Engineering of uniform spherical sulfur-containing polymer with short sulfur chain as cathode material for highly durable lithium storage

Abstract

Lithium-sulfur battery has ultra-higher theoretical specific capacity (1675 mA h g−1) and theoretical energy density (2600 W h kg−1) compared with other commercially applied rechargeable battery system. However, some drawbacks, such as shuttle effect, poor conductivity and so on, disrupt the process of its industrialization and commercializes. In this study, spherical sulfur-containing polymer with short sulfur chain (sulfur chain length controlled at -S2-) was synthesized as cathode material for lithium storage. Two sulfur-containing polymer samples with particle size of 300 nm and 1000 nm were designed and synthesized to investigate the electrochemical properties of lithium storage. The obtained two sulfur-containing polymer cathode materials both exhibit higher lithium electroactivity with only one single discharge plateau at 2.1 V. Moreover, the cathode material with larger particle size displays faster reaction kinetics, showing stable long cyclic performance, i.e. and high specific capacity of 618 mA h g−1 after 150 cycles at a current density of 100 mA g−1.