1,720,981 research outputs found
Lithium-ion batteries based on titanium oxide, nanotubes and LiFePO4
No full textIn this paper, the morphology, the conformation,
and the electrochemical performance of TiO2 nanotubes and
LiFePO4 have been studied by using scanning electron microscope,
XRD, and charge/discharge cycles. The electrochemical
tests comprised low rate cycling, cycling at C rate,
and cycling at different rates. This work was finalized to the
fabrication of lithium-ion batteries based on the TiO2/LiFePO4
redox couple. Battery cells were assembled and electrochemical
tests were performed to evaluate cell capacity, power, and
energy. Further tests were carried out to evaluate the capacity
retention as a function of cycle number and discharge curren
Lithium-ion batteries based on titanium oxide nanotubes and LiFePO 4
No full textIn this paper, the morphology, the conformation, and the electrochemical performance of TiO2 nanotubes and LiFePO4 have been studied by using scanning electron microscope, XRD, and charge/discharge cycles. The electrochemical tests comprised low rate cycling, cycling at C rate, and cycling at different rates. This work was finalized to the fabrication of lithium-ion batteries based on the TiO2/LiFePO4 redox couple. Battery cells were assembled and electrochemical tests were performed to evaluate cell capacity, power, and energy. Further tests were carried out to evaluate the capacity retention as a function of cycle number and discharge current. © 2013 Springer-Verlag Berlin Heidelberg
Poly vinyl acetate used as a binder for the fabrication of a LiFePO4-based composite cathode for lithium-ion batteries
No full textThis paper describes a method for the preparation of composite cathodes for lithium ion-batteries by using poly vinyl acetate (PVAc) as a binder. PVAc is a non-fluorinated water dispersible polymer commonly used in a large number of industrial applications. The main advantages for using of this polymer are related to its low cost and negligible toxicity. Furthermore, since the PVAc is water processable, its use allows to replace the organic solvent, employed to dissolve the fluorinated polymer normally used as a binder in lithium battery technology, with water. In such a way it is possible to decrease the hazardousness of the preparation process as well as the production costs of the electrodes. In the paper the preparation, characterization and electrochemical performance of a LiFePO4 electrode based on PVAc as the binder is described. Furthermore, to assess the effect of the PVAc binder on the electrode properties, its performance is compared to that of a conventional electrode employing PVdF-HFP as a binder
Sodium extraction from sodium iron phosphate with a Maricite structure
No full textThree materials based on sodium iron phosphate with a Maricite structure were synthesized by hydrothermal method and solid-state synthesis. The materials have been characterized by X-ray diffraction, thermal analysis, and surface analysis. The materials were used for the fabrication of electrodes and their electrochemical performance were evaluated in lithium batteries. The material with the highest reversible capacity was then characterized in sodium batteries. Both the capacity exhibited at low discharge rate as well as the capacity as a function of the discharge rate and cycle number were evaluated. The obtained values were used for the determination of the specific energy as a function of the specific discharge power. At the lower discharge rate (C/20), the material was able to deliver 52.0 mAh g- 1 with an average charge voltage of 2.5 V corresponding to a specific energy of 130 Wh kg- 1. The specific capacity recorded at the lowest discharge rate gradually increased with the number of cycles and reached a value of 63 mAh g- 1 at the 150th cycle. © 2014 Elsevier B.V
Preparation of a composite anode for lithium-ion battery using a commercial water-dispersible non-fluorinated polymer binder
No full textThis paper describes a method for the preparation of a composite anode for lithium ion-battery using a commercial non-fluorinated water-dispersible polymer (Pattex PL50) as a binder. The benefits offered by using this polymer are related to its low cost and negligible toxicity. Furthermore, since the polymer is water dispersible, its adoption allows to replace the organic solvents, traditionally used in lithium-ion battery technology, with water thus decreasing the hazardousness of the preparation process as well as the production costs of the electrodes. In this paper, the preparation, characterization, and electrochemical properties of electrodes using the Pattex PL50 as the binder are described. A commercial high-capacity mesocarbon microbead graphite was selected as the electrode active material. © 2015, Springer-Verlag Berlin Heidelberg
A composite electrode based on sub-micrometric iron metal and lithium fluoride
No full textIn this paper a general method to obtain a mixture of a transition metal embedded in a matrix of lithium fluoride is proposed. The method consists in the reduction of the oxide of the transition metal with lithium hydride to form the correspondent transition metal and lithium oxide. This latter is then converted into lithium fluoride by solid state reaction with ammonium fluoride. In this work the proposed method was applied to iron(III) oxide to obtain a mixture of iron metal and lithium fluoride. The crystal structure and phase purity of the intermediate as well as the final product were analyzed by X-ray diffraction measurement and the crystallite dimensions evaluated by using the Scherrer's formula. The iron metal/lithium fluoride mixture was used as a conversion material and its electrochemical properties evaluated by galvanostatic charge discharge cycles, impedance spectroscopy and galvanostatic intermittent titration technique. As the conversion material is in its reduced state it can be coupled with a carbonaceous negative electrode to build a lithium ion battery, opening new perspectives for using conversion materials in lithium ion batteries technology. © 2013 Elsevier Ltd. All rights reserved
Electrochemical performance of Li-ion batteries assembled with water-processable electrodes
No full textThis paper describes the preparation and electrochemical characterization of Li-ion batteries prepared with electrodes containing non-fluorinated water dispersible polymers as electrode binders. Two commercial adhesives based on polyvinyl acetate and polystyrene acrylate, were used as the positive and negative electrode binders, respectively. The main advantages to using these polymers are related to their low cost, large diffusion, and negligible toxicity. Furthermore, since the polymers are water dispersible their use allows replacing the organic solvent, employed to dissolve the fluorinated polymer normally used as the binder in lithium battery technology, with water. In such a way it is possible to decrease the hazardousness of the preparation process as well as the production costs of both the electrodes. In the paper the preparation, characterization and the electrochemical performance of the Li-ion batteries obtained by coupling the two electrodes are described. © 2015 Elsevier Ltd. All rights reserved
Ricerca su materiali e processi per la realizzazione di materiali catodici con prestazioni migliorate. Analisi morfologica dei prodotti finali
Full text linkI sali d’ammonio preparati con differenti metodologie sono stati trattati termicamente in presenza di litio per trasformarli in LiFePO4. Il trattamento termico è stato effettuato normalmente a 600°C per 2 ore mentre in due casi lo stesso è stato effettuato a differenti temperature (550 e 700°C). Le morfologie dei materiali così ottenuti sono state valutate sia in funzione della preparazione del precursore sia, per lo stesso precursore, in funzione del trattamento termico
A lithium-ion battery based on LiFePO4and silicon nanowires
No full textIn this paper the preparation and electrochemical characterization of silicon nanowires for using as the anode of a lithium-ion battery are reported. The nanowires were synthesized by CVD and characterized by SEM. The nanostructuredmaterialwas used as an electrode in a lithiumcell and its electrochemical properties were investigated by galvanostatic charge-discharge cycles at various charge rates. The electrode was coupledwith a LiFePO4 cathode to fabricate a lithium-ion battery and the battery performance evaluated as a function of the discharge rate and cycle number. © 2014 Elsevier B.V. All rights reserved
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