American Scientist

Recognized internationally for her work on the development of batteries that power hundreds of thousands of life- saving cardiac defibrillators implanted in patients each year, Esther Takeuchi has joint appointments at Stony Brook University and Brookhaven National Laboratory and is a prolific inventor with more than 150 patents. She is the recipient of the 2019 Sigma Xi Walston Chubb Award for Innovation, an annual award established in 2006. Previous awardees include engineer Akhlesh Lakhtakia, computer scientist Rosalind W. Picard, and materials scientist Stan Ovshinsky. American Scientist’s Robert Frederick spoke with Takeuchi about the future of battery development and the collaborations working to make those developments happen, including those of her own lab, where three principal investigators pool resources and expertise, creating a new model for how graduate education and research is done.

What are the innovations in implantable batteries that haven’t yet transferred to other battery types?

Today, the most dominant type of battery we’re familiar with is the lithium-ion battery used in phones and computers. Electronics change so quickly these days that the batteries only need to last about three years because that’s as long as anyone keeps a device. But new types of applications—for example, electric vehicles—now expect batteries to last 10 years. For batteries that may back up the electric grid or are linked to renewable forms of energy, such as wind farms or solar, sometimes we’re expecting them to last 15 or 20 years. That knowledge of how to extend the lifetime of batteries can be inspired by some of the methods that were used for the implementation of medical batteries, where longevities of 5 or 10 years are what’s expected.

Are there particular methods or tools to take from research on medical batteries and apply them to other battery applications?

What’s important to understand about batteries is that it’s usually not consumption of the active material that leads to the end of life for the battery. It’s usually some kind of parasitic reaction. For batteries that are well designed, those parasitic reactions are pretty small. But by using a tool such as isothermal microcalorimetry, we can measure the heat that a battery generates, both while it’s in an active state and while it’s in a resting state. By careful analysis of those heat signatures, we can determine how much of the heat is because of the battery’s working or functioning heat versus how much is parasitic heat. It’s that parasitic heat that’s associated with those degradation reactions that will eventually contribute to the end of service or to determining the lifetime of the batteries. Gaining insight into those specific parasitic reactions is something that I’ve derived from the years that I spent using that methodology associated with medical batteries. But in other fields of batteries, it’s not nearly as broadly used.

Is the reason isothermal microcalorimetry is not being used outside of medical battery applications because of cost?

It could be cost. It could also be speed. It’s a method that does take some time to get appropriate measurements and also to decipher what those measurements mean. For example, using it purely as a quality control check would probably be too slow. So it’s really more of a research tool—used to sort out the reactivity that’s taking place within batteries—than a quality control tool. Perhaps just lack of knowledge of the tool is why it’s not more broadly used.

As to recycling battery materials, I understand your research group is focused on, among other problems, creating regenerable electrodes. Is that because recycling battery materials is a scientific problem itself, or is the problem more to make the process of recycling battery materials less expensive?

Recycling is a really important question. Today the battery that’s very effectively recycled is the lead-acid battery. But when it comes to lithium-ion batteries, for example, they’re really not recycled very much, especially not in the United States, because it’s more of a question of economics. Current recycling methodology really depends on—essentially—taking a battery apart and then recovering the elements through dissolution in very strong acids. The element that’s commonly used in lithium-ion batteries that’s very expensive and does start to make sense in terms of economics is the recovery of cobalt.

The down side of cobalt is that it is mined in only very few locations on Earth, most commonly in the Democratic Republic of Congo, and there have been some allegations of questionable practices in how it’s mined. So there’s also a fairly significant effort to design cobalt out of lithium-ion batteries. The interesting part is that cobalt is what makes recycling economically viable. So if future lithium-ion batteries lack cobalt, then recovering the individual components again becomes a financial challenge. I think that’s why considering second-use or regeneration or repurposing of batteries becomes very important. It may not be possible economically to just simply recycle batteries in the conventional way, where you melt it or dissolve it or something else. I think we’ll have to be more creative in terms of repurposing and reusing either entire batteries or entire electrodes, like we’ve been trying to do in our research, where we’ve demonstrated a regenerable electrode, to make that whole battery life cycle last longer and have less impact on the environment.

