (LNMO) spinel material, a successful preparation strategy must drive the phase formation in order to obtain structural, morphological and surface properties capable to boost performances in lithium cells and minimize the electrolyte degradation. Here we discuss a novel simple and easily scalable mechanochemical synthetic route, followed by a high temperature annealing in air, to prepare LMNO materials starting from oxides. A synergic doping with chromium and iron has been incorporated, resulting in the spontaneous segregation of a CrOx-rich surface layer. The effect of the annealing temperature on the physico-chemical properties of the LMNO material has been investigated as well as the effect on the performances in Licells.
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| 21. |
- Agostini, Marco, 1987, et al.
(author)
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Designing a Safe Electrolyte Enabling Long‐Life Li/S Batteries
- 2019
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In: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 12:18, s. 4176-4184
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Journal article (peer-reviewed)abstract
- Lithium–sulfur (Li/S) batteries suffer from “shuttle” reactions in which soluble polysulfide species continuously migrate to and from the Li metal anode. As a consequence, the loss of active material and reactions at the surface of Li limit the practical applications of Li/S batteries. LiNO3 has been proposed as an electrolyte additive to reduce the shuttle reactions by aiding the formation of a stable solid electrolyte interphase (SEI) at the Li metal, limiting polysulfide shuttling. However, LiNO3 is continuously consumed during cycling, especially at low current rates. Therefore, the Li/S battery cycle life is limited by the LiNO3 concentration in the electrolyte. In this work, an ionic liquid (IL) [N-methyl-(n-butyl)pyrrolidinium bis(trifluoromethylsulfonyl)imide] was used as an additive to enable longer cycle life of Li/S batteries. By tuning the IL concentration, an enhanced stability of the SEI and lower flammability of the solutions were demonstrated, that is, higher safety of the battery. The Li/S cell built with a high sulfur mass loading (4 mg cm−2) and containing the IL-based electrolyte demonstrated a stable capacity of 600 mAh g−1 for more than double the number of cycles of a cell containing LiNO3 additive.
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| 22. |
- Agostini, Marco, 1987, et al.
(author)
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Designing Highly Conductive Functional Groups Improving Guest-Host Interactions in Li/S Batteries
- 2020
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In: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 16:2
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Journal article (peer-reviewed)abstract
- Li-sulfur batteries are of great interest due to their potential to surpass the energy densities of other battery types, but the low electronic conductivity of both sulfur and its discharge products requires the use of a conductive host material. The most common is the use of different porous carbons which normally are hydrophobic and hardly retain the polar discharge products of the Li/S reaction, such as Li2S and lithium polysulfides (LiPs), at the working electrode. Functionalized hosts have been proposed as a strategy to improve LiPs interactions, including the use of heteroatom doping, organic frameworks, metals, metal oxides, sulfide particles, and conductive polymers. Despite demonstrating an improved cycle life, the functionalized structures often have an intrinsic limitation related to a low electronic conductivity resulting in slow kinetics and poor rate capability of Li/S cells. Herein, recent research trends aimed at designing sulfur electrodes with highly conductive functional groups on nanostructured hosts surface are reviewed. The main concepts, key developments, and parameters for building 3D hosts architectures that enable fast charge rates and long cycle life at high sulfur loadings are discussed.
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| 23. |
- Agostini, Marco, 1987, et al.
(author)
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Free-Standing 3D-Sponged Nanofiber Electrodes for Ultrahigh-Rate Energy-Storage Devices
- 2018
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In: ACS Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 10:40, s. 34140-34146
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Journal article (peer-reviewed)abstract
- We have designed a self-standing anode built-up from highly conductive 3D-sponged nanofibers, that is, with no current collectors, binders, or additional conductive agents. The small diameter of the fibers combined with an internal spongelike porosity results in short distances for lithium-ion diffusion and 3D pathways that facilitate the electronic conduction. Moreover, functional groups at the fiber surfaces lead to the formation of a stable solid-electrolyte interphase. We demonstrate that this anode enables the operation of Li-cells at specific currents as high as 20 A g-1 (approx. 50C) with excellent cycling stability and an energy density which is >50% higher than what is obtained with a commercial graphite anode.
