Effect of the Linker in Terephthalate-Functionalized Conducting Redox Polymers

C2-Symmetrical 3,4-Ethylenedioxythiophene Monomers through a Divergent Approach

We present a divergent synthetic approach to C2-symmetrical 3,4-Ethylenedioxythiophene (EDOT) monomers in which functionalities can be introduced as pendant chains from the ethylene bridge. The key synthon, obtained through a high yielding trans-etherification, is the chiral EDOT with bromomethyl pendant groups and is prone to substitution reactions with oxygen-based nucleophiles. Elimination of the key precursor affords a diene that can be elaborated into unprecedented PhEDOT monomers using the Diels-Alder reaction. The strategy is further validated by the synthesis of a dithiane-containing EDOT.

Current computational trends in polyanionic cathode materials for Li and Na batteries

A long-standing effort has been devoted for the development of high energy density cathodes both for Li- and Na-ion batteries (LIBs and SIBs). The scientific communities in battery research primarily divide the Li- and Na-ion cathode materials into two categories: layered oxides and polyanionic compounds. Researchers are trying to improve the energy density of such materials through materials screening by mixing the transition metals or changing the concentration of Li or Na in the polyanionic compounds. Due to the fact that there is more stability in the polyanionic frameworks, batteries based on these materials mostly provide a prolonged cycling life as compared to the layered oxide materials. Nevertheless, the bottleneck for such compounds is the weight penalty from polyanionic groups that results into the lower capacity. The anion engineering could be considered as an essential way out to design such polyanionic compounds to resolve this issue and to fetch improved cathode performance. In this topical review we present a systematic overview of the polyanionic cathode materials used for LIBs and SIBs. We will also present the computational methodologies that have become significantly relevant for battery research. We will make an attempt to provide the theoretical insight with a current development in sulfate (SO₄), silicate (SiO₄) and phosphate (PO₄) based cathode materials for LIBs and SIBs. We will end this topical review with the future outlook, that will consist of the next generation organic electrode materials, mainly based on conjugated carbonyl compounds.

Conducting redox polymers with non-activated charge transport properties

The conduction mechanism of terephthalate-substituted polythiophene is dominated by residual scattering and shows a negative dependence on temperature.