Página 1 dos resultados de 565 itens digitais encontrados em 0.004 segundos

Synthesis and electrochemical properties of vanadyl phosphate di-hydrate/polyaniline derivatives hybrid films

ZAMPRONIO, Elaine C.; FERREIRA, Joao Paulo L.; OLIVEIRA, Herenilton P.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
48.47876%
Vanadyl phosphate and its hybrid compounds have proven to undergo electrochemical intercalation and de-intercalation of lithium ions, which enables its use as cathode material for Li ion rechargeable batteries. In this context, vanadyl phosphate di-hydrate/polyaniline derivatives hybrid films were synthesized via the exfoliation and reconstruction approach in order to evaluate their potential use as cathode in ion lithium batteries. X-ray diffraction patterns indicate that the lamellar structure of the inorganic matrix is maintained, consistent with the topotactic process. In the scanning electron micrographs, hybrid films exhibit rough surface consisting of warped and cracked crystallites, quite different from vanadyl phosphate di-hydrate square platelets crystallites. Electrochemical evaluation using cyclic voltammetry and charge-discharge galvanostatic techniques shows small differences between the charge and the discharge curves, indicating an irreversibility of the hybrid systems. (C) 2009 Elsevier B.V. All rights reserved.; FAPESP[05/58934-2]; CNPq[484137/2006-9]

Effects of Self-Assembled Materials Prepared from V(2)O(5) for Lithium Ion Electroinsertion

GALIOTE, Nelson A.; CAMARGO, Maiui N. L.; IOST, Rodrigo M.; CRESPILHO, Frank; HUGUENIN, Fritz
Fonte: AMER CHEMICAL SOC Publicador: AMER CHEMICAL SOC
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
48.60296%
Self-assembled materials consisting of V(2)O(5), polyallylamine (PAR) and silver nanoparticles (AgNPs) were obtained by the layer-by-layer (LbL) method, aiming at their application as electrodes for lithium-ion batteries and electrochromic devices. The method employed herein allowed for linear growth of visually homogeneous films composed of V(2)O(5), V(2)O(5)/PAH, and V(2)O(5)/PAH/AgNP with 15 bilayers. According to the Fourier transform infrared spectra, interaction between the oxygen atom of the vanadyl group and the amino group should be responsible for the growth of these films. This interaction also enabled establishment of an electrostatic shield between the lithium ions and the sites with higher negative charge, thereby raising the ionic mobility and consequently increasing the energy storage capacity and reducing the response time. According to the site-saturation model and the electrochemical and spectroelectrochemical results, the presence of PAH in the self-assembled host matrix decreased the number of V(2)O(5) electroactive sites. Thus, AgNPs were stabilized in PAR and inserted into the nanoarchitecture, so as to enhance the specific capacity. This should provide new conducting pathways and connect isolated V(2)O(5) particles in the host matrix. Therefore...

Influência do hidrocloreto de polialilamina e nanopartículas de prata na eletro-inserção de íons lítio em matrizes hospedeiras de V2O5; Poly(allylamine hydrochloride) and silver nanoparticles influence on the lithium ions electro-insertion in V2O5 host matrix.

Silva, Nelson Alexandre Galiote
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 05/05/2011 PT
Relevância na Pesquisa
48.454077%
Materiais automontados de V2O5, polialilamina (PAH) e nanopartículas de prata (AgNP) foram preparados pelo método camada-por-camada, visando a sua aplicação em baterias de íon-lítio e dispositivos eletrocrômicos. O método adotado permitiu o crescimento linear de filmes visualmente homogêneos de V2O5, V2O5/PAH e V2O5/PAH/AgNP com 15 bicamadas, como observado a partir de microscopia eletrônica de varredura (MEV) e espectroscopia eletrônica na região do visível. De acordo com os espectros de infravermelho com transformada de Fourier (FTIR), verificou-se que a interação entre o oxigênio do grupo vanadila e o grupo amino deve ser responsável pelo crescimento destes filmes, além de permitir uma blindagem eletrostática entre os íons lítio e os sítios com maior densidade de carga negativa, aumentando a velocidade difusional e, consequentemente, aumentando a capacidade de armazenamento de energia e diminuição do tempo de resposta. Resultados eletroquímicos e espectroeletroquímicos mostraram que a presença das AgNPs estabilizadas no PAH aumentou a capacidade de carga do eletrodo, propiciando novos caminhos condutores e aumentando o número de sítios eletroativos na matriz hospedeira. Espontaneamente, novas nanoarquiteturas com interações específicas foram formadas pelo método camada-por-camada...

