Discharge-charge property of lithium/PEO/sulfur battery with high sulfur content

Abstract

The sulfur electrodes were prepared from sulfur, carbon, and PEO as a binder. Poly(ethylene-oxide) with LiCF3SO3 Was used as a solid polymer electrolyte for Li/S cell. Sulfur content of the sulfur electrode was 70wt%, and the carbon content was varied from 10wt% to 25wt%. The weight ratio of PEO and LiCF3SO3 in the polymer electrolyte was 9:1. The lithium/PEO/sulfur cell showed two plateau potential regions (2.4V, 2.1V) and high discharge capacity, i.e., 1068mAh/g(63.7% utilization of sulfur). The discharge capacity decreased drastically during charge-discharge cycling. The capacity fade depended on the composition of sulfur electrode regardless of similar initial discharge capacity. The sulfur electrode with high carbon content retained high capacity after repeated cycling. The optimum composition of 70wt% sulfur electrode was composed of 20wt% carbon and 10% PEO.