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| 24. |
- Agostini, Marco, 1987, et al.
(author)
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Minimizing the Electrolyte Volume in Li–S Batteries: A Step Forward to High Gravimetric Energy Density
- 2018
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In: Advanced Energy Materials. - : Wiley. - 1614-6840 .- 1614-6832. ; 8:26
-
Journal article (peer-reviewed)abstract
- Sulfur electrodes confined in an inert carbon matrix show practical limitations and concerns related to low cathode density. As a result, these electrodes require a large amount of electrolyte, normally three times more than the volume used in commercial Li-ion batteries. Herein, a high-energy and high-performance lithium–sulfur battery concept, designed to achieve high practical capacity with minimum volume of electrolyte is proposed. It is based on deposition of polysulfide species on a self-standing and highly conductive carbon nanofiber network, thus eliminating the need for a binder and current collector, resulting in high active material loading. The fiber network has a functionalized surface with the presence of polar oxygen groups, with the aim to prevent polysulfide migration to the lithium anode during the electrochemical process, by the formation of S–O species. Owing to the high sulfur loading (6 mg cm−2) and a reduced free volume of the sulfide/fiber electrode, the Li–S cell is designed to work with as little as 10 µL cm−2of electrolyte. With this design the cell has a high energy density of 450 Wh kg−1, a lifetime of more than 400 cycles, and the possibility of low cost, by use of abundant and eco-friendly materials.
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| 25. |
- Agostini, Marco, 1987, et al.
(author)
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Rational Design of Low Cost and High Energy Lithium Batteries through Tailored Fluorine-free Electrolyte and Nanostructured S/C Composite
- 2018
-
In: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 11:17, s. 2981-2986
-
Journal article (peer-reviewed)abstract
- We report a new Li–S cell concept based on an optimized F-free catholyte solution and a high loading nanostructured C/S composite cathode. The Li2S8present in the electrolyte ensures both buffering against active material dissolution and Li+conduction. The high S loading is obtained by confining elemental S (≈80 %) in the pores of a highly ordered mesopores carbon (CMK3). With this concept we demonstrate stabilization of a high energy density and excellent cycling performance over 500 cycles. This Li–S cell has a specific capacity that reaches over 1000 mA h g−1, with an overall S loading of 3.6 mg cm−2and low electrolyte volume (i.e., 10 μL cm−2), resulting in a practical energy density of 365 Wh kg−1. The Li–S system proposed thus meets the requirements for large scale energy storage systems and is expected to be environmentally friendly and have lower cost compared with the commercial Li-ion battery thanks to the removal of both Co and F from the overall formulation.
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| 26. |
- Agostini, Marco, 1987, et al.
(author)
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Stabilizing the Performance of High-Capacity Sulfur Composite Electrodes by a New Gel Polymer Electrolyte Configuration
- 2017
-
In: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 10:17, s. 3490-3496
-
Journal article (peer-reviewed)abstract
- Increased pollution and the resulting increase in global warming are drawing attention to boosting the use of renewable energy sources such as solar or wind. However, the production of energy from most renewable sources is intermittent and thus relies on the availability of electrical energy-storage systems with high capacity and at competitive cost. Lithium–sulfur batteries are among the most promising technologies in this respect due to a very high theoretical energy density (1675 mAh g?1) and that the active material, sulfur, is abundant and inexpensive. However, a so far limited practical energy density, life time, and the scaleup of materials and production processes prevent their introduction into commercial applications. In this work, we report on a simple strategy to address these issues by using a new gel polymer electrolyte (GPE) that enables stable performance close to the theoretical capacity of a low cost sulfur–carbon composite with high loading of active material, that is, 70 % sulfur. We show that the GPE prevents sulfur dissolution and reduces migration of polysulfide species to the anode. This functional mechanism of the GPE membranes is revealed by investigating both its morphology and the Li-anode/GPE interface at various states of discharge/charge using Raman spectroscopy.
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| 27. |
- Ahmed, Mohammad Shamsuddin, et al.
