Electrochemical processes that occur inside an EV battery during a simple charging and discharging cycle, are complex but fascinating !
Dhevathi Rajan, our next pathbreaker, Manager for Battery Cell Testing in the R&D team at Romeo Power Inc, works on research and validation of batteries for various electric vehicle applications mainly for medium and heavy duty electric vehicle manufacturers.
Dhevathi talks to Shyam Krishnamurthy from The Interview Portal about several memorable experiences during the course of his PhD, conducting experiments, fabricating coin cell batteries, and exploring various battery materials.
For students, there will always be opportunities as long as you are open to learning new things. Learn to embrace the unknown because those experiences will give you ideas on the path you would like to take !
Dhevathi, can you tell us about your background?
I am from Neyveli, Tamil Nadu where I did the majority of my school education. After that, I did my undergraduate degree in Electrical and Electronics Engineering from an Anna University affiliated college in Chennai, India. My father is a businessman, and my mom is a homemaker who also supports in managing the business.
Neyveli which is home to a thermal power plant is one of my first inspirations to study for an engineering degree. During my schooling and undergraduate degree, I got many opportunities to explore various thermal power plants that helped me understand more about engineering applications.
I currently work as Manager for the Battery Cell Testing team within Battery Technology (R&D) where we work on research and validation of batteries for various electric vehicle applications.
What did you do for graduation/post graduation?
During my undergraduate degree I came to know about many people who pursued higher education outside India. I discussed with some of them about education and research activities which they were engaged in at that time. I was very much interested in research and started planning for pursuing higher studies during the last semester of my undergrad. After completing my undergraduate degree, I came to the United States to pursue M.S. and PhD in Electrical Engineering in 2016 and graduated in 2020. During the first 2 years of my program, I was fortunate to get academic scholarship and tuition waiver for working on a research project under FREEDM Systems Center. (FREEDM Systems Engineering Research Center is a collaborative effort between different universities to develop a more secure, sustainable environmentally friendly electric grid). For the rest of my program, I worked as a graduate assistant mainly teaching labs for undergraduate students. This helped me pursue my research with a tuition waiver, and the stipend provided for the work was helpful to cover my living expenses.
What were some of the drivers that led you to such an offbeat, unconventional and cool career?
During the first week of the PhD program, I had the opportunity to talk to many professors who were involved in different areas of research. When I was discussing with one of the professors about my experiences (during undergrad) on topics related to batteries, he told me that he had a research opportunity related to energy storage and asked if I wanted to work on it. I agreed and started working under his guidance, initially reviewing the literature and learning more about various lithium-ion battery related projects. Once I started reading more articles and learning more about batteries, I was fascinated by the internal electrochemical processes that take place in a battery during a simple process like charging and discharging.
Learning how to conduct experiments, how to fabricate coin cell batteries, and experiment with various battery materials made me realize there are so many different areas to explore in electrochemistry. After a few months of studying and understanding various research articles, and multiple discussions with professors I ended up researching the effects of different charging methods on commercial lithium-ion batteries for my dissertation.
How did you plan the steps to get into the career you wanted? Or how did you make a transition to a new career? Tell us about your career path
I was open to different opportunities to gain experience. I started applying for different internship positions by the end of 2018. During the Summer of 2019, I worked at Shell Technology Center in Houston where I was part of a team working on various projects related to microgrid solutions. Microgrid is a group of interconnected loads and distributed energy resources (DERs) such as microturbines, fuel cells, photovoltaics (PV), storage devices (e.g. batteries) and energy storage systems. In a microgrid, energy storage systems perform multiple functions such as frequency and voltage regulation, providing backup power for the system and playing a crucial role in cost optimization. It was a great experience to work in a large company and learn about applications of battery technology and research in industries. This helped me learn more about what I could do for my career after graduation.
How did you get your first break?
At the beginning of my graduate program I was looking to focus on research opportunities and career mainly in an academic setting. However, over the years, I learnt that there are many opportunities for research in universities, national laboratories and industries relevant to my experience. I try to keep my professional profile up to date with the latest information about my role. I started actively applying for an internship at the end of my 3rd year. I was contacted by a university recruiter from Shell through one of the online professional networking websites about an internship opportunity and was told to submit an application. I was also told that I might be a suitable candidate for the role related to battery technology. I applied online and went through multiple rounds of the interview process before being offered the intern role. Based on this experience I realized the importance and helpfulness of having up to date information in a professional networking website and having professional connections. Because, I was not aware of this opportunity in Shell until the recruiter directly contacted me. I assumed Shell is an oil company and they might not have opportunities related to battery technology.
