Nuevos materiales compuestos Si/carbono grafitizado como electrodos negativos de alta energía para baterías de litio-ión

II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC

Simple and Sustainable Preparation of Nonactivated Porous Carbon from Brewing Waste for High-Performance Lithium–Sulfur Batteries

The development of renewable energy sources requires the parallel development of sustainable energy storage systems because of its noncontinuous production. Even the most-used battery on the planet, the lithium-ion battery, is reaching its technological limit. In light of this, lithium–sulfur batteries have emerged as one of the most promising technologies to address this problem. The use of biomass to produce cathodes for these batteries addresses not only the aforementioned problem, but it also reduces the carbon footprint and gives added value to something normally considered waste. Here, the production, by simple and nonactivating pyrolysis, of a carbon material using the abundant “after-boiling waste” derived from beer brewing is reported. After adding a high sulfur loading (70 %) to this biowaste-derived carbon by the “melt diffusion” method, the sulfur–carbon composite is used as an effective cathode in Li–S batteries. The cathode shows excellent performance, reaching high capacity values with long-term cyclability at high current—847 mAh g−1 at 1 C, 586 mAh g−1 at 2 C, and even 498 mAh g−1 at 5 C after 400 cycles—drastically reducing capacity loss to values approaching 0.01 % per cycle. This work demonstrates the possibility of obtaining low-cost, highly sustainable cathodic materials for the design of advanced energy storage systems

Synthesis and Characterization of Aero-Eutectic Graphite Obtained by Solidification and Its Application in Energy Storage: Cathodes for Lithium Oxygen Batteries

Aero-eutectic graphite can be defined as a new light material with hierarchically structured porosity. It is obtained from the solidification of gray cast irons, followed by the dissolution of the ferrous matrix by an acidic sequence. The result is a continuous and interconnected network of graphite sheets with varied dimensions randomly oriented. X-ray diffraction characterization has revealed graphite crystallographic planes (002), (100), (101), (102) and (004), while the surface area measured by BET and Langmuir methods has been determined in the order of 90 m2 g−1 and 336 m2 g−1, respectively. The process of obtaining eutectic aero-graphite also allows the deposit of Cu nanofilms and TiC particles. Aero-eutectic graphite has been tested as cathode in Li–O2 batteries as it has been prepared, without the addition of binders or conductive carbons, showing an appropriate contact with the electrolyte, so that the oxygen reduction and evolution reactions may develop satisfactorily. In the discharge-charge galvanostatic tests, the battery accomplishes 20 complete cycles with area capacity limited to 1.2 mAh cm−2

Synthesis and Characterization of Aero-Eutectic Graphite Obtained by Solidification and Its Application in Energy Storage: Cathodes for Lithium Oxygen Batteries

Aero-eutectic graphite can be defined as a new light material with hierarchically structured porosity. It is obtained from the solidification of gray cast irons, followed by the dissolution of the ferrous matrix by an acidic sequence. The result is a continuous and interconnected network of graphite sheets with varied dimensions randomly oriented. X-ray diffraction characterization has revealed graphite crystallographic planes (002), (100), (101), (102) and (004), while the surface area measured by BET and Langmuir methods has been determined in the order of 90 m2 g−1 and 336 m2 g−1, respectively. The process of obtaining eutectic aero-graphite also allows the deposit of Cu nanofilms and TiC particles. Aero-eutectic graphite has been tested as cathode in Li?O2 batteries as it has been prepared, without the addition of binders or conductive carbons, showing an appropriate contact with the electrolyte, so that the oxygen reduction and evolution reactions may develop satisfactorily. In the discharge-charge galvanostatic tests, the battery accomplishes 20 complete cycles with area capacity limited to 1.2 mAh cm−2.Fil: Gregorutti, Ricardo Walter. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Laboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológica; ArgentinaFil: Tesio, Alvaro Yamil. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy. - Universidad Nacional de Jujuy. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy. - Gobierno de la Provincia de Jujuy. Centro de Investigacion y Desarrollo En Materiales Avanzados y Almacenamiento de Energia de Jujuy; ArgentinaFil: Gómez Cámer, Juan Luis. Universidad de Córdoba. Instituto Universitario de Investigación en Química Fina y Nanoquímica; EspañaFil: Roviglione, Alicia Norma. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Mecánica; Argentin

Anclaje de nanopartículas de silicio a nanofibras de carbón: electrodos de alta capacidad para baterías de ión litio

III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce

Baterías Li-ion de alta energía combinando silicio nanométrico y espinelas de alto potencial

II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC

Rechargeable Lithium-Ion Battery Based on a Cathode of Copper Hexacyanoferrate

In this work, the performance of copper(II) hexacyanoferrate(III) (CuHCF) as a cathode material for lithium-ion batteries was studied. The compound was synthesized by a precipitation reaction in aqueous solution in a closed system. The morphology and structure show nanoparticles with sizes between 40 and 70 nm with a high agglomeration and a crystalline phase with a cubic structure, respectively. The material exhibited a stable performance with a working potential of around 3.6 V vs Li+/Li and a decrease in the charge transfer resistance due to increased ionic conductivity. The gravimetric capacity obtained is near 60 mAh g−1 during 300 cycles at a rate of C/20, close to the practical capacity. Considering its electrochemical performance, CuHCF could be a promising cathode material for lithium-ion batteries

Síntesis y caracterización de composites nanométricos de silicio para su uso como electrodos en baterías de ión-litio

La Tesis presentada por el Ldo. D. Juan Luis Gómez Cámer, titulada "Síntesis y caracterización de composites nanométricos de silicio para su uso como electrodos en baterías de ión-litio", aborda la preparación y el estudio de las propiedades electroquímicas de materiales anódicos para baterías de litio-ión. La memoria se centra en dos temas principales; en primer lugar, en la síntesis y caracterización de sulfuros de cobalto, así como del estudio de sus propiedades en celdas de litio, y en segundo lugar en la preparación de materiales compuestos basados en silicio de tamaño de partícula nanométrico. En este último punto se estudia el efecto de la matriz dispersante del silicio, ya sea fibras de celulosa con y sin aditivo conductor o fibras de carbón, de manera que el cambio de volumen sufrido por el silicio durante los procesos de aleación electroquímica con litio quede minimizado, proporcionando altos valores de capacidad específica y buena retención de la capacidad. La memoria no se detiene en el mero estudio de las propiedades electroquímicas de los materiales, sino que afronta su uso como electrodos en baterías prácticas de litio-ión, objetivo último de la caracterización química y electroquímica desarrollada a lo largo del período de investigación expuesto en la memoria