After wrapping up my third week at Imprint Energy, it’s hard to summarize all the different things I’ve done! I’ve been working on my SQL and data analysis using Python, worked on a project under the materials team focused on improving the solvent used for the electrolyte and possibly the anode, tested the self-discharge of MnO2 mixtures, and assisted the R&D testing team with their shelf life testing and analysis. It’s been wonderful to work in so many different areas of the battery team because my understanding of each area has been fed so much by the others. Doing testing has given me an understanding of how the properties of the materials used to build the batteries affect battery performance immediately, 6 months, and even more than a year down the line. This has helped me understand what I should focus on while looking into solvent replacements for battery components. The solvent replacement project is mostly independent and using my understanding of the battery system I’ve gained from my testing efforts as a guide has been very rewarding. Additionally, I’ve been working on my data analysis skills with data management and engineering lead. In my other projects, I’ve gained an understanding of the battery system and all the variables present, which has allowed me to think about how I am analyzing the existing battery data in a much more nuanced way.
Below is a picture of one of the solutions I made to study the solubility of a potential binder in a potential solvent. For the first part of my project with the materials team, I wanted to create a functional “solubility curve.” For the polymer solution, it wasn’t feasible to create a proper solubility curve, but for the purposes of the battery engineering team, I could measure the extent of dissolution and temperature of dissolution along with some qualitative information. This experiment showed compatibility with electrolyte and anode components at the lowest level and served as the foundation for the second round of experiments.
After creating these solubility curves and identifying the most feasible solvents, I made samples of electrolyte to test the compatibility and stability of all components of the electrolyte ink. The stability and viscosity of the Electrolyte inks and how long they take to cure or dry are important to understand before manufacturing any of the inks tested in this experiment at a higher scale.
The past couple of weeks, I have been gaining a foundational understanding of the database and data organization at Imprint, and I have written some basic scripts to analyze their data. There are so many different factors affecting the data Imprint has recorded, which makes analysis packed with realizations and interesting deductions. Recently, I experienced a fun example of correlation vs causation. Looking at the relationship between anode thickness and resistivity, there is a strong negative correlation between the two. This increased conductivity would help in power delivery, so this relationship is an exciting find! However, it makes little sense based on this system. Looking at other possible causes for this increase in conductivity, one of the other engineers who knows the battery printing process knows that the anode layer is given the same drying time no matter the thickness. The solvent gradient in thicker anodes seems to be a more likely reason for increased conductivity. This hypothesis can be easily tested to understand if the drying pattern in thicker anodes increases conductivity. This experience illustrated to me how understanding a given system can affect data analysis on it, and how data can then drive further experimentation and understanding of the system.
Overall, I’ve learned a lot in the past couple of weeks. To find alternative solvents, I had to remember a lot of chemistry and learn some new ways of analyzing chemical structure to find solvents compatible with the battery components. I’ve learned all about Imprint's battery testing and also battery testing as a whole. I’ve learned a lot of SQL and about how great of an asset it is to understand your system and variables when conducting data analysis or managing data. I’m excited to continue building the hard skills I’ve used as a battery engineering intern so far and see what new experiences the coming weeks at Imprint will bring. Thank you for reading!