lithium-sulfur cell (battery)

The analysis of electrochemical impedance of lithium-sulfur cells is complicated by the complexity of the processes occurring inside them. Both electrochemical processes and mass transport processes simultaneously occur on the lithium and sulfur electrodes of the cells, as well as in the bulk electrolyte. A comparative analysis of the distribution functions of relaxation times of symmetric Li||Li, S||Sand and the full lithium-sulfur cell has been conducted.

The effect of the electrode sizes, the cell design and the compression force of the electrode modules on the impedance and discharge characteristics of lithium-sulfur cells was studied. It was shown that Swagelok and pouch cells with identical electrodes have different electrochemical characteristics – charge transfer resistance, discharge capacity and cycling duration. It was found that the discharge capacity at the first cycle of Swagelok and pouch cells differs by 20% approximately. The capacity of pouch cells decreases faster during cycling.