Síntese de filmes automontados de poli(o-metoxianilina) e nanopartículas de pentóxido de vanádio como cátodos em baterias de íon-lítio em líquido iônico; Self assembly of poly(o-methoxyaniline) and vanadium pentoxide nanoparticles as cathodes for lithium-ion batteries in ionic liquid

Nogueira, Filipe Braga
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 01/11/2012 PT
Relevância na Pesquisa
58.74786%
O presente trabalho utilizou a técnica de automontagem camada-por-camada para produzir eletrodos híbridos de poli(o-metoxianilina) e nanopartículas de pentóxido de vanádio. Foram obtidos filmes acusticamente rígidos, homogêneos com relação à massa depositada e com crescimento linear com o número de bicamadas depositadas. A caracterização eletroquímica foi realizada por voltametria cíclica, onde esse filme apresentou alta capacidade de intercalação/desintercalação de íons lítio e de forma reversível. A capacidade eletroquímica desse filme foi então comparada com filmes automontados de poli(dialildimetilamônio)/V2O5 e polialilamina/V2O5. O filme de Poli(dialildimetilamônio) apresentou um crescimento irregular com dissolução das nanopartículas, o que resultou em uma capacidade eletroquímica extremamente inferior ao filme de poli(o-metoxianilina). O filme de polialilamina apresentou uma deposição mais eficiente de V2O5 que o filme de poli(o-metoxianilina), entretanto essa maior quantidade de pentóxido de vanádio não refletiu em um aumento da capacidade do eletrodo. Os resultados de espectroscopia de impedância eletroquímica mostram que o filme de polialilamina é significativamente mais resistivo que o filme de poli(o-metoxianilina). Essa diminuição da condutividade...

Filmes Cu-V-O para aplicações em catodos de microbaterias; Cu-V-O films for application as cathode in microbatteries

Edvaldo Alves de Souza Júnior
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 21/02/2006 PT
Relevância na Pesquisa
48.51484%
O pentóxido de vanádio é um dos compostos de intercalação mais conhecidos na área de baterias de lítio. Dada sua estrutura lamelar, íons de lítio podem ser inseridos e extraídos de forma reversível, o que torna o pentóxido de vanádio promissor para uso como catodo. No entanto, o armadilhamento de parte dos íons de lítio a cada ciclo de carga e descarga provoca a perda gradativa da capacidade. A incorporação de íons metálicos na estrutura do V2 >O5 é uma das alternativas para melhorar seu desempenho nos ciclos de carga e descarga. Por outro lado, foi demonstrado que o óxido de cobre nanoparticulado é capaz de fornecer alta capacidade de carga em processos reversíveis de inserção e extração de íons lítio. Esta tese se propõe estudar a inserção/extração de íons de lítio em filmes finos de óxidos de cobre-vanádio objetivando sua aplicação em catodos de microbaterias. Um conjunto de amostras foi obtido iniciando-se com o pentóxido de vanádio, e através de acréscimos de cobre e decréscimos de vanádio, atingindo o óxido de cobre II. Óxidos bronzes, complexos, mistos e puros foram obtidos. As amostras foram depositadas através da técnica de sputtering. Na caracterização das amostras foram utilizadas técnicas de difração de raios-X...

Lithium polymer batteries: principles and application

Gray, Fiona; Smith, Michael John
Fonte: Elsevier B.V.: Oxford, United Kingdom Publicador: Elsevier B.V.: Oxford, United Kingdom
Tipo: Parte de Livro
Publicado em /11/2009 ENG
Relevância na Pesquisa
48.687095%
Lithium-ion polymer (LiPoly or LiPo) cells first appeared in consumer electronics in the mid-1990s. The technology for these devices evolved from previously established lithium-ion (Li-ion) cells. The difference between the two lies in the electrolyte; in Li-ion batteries it consists of a lithium salt dissolved in a low molecular weight solvent, whereas a LiPo electrolyte is a polymer gel network. Substitution of liquid electrolyte by a solid analogue allows simplification of the cell structure and many restrictions in terms of architecture and safety are eliminated. Three decades of research and development of solvent-free polyether-based electrolytes has seen many advances, but barriers still remain, restricting their commercial exploitation. Commercial viability was realized in polymer gel electrolytes, a compromise between the liquid and solvent-free systems. The all-solid-state LiPo concept translates into a battery that can be shaped to suit the device it will power, is lighter, and can undergo denser packaging than its liquid electrolyte counterpart. The battery energy density is potentially much greater than that achieved by competing cell chemistries, including the Li-ion cell. With recent advances in LiPo cell technology...