(author)
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Multiscale Understanding of Covalently Fixed Sulfur–Polyacrylonitrile Composite as Advanced Cathode for Metal–Sulfur Batteries
- 2021
-
In: Advanced Science. - : Wiley. - 2198-3844 .- 2198-3844. ; 8:21
-
Research review (peer-reviewed)abstract
- Metal–sulfur batteries (MSBs) provide high specific capacity due to the reversible redox mechanism based on conversion reaction that makes this battery a more promising candidate for next-generation energy storage systems. Recently, along with elemental sulfur (S8), sulfurized polyacrylonitrile (SPAN), in which active sulfur moieties are covalently bounded to carbon backbone, has received significant attention as an electrode material. Importantly, SPAN can serve as a universal cathode with minimized metal–polysulfide dissolution because sulfur is immobilized through covalent bonding at the carbon backbone. Considering these unique structural features, SPAN represents a new approach beyond elemental S8 for MSBs. However, the development of SPAN electrodes is in its infancy stage compared to conventional S8 cathodes because several issues such as chemical structure, attached sulfur chain lengths, and over-capacity in the first cycle remain unresolved. In addition, physical, chemical, or specific treatments are required for tuning intrinsic properties such as sulfur loading, porosity, and conductivity, which have a pivotal role in improving battery performance. This review discusses the fundamental and technological discussions on SPAN synthesis, physicochemical properties, and electrochemical performance in MSBs. Further, the essential guidance will provide research directions on SPAN electrodes for potential and industrial applications of MSBs.
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| 28. |
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| 29. |
- Calcagno, Giulio, 1990, et al.
(author)
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Effect of Nitrogen Doping on the Performance of Mesoporous CMK-8 Carbon Anodes for Li-Ion Batteries
- 2020
-
In: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 13:19
-
Journal article (peer-reviewed)abstract
- Designing carbonaceous materials with heightened attention to the structural properties such as porosity, and to the functionalization of the surface, is a growing topic in the lithium-ion batteries (LIBs) field. Using a mesoporous silica KIT-6 hard template, mesoporous carbons belonging to the OMCs (ordered mesoporous carbons) family, namely 3D cubic CMK-8 and N-CMK-8 were synthesized and thoroughly structurally characterized. XPS analysis confirmed the successful introduction of nitrogen, highlighting the nature of the different nitrogen atoms incorporated in the structure. The work aims at evaluating the electrochemical performance of N-doped ordered mesoporous carbons as an anode in LIBs, underlining the effect of the nitrogen functionalization. The N-CMK-8 electrode reveals higher reversible capacity, better cycling stability, and rate capability, as compared to the CMK-8 electrode. Coupling the 3D channel network with the functional N-doping increased the reversible capacity to similar to 1000 mAh center dot g(-1) for the N-CMK-8 from similar to 450 mAh center dot g(-1) for the undoped CMK-8 electrode. A full Li-ion cell was built using N-CMK-8 as an anode, commercial LiFePO4, a cathode, and LP30 commercial electrolyte, showing stable performance for 100 cycles. The combination of nitrogen functionalization and ordered porosity is promising for the development of high performing functional anodes.
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| 30. |
- Carbone, Lorenzo, et al.
(author)
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Carbon Composites for a High-Energy Lithium–Sulfur Battey with a Glyme-Based Electrolyte
- 2017
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In: ChemElectroChem. - : Wiley. - 2196-0216. ; 4:1, s. 209-215
-
Journal article (peer-reviewed)abstract
- A comparative study of sulfur composites using carbon of various natures, namely, graphite, mesocarbon microbeads, and multi-walled carbon nanotubes, is performed in lithium battery design and evaluation. Morphological and structural analyses, by means of SEM and XRD, cyclic voltammetry and galvanostatic cycling in lithium cells are employed for characterization of the materials. Tetraethylene glycol dimethyl ether containing lithium trifluoromethansulfonate is considered the preferred electrolyte for performing the electrochemical tests. Prior to use in cells, the electrolyte characteristics in terms of 1H, 7Li, and 19F nuclei self-diffusion coefficients, ionic conductivity, and ionic association degree are studied by combining NMR and impedance spectroscopy. The best lithium–sulfur composite reported herein achieves a capacity higher than 500 mAh g?1 over 140 cycles with no sign of dendrite formation or failure. This performance is considered sufficiently suitable for the development of high-energy lithium batteries, in particular, considering the expected safety of the cells by employing a nonflammable glyme electrolyte instead of a conventional carbonate-based one.