By the end of my last semester, I applied for OPT (Optional Practical Training) which is to obtain an Employment Authorization Document (EAD) that allow students who studied and graduated in the US to work for a year. Due to the pandemic and other additional delays it took 4 months for me to receive EAD. In the meantime, I was applying for various positions and attending interviews for different companies. In March 2021, I got an opportunity to interview with Romeo Power for the position of a Battery Test Engineer. This position was within the Battery Technology (R&D) team. After multiple rounds of interview, I was offered the role and was able to join the company in April 2021.
What were some of the challenges you faced? How did you address them?
There were many challenges that I faced, from undergraduate all the way through to my graduate degree. I would like to talk about a couple of challenges and what I learnt before I started working in this current role.
Challenge 1: Towards the end of my graduate program and after, I had applied to various positions relevant to my experience and skills through various job sites without much luck. I realized that reaching out to people directly for job opportunities and having up to date relevant information on professional networking websites were helpful in presenting my qualifications. Even though applying online through job portals or company websites is helpful in getting interview calls, I realized that networking and having conversations directly with the people who are hiring were more effective approaches.
Challenge 2: Over the course of my education, I had many opportunities to participate and present in technical discussions, though not many opportunities to discuss non-technical topics or discuss technical topics to people who are not familiar with the subject. I joined toastmasters where I had opportunities to discuss a wide range of topics and get to know people from various backgrounds. I believe toastmasters also played an important role in increasing my confidence to talk in public.
Where do you work now? What problems do you address?
During my PhD, my thesis was on understanding the effects of different charging methods on commercial lithium-ion batteries. For my research, I developed various battery test experiments, and worked with different chemistries of commercial lithium-ion batteries. In addition, I have also used various test instruments, created test scripts, managed and analyzed the test data to determine the behaviour and performance of the batteries. These experiences were helpful in getting an opportunity to work as a Battery Test Engineer.
I started working as a Battery Test Engineer in the R&D team at Romeo Power, Inc. which is a startup that supplies products such as battery modules and packs mainly for medium and heavy duty electric vehicle manufacturers.
In my role as a Test Engineer I conducted cell level testing and analyzed the data. We collect a lot of data from various tests that we perform. When I joined, I was struggling to analyze the data in a faster and a more effective way. I started using Microsoft Excel which was difficult when analyzing large data sets. I had used software like Matlab during my coursework and research, but for different purposes. During the initial months on this job, with the help from other team members I was able to familiarize myself with programming in Matlab and Python. This saved a significant amount of time in processing and analyzing data.
Currently, I am working as Manager for the Battery Cell Testing team where my role is to manage cell testing related activities, expand the testing capabilities, interact and provide support to various teams. Since this is a startup, there are multiple projects or tasks that we have to work on in parallel. Learning how to manage and allocate time effectively for various tasks is one of the key responsibilities of the role.
This position and job in this company offer great opportunities for me to work with an excellent team and to learn new things everyday. It is exciting to be a part of a battery technology team in the electric vehicle sector.
How does your work benefit society?
Global warming and climate change are a serious concern for our planet. There are various approaches that can be taken to mitigate and slow down global warming. Electric vehicles play a vital role in reducing harmful greenhouse gas emissions on the roads significantly which helps slow down global warming. I am happy to be part of a company that plays a role in the electrification of medium and heavy duty vehicles.
Tell us an example of a specific memorable work you did that is very close to you!
I had great experiences during the course of my research work and job. During my research, one of the interesting things I learnt is to make coin cell batteries. Coin cells are widely used in research labs to test new battery materials, test their capabilities and to better understand various components of batteries in a smaller scale during the initial stages. For the research, I learnt using various instruments and working in a glovebox where I needed to assemble the coin cells before testing. Various steps involved in making these cells are time consuming and require a lot of patience. If any of the steps goes wrong before making the cell or if the cell falls down while removing it from the instrument then we need to start over again. Initially, the success rate of the cells I fabricated was very low, but over time, with practice it got better. Once the coin cells are made, they need to be tested and analyzed.
After months of work, I was able to successfully publish my first research article in a journal. This was one of the first research projects I worked on. One of the important things I learnt from the work was patience and how it is important for doing research. Also, I kind of understood why it might take a long time for any kind of breakthrough in research, as topics within subject areas are vast require continuous, dedicated work and exploration of different ideas. To this day, working on my first research project is one of the most memorable, joyous and a satisfying experiences for me.
Your advice to students based on your experience?
One of my suggestions to students is, there will be opportunities over time where we can learn and work on things that have a greater impact on society. Think of choosing an undergraduate degree as an entry into an advanced education from school, and always be open to learning new things. Experiences that we gain over time will give us ideas on the path and career that we would like to choose.
I would like to continue to be a part of the energy storage and electric vehicle technologies sector and contribute my knowledge and expertise in any way possible.