Development of new organic electroactive materials for rechargeable batteries

Furtado, Olívia; Rangel, C. M.
Fonte: Laboratório Nacional de Energia e Geologia Publicador: Laboratório Nacional de Energia e Geologia
Tipo: Conferência ou Objeto de Conferência
Publicado em 10/11/2011 ENG
Relevância na Pesquisa
48.51747%
The need for a clean and sustainable energy supply in the transportation sector have prompted electric vehicles as one of the options to reduce fossil fuel dependency and greenhouse gases emissions. Furthermore, electric vehicles are seen as enablers of the storage capacity of electric grids. In this context, the reasobnable energy density and cyclability reached by lithium-ion batteries based on inorganic cathodes have placed them in considerable advantage regarding energy conversation and storage [1, 2]. For higher energy density, lower cost and more environmentally acceptable batteries research efforts are presently focus on organic-based electrodes as a new approach to conventional inorganic cathodes. [3]. In his work, we carried out the development of a derivative of polymide (PI) for use as electrochemically active cathode material in rechargeable lithium batteries. Even though the application of polyimide as electrode material is scarcely found due to its insulating character, its aromatic imide group can be electrochemically oxidized and reduced in a reversible manner [4, 5]. This paper will present the studies on the synthesis and chemical characterization of a polyimide derivate and its evaluation as cathode organic polymer after electrochemical characterization. Test half-cell testing and battery constitution are being planned. The use of polyimide derivates is considered promising because of the potentiial increase in specific discharge capacity...

Novel Li3ClO based glasses with superionic properties for lithium batteries

Braga, M. H.; Ferreira, Jorge Amaral; Stockhausen, V.; Oliveira, J. E.; El-Azab, A.
Fonte: Laboratório Nacional de Energia e Geologia Publicador: Laboratório Nacional de Energia e Geologia
Tipo: Artigo de Revista Científica
Publicado em /04/2014 ENG
Relevância na Pesquisa
48.8425%
Three types of next generation batteries are currently being envisaged among the international community: metal-air batteries, multivalent cation batteries and all-solid-state batteries. These battery designs require high-performance, safe and cost effective electrolytes that are compatible with optimized electrode materials. Solid electrolytes have not yet been extensively employed in commercial batteries as they suffer from poor ionic conduction at acceptable temperatures and insufficient stability with respect to lithium-metal. Here we show a novel type of glasses, which evolve from an antiperovskite structure and that show the highest ionic conductivity ever reported for the Li-ion (25 mS cm-1 at 25 °C). These glassy electrolytes for lithium batteries are inexpensive, light, recyclable, non-flammable and non-toxic. Moreover, they present a wide electrochemical window (higher than 8 V) and thermal stability within the application range of temperatures.

A Flexible Three-in-One Microsensor for Real-Time Monitoring of Internal Temperature, Voltage and Current of Lithium Batteries

Lee, Chi-Yuan; Peng, Huan-Chih; Lee, Shuo-Jen; Hung, I-Ming; Hsieh, Chien-Te; Chiou, Chuan-Sheng; Chang, Yu-Ming; Huang, Yen-Pu
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
Publicado em 19/05/2015 EN
Relevância na Pesquisa
48.560786%
Lithium batteries are widely used in notebook computers, mobile phones, 3C electronic products, and electric vehicles. However, under a high charge/discharge rate, the internal temperature of lithium battery may rise sharply, thus causing safety problems. On the other hand, when the lithium battery is overcharged, the voltage and current may be affected, resulting in battery instability. This study applies the micro-electro-mechanical systems (MEMS) technology on a flexible substrate, and develops a flexible three-in-one microsensor that can withstand the internal harsh environment of a lithium battery and instantly measure the internal temperature, voltage and current of the battery. Then, the internal information can be fed back to the outside in advance for the purpose of safety management without damaging the lithium battery structure. The proposed flexible three-in-one microsensor should prove helpful for the improvement of lithium battery design or material development in the future.

