Training

Sorry this is such dry reading so far – it’s actually a lot more interesting for me than it sounds. I’m still in the training phase of my internship – getting familiar with how to work all the equipment, reading the data from the graphs, and building different test cells, etc. Today I was shown how to do calculations for preparing polymer-electrolyte solution. This is a mix of polymer, SEEO polymer in this case, and Lithium salt. This is where the ion transfer occurs and the reactions happen in the battery. So unlike what I’ve learned in chem. Class, where measurements are rigidly taken and chemicals are applied mostly in terms of molarity, here, the primary measurements are made in weight percent and ratios. When dissolving the polymer in solvent, the amount of solvent used is determined in the weight percent of polymer in solution, which makes calculations a bit easier since you just measure out a certain number of grams of solvent and polymer on a scale. For the amount of salt, a value called the r-value is used. This does require some chemistry, as you have to calculate the number of moles of EO, a molecule in the polymer, and Lithium from the salt, and they must match a certain ratio, or r-value. Not to bad. So I performed these calculations relatively easily, and I mixed some polymer electrolyte solution with Seeos8 polymer and LiTFSi salt. I mixed a second one also with Seeos8 polymer and LiTFSi salt, but this time I added an additive, PEG 500, according to the corresponding combined r-value, which needed to be modified since additive introduces more EO into the system. Other than that, I built some blocking cells for Albert. I think I’m getting the hang of this, and I’m starting to think I can handle this.