Electric vehicles, a modernized electrical grid and even smartphones would be little more than pipe dreams without the ability to store energy. More specifically, they rely on batteries, a centuries-old technology forced to mature ever more quickly to meet our growing demands for portable power.
Progress, at least when it comes to technology, poses myriad challenges for battery researchers. Their devices must work harder without generating more heat and do so without significantly driving up the prices of the technologies they power. About half of an electric vehicle’s retail price is the battery, for example, although this is expected to drop as more hit the road.
Painfully aware of this, the U.S. Department of Energy’s Office of Science created the Energy Frontier Research Center (EFRC) program in 2009 to encourage researchers to rethink how we generate, supply, transmit, store and use energy. In June the Energy Department awarded $100 million to 32 EFRCs, $10 million of which is funding complex battery system research at Stony Brook University, S.U.N.Y. led by materials scientist and chemical engineer Esther Takeuchi. A distinguished professor at Stony Brook with a long list of engineering accolades, Takeuchi is best known for developing an improved battery for powering implantable defibrillators.
Takeuchi’s EFRC is known as the Center for Mesoscale Transport Properties (m2M), and its aim is to unlock the mysteries of how charges move and are transferred inside lithium ion batteries. Any leaps in knowledge that the lab makes would go toward developing batteries that store a lot of energy while producing as little heat as possible (pdf). Stony Brook’s m2M partners include Brookhaven National Laboratory, Columbia University and the University of California, Berkeley.
Scientific American spoke with Takeuchi about her new work with the Department of Energy, her team’s efforts to completely rethink the battery and the value of diversity in the lab when pursuing scientific breakthroughs.
[An edited transcript of the conversation follows.]
Why do you focus your research on batteries?
Today’s most familiar high-performing batteries are the lithium ion cells that have flourished in portable electronics, including cell phones and laptops. Of course, a battery for a cell phone or laptop doesn’t need to last for a decade—who could imagine having a 10-year-old mobile phone? Applying lithium ion batteries to power electric vehicles or something as large as a smart power grid makes developing long-lasting batteries—those that can operate for 10 or even 20 years—really significant. To improve a battery in that way, you have to really understand at a systems level the interactions that are going on inside.
What does it mean to understand a battery at a systems level?
We use materials that are very strong oxidizers to make the cathode and materials that are strong reducing agents to make the anode. Put these materials in an electrolyte and some kind of a membrane, and then ideally we would want everything to just sit there until we call upon it to deliver electricity. But there are many complex chemical reactions taking place, particularly at the interfaces where one type of solid touches another type of solid or a solid touches the liquid electrolyte. There can be a lot of chemistry going on, and understanding the types of phenomena that limit lifetime—in other words what it is that's going wrong—is one of the keys to extending lifetime. You need to understand what the failure modes are in order to be able to address them.
How is this a new approach to researching energy storage?
In the past batteries have been developed more by optimization rather than fundamental insight. My optimism today is that there are analytical methods and techniques that will provide unprecedented insight by probing what's going on inside active batteries while they're working by in situ or even in operando. The opportunity for breakthrough science and real insights is something we’re beginning to be able to envision, and that makes it very exciting.
How do the Stony Brook Energy Frontier Research Center’s resources compare with other research efforts studying energy storage?
EFRCs are big, 10 times or so larger than a typical academic research grant, and the funding is for four years. This is definitely a flagship program for the Department of Energy. We have designated Stony Brook’s Advanced Energy Research and Technology Center as the headquarters for the EFRC. There are also multiple partners and multiple labs that are participating at other locations.
What do you hope to accomplish over the next four years?
Our goals are certainly that we make significant contributions to the fundamental science of understanding the phenomena taking place in these energy storage systems. Our initial focus is on lithium-based batteries. This will help us conceptualize and design new approaches that generate less heat and do more work.
Which technologies are researchers using to study batteries?
MRI is one tool. And I'm using very high-energy x-rays from a synchrotron [a type of particle accelerator] that can actually penetrate a battery’s steel can—its skin—and get diffraction patterns of the solid inside. This way we can probe not only reaction products, we can also get enough spatial resolution to find out where those products are forming. An electrode has several interfaces—one is toward the electrolyte and the other interface would be towards the electric current collector. The electrolyte is in a sense delivering ions and the current collector is where the electrons either go or come from so we can tell where the reaction is happening. This [technology] tells us about what's limiting the reaction. Is it electron access? Is it ion access? This is pretty remarkable stuff.
Anyone who has worked with a notebook computer on their lap will tell you battery heat can be a problem. Aside from making a laptop less lap-friendly, how does heat affect the battery itself?