Electrode-Electrolyte Interfaces in Solid Polymer Lithium Batteries

Hu, Qichao
Fonte: Harvard University Publicador: Harvard University
Tipo: Thesis or Dissertation
EN_US
Relevância na Pesquisa
58.793804%
This thesis studies the performance of solid polymer lithium batteries from room temperature to elevated temperatures using mainly electrochemical techniques, with emphasis on the bulk properties of the polymer electrolyte and the electrode-electrolyte interfaces. Its contributions include: 1) Demonstrated the relationship between polymer segmental motion and ionic conductivity indeed has a Vogel-Tammann-Fulcher (VTF) dependence, and improved the conductivity of the graft copolymer electrolyte (GCE) by almost an order of magnitude by changing the ion-conducting block from poly(oxyethylene) methacrylate (POEM) to a block with a lower glass transition temperature ((T_g)) poly(oxyethylene) acrylate (POEA). 2) Identified the rate-limiting step in the battery occurs at the cathode-electrolyte interface using both full cell and symmetric cell electrochemical impedance spectroscopy (EIS), improved the battery rate capability by using the GCE as both the electrolyte and the cathode binder to reduce the resistance at the cathode-electrolyte interface, and used TEM and SEM to visualize the polymer-particle interface (full cells with (LiFePO_4) as the cathode active material and lithium metal as the anode were assembled and tested). 3) Applied the solid polymer battery to oil and gas drilling application...

Silicon nitride thin-films by RF sputtering : application on solid state lithium batteries

Sousa, R.; Ribeiro, J. F.; Sousa, J. A.; Montenegro, R. T.; Gonçalves, L. M.; Correia, J. H.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /09/2013 ENG
Relevância na Pesquisa
68.60296%
Silicon nitride is the most common barrier material to protect microsystems from atmosphere, usually deposited through CVD techniques. In this paper our aim is to highlight the advantages brought by using PVD techniques, namely RF sputtering, to deposit silicon nitride thin-films. In particular, we intend to protect microsystems fabricated only by PVD techniques and avoid the necessity of a second CVD chamber to do the microsystem coating. The influence of gases (Ar/N2) during deposition was correlated with film composition and with measured electrical and optical properties. Featuring electric resistivity of 9.51E11 Ω.cm, a breakdown field of 1.67 MV/cm and refractive index between 1.92 and 1.84 (measured at 650 nm) silicon nitride deposited by RF sputtering is a good complementary layer of Li3PO4 or Ti for the protection of metallic lithium anode of solid state lithium batteries.; This work was financial supported by FCT funds with the project PTDC/EEAELC/114713/2009, second author scholarship SFRH/BD/78217/2011 and strategic project from Algoritmi Centre FCOMP-01-0124-FEDER-022674

Fabrication of Cathode Materials Based on Limn2o4/Cnt and Lini0.5mn1.5o4/Cnt Nanocomposites for Lithium – Ion Batteries Application

Van Le,Thang; Le,My Loan Phung; Van Tran,Man; Nguyen,Nguyet Minh Thi; Luu,Anh Tuan; Nguyen,Ha Tran
Fonte: ABM, ABC, ABPol Publicador: ABM, ABC, ABPol
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2015 EN
Relevância na Pesquisa
48.62216%
AbstractCarbon nanotubes (CNTs) are a promising candidate material for use in lithium batteries due to 1D tubular structure, high electrical, thermal conductivities, and extremely large surface area. In this work, the MWCNTs were purified by dispersion in a mixture of HNO3 and H2SO4acids. The oxidized-MWCNTs were used as conducting addition to prepare a nanocomposites as high performance cathode material for Li-ion batteries (LIBs). The spinel cathode materials of LiMn2O4 (LMO), doped spinel LiNi0.5Mn1.5O4 (LNMO) were synthesized and characterized via X-rays diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical properties of nanocomposites based on LMO/CNTs and LMNO/CNTs were investigated by cyclic voltammetry (CV) as well as electrochemical impedance spectroscopy (EIS). The EIS measurement indicated that the LMO (LNMO)/CNTs nanocomposites showed lower charge transfer resistance (Rct) than that of LMO(LNMO)/ Vulcan carbon materials. In addition, the studied nanocomposites cathodes gave a specific capacity of 145 Ah.kg–1 and 120 Ah.kg–1 for LMO/CNTs (10 wt%) and LNMO/CNTs (10 wt%), respectively, measured at a charge/discharge rate of 0.1C.

