Evaluation of polyolefin-based macroporous separators for high temperature Li-ion batteries

Macroporous separators are critical components in liquid electrolyte batteries. Besides preventing physical contact between electrodes, they enable free ionic transport, electronic isolation and thermal shutdown. Nevertheless, separators also increase electrical resistance and takes up limited space inside the battery, affecting ionic conductivity. Widely used in lithium-ion batteries, commercial polyolefin-based separators operate in a limited temperature range, mainly ranging from -20 degrees C to + 60 degrees C. The purpose of this contribution is to assess the possibility to use these separators in lithium-ion batteries operating at extended temperatures, i.e. between -20 degrees C and 120 degrees C. For this purpose, four commercially available macroporous separators based on polyethylene and polypropylene, were investigated. To determine the effect of temperature on their performance, they were aged for one week at 120 degrees C. Evolution of their morphology and thermomechanical behavior was investigated using XRD, SEM, DSC, TGA and DMA. The thermal aging impact on the ionic conductivity was also investigated using LP30 (R) as reference electrolyte. Thermal aging, i.e. partial clogging of the porosity, was found to have significant effects mainly on mechanical strength, morphology and conductivity. (C) 2016 Elsevier Ltd. All rights reserved.This work has been supported by Projects funded by the regional government (Comunidad de Madrid through MATERYENER3CM S2013/MIT-2753) and the Spanish Government, MICINN (MAT2013-46452-C4-3R).J-Y Sanchez acknowledges the CONEX Programme, funding received from Universidad Carlos III de Madrid, the European Union’s Seventh Framework Programme for research, technological development and demonstration (Grant agreement n 600371), Spanish Ministry of Economy and Competitiveness (COFUND2013- 40258) and Banco Santander

LTCC microflow analyzers with monolithic integration of thersmal control

Recently, the low temperature co-fired ceramics technology has shown to be an excellent alternative to silicon-based microfabrication techniques for the production of three-dimensional structures using a multi-layer approach. This enables the integration of several unitary operations of a classical analytical process and also the integration of sensors, actuators and electronics in the same substrate. In this work, we show the integration of the actuators and the sensors needed for the control of temperature inside a miniaturized fluidic device. The proposed device presents enough thermal accuracy to be used in chemical systems where temperature control is a crucial factor, such as enzyme reactions or polymerase chain reaction systems.The authors would like to thank the Spanish MEC for its financial support through: Consolider-Ingenio 2010 (CSD2006-00012), TEC2006-13907-C04-04/MIC and CIT-310200-2007-29. CSM is also thankful to the Alban Program (High-level grants from the European Union to Latin America for its financial support (Grant number: E05D053315MX)

Microreactor with integrates temperature control for the synthesis of CdSe nanocrystals

The recent needs in the nanosciences field have promoted the interest towards the development of miniaturized and highly integrated devices able to improve and automate the current processes associated to the efficient nanomaterials production. Herein, a green tape based microfluidic system to perform high temperature controlled synthetic reactions of nanocrystals is presented. The device, which integrates both, the microfluidics and a thermally controlled platform, was applied to the automated and continuoussynthesis of CdSe quantum dots. Since temperature can be accurately regulated as required, sizecontrolled and reproducible quantum dots could be obtained by regulating this parameter and the molar ratio of precursors. The obtained nanocrystals were characterized by UV-Vis and fluorescencespectrophotometries. The band width of the emission peaks obtained indicates a narrow size distribution of the nanocrystals, which confirms the uniform temperature profile applied for each synthetic process, being the optimum temperature at 270° C (Full Width at Half Maximum = 40 nm). This approach allows a temperature controlled, easy, low cost and automated way to produce quantum dots in organic media, enhancing its application from laboratory-scale to pilot-line scale processes.This work has been supported by the Spanish Ministry of Science and Innovation (MICINN) through projects CTQ2009-12128 and the Consolider Ingenio 2010 project CSD2006 -12 and Catalonia 15 Government through SGR 2009 -0323

