EN06.04.21 : An Analysis of Lithium Sulfur Interactions via GITT Measurements

5:00 PM–7:00 PM Apr 3, 2018 (America - Denver)

PCC North, 300 Level, Exhibit Hall C-E

Daisy Patino1 Rachel Ye1 Jeffrey Bell1 Mihri Ozkan1 Cengiz Ozkan1

1, University of California, Riverside, Riverside, California, United States

The galvanostatic intermittent titration technique (GITT) is an electroanalytical tool commonly used in lithium ion technologies which uses transient and steady state measurements to obtain kinetic and thermodynamic properties of electrodes materials. The GITT procedure involves applying short current pulses followed by relaxation periods. In conventional lithium ion cells, when we apply current pulses, we induce concentration changes within the host electrodes. In lithium sulfur batteries however, the concentration change occurs in the electrolyte due to the reduction process of sulfur to electrolyte-soluble polysulfides. Hence, it is a complex procedure to quantify values such as, chemical diffusivity coefficient of lithium ions and the resistivity through the electrolyte in lithium sulfur cells, as opposed to conventional solid state lithium ion cells. Accordingly, research efforts to utilize GITT for lithium sulfur cells, omit the polysulfide shuttle mechanism to obtain a semi-solid state model. Herein, we explore a complete lithium sulfur model that enables more accurate quantitative depictions for mass transport rates, chemical reaction rates, and sulfur utilization.