Taichi-inspired rigid-flexible coupling cellulose-supported solid polymer electrolyte for high-performance lithium batteries

Zhang, Jianjun; Yue, Liping; Hu, Pu; Liu, Zhihong; Qin, Bingsheng; Zhang, Bo; Wang, Qingfu; Ding, Guoliang; Zhang, Chuanjian; Zhou, Xinhong; Yao, Jianhua; Cui, Guanglei; Chen, Liquan
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Publicado em 03/09/2014 EN
Relevância na Pesquisa
48.793804%
Inspired by Taichi, we proposed rigid-flexible coupling concept and herein developed a highly promising solid polymer electrolyte comprised of poly (ethylene oxide), poly (cyano acrylate), lithium bis(oxalate)borate and robust cellulose nonwoven. Our investigation revealed that this new class solid polymer electrolyte possessed comprehensive properties in high mechanical integrity strength, sufficient ionic conductivity (3 × 10−4 S cm−1) at 60°C and improved dimensional thermostability (up to 160°C). In addition, the lithium iron phosphate (LiFePO4)/lithium (Li) cell using such solid polymer electrolyte displayed superior rate capacity (up to 6 C) and stable cycle performance at 80°C. Furthermore, the LiFePO4/Li battery could also operate very well even at an elevated temperature of 160°C, thus improving enhanced safety performance of lithium batteries. The use of this solid polymer electrolyte mitigates the safety risk and widens the operation temperature range of lithium batteries. Thus, this fascinating study demonstrates a proof of concept of the use of rigid-flexible coupling solid polymer electrolyte toward practical lithium battery applications with improved reliability and safety.

Estudios de materiales de cátodos híbridos y ánodos vítreos. Caracterización en celdas de ion litio; Study of Hybrid Cathode Materials and Vitreous Anodes. Characterization in Lithium Ion Cells

Jurado Egea, José Ramón; Cuentas Gallegos, A. K.; Colomer, María T.; Palacín, M. R.; Gómez-Romero, P.
Fonte: Sociedad Española de Cerámica y Vidrio Publicador: Sociedad Española de Cerámica y Vidrio
Tipo: Artículo Formato: 1109521 bytes; application/pdf
SPA
Relevância na Pesquisa
58.60296%
[ES] Como parte de nuestros estudios de nuevos materiales de electrodos para aplicación en celdas reversibles de litio, hemos abordado el estudio de materiales vítreos e híbridos [1] como posibles alternativas a los materiales activos cristalinos, que ven frecuentemente limitada su capacidad como resultado de transiciones de fase irreversibles. Dentro de este trabajo se presentan aquí los resultados recientes sobre cátodos híbridos de PPi/MnO2 (PPi= polipirrol) y de PAni/V2O5 (PAni= polianilina), y de ánodos basados en vidrios en el sistema V-Ni-Te-O, así como de su combinación en celdas reversibles de ion litio. Hemos logrado obtener mediante reacción directa de pirrol con permanganato el híbrido PPi/MnO2, y hemos observado que en la síntesis de PAni/V2O5 existen factores que influyen positivamente en su comportamiento electroquímico.; [EN] This paper is based on new materials applied as electrodes in rechargeable lithium batteries. We have approached the study of glassy and hybrid materials as an alternative to crystalline active materials, which capacity is frequently limited by irreversible phase transitions. We present here our latest results on hybrid cathodes, PPy/MnO2 (PPy= PPi= polypirrol) and PAni/V2O5 (PAni= polyaniline)...

The Organic-Inorganic Polyaniline/V2O5 System. Application as a High-Capacity Hybrid Cathode for Rechargeable Lithium Batteries