Integration of a sensitive carbon nanotube composite electrode in a ceramic microanalyzer for the amperometric determination of free chlorine

In this paper we report a green tape ceramic microfluidic analyzer that integrates a complete amperometric detection system based on a highly sensitive carbon nanotube composite electrode. As a proof of the integration concept, reference and counter electrodes were embedded into the microanalyzer body during the fabrication process.In order to increase the system functionality, and taking advantage of the surface renewability associated to composite electrodes, the working electrode was integrated in an exchangeable configuration. The microanalyzer was automated by means of the multicommutation technique, which allowed its autocalibration by the on-line preparation of standard solutions from a unique stock solution. The system was applied to the analysis of free chlorine in water samples. A noticeable low detection limit (0.05 mg L-1) and a high-term stability were observed. To demonstrate the potentiality of thisapproach, in terms of analytical performance, it was also applied to the analysis of real samples obtained from a public swimming pool. The system characteristics make it ideal for unattended applications where the minimum user interaction and the maximum analyzer autonomy are required.This work was partly supported by the Spanish MICINN project CTQ2009-13873 (BQU subprogram). R. Olivé-Monllau thanks Universitat Autònoma de Barcelona (UAB) for the award of PIF studentship

PEO: An immobile solvent?

Despite used for half a century as host for salt-polymer complexes, PEO is still not a fossil and due to its availability, remains regularly used as a reference in solvent-free polymer electrolytes and related electrochemical cells. Often qualified as macromolecular solvent or immobile solvent, its drawbacks (crystallinity, mechanical strength) are well identified. On the other hand, its electrolyte conductivity maxima are considered as the best possible in absence of molecular solvents or ionic liquids. The comparison of PEO/LiTFSI based on raw PEO and ultrafiltrated one, shows unambiguously the impact of unentangled oligomers not only on ionic transport but also on mechanical behavior. Conductivity, cationic transference numbers and storage modulus data go in the same direction and the cationic conductivity (O/Li = 30) is divided by 2, following PEO purification.Jean-Yves Sanchez acknowledges the CONEX Programme, funding received from Universidad Carlos III de Madrid, the European Union's Seventh Framework Programme for research, technological development and demonstration (Grant agreement nº 600371), Spanish Ministry of Economy and Competitiveness (COFUND2013-40258) and Banco Santander. Amadou Thiam acknowledges ANR for his fellowship. Yannick Molméret acknowledges KICINNO Energy for the granting of his post-doc fellowship, in the frame of the project PENLiB coordinated by Prof. Jean-Yves Sanchez

Thermal activation of catalytic microjets in blood samples using microfluidic chips

We demonstrate that catalytic microjet engines can out-swim high complex media composed of red blood cells and serum. Despite the challenge presented by the high viscosity of the solution at room tem perature, the catalytic microjet s can b activatedat physiological temperature and, consequently, selfpropelin diluted solutions of blood samples. We prove thatthese microjets self-propel in 10× diluted blood samples usingmicrofluidic chips.European Commission European Community's Seventh Framework Program Volkswagen Foundation (# 86 362

Trapping self-propelled micromotors with microfabricated chevron and heart-shaped chips

We demonstrate that catalytic micromotors can be trapped in microfluidic chips containing chevron and heart-shaped structures. Despite the challenge presented by the reduced size of the traps, microfluidic chips with different trapping geometries can be fabricated via replica moulding. We prove that these microfluidic chips can capture micromotors without the need for any external mechanism to control their motion.The research leading to these results has received funding from S.S. and L.S. thank DFG (grant SA 2525/1-1) for financial support.European Community's Seventh Framework ProgramEuropean Commissio

Sodium polymer electrolytes composed of sulfonated polysulfone and macromolecular/molecular solvents for Na-batteries

