173 research outputs found
Dataset for Impedance Characterisation of the Transport Properties of Electrolytes Contained Within Porous Electrodes and Separators Useful For Li-S Batteries
No full textDataset supports: Raccichinia, Rinaldo (2018). Impedance Characterization of the Transport Properties of Electrolytes Contained within Porous Electrodes and Separators Useful for Li-S Batteries. Journal of the Electrochemical Society.
Impedance spectroscopy is used to characterise the key transport properties (effective conductivity, MacMullin number, porosity and tortuosity) of electrolyte solutions confined in porous separators and carbon-sulfur composite electrodes useful for application in Li-S batteries. Three relevant electrolyte concentrations, ranging between 1 molal and 5 molal, are studied. Impedance measurements are carried out using symmetrical cell configurations, which significantly improve the accuracy of the results and avoids complications associated with the contributions of the counter-reference electrode in two-electrode cell measurements. The impedance response of the electrolyte-filled carbon-sulfur composite electrodes can be represented by an “open” Warburg element, modelling the finite-diffusion of ions through the pores coupled to the double-layer charging of the electrode-electrolyte interface. The as-prepared carbon-sulfur composite electrodes are at a high enough potential (ca. 3 V vs. Li+/Li) so that charge-transfer reactions of sulfur reduction to polysulfide species are absent during the impedance measurements, and hence capacitive-like behaviour (i.e., blocking behaviour) is observed at low frequencies. The analysis of the results shows that the rate of transport of ions through porous structures is markedly dependent on the electrode’s structure and composition as well as the electrolyte concentration. Synergistic effects, able to enhance the effective conductivity of the electrolyte inside porous composite electrodes, are observed for particular electrode/electrolyte combinations, which are correlated to enhanced performance in Li-S cells.</span
A Critical Evaluation of the Effect of Electrode Thickness and Side Reactions on Electrolytes for Aluminum–Sulfur Batteries
No full textThe high abundance and low cost of aluminum and sulfur make the Al–S battery an attractive combination. However, significant improvements in performance are required, and increasing the thickness and sulfur content of the sulfur electrodes is critical for the development of batteries with competitive specific energies. This work concerns the development of sulfur electrodes with the highest sulfur content (60 wt %) reported to date for an Al–S battery system and a systematic study of the effect of the sulfur electrode thickness on battery performance. If low‐cost electrolytes made from acetamide or urea are used, slow mass transport of the electrolyte species is identified as the main cause of the poor sulfur utilization when the electrode thickness is decreased, whereas complete sulfur utilization is achieved with a less viscous ionic liquid. In addition, the analysis of very thin electrodes reveals the occurrence of degradation reactions in the low‐cost electrolytes. The new analysis method is ideal for evaluating the stability and mass transport limitations of novel electrolytes for Al–S batteries
Impedance characterization of the transport properties of electrolytes contained within porous electrodes and separators useful for Li-S batteries
No full textImpedance spectroscopy is used to characterize the key transport properties (effective conductivity, MacMullin number, porosity and tortuosity) of electrolyte solutions confined in porous separators and carbon-sulfur composite electrodes useful for application in Li-S batteries. Three relevant electrolyte concentrations, ranging between 1 and 5 molal, are studied. Impedance measurements are performed in symmetrical cells with two identical electrodes, which overcome complications associated with the contributions of the counter-reference electrode. The electrolyte-filled carbon-sulfur composite electrodes can be represented by an “open” Warburg element, modelling the finite-diffusion of ions through the pores coupled to the double-layer charging of the electrode-electrolyte interface. The carbon-sulfur composite electrodes are at a high enough potential (ca. 3 V vs. Li+/Li) so that charge-transfer reactions of sulfur reduction to polysulfide species are absent during the impedance measurements, and hence capacitive-like behavior is observed at low frequencies. The analysis of the results shows that the rate of transport of ions through porous structures is markedly dependent on the electrode's structure and composition as well as the electrolyte concentration. Synergistic effects, able to enhance the effective conductivity of the electrolyte inside porous composite electrodes, are observed for particular electrode/electrolyte combinations, which are correlated to enhanced performance in Li-S cells
