Effect of sulfur electrode composition on the electrochemical property of lithium/PEO/sulfur battery

Abstract

The lithium/sulfur cell is very attractive because of its high theoretical specific capacity and low production cost. The sulfur electrode is prepared from sulfur, with carbon as an electronic conductor and PEO as an ionic conductor. We changed the carbon content of a 50 wt.% sulfur electrode from 10 wt.% to 40 wt.%. The lithium/PEO/sulfur cell showed two plateau potential regions (2.4 V, 2.1 V) and high discharge capacity, i.e., 1484 mAh/g (88 % utilization) for optimum composition. The discharge capacity decreased drastically by charge-discharge cycling. The degradation rate as well as the first discharge capacity depended on the composition of the sulfur electrode. The optimum composition of the 50 wt.% sulfur electrode was 30 wt.% carbon and 20 % PEO.

Electrochemical properties of all solid state Li/S battery

“…The discharge capacity of 512 mAh g À1 -sulfur after 10 cycles was about 49% of the first discharge capacity. This data was similar to previous Li/S cell [3,8] and coincided with the CV result of Fig. 4.…”

“…Several works have been performed in the field of all-solid-state Li/S battery using solid electrolyte. Polyethylene oxide (PEO) was adopted as the solid electrolyte of Li/S battery [6][7][8]. Li/PEO/S battery had high discharge capacity as well as high level of safety [8].…”

“…Polyethylene oxide (PEO) was adopted as the solid electrolyte of Li/S battery [6][7][8]. Li/PEO/S battery had high discharge capacity as well as high level of safety [8]. However, Li/ PEO/S battery was operated above 80 8C because PEO electrolyte had low ionic conductivity at room temperature.…”

Novel Li[(CF3SO2)(n-C4F9SO2)N]-Based Polymer Electrolytes for Solid-State Lithium Batteries with Superior Electrochemical Performance

“…It can be seen that two characteristic diffraction peaks of the crystalline PEO at 2θ = 19.2 and 23.3°a re observed. 29,30 With the increase in Li salt content, the intensities of these two characteristic diffraction peaks for neat PEO decrease rapidly in the series of the LiTNFSI/PEO (EO/ Li + = 8, 16, 20, and 30) blended electrolytes. It is interesting to note that these two peaks become very broad at the lowest molar ratio of EO/Li + = 8, confirming that the presence of mainly amorphous phase.…”

Perspective of polymer-based solid-state Li-S batteries

“…However, LiTFSI/PEO-based ASSPEs provide inferior SEI formation in contact with the Li° anode due to the unfavorable anion chemistry. Furthermore, PS can still be dissolved in PEO at high temperatures (i.e., 70 °C), resulting in infinite charging (PS shuttle) already in the first cycles and notorious lithium dendrite growth [28,31] . The same phenomenon and cell performance are also observed in Li-S cells with lithium trifluoromethanesulfonate (LiTf)/PEO-based ASSPEs [32,33] .…”