Dr. Shirley Meng is a professor and Zable Endowed Chair at the Jacobs School of Engineering, UC San Diego. She is the principal investigator for the Laboratory for Energy Storage and Conversion (LESC), and also the founding director of the Sustainable Power and Energy Center (SPEC) at UCSD, whose faculty studies materials and devices for energy capture, conversion, and utilization. Dr. Meng was the featured speaker at the Women in Microscopy Breakfast at M&M 2020, where she spoke about her career and the continued importance of women in science. This interview has been edited for length and clarity.
When did you first start using electron microscopy?
I’m actually a microscopist by training. My undergraduate and graduate degrees are both in materials science and engineering, and I have operated electron microscopes and used electron microscopy since I was an undergraduate student.
I still remember seeing the rows of atoms show up in the detector for the first time. It’s a thrilling feeling that’s indescribable. They weren’t just drawings of balls in a textbook, I was actually seeing the atoms on the screen right in front of me. You’re essentially making the invisible visible, and there are no other tools that allow you to do this, only top-of-the-line microscopes allow you to see atom columns like that.
The center consists of a group of faculty members who are working on the materials and devices that can capture and store energy, convert it from one form to the other, and utilize it. Broadly, we call this distributed energy generation and storage as well as integrated power management.
What about your research group specifically?
I lead the Laboratory for Energy Storage and Conversion (LESC), where we work to diagnose and characterize materials for energy storage.
For instance, we look at state-of-the-art lithium-ion batteries in order to understand why their electrode materials degrade and how we can capture this degradation while the device is in operation. We call this operando characterization. Once we figure out how and why the materials degrade, we can formulate engineering strategies to improve their properties – in this case, make the batteries safer, more powerful, and longer-lasting.
We use X-ray, neutron, and electron-based tools. For the X-ray and neutron-based experiments, we work with national laboratories in order to access their instrumentation, but we have local access to the electron-based tools, such as electron microscopes and focused ion beam instruments. These are oftentimes Thermo Fisher Scientific products.
You mentioned battery safety. What’s the concern there?
Let’s be clear; at the moment, batteries are a very safe product. Safe enough that people carry them around every day in their phones, laptops, etc.
The typical accident rate is less than 1 in 10 million cells; however, we now have hundreds of thousands of electric cars (running on lithium-ion batteries) being sold everywhere around the world. As they are part of a vehicle, the safety of the batteries is now extremely important; when there’s a vehicular accident, we don't want to see it amplified by the battery catching fire or exploding. That’s why current research focuses on things like solid-state batteries, where the flammable liquid electrolyte is replaced by a solid-state electrolyte, making the battery safer without sacrificing energy or power.
So, that’s one of the main areas of battery research, and we are very excited to be part of it. At the same time, characterization and diagnostic tools allow us to figure out which solid-state electrolytes are the best choice for the next generation of batteries.
Why is energy storage such a critical avenue of research?
Energy storage is typically considered the Achilles’ heel of the renewable energy transition and is one of the biggest drivers of research in the field. When you’re producing wind and solar energy, you have to have sufficient energy storage capacity so that it can be stored when it’s available and then used later, when it’s needed.
In this regard, electrochemical devices, like batteries, are really critical. They convert the electricity to chemical bonding energy and then back from chemical energy to electricity without combustion. So, it's an extremely efficient process. This technology will really be a game-changer if we want to cut CO2 emission and enable renewable energy technologies. Electric motors can have infinite torque, therefore, the transition to electric vehicles (EV) is driven by the combination of better technology and societal benefits – we can be “green” while enjoying a better vehicle driving experience.
In fact, I think what’s different now, compared to 20 years ago, is that corporations can be green, can achieve sustainability, and can make a profit. I believe a lot of industry leaders are going to step in and say, you know, this is an economic decision. We're no longer doing this because there are government subsidies or because we're just getting social returns.
If companies can be even more profitable by being green and being sustainable, this would go a long way to addressing climate change, really slow it down and make the planet a more livable and enjoyable place. I think that’s the message I really want to give; you can now be sustainable and make a lot of money.
You’ve talked about the importance of industry partnerships for your research. Why is that the case?
I think the motivation for all the researchers, graduate students, and postdocs in my laboratory is a fundamental understanding of a material’s properties, but this knowledge is only impactful if we find the end-users, the companies, who are actually going to make or utilize these materials in their products. I want to know how we can help them make a better product that is going to positively impact society. That’s why I am actually very motivated to have a strong collaboration with industry partners.
For instance, SPEC has a program where companies can partner with us to fund a graduate student fellowship. This way, they can get a first-hand look at all the intellectual property that is generated. Meanwhile, the students have a very oriented mission for their research, since what they are doing is clearly connected to a final product.
