San Diego, CA, March 6, 2017 -- All science is exciting. If that sounds like the premise for a podcast series focused on graduate students, you’re right. The all-science-is-exciting comment recently landed University of California San Diego NanoEngineering Ph.D. student Jungwoo Lee in front of a microphone. She is the first of a series of current and former graduate students from the UC San Diego Jacobs School of Engineering who will be sharing perspectives on research in not-too-technical terms as well as talking about what motivates them.
Jungwoo Lee is a materials scientist working to make better batteries in the Laboratory for Energy Storage and Converstion run by NanoEngineering professor Shirley Meng at the UC San Diego Jacobs School of Engineering. Lee is also a key member of a UC San Diego battery startup called South 8 Technologies. The team is commercializing breakthrough research led by Cyrus Rustomji (UC San Diego PhD ‘15) in Shirley Meng’s lab. The researchers’ advances in electrolyte chemistry enable lithium-ion batteries to run at temperatures as low as -60 degrees Celsius with excellent performance. For comparison, today’s lithium-ion batteries stop working at -20 degrees Celsius. A full look at the research is outlined in this story by the Jacobs School’s Liezel Labios describing a 2017 Science paper: Electrolytes made from liquefied gas enable batteries to run at ultra-low temperatures. The South 8 Technologies team aims to leverage their work to provide unique battery solutions for a variety of transportation, high-atmosphere, aerospace and defense applications.
Jungwoo got involved in this startup project as a Technology Management and Entrepreneurism Fellow taking classes with UC San Diego Rady School of Management MBA students though a program run by the Institute for the Global Entrepreneur, which itself is a collaboration between the Jacobs School of Engineering and the Rady School of Management.
Audio Transcript: “Batteries need to breathe” and other topics
A lightly edited transcript of Jungwoo Lee’s conversation is below. Subscribe to the Jacobs School of Engineering on SoundCloud to catch the entire series.
This is Daniel Kane from the Jacobs School of Engineering here at the University of California San Diego, and I’m here with…
|Jungwoo Lee is a materials scientist and nanoengineering Ph.D. student at UC San Diego working in the lab of professor Shirley Meng. Listen to the six-minute conversation on SoundCloud.|
Hi, I’m Jungwoo Lee and I’m a Ph.D. student at the UC San Diego Jacobs School of Engineering in the NanoEngineering Department.
DK: You got pulled in here today partially because you sent an email that said, “All science is exciting.”
JL: Which is TRUE! All science is very, very exciting. In general, science drives innovation which drives growth which drives all the advances in our world.
DK: Absolutely, and let’s just dive into it.
JL: The group I work in, the Laboratory for Energy Storage and Conversion in the NanoEngineering Department
DK: And that lab is run by Shirley Meng.
JL: PI. Professor. Shirley Meng. Now the Zable Endowed Chair in Energy Technologies. So our whole group is 30 to 50 people, I can’t keep track any more. Our group is fully devoted to studying the fundamental science around the materials and properties that really drive energy storage and conversion, reactions, and devices.
DK: That’s a lot of words, right there.
JL: That’s a lot of words that basically say, “We study batteries” in fancy terms. We study batteries, battery reactions, battery materials, battery degradation, anything along those lines.
DK: You’re talking about Lithium ion batteries?
JL: Yes. Lithium-ion batteries were invented way back in the 1970s. The first commercial lithium ion battery was from Sony, in 1991. And it was basically 20 years of materials development research to really understand the phenomenon and how these different materials interact. Because if the materials are really unhappy together, they degrade really rapidly. We all expect a certain amount of lifetime from our batteries. Theoretically, we’d want them to last years to decades. Right now, what a year or two is sort of normal for us. But before any of this stabilization work, they would die almost instantly.
DK: Die almost instantly. That sounds kind of dramatic.
JL: You know, like 5 or 10 times before they would be kaput. And a lot of the work around new and emerging materials is really sort of understanding how we can get materials to last longer. Lithium-ion batteries are really, really useful for everyday life, and I know that they will be the commercial leaders for quite some time, going forward.
DK: Lithium-ion batteries, that’s what’s in our phones?
JL: Yes, Lithium-ion batteries are in our phones. But there is a lot of exciting research around new materials that would be theoretically cheaper….Why are batteries so hard to improve upon? First, we are expecting to get a lot of energy from a very small thing. Just in terms of thermodynamics, that’s quite difficult.
My background is actually in electronics. I’m a physicist by training. All the devices I used to work with before were all electronics-based; and I didn’t really appreciate the complexity of batteries until I started my Ph.D. here at UC San Diego. Batteries, if you study them: it’s not just the electrons that move around. There are actually physically moving ions. That’s why it’s called a lithium-ion battery. Lithium ions are moving from cathode to anode, or from anode to cathode. And the physical moving of actual ions or physical things creates a lot of strain. It’s not just these tiny electrons that float around in these theoretical clouds. It’s actually mechanical properties that happen, which is what creates a much more complex problem here.
DK: That makes a lot of sense. I was listening to Shirley Meng give a talk last week about batteries, and she was very loosely saying that batteries are kind of like a “living organism.”
JL: They are. At least a lot of the studies we are doing lead us to believe that. Because you are actually physically moving things around, there is a lot of strain that builds up. So you need things that can “breathe.” Or something along those lines. Something that has a bit of flexibility to it, something that can accommodate all these large volume changes. Well they are not that large compared to what we see in the world, but on their scale these are actually quite catastrophic, relative to the size of the battery. These are huge changes that are happening around them. And I really didn’t appreciate this myself, with my background, until I really started thinking about it here at UC San Diego from a materials science perspective.
DK: So is that one of the reasons it’s so hard to improve batteries? Because there are these crazy physical strains and actual physical things happening?
JL: That is one aspect, and I think it’s a fairly new way of thinking about it. It’s at this precipice where there are a bunch of different phenomena interacting with each other inside of batteries. There is the electron work, the materials science work, the mechanical properties work, the electrochemistry work – there is a whole chemistry side that just blows my mind. And to make a really, really good battery system, you basically have to have a good comprehensive knowledge of all those fields. I definitely don’t have that. Battery research requires a good collaborative effort amongst smart people to understand all these different phenomena that are going on.
But, if you take another step back, it’s kind of frickin’ cool that they got this far, already. If you think about it.
DK: So are you one of those people, when you are in the trenches, you’ll step back and say, “This is hard, but at least we are working for something that is going to be important for the future of society?”
JL: Yes, it’s nice to have something like that to ground you. But I think it’s short sighted to say what is and isn’t important for the future. Any science could theoretically be incredibly valuable to the future, given the right applications. It is nice that I don’t have to work as hard to justify what I do. Everyone knows what a battery is. Everyone knows that they are important. Everyone has the pain of having to plug in their phone every 12 hours, because our lives revolve around the phone.
DK: Or less than 12 hours, if you have too many apps open.
JL: Right…or accidentally leave it out in the sun. The (lithium-ion) battery has been in our lives for what, 25 years now, and it’s completely changed our lives and we are completely dependent on it now. But in terms of grand innovation cycles, 25 years isn’t that long. The advances they have had in the last 25 years have been quite extraordinary, but our battery needs have grown even more, which is why we are all so anxious about getting better batteries out there.
Follow the podcast series on SoundCloud.