Polysulfone acidic ionomers have been extensively used as Fuel Cell membranes, mainly because of their mechanical, thermal, chemical and electrochemical stability as well as their excellent film-forming capability. This contribution deals with the development of blends based on polysulfone-sodium sulfonate and macromolecular/molecular solvents, consisting of poly(oxyethylene), POE, and propylene carbonate, PC, respectively. The objectives were to take advantage of both the thermomechanical performances and the macromolecular polyanions provided by the polysulfone ionomer. Combining POE/PC solvents, didn't allow obtaining sufficient blend's conductivities. Nevertheless, the addition of very low amounts of sodium perchlorate led to appreciable conductivities.This work has been supported by Projects funded by the regional government (Comunidad de Madrid through MATERYENER3CM S2013/MIT-2753), the Spanish Government, MICINN (MAT2016-78362-C4-3-R) and Fundación Iberdrola España for the Energy and Environment Research Grants 2016. J-Y Sanchez acknowledges the CONEX Programme, funding received from Universidad Carlos III de Madrid, the European Union’s Seventh Framework Programme for research, technological development and demonstration (Grant agreement nº 600371), Spanish Ministry of Economy and Competitiveness (COFUND2013-40258) and Banco Santander

Design, fabrication and characterization of microreactors for high temperature syntheses

Microfluidic reactors offer many potential advantages in several research and industrial fields such as processes intensification, which includes a better reaction control (kinetics and thermodynamics), a high throughput and a safer operational environment (reduced manipulation of dangerous reagents and low sub-products generation). Nevertheless, scaling-down limitations appear concerning the materials used in the fabrication of microreactors for most of the liquid-phase reactions, since they usually require high temperatures (up to 300 °C), solvents and organic reagents. In this work, the development of a set of modular and monolithic microreactors based on the integration of microfluidics and a thermal platform (sensor/high-temperature heater) is proposed to perform high temperature reactions. The reliability and performance of both configurations were evaluated through an exhaustive characterization process regarding their thermal and microfluidic performance. Obtained results make the devices viable for their application in controlled and reproducible synthetic processes occurring at high temperatures such as the synthesis of quantum dots. The proposed microfluidic approach emerge as an engaging tool for processes intensification, since it provides better mass and temperature transfer than conventional methods with a reduction not only of the size and energy consumption, but also of by-products and reagents consumption.This work has been supported by the Spanish Ministry of Science and Innovation (MICINN) through projects CTQ2009-12128 and the Consolider Ingenio 2010 project CSD2006 -12 and Catalonia Government through SGR 2009 -0323

Flexible solvent-free polymer electrolytes for solid-state Na batteries

Post-lithium batteries, based on alkaline and alkaline earth elements, are cheaper technologies with the potential to produce disruptive changes in the transition towards cleaner and sustainable energy sources less dependent on fossil fuels. This contribution deals with the development and characterization of sodium-conducting solvent-free polymer electrolytes towards the attainment of Sodium Polymer Batteries. Obtained via the polycondensation of α, ω-dihydroxy-oligo(oxyethylene) with an unsaturated dihalide, whose further curing leads to amorphous networked electrolyte films. Using NaClO4 and NaCF3SO3 at different O/Na ratios, the best polymer electrolyte reaches a cationic conductivity (σ+) exceeding 1 mS cm−1 at 90 °C whereas maintaining mechanical integrity up to at least 120 °C.The authors would like to thank the Agencia Española de Investigación/Fondo Europeo de Desarrollo Regional (FEDER/UE) for funding the project PID2019-106662RBC43. This work has been supported by the Madrid Government (Comunidad de Madrid-Spain) through three projects: 1) the Multiannual Agreement with UC3M ("Fostering Young Doctors Research", CIRENAICA-CM-UC3M), and in the context of the VPRICIT (Research and Technological Innovation Regional Programme); 2) the Multiannual agreement with UC3M ("Excelencia para el Profesorado Universitario" - EPUC3M04) - Fifth regional research plan 2016-2020; 3) DROMADER-CM (Y2020/NMT6584). B.P. and A.V. acknowledge support from the CONEX-Plus programme funded by Universidad Carlos III de Madrid and the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 801538