Lira-Cantú, Monica; Gómez-Romero, P.
Fonte: Electrochemical Society Publicador: Electrochemical Society
Tipo: Artículo Formato: 579917 bytes; image/jpeg
ENG
Relevância na Pesquisa
58.454077%
Texto completo disponible en la web del autor: http://www.cienciateca.com/PAniV2O5%20J%20Electrochem%20Soc%201999%20146_6_2029_2033.pdf; The application of a hybrid polyaniline/V2O5 cathode material in reversible lithium electrochemical cells is reported. We have studied the influence of synthesis conditions and subsequent treatments of this hybrid electrode under oxygen in order to optimize its performance as a lithium-insertion cathode. The temperature and duration of this treatment are key parameters in determining the final specific charge of the cathode. The optimal material yielded a specific charge as high as 302 Ah/kg measured at a low discharge rate (C/48) corresponding to the insertion of 2.72 lithium ions per formula unit (C6H4N)0.6V2O5·0.3H2O). Higher scan rates of C/12 lead to specific capacities of 200 Ah/kg. The thermal and electrochemical stability of the hybrid electrode, especially in relation to the decomposition of the organic polymer and its effect on battery performance and cyclability, are also discussed. ©1999 The Electrochemical Society. All rights reserved.; This work was partially supported by CICYT (Spain, MAT98- 0807-C02-02). We also thank the Ministerio de Educación y Ciencia (Spain, MEC-AECI) and CONACYT (Mexico) for a predoctoral fellowship to M.L.C.; Peer reviewed

Materiales híbridos basados en fosfato de vanadilo y polímeros conductores como cátodos en baterias reversibles de litio; Hybrid Materials Based on Vanadyl Phosphate and Conducting Polymers as Cathodes in Rechargeable Lithium Batteries

Casañ Pastor, Nieves; Gómez-Romero, P.; Cuentas Gallegos, A. K.; Vijayaraghavan, V.
Fonte: Sociedad Española de Cerámica y Vidrio Publicador: Sociedad Española de Cerámica y Vidrio
Tipo: Artículo Formato: 283533 bytes; application/pdf
SPA
Relevância na Pesquisa
58.36994%
[ES] El fosfato de vanadilo es bien conocido como una fase inorgánica laminar capaz de intercalar una gran variedad de moléculas orgánicas. Mediante la polimerización in-situ, de anilina o pirrol, en la fase inorgánica es posible preparar materiales híbridos orgánico-inorgánicos en los que el polímero queda intercalado. Se describe la síntesis y caracterización de este tipo de híbridos y algunos resultados preliminares de su aplicación como materiales activos de cátodo en celdas reversibles de litio.; [EN] Vanadyl phosphate is a well known layered inorganic phase, capable of intercalating a great variety of organic molecules. By means of an in-situ polymerisation of aniline or pyrrole between the layers of the inorganic phase, it is possible to obtain organic-inorganic hybrids. We describe the synthesis and characterization of these type of hybrids, and some preliminary results of their application as active cathodic materials for positive electrodes in reversible lithium cells.; Agradecemos la financiación de este trabajo a través de los proyectos MAT2001-709-C04-01 y MAT2002-04529-C03, y al Consejo Nacional de Ciencia y Tecnología de México (CONACYT) por la concesión de una beca predoctoral a A.KCuentas-Gallegos.; Peer reviewed

Morphological, structural and electrochemical properties of lithium iron phosphates synthesized by Spray Pyrolysis

Martín Hernández, María Isabel; Gómez, L. S.; Meatza, I. de; Bengoechea, M.; Cantero, I.; Rabanal, M. Eugenia
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 1403281 bytes; application/pdf
ENG
Relevância na Pesquisa
48.89126%
Article in Press, Accepted Manuscript.; In the field of materials for Lithium ion batteries, the lithium iron phosphate LiFePO4 has been proven for use as a positive electrode due to its good resistance to thermal degradation and overcharge, safety and low cost. The use of nanostructured materials would improve its efficiency. This work shows the results of the synthesis of nanostructured materials with functional properties for Lithium batteries through aerosol techniques. The Spray Pyrolysis method allows synthesizing nanostructured particles with spherical geometry, not agglomerates, with narrow distribution of particle size and homogeneous composition in respect to a precursor solution. Experimental techniques were focused on the morphological (SEM and TEM), structural (XRD and HRTEM-SAED), chemical (EDS) and electrochemical characterization.; The authors gratefully appreciate the financial support of the Ministry for Education and Science of Spain in the project “Advanced materials for Lithium batteries through alternative synthesis” (PIROLION project-PROFIT 2007-2008), MAT2007-64486-C07-05 (FEDER) and the Juan de la Cierva program JCI-2005-1892-13 (M.I. Martín). We thank I. Boyano for helpful discussions and A. Lago for experimental aid. The assistance in TEM characterization of the Electron Microscopy and Citometry Center...

