Ten years ago, if you needed a battery for something more than a flashlight or an alarm clock, your options were pretty limited. Lithium-ion batteries had found their way into consumer electronics in the 1990s, and researchers were just beginning to explore their potential for certain automotive applications.

Even in 2010, however, scientists and policymakers knew that lithium-ion batteries would not be the only solution to the energy storage challenge. Different applications, from heavy-duty trucking to electric airplanes to storing intermittently produced renewable energy in large-scale installations on the electric grid, required scientists to think more broadly in terms of chemistry and technology.

To discover pivotal battery technologies beyond lithium-ion, the U.S. Department of Energy (DOE) started the Joint Center for Energy Storage Research (JCESR), an Energy Innovation Hub led by DOE’s Argonne National Laboratory designed to bring laboratories, academia, and industry together to leapfrog current lithium-ion battery technology. 

In the Q&A below, JCESR director George Crabtree discusses the hub’s impact and how it continues to push the frontier of energy storage.

Q: The performance of batteries has improved remarkably in the past 10 years. How big a role has JCESR played in that since its establishment in 2012?

A: The last decade has revealed new energy storage needs for transportation and the grid that are difficult or impossible for today’s lithium-ion batteries to fulfill. A prominent one is long duration discharge storage to stabilize the grid against consecutive days of cloudy or calm weather. Lithium-ion batteries are fundamentally limited to a four-hour discharge at full power, enough for intraday weather variations and extending solar electricity into the evening to meet peak demand, but not enough to cover consecutive cloudy or calm days. Similarly, lithium-ion  batteries have the energy to power personal cars on daily trips without recharging, but heavy duty transportation including long-haul trucks, rail, marine shipping and aviation require batteries with higher energy densities. About half of transportation carbon emissions come from these heavy-duty modes. These two challenges, long duration discharge storage and high energy density batteries, need to be solved.

This is where JCESR has been applying its talent, looking beyond lithium-ion batteries to a new kind of redoxmer flow battery that we introduced and to so-called multivalent batteries based on magnesium, calcium and zinc, all of which have two charges instead of the single charge on lithium. This means that twice as much energy is stored or released for each chemical reaction, offering the higher energy density batteries.

Q: JCESR was renewed for another five years of funding in 2018. What have been some of its key achievements been since then?

A: We have significantly advanced redoxmer flow batteries, discovering several classes of new redoxmer materials that have high solubility, work at high voltage and have longer life than conventional redox flow battery materials. We have established a new operating voltage record for redoxmer batteries, 3.2 volts, which just begins to explore the new territory these materials offer. We have also shown how to add self-reporting of the redoxmer battery state of health through a fluorescent signal, a qualitatively new feature that promises to simplify regenerating redoxmers to their original state of health and prolonging battery life.

JCESR has been looking beyond lithium-ion batteries to a new kind of redoxmer flow battery that we introduced and to so-called multivalent batteries based on magnesium, calcium and zinc, all of which have two charges instead of the single charge on lithium. — JCESR Director George Crabtree

On the multivalent battery front, we have shown that magnesium can be de-intercalated from a high voltage transition metal oxide cathode, a promising advance for magnesium battery materials.

In our first five years, we took materials simulation to a new level, creating high throughput simulation studies of hundreds or thousands of cathode and solid-state materials on the computer to find the most promising candidates for laboratory simulation. Since the 2018 renewal we have added a new feature to our computational program: artificial intelligence and machine learning to significantly extend the range, scope, speed and level of detail of our simulations. The addition of artificial intelligence and machine learning bring many more materials, redoxmers as well as high energy electrodes, into play and accelerates the pace of material discovery.

Q: What makes the JCESR Hub model effective?

A: JCESR is able to recruit many of the best researchers and brightest students and postdocs to our forefront research agenda at the very frontier of battery science and technology. This ​“dream team” is self-perpetuating–when one excellent student or postdoc graduates, another is ready to move in. We can recruit the best energy storage researchers to JCESR without requiring that they relocate. We foster close personal relationships within our team and frequent meetings in large and small groups to share information, evaluate progress and brainstorm new directions. We are reviewed annually by our sponsor, the Basic Energy Sciences program of DOE, and six to eight external reviewers, giving us the benefit of outside opinion and the opportunity to revise strategy and change course regularly. Our ten-year term helps enormously as well—long enough to tackle the big challenges. JCESR and the other hubs were an experiment when they first started; their experience has shown them to be exciting new research modalities.

Q: What does the future hold for JCESR?

A: JCESR has two more years to run, sufficient time to finish the research we have started in redoxmer, multivalent battery materials, and building batteries from the bottom up. We are also uncovering rich and ripe new research directions which will continue next generation battery research beyond JCESR’s ten-year term. By then we will have graduated approximately 200 graduate students and postdocs many of whom are now leading research programs in universities, national labs, and industry. We look forward to working with them as early- and mid-career colleagues to carry on the frontier energy storage work that we started in JCESR.