| 1. |
- Bombarda, F., et al.
(författare)
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Runaway electron beam control
- 2019
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Ingår i: Plasma Physics and Controlled Fusion. - : IOP Publishing. - 1361-6587 .- 0741-3335. ; 61:1
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Cavallo, Carmen, 1986, et al.
(författare)
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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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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 416, s. 111-117
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Tidskriftsartikel (refereegranskat)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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| 3. |
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| 4. |
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| 5. |
- Agostini, Marco, 1987, et al.
(författare)
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Designing a Safe Electrolyte Enabling Long‐Life Li/S Batteries
- 2019
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Ingår i: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 12:18, s. 4176-4184
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Tidskriftsartikel (refereegranskat)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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| 6. |
- Haridas, Anupriya K., et al.
(författare)
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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
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Ingår i: ACS Applied Materials & Interfaces. - : American Chemical Society (ACS). - 1944-8252 .- 1944-8244. ; 11:33, s. 29924-29933
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Tidskriftsartikel (refereegranskat)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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| 7. |
- Maroni, Fabio, et al.
(författare)
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V2O5 Cryogel: A Versatile Electrode for All Solid State Lithium Batteries
- 2019
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Ingår i: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 166:16, s. A3927-A3931
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Tidskriftsartikel (refereegranskat)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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| 8. |
- Nicotera, Isabella, et al.
(författare)
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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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Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 123:45, s. 27406-27416
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Tidskriftsartikel (refereegranskat)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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| 9. |
- Tsurumaki, Akiko, et al.
(författare)
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Enhanced safety and galvanostatic performance of high voltage lithium batteries by using ionic liquids
- 2019
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Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686. ; 316, s. 1-7
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Tidskriftsartikel (refereegranskat)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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