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| 31. |
- Celeste, Arcangelo, et al.
(author)
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Enhancement of Functional Properties of Liquid Electrolytes for Lithium-Ion Batteries by Addition of Pyrrolidinium-Based Ionic Liquids with Long Alkyl-Chains
- 2020
-
In: Batteries and Supercaps. - : Wiley. - 2566-6223. ; 3:10, s. 1059-1068
-
Journal article (peer-reviewed)abstract
- Three ionic liquid belonging to the N-alkyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl) imides (Pyr(1),nTFSI with n=4,5,8) have been added as co-solvent to two commonly used electrolytes for Li-ion cells: (a) 1 M lithium hexafluorophosphate (LiPF6) in a mixture of ethylene carbonate (EC) and linear like dimethyl carbonate (DMC) in 1 : 1 v/v and (b) 1 M lithium bis-(trifluoromethanesulfonyl)imide (LiTFSI) in EC : DMC 1 : 1 v/v. These electrolyte formulations (classified as P and T series containing LiPF6 or LiTFSI salts, respectively) have been analyzed by comparing ionic conductivities, transport numbers, viscosities, electrochemical stability as well as vibrational properties. In the case of the Pyr(1,5)TFSI and Pyr(1,8)TFSI blended formulations, this is the first ever reported detailed study of their functional properties in Li-ion cells electrolytes. Overall, P-electrolytes demonstrate enhanced properties compared to the T-ones. Among the various P electrolytes those containing Pyr(1,4)TFSI and Pyr(1,5)TFSI limit the accumulation of irreversible capacity upon cycling with satisfactory performance in lithium cells.
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| 32. |
- Haridas, Anupriya K., et al.
(author)
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A flexible and free-standing FeS/sulfurized polyacrylonitrile hybrid anode material for high-rate sodium-ion storage
- 2020
-
In: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 385:1 April
-
Journal article (peer-reviewed)abstract
- Sodium-ion based energy storage systems have attracted extensive attention due to the similarities in the mechanism of operation with lithium-ion batteries along with the additional benefit of low cost and high abundance of sodium resources. Iron sulfide-based electrodes that operate via conversion mechanism have shown ample potential for high energy sodium-ion storage. However, the problems related with tremendous volume changes and the dissolution of sodium polysulfides in the electrolyte deteriorate the cycle life and limit their application in sodium-ion batteries (SIBs). Herein, a hybrid anode material, FeS/SPAN-HNF, with iron sulfide (FeS) nanoparticles decorated in a sulfurized polyacrylonitrile (SPAN) fiber matrix is demonstrated as flexible and free-standing anode material for high-rate SIBs. Unlike previous strategies in which FeS is encapsulated in an electrochemically inactive carbon matrix, this study utilizes SPAN, an electrochemically active material, as a dual functional matrix that can efficiently buffer volume expansion and sulfur dissolution of FeS nanoparticles as well as provide significant capacity improvement. The as-designed electrode is self-standing and flexible, without current collectors, binders or additional conductive agents, thus rendering enhanced practical capacity and energy density. This electrode showed a high reversible capacity of 782.8 mAh g−1 at 200 mA g−1 with excellent high rate capability, maintaining 327.5 mAh g−1 after 500 cycles at 5 A g−1, emphasizing promising prospects for the development of flexible and high energy density SIBs.
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| 33. |
- Haridas, Anupriya K., et al.