You have many concurrent projects in your lab with funding from a variety of sources. Are there other projects that you would like to start but don’t have the bandwidth or resourcing for?

This is really a very exciting time to be involved in energy storage because the applications are expanding. There are significant needs in that new applications demand new types of batteries. And then every new battery technology, I believe, demands fundamental understanding—where we do the science to come to grips with how the battery works, what the mechanisms are, and, equally as important, what the failure mechanisms are. There are many projects, but there’s a unifying theme: How do we make batteries big and what parameters do we need to understand and control to allow effective and efficient design of larger-scale batteries?

We’ve been focused on three topic areas there. The first is multifunctional materials, where materials are [chemically] active materials, but they can serve some other role. For example, often active materials are not conductive. We’re developing active materials that have some electrical conduction as well. The second part is that we’re investigating interface stability [between battery components]. How do we control [electrochemical] interfaces? How do we create artificial interfaces instead of just allowing them to spontaneously or serendipitously form inside of the battery? The third area that we’re pursuing is electrode architectures that have a defined and controlled porosity [affecting the rate of the electrochemical reaction], to probe the defining parameters and how, ultimately, we could define and design the ideal electrode for a certain application.

Although each one of those projects seems like an individual project, they are part of the Energy Frontier Research Center (EFRC) activity. The efforts that we have in our research group and our partner investigators and partner institutions play a large role in making those initiatives move forward. I really credit the Department of Energy with the EFRC program. It’s a program that’s big enough to allow principal investigators who ultimately, in other circumstances, may not have the opportunity to work together. But EFRC is not so big that it can’t be managed in an efficient way.

Speaking of partners and principal investigators, your multidisciplinary research group has multiple principal investigators. What led to organizing your research group that way?

My husband, Ken Takeuchi, and professor Amy Marschilok are two principal investigators that I collaborate with all the time. What we decided to do is pool our resources and essentially have one collective group where we jointly advise our students and postdocs. There are two staff members at Brookhaven National Lab as well that are part of our research effort.

By pooling our resources, we believe that the students benefit in that they get really special and unique perspectives from each of us. Ken Takeuchi, for example, is a very widely decorated teacher, mentor, and tremendously insightful inorganic chemist, synthetic chemist, and analytical chemist. Amy Marschilok is expert in advanced characterization and advanced electrochemical techniques. My expertise is more in terms of understanding batteries at the systems level and how to probe them, how to control them, how to think about the next-generation battery. Students get perspectives from all three of us by having the opportunity to interact with us on a regular basis. It also allows us to advance our research in a unique way.

I think we’ll have to be more creative in terms of repurposing and reusing either entire batteries or entire electrodes, like we’ve been trying to do in our research.

• Facebook
• Twitter

We run our group in a very collaborative way, where the students collaborate with one another. We’re also integrating research projects at a university with those at a national lab, and incorporating industrially supported research projects as well. Learning how those different environments work and function gives our students and postdocs unique insight into advancing their own fields and being able to pursue their careers in directions that make sense for them. They become well prepared because they understand the concept of team science. That’s where the future of science is. That’s how big problems are going to be solved. Our fields are moving beyond what used to be the more conventional approach of one student, one project, one principal investigator. We’re creating a new model for how graduate education and research are done.

I think progress is being made in terms of diversity and inclusion, too. When I started my career in industry, I remember going to various technical conferences where the number of women in the room was pretty limited. Progress is being made, and I’m convinced that progress is essential, not just because it may be the morally right thing to do but because we need to involve the brightest minds that can make a contribution. We as a society have significant issues and challenges ahead of us. We don’t want to arbitrarily eliminate people who can make a contribution just because of who they are or what their background may or may not be.

I think of each person as potentially holding a puzzle piece. The problem that we’re trying to solve is a big puzzle, so we need everybody prepared and participating to put in their piece so we can finally reveal the answers that we need. If we leave people out and don’t encourage or support those who have talent to pursue a field in which they have ability, it’s going to take a lot longer to fill in those puzzle pieces and get answers. So I’m very much in favor of nurturing and encouraging people in their abilities—their special gifts—so they can participate and make a contribution to society as a whole.