This study varies salt concentrations of lithium bis-trifluoromethanesulfonylimide (LiTFSI) in the block copolymer polystyrene-poly(ethylene oxide) (SEO), at different temperature gradients, analyzing the effect these parameters have on the magnitude of the Soret coefficient. The Soret Coefficient is the phenomena resulting in a concentration gradient via a temperature gradient. It is quantified by the ratio of thermal diffusion to mutual diffusion. The Soret effect can be utilized in thermogalvanic cells, by re-harvesting wasted heat from most power generating systems. Thermogalvanic cells, are a way to utilize a heat sink to create electrical energy, having the temperature gradient drive the system. Specifically, solid state polymer electrolytes are of interest in these cells as they offer benefits such as low flammability, high safety, and improved energy density, compared to common liquid electrolytes. Thus, application of the Soret effect in thermogalvanic cells is a clear way to greatly increase global energy efficiency, saving money for companies, and decreasing the global environmental footprint. To gain insight as to direction of diffusion in solid-state polymer electrolytes, and make this cell a reality, time resolved Fourier Transform Infrared spectroscopy (FTIR-ATR) measurements provide an unprecedented data accuracy for modeling. The FTIR makes the correlation between the infrared absorbance of the presented salt and its boundary concentration in the polymer through the Beer Lambert law, which has been proven true for salts in previous work. This technique overcomes many previous limitations to experimental techniques measuring the Soret Coefficient, making the FTIR-ATR an effective and repeatable instrument to use for collecting diffusion coefficients.