(author)
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Boosting High Energy Density Lithium-Ion Storage via the Rational Design of an FeS-Incorporated Sulfurized Polyacrylonitrile Fiber Hybrid Cathode
- 2019
-
In: ACS Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 11:33, s. 29924-29933
-
Journal article (peer-reviewed)abstract
- In order to satisfy the escalating energy demands, it is inevitable to improve the energy density of current Li-ion batteries. As the development of high-capacity cathode materials is of paramount significance compared to anode materials, here we have designed for the first time a unique synergistic hybrid cathode material with enhanced specific capacity, incorporating cost-effective iron sulfide (FeS) nanoparticles in a sulfurized polyacrylonitrile (SPAN) nanofiber matrix through a rational in situ synthesis strategy. Previous reports on FeS cathodes are scarce and consist of an amorphous carbon matrix to accommodate the volume changes encountered during the cycling process. However, this inactive buffering matrix eventually increases the weight of the cell, reducing the overall energy density. By the rational design of this hybrid composite cathode, we ensure that the presence of covalently bonded sulfur in SPAN guarantees high sulfur utilization, while effectively buffering the volume changes in FeS. Meanwhile, FeS can compensate for the conductivity issues in the SPAN, thereby realizing a synergistically driven dual-active cathode material improving the overall energy density of the composite. Simultaneous in situ generation of FeS nanoparticles within the SPAN fiber matrix was carried out via electrospinning followed by a one-step heating procedure. The developed hybrid cathode material displays enhanced lithium-ion storage, retaining 688.6 mA h g(FeS@SPAN composite)-1 at the end of 500 cycles at 1 A g-1 even within a narrow voltage range of 1-3.0 V. A high discharge energy density > 900 W h kg(FeS@SPAN composite)-1, much higher than the theoretical energy density of the commercial LiCoO2 cathode, was also achieved, revealing the promising prospects of this hybrid cathode material for high energy density applications.
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| 34. |
- Lee, Suyeong, et al.
(author)
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Recent developments and future challenges in designing rechargeable potassium-sulfur and potassium-selenium batteries
- 2020
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In: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 13:11
-
Journal article (peer-reviewed)abstract
- The use of chalcogenide elements, such as sulfur (S) and selenium (Se), as cathode materials in rechargeable lithium (Li) and sodium (Na) batteries has been extensively investigated. Similar to Li and Na systems, rechargeable potassium-sulfur (K-S) and potassium-selenium (K-Se) batteries have recently attracted substantial interest because of the abundance of K and low associated costs. However, K-S and K-Se battery technologies are in their infancy because K possesses overactive chemical properties compared to Li and Na and the electrochemical mechanisms of such batteries are not fully understood. This paper summarizes current research trends and challenges with regard to K-S and K-Se batteries and reviews the associated fundamental science, key technological developments, and scientific challenges to evaluate the potential use of these batteries and finally determine effective pathways for their practical development.
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| 35. |
- Lim, Du Hyun, 1983, et al.
(author)
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An Electrospun Nanofiber Membrane as Gel-Based Electrolyte for Room-Temperature Sodium–Sulfur Batteries
- 2018
-
In: Energy Technology. - : Wiley. - 2194-4296 .- 2194-4288. ; 6:7, s. 1214-1219
-
Journal article (peer-reviewed)abstract
- We report on the synthesis and characterization of an electrospun gel polymer electrolyte (GPE) membrane based on polyacrylonitrile nanofibers (PAN) swollen in a polyethylene glycol dimethyl ether/Na-salt electrolyte solution, for application in room temperature sodium–sulfur (Na–S) batteries. The membranes show a high ionic conductivity, wide electrochemical stability window, and good thermal stability. We demonstrate the performance of the membrane in an Na–S cell using a sulfur–carbon nanotubes composite cathode and Na metal as anode. Our results show that the GPE membrane stabilizes the Na metal anode resulting in stable cycling behavior. The capacity of the Na–S cell, using the GPE membrane and operating at room temperature, is approximately 500 mAh g−1over 40 cycles. The selected electrolyte configuration also provides improved safety by replacing the highly reactive sodium perchlorate (NaClO4) salt previously used in literature. All these benefits make the gel-polymer electrolyte membrane a very promising system for application in room-temperature sodium and sodium–sulfur batteries.
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| 36. |
- Lim, Du Hyun, 1983, et al.
