New Diglyme-based Gel Polymer Electrolytes for Na-based Energy Storage Devices.

This work presents for the first time a new diglyme-based gel polymer (DOBn-GPE) suitable for Na-based energy storage devices. The DOBn-GPE, which contains a methacrylate-based polymer, exhibited an excellent high ionic conductivity (2.3 mS cm-1 at 20 °C), broad electrochemical stability (>5.0 V), and high mechanical stability. DOBn-GPE could be successfully used for the realization of Na-ion capacitors, sodium-metal batteries, and sodium-ion batteries, displaying performance comparable with those of systems containing liquid electrolytes at room temperature and at 60 °C. The results of these investigation indicated that the development of diglyme-based gel polymer electrolytes represents a promising strategy for the realization of advanced Na-based energy storage devices.

Emulsion Polymerizations for a Sustainable Preparation of Efficient TEMPO-based Electrodes.

Organic polymer-based batteries represent a promising alternative to present-day metal-based systems and a valuable step toward printable and customizable energy storage devices. However, most scientific work is focussed on the development of new redox-active organic materials, while straightforward manufacturing and sustainable materials and production will be a necessary key for the transformation to mass market applications. Here, a new synthetic approach for 2,2,6,6-tetramethyl-4-piperinidyl-N-oxyl (TEMPO)-based polymer particles by emulsion polymerization and their electrochemical investigation are reported. The developed emulsion polymerization protocol based on an aqueous reaction medium allowed the sustainable synthesis of a redox-active electrode material, combined with simple variation of the polymer particle size, which enabled the preparation of nanoparticles from 35 to 138 nm. Their application in cell experiments revealed a significant effect of the size of the active-polymer particles on the performance of poly(2,2,6,6-tetramethyl-4-piperinidyl-N-oxyl methacrylate) (PTMA)-based electrodes. In particular rate capabilities were found to be reduced with larger diameters. Nevertheless, all cells based on the different particles revealed the ability to recover from temporary capacity loss due to application of very high charge/discharge rates.

Sustainable Energy Storage: Recent Trends and Developments toward Fully Organic Batteries.

In times of spreading mobile devices, organic batteries represent a promising approach to replace the well-established lithium-ion technology to fulfill the growing demand for small, flexible, safe, as well as sustainable energy storage solutions. In the last years, large efforts have been made regarding the investigation and development of batteries that use organic active materials since they feature superior properties compared to metal-based, in particular lithium-based, energy-storage systems in terms of flexibility and safety as well as with regard to resource availability and disposal. This Review compiles an overview over the most recent studies on the topic. It focuses on the different types of applied active materials, covering both known systems that are optimized and novel structures that aim at being established.

Macromol. Rapid Commun. 14/2016.

Back Cover: Quaternary polymer electrolytes, containing PEO, LiTFSI, ionic liquid and ceramic filler, show higher limiting current density, conductivity and improved cycling performance in lithium metal/solid polymer electrolyte/LiFePO4 cells with respect to ternary electrolytes with either ionic liquid or ceramic filler. Further details can be found in the article by V. Sharova, G.-T. Kim, G. A. Giffin, A. Lex-Balducci,* and S. Passerini* on page 1188.

Quaternary Polymer Electrolytes Containing an Ionic Liquid and a Ceramic Filler.

In this work, the individual and combined effects of an ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide and ceramic filler silicon dioxide on the thermal and electrochemical properties of poly(ethylene oxide) electrolytes have been investigated. The electrolyte containing both components has the lowest glass transition (-60 °C) and melting temperatures (27 °C), the highest conductivity at any investigated temperature, and the highest limiting current density (at 40 °C). This solid polymer electrolyte also exhibits the best long-term cycling performance in Li/LiFePO4 cells.

Local Li coordination and ionic transport in methacrylate-based gel polymer electrolytes.

The local Li cation coordination motifs and the interactions between the hosting methacrylate-based polymer membrane and the liquid electrolyte [1 M LiPF6 in ethylene carbonate (EC)/dimethyl carbonate (DMC)] are studied by employing liquid and solid-state NMR spectroscopy. At low temperatures, two different coordination modes for Li cations are identified with the help of dipolar-based solid-state NMR techniques, one of which is the exclusive coordination by DMC molecules, while the other is a co-coordination by the polymer and DMC molecules. At room temperature, Li cations are found to be extremely mobile, coordinated by EC and DMC molecules as well as the copolymer, as found by liquid-state NMR spectroscopy.