Editor’s Note: This is part of a series called Inside the Lab, which gives audiences a first-hand look at the research laboratories at the University of Chicago and the scholars who are tackling some of the world’s most complex problems.
As the world’s energy needs diversify, all forms of energy will require storage. Power grids, in particular, will need better batteries to store renewable energy.
University of Chicago electrochemist Chibueze Amanchukwu is working to create a more sustainable future. His lab uses AI and machine learning, along with experiments, to develop better batteries and systems to turn carbon dioxide into fuels. The goal is to create energy storage systems that are cheap, safe and can perform well over time.
To learn more, we spoke to Amanchukwu, a Neubauer Family Assistant Professor in UChicago’s Pritzker School of Molecular Engineering; and two graduate students in his lab, Hrishikesh Srinivasan and Ke-Hsin Wang.
You are an electrochemist. What does that mean?
Amanchukwu: Electrochemistry uses electricity to drive chemical reactions. You can get electricity in a clean, sustainable manner from solar and wind, and then you can use that electricity to drive chemical reactions within a battery. We can also use electrochemistry to convert CO2 to a fuel or a chemical.
That is distinct from what we've done for the past 200 years of the Industrial Revolution. We were able to get coal and natural gas very cheaply, and we could burn it and generate heat to power our homes. That was thermal chemistry. Everything that society has done has really been from the bedrock of thermal chemistry.
Srinivasan: If we want to electrify our society using renewable energy like solar and wind, electrochemistry is going to be very important in doing that.
How does your research group harness the power of electrochemistry to create better batteries?
Amanchukwu: We focus on designing new battery chemistries enabled by new electrolyte design. A battery has at minimum three components: an anode, a cathode and an electrolyte in between. When you buy a new phone, you plug it to the wall to charge it. What you're doing is taking electrons from the grid and using that to charge the battery. You're taking lithium ions from the cathode to the anode – through the electrolyte. And when you’re using your phone, the lithium ions that are in your anode move back to the cathode.
We are working on developing energy storage systems that allow us to store energy cheaply, using abundant materials that are intrinsically safe. We are interested in creating safe electrolytes that have no volatile or flammable organic solvents.
How does your group design better electrolytes for batteries?
Amanchukwu: We started doing a lot of work in data science and artificial intelligence to help accelerate how we come up with new electrolytes. My group is a combination of experimentalists and computational researchers, and that's unusual because it requires different skill sets.
Some students run machine learning models to predict what property an electrolyte should have. Right next to them is an experimentalist who can go into the lab and make that electrolyte. A student actually goes into the fume hood, mixes a few compounds, and makes this compound that was predicted to be excellent. Then they put it into a battery and cycle the battery to see how it performs.
Wang: I’m developing new electrolytes as part of my research. Different kinds of battery chemistries require different electrolytes. We are looking for stable, safe electrolytes, but we also want to develop environmentally friendly electrolytes.
We also want to develop electrolytes that can cycle at extreme temperatures. If you have an electric vehicle in Chicago, you don’t want a battery that cannot be charged or discharged at minus-20 degrees. Many state-of-the-art batteries currently freeze at those temperatures, and we want to find electrolytes that won’t.
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What new electrolyte have you developed recently?
Amanchukwu: We have developed several novel electrolytes that are high-performing for different battery chemistries. More importantly, our new electrolytes would not be classified as PFAS (perfluoroalkyl substances), which are environmental hazards.
We have also used our machine learning models to develop new solvents that make an excellent battery electrolyte. Overall, we have made significant strides to develop electrolytes that are not PFAS, but we also turned our attention to degrading PFAS using ideas we learned from batteries. We have PFAS in the environment, but there are no good methods to break them down. Recently, we developed a novel method to break down those PFAS compounds into inorganic fluorides. Then we used that fluoride to make a non-PFAS fluorinated electrolyte compound for batteries. That was an amazing loop.
How does your research group innovate in CO2 capture?
Amanchukwu: We’re interested in how you take carbon dioxide from the air and combine that with water to make fuels and chemicals.
We are trying to make energy-dense fuels and chemicals by designing new electrolytes inspired from the battery space. That ensures that when you do catalytic reactions, you can actually make the products with high activity and high selectivity.
What about innovations in battery structure?
Srinivasan: Right now, lithium-ion batteries have two electrodes: one is carbon-based, and the other relies on transition metals like cobalt, which is limited in the Earth’s crust. We want to move to a battery that uses more ethically sourced materials.
We are looking at creating batteries with two carbon electrodes. Carbon is more abundant, but there are tradeoffs. You sacrifice how much you can store in the electrodes.
Amanchukwu: We have people who have backgrounds in chemistry, in chemical engineering, in polymer engineering and in materials science. All of that really fosters an amazing environment where they all approach problems differently. We want different perspectives towards solving these grand challenges. I think the interdisciplinary nature and the diverse nature of students that we attract has made it possible for us to tackle these problems from a different lens.
“We are working on developing energy storage systems that allow us to store energy cheaply, using abundant materials that are intrinsically safe.”
What are the issues of trying to scale energy storage?
Amanchukwu: If you really want to power a city, which is our vision, you need to incorporate more renewables like solar and wind. And when you start thinking about scale for storage, you start thinking about what is inside the battery. We have safety incidents with lithium-ion batteries because the solvents are volatile and flammable.
On a large scale, if there are any fire incidents, the whole city can burn. And so that forced us to rethink what type of battery chemistries we work on. When we start thinking about that scale, you want materials that are dirt cheap. You want things that are intrinsically safe. You want them to be easy to recycle. You want them to be sustainable.
We want to eliminate all transition metals and solvents and have chemistry that can scale to terawatt hours and that is intrinsically safe and is made with abundant materials.
What challenges remain?
Amanchukwu: Some of the batteries that we're making for grid-scale storage are not storing as much energy as we think that they should, and they're not cycling for as long as we think that they should. Can we come up with new materials that help solve our current problems? Can we develop new methods that allow us to probe and understand these systems much better to give us insight into why they are degrading? Then we can come up with new ideas to address them.
What motivates you in your work?
Amanchukwu: I have a young child. I have to start thinking about what her future will look like. And coming from Nigeria, it's important that whatever technologies I make don’t just live and dwell in the Western parts of the world.
When things are really inexpensive, everybody can incorporate them. My family in Nigeria, for example, can take advantage of all the discoveries that we've made to also ensure that they can get the energy that they need to really transform their own society. That will not happen if it is not cheap, and it will not happen if it's not sustainable—and it will not happen if you cannot store energy in a large format.
How does the University of Chicago pave the way for this work?
Wang: The University of Chicago is a really cool hub for electrochemistry. We have a partnership with Argonne National Laboratory, and there are many labs besides ours that are focusing on related subjects. We can all discuss the science together without competing.
Srinivasan: I’m from Houston, and when Hurricane Harvey hit in 2017, it displaced many of my friends and was devastating to the region. That’s when I started thinking about climate change more seriously. I joined UChicago and Professor Amanchukwu’s lab at the UChicago Pritzker School of Molecular Engineering because it is a hub for electrochemistry research in Chicago. It’s very rare to find these resources and this partnership with a national lab anywhere else, and I know this research will have a real impact.