If we think about batteries or energy in general, there are two components. One is work, which in the context of a battery is delivering electricity. The second is heat. The more electricity a battery can deliver while generating less heat, the more effective the battery is at doing its job. Our whole investigational premise for the new program with the Department of Energy is to minimize the amount of heat that's generated by batteries and maximize the amount of work so we can overall improve the efficiency of the batteries.
The problem becomes even more aggravated when the batteries get big, like the ones used for electric vehicles or to power an electrical grid. There's so much heat that you have to develop ways to remove the heat from the battery because not only will the heat damage the battery, it could also get to the point where it becomes unsafe. Engineers then have to develop systems that cool batteries using either liquid or air. Dealing with waste heat is expensive and adds a lot of complexity.
Are there other energy-storage technologies that could serve as alternatives to batteries?
There are many ways to store energy, and many of these approaches are very much application dependent. Batteries are good at accepting and delivering electricity directly, compared with other means of energy storage such as flywheels or compressed air. Oftentimes there's some kind of conversion where you have to take that energy and turn it back into electricity. For example, with the grid or with a car you can use the electricity directly and pump it back into the battery directly without having to go through another step of turning steam or motion into electricity.
Capacitors are another energy-storage option. Typically batteries have more energy content per mass or per volume. Where capacitors can excel is that they can respond extremely quickly, probably faster than a battery, but for a much shorter period of time. That's kind of the application trade-off. Do you need just a really quick flash of power or do you need something that sustains over a longer period of time?
How did your project with the Energy Department come about, and what will your EFRC work on?
About a year ago the Department of Energy put out a call for proposals for ideas relating to the grand challenges and strategic areas of interest to the department. My understanding is that they received about 200-plus proposals, and ours was one of them. This is the second round of the program. The first started five years ago with 46 centers. Half were renewed for the second round and 10 new centers were funded, including ours at Stony Brook University. Not all of the EFRCs have to do specifically with batteries or chemical energy storage.
How does the new EFRC mesh with the research you and your colleagues are already conducting?
The center allows us to involve broader areas of expertise. We're able to bring together a larger group of people with more diverse backgrounds that you wouldn’t be able to with a smaller grant. We can start working across boundaries of expertise to see how we can address problems in even a more profound way because we've gotten multiple perspectives now looking at the same problem. Our objectives are to understand more about specific transport properties in batteries. We're thinking about ion and electron movements, both of those are critical to the function of the battery. We are focused on the fundamental materials used in batteries but also critically important to us are all of the interfaces through which ions and electrons move inside the battery.
Your research into batteries stretches back to when you developed the battery for the implantable cardiac defibrillators. How were those devices powered prior to your invention?
The device had already been demonstrated but the life of the battery was a real problem. It lasted only about a year and a half. When it's time to replace the battery you have to do surgery on a patient.
In order for the device to be used in a widespread way clinically it was important to have a battery with a longer lifetime. So the key aspect of my work really was developing a battery that was small but had longer lifetime than the battery they initially used. I think in many ways the silver vanadium oxide battery I developed enabled the growth of the defibrillator’s clinical implementation. The battery’s life varies depending on the device and the patient but the goal was for it to last about five years.
Thanks to your work on the implantable cardiac defibrillator battery and several other technologies, you hold many U.S. Why are patents important?
Patents allow companies or inventors to practice their technology for a period of time, typically about 20 years. This gives them the opportunity to develop, implement and sell their invention before competition jumps in. So it allows small inventors to actually demonstrate their concept and it allows any invention, even at a large company, to recoup the investment made to develop the technology and launch it as a product. The patent owner can also make some money from the invention before everybody else can do it as well.
As a woman engineer and scientist, have you faced any specific obstacles entering the field or as your career has progressed?
What I can say is that from what I have observed over the course of my career, there are more and more women involved in the field. If anything, the challenges with diversity are that people come from different backgrounds and if you're female or if you come from a different socioeconomic group, you approach things from a different perspective. That can be challenging because sometimes people who have a different perspective are viewed as—or can be sometimes viewed as—well, they just don't get it or they don't know how to play well with others. There's a little bit of prickliness, discomfort, sometimes when you're dealing with people who aren't like yourself.
That's one of the things that we all need to be mindful of—if somebody is approaching something from a different perspective, it may not mean that they're wrong or they're uncooperative, it just means that they have a different perspective. And a different perspective can oftentimes lead one to ask questions or solve problems that may not otherwise have been tackled. If everybody is looking at a problem in one way, you may not see all the dimensions of the problem that are actually there. It's a real advantage to have diversity.

Editor's Note (11/19/14): This Q&A was edited after posting to remove two referrals to Takeuchi as the woman holding the most U.S. patents. The U.S. Patent and Trademark Office could not confirm that she holds more U.S. patents than any other woman, as originally claimed in this article.