1,721,108 research outputs found
Electrodeposited Ni-Sn intermetallic electrodes for advanced lithium ion batteries
No full textVarious samples of NixSny metallic alloys electrodeposited under different current and time regimes have been prepared and tested in lithium cells. The results clearly demonstrate that the electrochemical performance of these intermetallic electrodes greatly depends on the synthesis conditions which in turn reflect on the type of morphology and phase of the various samples. The best electrode cycled with a high capacity delivery, i.e. of the order of 550 mA hg−1 and showed an efficient behaviour when used as anode in a lithium ion battery using LiNi0.5Mn1.5O4 as cathode. These results confirm that the electrodeposition is a very promising synthesis tool for monitoring the morphological and phase conditions of NixSny and that the approach described in this work may be used for further optimizing this intermetallic electrode
Electrochemical and spectroscopic study of the transport-properties of composite polymer electrolytes
No full textThe addition of inert filler are known to increase the mechanical
properties of polymer electrolytes in their conductive
amorphous phase. So the addition of a-A1203 to PEO-LiC104 complexes produced a significant improvement
in the mechanical stability of the material at temperatures
in excess of 100 "C. This improvement was
explained assuming that the ceramic dispersoid act as a
filler providing a supporting matrix for the conductive
amorphous polymer complex, so as to retain an overall
solid structure even at high temperature. In this paper, thermal, electrical and spectroscopic characterization results all support a structural model which accounts for the effects exerted by finely dispersed ceramic additives on the trasnport properties of PEO-based polymer electrolytes. The addition of the dispersoid prevents the agglomeration of the polymer chain to form extended coiled crystalline clusters. While maintaining an overall rigid structure, these electrolytes assume structural and transport properties comparable to those of systems based on ow-molecular weight poly(ethy1ene glycol)-lithium salt solutions,
which are currently used to mimic low-crystallinity polymer
electrolytes
An Advanced Lithium-Ion Sulfur Battery for High Energy Storage
No full textA lithium-ion battery is reported using a sulfur-carbon composite cathode, a graphite anode, and a dimethoxyethane-dioxolane-lithium bis-(trifluoromethanesulfonyl)imide (DOL-DME-LiTFSI) electrolyte advantageously added by lithium nitrate (LiNO3) and a selected polysulfide (Li2S8). The suppressed sulfur dissolution, due to the Li2S8 buffer action, as well as reduced shuttle reactions by the film-forming properties of the LiNO3 positively affect the lithium-ion cell behavior in terms of delivered capacity, coulombic efficiency, and cycle life. The lithium-sulfur cell shows a stable capacity of 750 mAh g-1 for over 200 cycles with an enhanced cycling efficiency. Furthermore, the full lithium-ion sulfur battery using a graphite-based anode shows a working voltage of about 2 V and delivers a stable capacity of 500 mAh g-1. The full cell has enhanced safety content, due to the replacement of the lithium metal anode by suitable intercalation electrode, and shows a theoretical energy density as high as 1000 Wh kg-1 at high current rate of 1 C. The remarkable safety level, low materials cost, and high practical energy density, expected to exceed 300 Wh kg-1, suggest the battery reported is a suitable energy storage system for future applications. An efficient, long life lithium-ion battery is formed using a sulfur cathode, lithiated graphite anode, and polysulfide added electrolyte. The battery combines remarkable safety content with low cost
LA BIOSENSORISTICA: IMMOBILIZZAZIONE DI MOLECOLE DI INTERESSE FARMACOLOGICO IN MATRICI POLIMERICHE ELETTROCONDUTTRICI
No full textA high capacity, template-electroplated Ni-Sn intermetallic electrode for lithium ion battery
No full textIn this paper we describe a Ni-Sn intermetallic material obtained via template electroplating synthesis. The structure and the morphology of this material are investigated by X ray diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses. We demonstrate that Ni-Sn behaves as a sub-micrometric electrode showing a favourable response when cycled in a lithium cell. The results here reported suggest that the template electroplating is a promising synthetic approach that can lead to an optimized structure and morphology of the Ni-Sn electrode, such as to confer it a role of a high capacity anode in advanced lithium ion batteries. © 2010 Elsevier B.V. All rights reserved
An electrochemical impedance study on the interfacial behaviour of KC8 electrodes in LiCl04 containing electrolytes
No full textElectrochemical characterization of a polymer/polymer rechargeable lithium solid-state cell
No full textThe characteristics of solid-state lithium cells, using (PEO)20 LiClO4 as electrolyte and the electrosynthesized polymers polypyrrole, polybithiophene and polydithienothiophene as positive electrodes, were investigated by cyclic voltammetry, charge-discharge galvanostatic cycles and a.c. impedance spectroscopy. The experimental data suggest that solid-state polymeric systems can be employed in ultrathin batteries at 70°C operating temperature. © 1989
- …
