A review on electronically conducting polymers for lithium-sulfur battery and lithium-selenium battery: Progress and prospects

Lithium-sulfur (Li-S) batteries and lithium-selenium (Li-Se) batteries, as environmental protection energy storage systems with outstanding theoretical specific capacities and high energy densities, have become the hotspots of current researches. Besides, elemental S (Se) raw materials are widely sourced and their production costs are both low, which make them considered one of the new generations of high energy density electrochemical energy storage systems with the most potential for development. However, poor conductivity of elemental S/Se and the notorious “shuttle effect” of lithium polysulfides (polyselenides) severely hinder the commercialization of Li-S/Se batteries. Thanks to the excellent electrical conductivity and strong absorption of lithium polysulfide (polyselenide) about electronically conducting polymer, some of the above thorny problems have been effectively alleviated. The review presents the fundamental studies and current development trends of common electronically conducting polymers in various components of Li-S/Se batteries, which involves polyaniline (PANI) polypyrrole (PPy), and polythiophene (PTh) with its derivatives, e.g. polyethoxythiophene (PEDOT) and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS). Finally, the review not only summarizes the research directions and challenges facing the application of electronically conducting polymers, but also looks forward to the development prospects of them, which will provide a way for the practical use of electronically conducting polymers in Li-S/Se batteries with outstanding electrochemical properties in the short run.