(author)
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Route to sustainable lithium-sulfur batteries with high practical capacity through a fluorine free polysulfide catholyte and self-standing Carbon Nanofiber membranes
- 2017
-
In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 7:1, s. Article no. 6327 -
-
Journal article (peer-reviewed)abstract
- We report on a new strategy to improve the capacity, reduce the manufacturing costs and increase the sustainability of Lithium-Sulfur (LiS) batteries. It is based on a semi-liquid cathode composed of a Li2S8 polysulphide catholyte and a binder-free carbon nanofiber membrane with tailored morphology. The polysulphides in the catholyte have the dual role of active material and providing Li+-conduction, i.e. no traditional Li-salt is used in this cell. The cell is able to deliver an areal capacity as high as 7 mAh cm(-2), twice than that of commercial Lithium-ion batteries (LiBs) and 2-4 times higher than that of state-of-the-art LiS cells. In addition, the battery concept has an improved sustainability from a material point of view by being mainly based on sulfur and carbon and being completely fluorine-free, no fluorinated salt or binders are used, and has potential for upscaling and competitive price. The combination of these properties makes the semi-liquid LiS cell here reported a very promising new concept for practical large-scale energy storage applications.
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| 37. |
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| 38. |
- Maroni, F., et al.
(author)
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Highly Stable Fe3O4/C Composite: A Candidate Material for All Solid-State Lithium-Ion Batteries
- 2020
-
In: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 167:7
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Journal article (peer-reviewed)abstract
- Fe3O4 nanoparticles synthesized by a base catalyzed method are tested in an All-Solid-State (ASLB) battery using a sulfide electrolyte. The pristine nanoparticles were morphologically characterized showing an average size of 12 nm. The evaluation of the electrochemical properties shows high specific capacity values of 506 mAhg(-1) after 350 cycles at a specific current of 250 mAg(-1), with very high stability and coulombic efficiency. (C) 2020 The Author(s). Published on behalf of The Electrochemical Society by IOP Publishing Limited.
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| 39. |
- Maroni, Fabio, et al.
(author)
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V2O5 Cryogel: A Versatile Electrode for All Solid State Lithium Batteries
- 2019
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In: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 166:16, s. A3927-A3931
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Journal article (peer-reviewed)abstract
- All solid-state lithium batteries (ASLB) are paving the attention of the battery community due to the possibility of improving safety at good energy level. Their future development requires the investigation of new electrodes chemistries both based on intercalation or conversion mechanism. In this work we report on the synthesis and characterization of a V2O5 cryogel electrode and its application in ASLB. The combination of V2O5 cryogel and a solid-state electrolyte shows appealing properties of high capacity and enhanced safety.
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| 40. |
- Nicotera, Isabella, et al.
(author)
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A Novel Li+-Nafion-Sulfonated Graphene Oxide Membrane as Single Lithium-Ion Conducting Polymer Electrolyte for Lithium Batteries
- 2019
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In: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 123:45, s. 27406-27416
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Journal article (peer-reviewed)abstract
- Single lithium-ion conducting polymer electrolytes are an innovative concept of solid-state polymer electrolytes (SPEs) for lithium-battery technology. In this work, a lithiated Nafion nanocomposite incorporating sulfonated graphene oxide (sGO-Li+), as well as a filler-free membrane, have been synthesized and characterized. Ionic conductivities and lithium transference number, evaluated by electrochemical techniques after membrane-swelling in organic aprotic solvents (ethylene carbonate-propylene carbonate mixture), display significant values, with sigma approximate to 5 x 10(-4) S cm(-1) at 25 degrees C and t(Li+) close to unity. The absence of solvent leaching on thermal cycles is also noteworthy. The description at molecular level of the lithium transport mechanism has been carefully tackled through a systematic study by Li-7 NMR spectroscopy (pulsed field gradient-PFG and relaxation times), while the mechanical properties of the film electrolytes have been evaluated by dynamic mechanical analysis (DMA) in a wide temperature range. The electrochemical performances of the graphene-based electrolyte in Li/Li symmetric cells and in secondary cells using LiFePO4 as positive electrode show good compatibility and functionality with the Li-metal anode by forming a stable interphase, as well as displaying promising performance in galvanostatic cells.
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| 41. |
- Nitze, Florian, 1981, et al.