Integration of Hexacyanoferrate as Active Species in a Molecular Hybrid Material. Transport Properties and Application of PAni/HCF as Cathode in Rechargeable Lithium Batteries

Torres-Gómez, G.; Tejada Rosales, E. M.; Gómez-Romero, P.
Fonte: American Chemical Society Publicador: American Chemical Society
Tipo: Artículo Formato: 579917 bytes; image/jpeg
ENG
Relevância na Pesquisa
58.24574%
Especial Issue on Nanocomposite Materials.; The hybrid organic-inorganic material formed by polyaniline and the hexacyanoferrate anion (PAni/HCF) constitutes a molecular hybrid where the anchoring of the electroactive anion within the polymer leads to its application as a functional material that harnesses the activity of the molecular species. Transport measurements of the hybrid have been carried out, both by cyclic voltammetry at different scan rates and ac impedance spectroscopy. An apparent diffusion coefficient of 5 10-8 cm2/s and an activation energy of 15.5 kJ/mol (0.16 eV) have been obtained. The particular application of these hybrids to energy storage is shown here through their use as cathodes in lithium rechargeable cells. In this respect, the PAni/HCF hybrids show very good cyclabilities and high specific charges of up to 140 A.h/ kg, unprecedented for this type of hybrid materials; This work was funded by CICYT (Spain) (MAT98-0807-C02-02). We thank the Ministry of Education and Culture (Spain) for predoctoral fellowships awarded to G.T.G. and E.M.T.R.; Peer reviewed

Electrodos híbridos a base de Polianilina/V2O5 para el desarrollo de baterías plásticas de litio; Hybrid Electrodes based on Polyaniline/V2O5 for the development of plastic lithium batteries

Cuentas Gallegos, A. K.; Gómez-Romero, P.; Lira-Cantú, Monica; Torres-Gómez, G.
Fonte: Sociedad Española de Cerámica y Vidrio Publicador: Sociedad Española de Cerámica y Vidrio
Tipo: Artículo Formato: 486462 bytes; application/pdf
SPA
Relevância na Pesquisa
68.687095%
[ES] Presentamos la síntesis y caracterización del híbrido PAni/V2O5 y su aplicación como cátodo en baterías reversibles de litio. La síntesis se realizó directamente a partir del hidrogel de V2O5. Observamos una relación directa entre las condiciones de síntesis y la carga específica (Ah/Kg) obtenida durante el análisis del material como cátodo en baterías recargables de litio. Por otro lado, se llevaron a cabo tratamientos con oxígeno para aumentar el estado de oxidación del V2O5 en el material híbrido. El uso de mayores temperaturas y tiempos de reacción provoca la descomposición de la parte orgánica del híbrido PAni/V2O5. La carga específica y tratamientos posteriores de los híbridos obtenidos son muy sensibles a las condiciones de síntesis. Se observaron valores tan elevados como 302 Ah/Kg a baja velocidad de descarga (C/48) y 200-238 Ah/Kg a una velocidad de descarga de C/12, valores que corresponden a la inserción de 2.7 y 2.08 iones litio respectivamente. Estos valores demuestran la respuesta sinérgica entre PAni y el material óxido V2O5.; [EN] We present the synthesis and characterization of the hybrid PAni/V2O5 and its performance as cathode in reversible lithium cells. The synthesis was made directly from the V2O5 gel. We observe a direct relationship between the synthesis conditions and the specific charge (Ah/Kg) obtained during the analysis of the material as cathode in lithium batteries. On the other hand...

Synthesis and characterization of the solid ionic conductor La0.43Ce0.1Li0.30TiO3

Fernández Fernández,Néstor; García Sánchez,Mario Fidel; Mariño Otero,Teobaldo; Romero Ibarra,Issis Claudette
Fonte: Universidad de La Salle Bajío A. C., Coordinación de Investigación Publicador: Universidad de La Salle Bajío A. C., Coordinación de Investigación
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2013 EN
Relevância na Pesquisa
48.36994%
The improvement of storing energy devices is an important subject in present days. This paper deals with materials that potentially could be employed as solid electrolytes in secondary lithium batteries. The complex oxide La0.43Ce0.1Li0.30TiO3 was prepared by a ceramic method. The structural characterization was carried out by X ray powder diffraction and electric properties were analyzed by Electric Polarization in Solid State technique and the Seebeck coefficient calculus. The obtained solids have orthorhombic perovskite-like crystalline structure and they are ionic conductors of lithium ion whereas electronic conduction is absent.