Ion speciation and transport properties of LiTFSI in 1,3-dioxolane solutions: A case study for Li–S battery applications
No full textThe Lithium–Sulfur battery is considered to be one of the main candidates for the “post-lithium-ion” battery generation, because of its high theoretical specific capacity and inherently low cost. The role of the electrolyte is particularly important in this system and remarkable battery performances have been reported by tuning the amount of salt in the electrolyte. To further understand the reasons for such improvements we chose the lithium bis(trifluoromethanesulfonyl)imide in 1,3-dioxolane electrolyte as a model salt-solvent system for a systematic study of conductivity and viscosity over a wide range of concentration from 10-5 up to 5 molal. The experimental results, discussed and interpreted with reference to the theory of electrolyte conductance, lead to the conclusion that triple ions formation is responsible for the highest molal conductivity values before reaching the maximum at 1.25 molal. At higher concentrations, the molal conductivity drops quickly due to a rapid increase in viscosity and the salt–solvent system can be treated as a diluted form of molten salt
Enhanced stability of SnSb/graphene anode through alternative binder and electrolyte additive for lithium ion batteries application
No full textA graphene-based composite containing Sn and Sb is synthesized and characterized. Structural and morphological characterizations demonstrate the achievement of multilayer graphene with anchored SnSb nanoparticles. The composite is tested as active material for lithium-ion battery anodes and, as a result of the use of poly acrylic acid binder and vinylene carbonate electrolyte additive, remarkable electrochemical performance are achieved in terms of stable cycling stability and specific gravimetric capacity (468 mAh g1 after 75 cycles with a capacity retention of about 80%). Moreover, impedance spectroscopy analysis further demonstrates the enhanced stability obtained by using, together with vinylene carbonate electrolyte additive, poly acrylic acid binder instead of poly vinylidene difluoride
Dataset for "Novel Electrolytes for Aluminium-Sulfur Batteries: Critical Evaluation of Electrode Thickness Effects and Side Reactions"
No full textThis dataset supports the publication: Lampkin, John et al (2020). A Critical Evaluation of the Effect of Electrode Thickness and Side Reactions on Electrolytes for Aluminum–Sulfur Batteries ChemSusChem. DOI: 10.1002/cssc.202000447</span
High-stability graphene nano sheets/SnO2 composite anode for lithium ion batteries
No full textThe electrochemical behavior of a composite anode based on tin oxide nanoparticles embedded in elec- trically conductive graphene matrix is reported. The composite has been synthetized through microwave reduction of poly acrylic acid functionalized graphene oxide and a tin oxide organic precursor both dis- persed in ethylene glycol. The poly acrylic functionalization of graphene oxide partially prevent the re-stacking of the graphene layers. In addition, poly acrylic acid acts as a surfactant favoring an optimized dispersion of the metal and, after thermal decomposition, contributes in creating a carbon layer for an improved conductivity. The final product morphology reveals a composite in which SnO2 nanoparticles are homogenously distributed into the reduced graphene oxide matrix. Graphene/SnO2nanocomposite electrodes, prepared using Super-P carbon as conducting additive and polyvinylidenedifluoride as binder, exhibit high rate capability and cycle life during galvanostatic charge/discharge tests. After more than 140 cycles, mostly performed at 500 mA g−1 , the electrodes show a remarkable stable specific capacity of about 430 mAh g−1 with a Coulombic efficiency close to 100%.The morphological stability of the electrode is also confirmed by impedance spectroscopy analysis, which shows solid-electrolyte interphase related resistance values constant up to 100 cycles.