(author)
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A binder-free sulfur/reduced graphene oxide aerogel as high performance electrode materials for lithium sulfur batteries
- 2016
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In: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322 .- 2045-2322. ; 6
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Journal article (peer-reviewed)abstract
- Societies' increasing need for energy storage makes it necessary to explore new concepts beyond the traditional lithium ion battery. A promising candidate is the lithium-sulfur technology with the potential to increase the energy density of the battery by a factor of 3-5. However, so far the many problems with the lithium-sulfur system have not been solved satisfactory. Here we report on a new approach utilizing a self-standing reduced graphene oxide based aerogel directly as electrodes, i.e. without further processing and without the addition of binder or conducting agents. We can thereby disrupt the common paradigm of "no battery without binder" and can pave the way to a lithium-sulfur battery with a high practical energy density. The aerogels are synthesized via a one-pot method and consist of more than 2/3 sulfur, contained inside a porous few-layered reduced graphene oxide matrix. By combining the graphene-based aerogel cathode with an electrolyte and a lithium metal anode, we demonstrate a lithium-sulfur cell with high areal capacity (more than 3 mAh/cm(2) after 75 cycles), excellent capacity retention over 200 cycles and good sulfur utilization. Based on this performance we estimate that the energy density of this concept-cell can significantly exceed the Department of Energy (DEO) 2020-target set for transport applications.
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| 42. |
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| 43. |
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| 44. |
- Park, Jimin, et al.
(author)
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Introduction of a nitrate anion with solubility mediator in a carbonate-based electrolyte for a stable potassium metal anode
- 2024
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In: Energy Storage Materials. - 2405-8297. ; 69
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Journal article (peer-reviewed)abstract
- In this study, sodium nitrate (NaNO3) dissolves in a carbonate electrolyte for K-metal batteries (KMBs) using a dimethylacetamide (DMA) solvent with a higher Gutmann donor number than that of NO3−. The K-metal anode in 0.02 M NaNO3 electrolyte exhibits enhanced stability due to the modified solid-electrolyte interphase (SEI) layer resulting from the preferential reduction of NaNO3. Reduced NaNO3 forms ionically conductive and mechanically robust compounds in the SEI layer. This compound plays a critical role in altering the morphology of electrodeposited K-metal from dendritic to spherical, reducing the barrier energy of nucleation potential for K-ions. These unique features make K-metal highly resistant to dendrite formation and aggressive electrolyte chemistry. Therefore, the K-metal anode in the proposed electrolyte containing 0.02 M NaNO3 additive ensures excellent cycle life with stable Coulombic efficiency in both symmetrical K/K half cells and full-cells coupled with a Prussian green FeFe(CN)6 cathode.
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| 45. |
- Renzi, M., et al.
(author)
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An innovative membrane-electrode assembly for efficient and durable polymer electrolyte membrane fuel cell operations
- 2017
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In: International Journal of Hydrogen Energy. - : Elsevier BV. - 0360-3199. ; 42:26, s. 16686-16694
-
Journal article (peer-reviewed)abstract
- An innovative membrane-electrode assembly, based on a polyoxometalate (POM)-modified low-Pt loading cathode and a sulphated titania (S-TiO2)-doped Nafion membrane, is evaluated in a polymer electrolyte membrane fuel cell. The modification of fuel cell cathode with Cs3HPMo11VO40 polyoxometalate is performed to enhance particles dispersion and increase active area, allowing low Pt loading while maintaining performance. The POM's high surface acidity favors kinetics of oxygen reduction reaction. The mesoporous features of POM allow the embedding of Pt inside the micro-mesopores, avoiding the Pt aggregation during fuel cell operation and delaying the aging process, with consequent increase of lifetime. On the other hands, commercial Nafion is modified with superacidic sulphated titanium oxide nanoparticles, allowing operation at low relative humidity and controlled polarization of the MEA. Further MEAs, formed by unmodified Nafion membrane and the POM-based cathode, as well as sulphated titanium-added Nafion and commercial Pt-based electrodes, are used as terms of comparison. The cell performances are studied by polarization curves, electrochemical impedance spectroscopy, Tafel plot analysis and high frequency resistance measurements. The dependence of cell performances on relative humidity is also studied. The catalytic and transport properties are improved using the coupled system, despite the reduced Pt loading, thanks to rich proton environment provided by cathode and membrane.
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| 46. |
- Rubino, Antonio, et al.
