1,721,064 research outputs found
Le Tribolazioni del Filosofare. Comedia Metaphysica ne la quale si tratta de li errori e de le pene de l'Infero
No full textRilettura poetico-filosofica dell'inferno dantesco, una introduzione alla metafisica analitic
Back to Black
Full text linkThis is a brief sequel to Max Black’s classic dialogue on the Identity
of Indiscernibles. Interlocutor A defends the bundle theory by
endorsing the (by now popular) view according to which Black’s
world does not contain two indiscernible spheres but rather a
single, bi-located sphere. His opponent, B, objects that A cannot
distinguish such a world from a world with a single, uniquely
located sphere, hence that the view in question adds nothing to A’s
original response to Black’s challenge. A is simply denying that
there can be worlds with two or more indiscernible entities
Natural Polymers as Green Binders for High-Loading Supercapacitor Electrodes
Full text linkThe state-of-the-art aqueous binder for supercapacitors is carboxymethyl cellulose (CMC). However, it limits the mass loading of the coatings owing to shrinkage upon drying. In this work, natural polymers, that is, guar gum (GG), wheat starch (WS), and potato starch (PS), were studied as alternatives. The flexibility and adhesion of the resulting coatings and electrochemical performance was tested. The combination of 75:25 (w/w) ratio PS/GG showed a promising performance. Electrodes were characterized by SEM, thermal, adhesion, and bending tests. Their electrochemical properties were determined by cyclic voltammetry, electrochemical impedance spectroscopy, and cycling experiments. The PS/GG mixture conformed well to criteria for industrial production, enabling mass loadings higher than CMC (7.0 mg cm−2) while granting the same specific capacitance (26 F g−1) and power performance (20 F g−1 at 10 A g−1). Including the mass of the current collector, this represents a +45 % increase in specific energy at the electrode level
Green and low-cost acetate-based electrolytes for the highly reversible zinc anode
No full textA highly concentrated solution of potassium, lithium and zinc acetate is proposed as green “Water-in-Salt” electrolyte (WiSE). In this halide-free electrolyte, investigated by classical Molecular Dynamics simulations, differential scanning calorimetry (DSC) and Raman spectroscopy, the water molecules are coordinated by the acetate anion as well as the various cations. As a result of the strong coordination of water molecules, the WiSE enables outstanding zinc (Zn) plating/stripping average Coulombic efficiency (CE) (99.6%) and long-term cycling stability. Dual ion cells using this electrolyte and featuring the Zn metal anode and either LiFePO4 (LFP) or spinel LiMn2O4 (LMO)-based cathodes deliver discharge capacity of 155 mA h g−1 and 121 mA h g−1 at 0.05C, respectively. The Zn/LFP cells demonstrate better cycling stability compared to Zn/LMO, which is attributed to the more stable crystal structure of LFP
Revisiting the energy efficiency and (potential) full-cell performance of lithium-ion batteries employing conversion/alloying-type negative electrodes
No full textThe energy efficiency of new lithium-ion chemistries is a very important, but frequently not provided performance measure for new alternative active materials for application as negative and positive lithium-ion battery (LIB) electrodes. This is particularly true for those active materials, not hosting lithium cations via insertion mechanisms, but via alloying and/or conversion reactions. Herein, the energy efficiency of alternative negative electrode active materials hosting lithium via combined conversion and alloying processes and the impact factors on the energy efficiency of such compounds in complete battery cells (full-cells) is revisited. Specifically, the effect of (i) varying the relative contribution of the conversion and alloying reaction, (ii) limiting the specific capacity, (iii) pre-cycling and pre-lithiating the anode, as well as (iv) the choice of the active material for the positive electrode, is investigated. The results show that a proper combination of these measures may enable lithium-ion cells based on conversion/alloying anodes that provide energy efficiencies of >95%, accompanied by gravimetric energy densities that might outperform graphite-based lithium-ion cells
Green and low-cost acetate-based electrolytes for the highly reversible zinc anode
No full textA highly concentrated solution of potassium, lithium and zinc acetate is proposed as green “Water-in-Salt” electrolyte (WiSE). In this halide-free electrolyte, investigated by classical Molecular Dynamics simulations, differential scanning calorimetry (DSC) and Raman spectroscopy, the water molecules are coordinated by the acetate anion as well as the various cations. As a result of the strong coordination of water molecules, the WiSE enables outstanding zinc (Zn) plating/stripping average Coulombic efficiency (CE) (99.6%) and long-term cycling stability. Dual ion cells using this electrolyte and featuring the Zn metal anode and either LiFePO4 (LFP) or spinel LiMn2O4 (LMO)-based cathodes deliver discharge capacity of 155 mA h g−1 and 121 mA h g−1 at 0.05C, respectively. The Zn/LFP cells demonstrate better cycling stability compared to Zn/LMO, which is attributed to the more stable crystal structure of LFP. © 2020 Elsevier B.V
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