Influence of Ionic Coordination on the Cathode Reaction Mechanisms of Al/S Batteries
No full textThe lack of knowledge on electrochemical reaction pathways for Al/S batteries prevents the development of practical approaches to mitigate the irreversibility and poor cycling performances of this appealing secondary battery system, which is, in theory, scalable, inexpensive, and energy-dense. Different from the Li/S system, Al/S batteries use ionic liquids (ILs) as electrolytes. The choice of the IL, i.e., whether the IL is based on a conventional EMImCl-based electrolyte or in a deep eutectic mixture of aluminum chloride with urea (or any of its derivatives), strongly affects the electrochemical energy-storage performance of the cell. To shed some light on the Al/S battery chemistry, here, we present the computational electrochemistry research work to determine the most favorable reaction pathways and thermodynamically stable reaction intermediates. We also discuss the effect of the coordination of ionic species (originated from aluminum-containing deep eutectic electrolytes) with polysulfide intermediates, which lead to alterations in the reaction pathway and electrochemical behavior of the Al/S system. The spectroscopic signatures from various reaction intermediates are also reported and validated via comparison with experimental observations
Honour and recognition in the German novel of banditry ca 1800
No full textThis article performs a reading informed by Honneth’s theory of recognition of the two best-known German novels of banditry of the 1790s, Johann Heinrich Zschokke’s Abaellino der große Bandit (1794) and Christian August Vulpius’ Rinaldo Rinaldini (1799) in an effort to understand how popular literature participates in and reflects upon the discourse on honour and recognition around 1800. Its status as popular genre makes the novel of banditry (Räuberroman) a potentially interesting source on shifts in the theory and practice of honour as experienced by ordinary Europeans at the turn of the 19th century. The genre was found to relate to the honour discourse not directly, but in the manner of a heterotopia, simultaneously located outside that discourse and referentially connected to it. Taken in isolation, the novel of banditry is not an informative source on the changing role of honour and new patterns of intersubjective recognition in late 18th century Europe. Seen as part of a particular constellation of textual production and reception, however, the genre sheds light on the aporias of honour experienced by those socially marginal ‘new readers’ intent on exploiting literature in the struggle for enhanced social recognition.Peer reviewe
Albori di Entomologia merceologica e urbana nell'opera del microscopista Filippo Bonanni (1638-1725)
No full textFILIPPO BONANNI (1638-1725)
The Roman Jesuit Filippo Bonanni (1638-1725) is a prominent figure in the European cultural
landscape of the seventeenth and eighteenth centuries. He was a scholar, a man of many interests,
both humanistic and scientific, an eclectic writer; in the history of biological sciences Bonanni
occupies a non-marginal position for his contributions in the malacological and entomological
fields, but he is best known for being, in the wake of his master the Jesuit Athanasius Kircher, a
staunch defender of the theory of spontaneous generation. This certainly damaged his reputation
as a scholar in comparison with more or less contemporary scientists who instead contributed to
refuting this theory with accurate experimental research (among the Italians, in this regard, Redi,
Malpighi, Marsili, Cestoni and Vallisnieri stand out). Bonanni’s observations on insects and other
arthropods, which he carried out above all with the aim of finding arguments in favor of the
generatio aequivoca, are found in his work Observationes circa viventia, quae in rebus non
viventibus reperiuntur. Cum micrographia curiosa sive rerum minutissimarum observationibus,
quae ope microscopii recognitae ad vivum exprimuntur, published in Rome in 1691. Written
observations thus supporting spontaneous generation, but accompanied by numerous valuable
illustrations made with the aid of the microscope which Bonanni, valiant microscopist as well as
a skilled draftsman and engraver, perfected himself, in order to investigate the microcosm of
arthropods beyond the potential of the human eye - apart from the dialectical intent mentioned
above. This is the primary objective of the Micrographia curiosa, the appendix to his work, which
enriches what is presented in the main part of the volume with further findings and tables. A
valuable work, above all related to commodity, urban and stored product entomology, given that
the author finds in the arthropods of the urban and domestic environment the raw material most
at hand as a source for observations and experiences. With surprising precision for the time, in
the Observationes mosquito, sand fly, flea, lice, booklice, coleopteran larvae, moths, other
dipterans and their details, mites, etc. are illustrated. Bonanni is the first descriptor and illustrator
ever of certain insects. Among others, worthy of note is a dermestid larva, very probably of the
genus Anthrenus, with much enlarged detail of the typical hastisetae or spear bristles, and some
figures of pretarsi of Diptera Brachycera. As a microscopist he can be compared to the
Englishman Robert Hooke (1635-1709), almost coeval, who published a Micrographia in London
(1667), from which Bonanni seems to have drawn useful insights
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