(author)
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TiO2nanotubes in lithium-ion batteries
- 2020
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In: AIP Conference Proceedings. - : AIP Publishing. - 1551-7616 .- 0094-243X. ; 2257
-
Conference paper (peer-reviewed)abstract
- In this contribution we report on electrochemical approaches in TiO2 based electrodes synthesis. TiO2 nanotubes (NTs) were synthesized following a facile anodization of titanium sheets. Optimizing the experimental conditions two electrodes with NTs lengths of ∼10 μm (Long) and ∼2 μm (Short), were obtained. At the end of the anodization the amorphous TiO2 (a-TiO2) was thermally treated to promote the conversion in the anatase crystal phase (c-TiO2). Both the Long and Short NTs electrodes were tested for their applications as anodes in lithium-ion batteries (LIBs). A preliminary comparison was performed to evaluate the role of a-TiO2 and c-TiO2 phases. Here, Short a-TiO2 NTs exhibited a fast storage rate respect to Short c-TiO2. Comparing the NTs length, Long a-TiO2 electrodes exhibited the highest specific capacity, close to the theoretical value. Furthermore, all the electrodes tested showed an excellent capacity retention proceeding with Discharge/Charge cycles.
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| 47. |
- Sadd, Matthew, 1994, et al.
(author)
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Polysulfide Speciation and Migration in Catholyte Lithium−Sulfur Cells
- 2022
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In: ChemPhysChem. - : Wiley. - 1439-7641 .- 1439-4235. ; 23:4
-
Journal article (peer-reviewed)abstract
- Semi-liquid catholyte Lithium−Sulfur (Li−S) cells have shown to be a promising path to realize high energy density energy storage devices. In general, Li−S cells rely on the conversion of elemental sulfur to soluble polysulfide species. In the case of catholyte cells, the active material is added through polysulfide species dissolved in the electrolyte. Herein, we use operando Raman spectroscopy to track the speciation and migration of polysulfides in the catholyte to shed light on the processes taking place. Combined with ex-situ surface and electrochemical analysis we show that the migration of polysulfides is central in order to maximize the performance in terms of capacity (active material utilization) as well as interphase stability on the Li-metal anode during cycling. More specifically we show that using a catholyte where the polysulfides have the dual roles of active material and conducting species, e. g. no traditional Li-salt (such as LiTFSI) is present, results in a higher mobility and faster migration of polysulfides. We also reveal how the formation of long chain polysulfides in the catholyte is delayed during charge as a result of rapid formation and migration of shorter chain species, beneficial for reaching higher capacities. However, the depletion of ionic species during the last stage of charge, due to the conversion to and precipitation of elemental sulfur on the cathode support, results in polarization of the cell before full conversion can be achieved.
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| 48. |
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| 49. |
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| 50. |
- Tsurumaki, Akiko, et al.
(author)
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Enhanced safety and galvanostatic performance of high voltage lithium batteries by using ionic liquids
- 2019
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In: Electrochimica Acta. - : Elsevier BV. - 0013-4686. ; 316, s. 1-7
-
Journal article (peer-reviewed)abstract
- We demonstrate that the addition of 1-butyl-1-methylpyrrolidinium hexafluorophosphate ([Py-14]PF6) to 1.0 M LiPF6 in ethylene carbonate-dimethyl carbonate (LP30) widens the temperature range, in which the electrolyte mixtures are ion conductive and safe. Specifically, at the concentrations of [Py-14]PF6 above 50 wt%, the electrolyte mixtures exhibit a flash point higher than room temperature and fulfill the requirements of liquids having controlled flammability. In this concentration range, also crystallization of the mixtures is completely suppressed, and low temperature ionic conductivity is improved. With respect to the electrochemical properties at room temperature, electrochemical stability window is widened by the addition of [Py-14]PF6 to LP30. However, it comes at the cost of slightly increased overall impedance and overpotential in Li vertical bar Li symmetric cells. We utilize these mixed electrolytes in high voltage Li vertical bar LiNi0.5Mn1.5O4 cells. In the presence of 30 wt% and 50 wt% of [Py-14]PF6 in LP30, the cells exhibit high specific capacity of about 110 mAh g(-1) over 200 cycles and improved coulombic efficiency, suggesting [Py-14]PF6 is a promising additive for the electrolyte in high-voltage, stable and safe lithium batteries.
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