Synergistic Effect of Covalent Bonding and Physical Encapsulation of Sulfur in the Pores of a Microporous COF to Improve Cycling Performance in Li-S Batteries

This is the peer reviewed version of the following article: Royuela, S., Almarza, J., Mancheño, M. J., Pérez Flores, J. C., Michel, E. G., Ramos, M. M., Zamora, F., Ocón, P. & Segura, J. L. (2019). Synergistic effect of covalent bonding and physical encapsulation of sulfur in the pores of a microporous COF to improve cycling performance in Li‐S batterie. Chemistry - A European Journal 25.53 (2019): 12394-12404, which has been published in final form at https://doi.org/10.1002/chem.201902052. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsLithium-sulfur batteries stands out as a promising technology for energy storage owing to a combination of favorable characteristics including a high theoretical gravimetric capacity, energy density, inexpensive character, and environmental benignity. Covalent organic frameworks (COFs) are a rapidly developing family of functional nanostructures which combine porosity and crystallinity, and which have been already used in these kinds of batteries to build sulfur electrodes, by embedding sulfur into porous COFs in order to enhance cycle lifetimes. In this contribution, this is taken one step forward and a COF endowed with vinyl groups is used, in order to graft sulfur to the COF skeleton through inverse vulcanization. The main aim of the article is to show the synergistic effect of covalent bonding and physical encapsulation of sulfur in the pores of the COF in order to alleviate the fatal redox shuttling process, to improve the cycling performance, and to provide faster ion diffusion pathways. In addition, it is shown how the material with covalently-bound S provides better electrochemical performance under demanding and/or changeable charge conditions than a parent analogue material with sulfur physically confined, but without covalent linkageFinancial support from Spanish Government (Projects MAT2016‐77608‐C3‐1‐P, MAT2016‐77608‐C3‐2‐P, FIS2017‐82415‐R, ENE2016‐77055‐C3‐1‐R), the “María de Maeztu” Programme for Units of Excellence in R&D (MDM‐2014‐0377) and the UCM (INV.GR.00.1819.10759) is acknowledged. We thank the BACH beamline team at Elettra for technical assistance with XPS measurements. The research leading to these results has received funding from the European Community's Horizon 2020 Framework Programme under grant agreement No 73087

Sob o signo neoliberal: as relações internacionais da América Latina

As relações internacionais da América Latina são vistas sob o ângulo da transição da diplomacia do desenvolvimento para a diplomacia neoliberal. Os estudos de relações internacionais, particularmente no Brasil e na Argentina, fundamentam a interpretação do autor sobre benefícios e malogros do paradigma neoliberal, visto como uma opção ideológica. A noção de Estado logístico é sugerida como alternativa estratégica ao Estado normal.<br>In this article, international relations in Latin America are analysed through the viewpoint of the transition from a diplomacy of development to a neoliberal model. Studies in International Relations as a discipline, especially those carried out in Brazil and Argentina, are the basis for the author's interpretation about benefits and failures of the neoliberal paradigm, understood as an ideological option. The author forwards the notion of Logistic State as a strategic alternative to the Normal State