Getting the Hang of It

I’ve officially found my place at Imprint Energy. Every day when I arrive at the office, I go through my checklist of to-dos. At the top of the priority list are my two projects: one helping to further characterize the lifespan of the batteries and the other to improve correlation of easy-to-measure electrical properties with capacity. I also fill in wherever a hand is needed around the lab from time to time. I’m learning a lot every day and am very lucky to be a part of the Imprint team.

In the lifespan project, I perform weekly yield checks on different production-run sheets of batteries to gather voltage and resistance data. As more data is collected, a model can potentially be fit to predict long-term performance. It’s interesting to see the graph become more complete after every measurement. I’m on track to collect thousands of data points by the end of my internship!

The correlation project, in my opinion, is a lot more interesting. Capacity is a hugely important propety, as it dictates how much charge a battery holds. Measuring capacity directly, however, is a destructive process. Being able to correlate non-destructive electrical measurements with capacity would be incredibly useful. I’ve begun looking into different data transformations to see if any strong correlations arise. I’ve found some correlation, but it’s not strong enough to warrant anything ground-breaking. An older attempt yielded a correlation coefficient of 0.17, which isn’t that strong. For reference, a correlation coefficient ranges from -1 to 1, where -1 represents a perfect negative correlation and 1 represents a perfect positive correlation. My first attempt at correlating some of the newly gathered data yielded a correlation coefficient of 0.50, a nice improvement over the previous value. However, it isn’t strong enough. My goal is find a correlation factor of around 0.80 or better.  Hopefully I’ll find something in the next few weeks! In the mean time, I’m going to continue to gather as much data as possible to further substantiate my findings.

When I’m not working on my two long-term projects, I’m helping out with whatever is needed around the lab. Last week, a potential customer asked for data showcasing the ability of our batteries to function after being cut, which I personally find fascinating! After being instructed on what kind of measurements to perform, I got to work. To demonstrate that cutting does not drastically affect the battery performance, I set up a small experiement. I took twelve battery cells and cut eight of them at the end. The remaining four were used as a control. Four of the cut cells were repackaged so that they would not be exposed to the ambient environment whereas the other four were not. I then brought all twelve batteries to the testing room, loaded the test files specified by the potential customer, and started the tests. Because the tests take so long to run, I’m not expecting to get the resulting data until early this week, but I’ll be sure to keep you all updated in the next blog post!

The "control" in the experiment - an uncut cell     One of the tests in the experiment - a cut and repackaged cell

On a personal note, I’ve began adjusting to the full work-week lifestyle. I’ve had jobs in the past, but never anything as frequent. But in all honesty, I’m finding that I actually like working full-time. Perhaps it’s because I’ve only been at it for a month now, but nonetheless, I enjoy how work tests me day after day. I love school for the same reason – I’m consistently challenged by my professors as well as by my peers. After the end of the semester, I was somewhat worried that I would fall into a “boredom” trap this summer. But working full time has helped me to avoid that. Furthermore, the dichotomy of work and free time that makes the latter so much more enjoyable. I’m definitely enjoying my weekends much more than I used to!