ABSTRACT
Sustainability is one of the hot topics of today's research, in particular when it comes to energy-storage systems such as batteries. Redox-active molecules implemented in organic batteries represent a promising alternative to lithium-ion batteries, which partially rely on non-sustainable heavy metal salts. As an alternative, we propose benzothiazole, -oxazole and -imidazole derivatives as redox-active moieties for polymers in organic (radical) batteries. The target molecules were identified by a combination of theoretical and experimental approaches for the investigation of new organic active materials. Herein, we present the synthesis, electrochemical characterization and theoretical investigation of the proposed molecules, which can later be introduced into a polymer backbone and used in organic polymer batteries.
ABSTRACT
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 138â 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.
ABSTRACT
The first polymer bearing exTTF units intended for the use in electrical charge storage is presented. The polymer undergoes a redox reaction involving two electrons at -0.20 V vs Fc/Fc(+) and is applied as active cathode material in a Li-organic battery. The received coin cells feature a theoretical capacity of 132 mAh g(-1) , a cell potential of 3.5 V, and a lifetime exceeding more than 250 cycles.