We use high-end instruments, like transmission electron microscopes (TEMs) and synchrotron X-ray sources, to answer specific questions that our industrial partners can’t. We can actually dissect the samples and go down to the atomic level, to the nanoscale, to find true answers. Where are the defects? Where are the problems that have happened? Then we feed that knowledge back to our industry partners.
If things like battery failure are happening at the nanoscale, at a molecular level, you need advanced tools to really dig into where the failure starts. You also need the ability to interpret the results of your experiments. This is where academic institutions are extremely useful; our skills are complementary to what the industry is trying to accomplish, and its why our partnership usually works very well.
But you also get more traditional funding for your work.
Yes, our group is also funded through the National Science Foundation, Department of Energy, and several other federal agencies. Our researchers can use these resources to generate a lot of fundamental understanding and knowledge.
Of course, ideally, this research can reach a point where some actual impact can be measured; I think our most impactful work is directly applicable to the products created by our industry partners. So, really, it’s a collaborative effort between academia, industry, and the federal government; they all complement each other.
Obviously, there are very clear boundaries as well. As a research institution, we don't develop a product. Our students and postdocs, the human capital, is what we'll offer to society later – knowledge and human resources.
Can you talk a bit more about how electron microscopy tools are used in your research?
The common tool we use is scanning electron microscopy (SEM). However, if you take a battery, it's very bulky and there are layers of cathode, anode, electrolytes, and separators. And on these layers, you have millions of particles you want to analyze. In order to do a detailed diagnosis of the battery, we need some kind of tool to extract samples. For this, we use a focused ion beam (FIB). In the past, this was a gallium ion beam, but through our collaboration with Thermo Fisher Scientific, we now have access to a plasma FIB, where we can cut a much larger area with higher efficiency.
With the combined FIB and SEM, we can see particles at the micrometer level. Once we have processed the sample, we can then go to the transmission electron microscope, where we can look at the sample at the nanoscale or even the angstrom scale, allowing us to see atoms and molecules. We do this because, to really diagnose battery materials properly, we need to have access to multiple scales with a suite of tools, allowing us to actually probe materials and understand their properties.
Why do you think it’s so important to keep improving battery materials and devices?
So, in my world, I view myself as a doctor for batteries. When a person is sick, the doctor needs a correct diagnosis in order to give the right prescription. To do that, they run many different tests; they draw blood, they take an X-ray or an MRI, etc.
Similarly, we diagnose and characterize materials in order to make sure they are operating at their best optimum conditions. This is critical because they end up in devices that billions of people are carrying every day, everywhere, in the car, on planes, everywhere. We need to diagnose where failures could happen, where issues might occur, using the most advanced tools, characterization, and computations possible. That's why I'm doing what I'm doing, and I'm very excited to share this experience.
We now have a very big community of battery researchers across the world, and I'm hoping that even more, bright and brilliant young scientists will join this field in the future. We’re already seeing the younger generation of researchers introduce things like higher throughput characterization and artificial intelligence for data interpretation. The field is really exciting, and there are so many things that could be enabled with advanced characterization tools.
At the M&M 2020 Women in Microscopy Breakfast you talked about the importance of women in science; can you tell us a bit more?
Diversity and inclusion drive innovation and creativity. My own journey as a woman in science started at the age of seven when my dad introduced to me the story about Dr. Marie Curie, the only woman who was awarded the Nobel Prize twice: “Nothing in life is to be feared, it is only to be understood.” Her words have been the guiding principle for me since then. Over the last hundred years, women collectively have made a lot of inroads in the STEM field, but to achieve true equity, our journey will continue. The field of science will attract more talent and become the first choice for women to launch and build their careers if all of us (men and women) are in this together. I feel privileged to be one of the women in science and to be part of the force to implement change. I hope these messages are clearly conveyed to the attendees of the Women in Microscopy Breakfast.
About Dr. Y. Shirley Meng
Dr. Y. Shirley Meng received her Ph.D. in Advance Materials for Micro & Nano Systems from the Singapore-MIT Alliance for Research and Technology (SMART) Centre in 2005, after which she worked as a postdoc research fellow and subsequent research scientist at MIT. Dr. Meng is currently a professor at the Jacobs School of Engineering at the University of California San Diego (UCSD), where she holds the position of Zable Endowed Chair in Energy Technologies.
Dr. Meng is the principal investigator of the Laboratory for Energy Storage and Conversion (LESC) and is the founding Director of the Sustainable Power and Energy Center (SPEC) at UCSD. In 2020, she was also named as the inaugural director of the Institute for Materials Discovery and Design (IMDD).
She is the author and co-author of more than 200 peer-reviewed journal articles, two book chapters and four issued patents, and is the Editor-in-Chief for the Materials Research Society journal MRS Energy & Sustainability.
Disclaimer: The views expressed here are those of the interviewee and do not necessarily represent the views of AZoM.com Limited (T/A) AZoNetwork, the owner and operator of this website. This disclaimer forms part of the Terms and Conditions of use of this website.