A high-performance biomass carbon separator loaded with MnO2 designed for lithium sulfur batteries

Abstract

Lithium polysulfide (LPS) is a crucial component obstructing the cycle performance of Li–S battery. At the same time, the utilization of agricultural waste straws has been in the stage of inefficient utilization. Here, the straws were used as raw materials to prepare the Mn-doped biomass carbon-loaded separator. The as-prepared separator not only provided abundant functional group sites for adsorbing and catalyzing LPS, but also offered the electronic transport paths to improve rate performance. At the same time, this separator reduced the density per unit area of lithium ions, guided Li-ions for uniform deposition and greatly decreased the generation of lithium dendrites. Thanks to the above-mentioned advantages, the Li–S battery prepared by the separator possessed excellent electrochemical performances. More importantly, under harsh conditions (sulfur load = 6 mg/cm2, lithium foil = 50 μm, E/S = 5), the modified sample still had higher capacity and retention rate.