Inside Berkeley Lab’s Search for Better Batteries 

As we look to develop the car of the future, it’s clear that electric vehicles are the automobiles to beat. Not only will they cut dependence on foreign oil and lower energy costs for the average American, but some impressive sports cars like the Tesla Roadster or the Mercedes AMG SLS Electric have proven that electric cars can offer every bit of excitement that their petrol counterparts are known for.

But the one thing that’s holding us back on the quest to go electric is batteries - too often they store too little power, and pack too much weight. So the Department of Energy (DoE) has offered to fund research whose aim is to tackle these problems, and Berkeley Laboratory has responded by using supercomputers at the National Energy Research Scientific Computing Center (NERSC) on several project that could help us to meet this end.

Redefining Battery Development

As it stands, developing new materials that could unlock the the ideal battery is at the core of almost every research effort, but the development cycle that takes each material from conception to commercialization runs at a glacial 15 to 18 years.

To try to curb the time that these development cycles will take, Berkeley Lab along with MIT have created a computational tool called the Materials Project, which NERSC is hosting. This will entail using NERSC’s supercomputers to characterize the properties of inorganic compounds and storing them in a database that will allow researchers to easily search for materials whose properties will offer the greatest promise to their research efforts.

If this sounds familiar, it’s because the Materials Project ties in with the Materials Genome Initiative, which earlier this year received additional commitments to offer the effort a leg up. Namely, in early 2013 the DoE pledged $120 million over five years to establish the Joint Center for Energy Storage Research (JCESR). Here, Berkeley Lab and MIT will run simulations at NERSC to predict the properties of electrolytes and incorporate the results into a database similar to that of the Materials Project.

One complete, the Materials Project and JCESR will be combined to offer a comprehensive overview of materials for every battery component.

Bumping up anode storage

While lithium-ion batteries remain the staple of energy storage from smart phones to airplanes, the fact remains that this particular type of battery is far from reaching its potential. The problem is that considering the storage capacity, lithium-ion batteries need to lose some weight—a problem that’s particularly bad for developing quick and efficient electric vehicles.

To try to squeeze out more energy per pound, Berkeley Lab used supercomputers at NERSC to develop a completely new type of energy storage component (or “anode”) that can absorb eight times the lithium that current anodes are capable of.

The trick was tailoring a polymer to conduct electricity and bind closely to lithium-storing particles, which was made possible by tapping NERSC’s compute resources to identify the perfect polymer from a multitude of options.

One year and a few hundred charge-discharge cycles later, Berkeley researchrs found that their anode was able to maintain its an energy capacity—something we just can’t expect from the batteries of today. Not only that, but because of the increased anode storage, the entire battery stores eight times the power, and are made from low-cost materials and standard lithium-ion manufacturing practices.

From ions to air

An additional approach to extending the battery life of electric vehicles comes from a new battery type called “lithium-air.” And compared to the 100-200-mile charge that most EV’s today are capable of, the lithium-air would offer 300 miles or more between recharges.

For this research, NERSC’s supercomputers were paired with one of the oldest and most fundamental tools of scientific research—the microscope. There, researchers from the Pacific Northwest National Laboratory and Princeton University built a new type of graphene membrane that could unlock the greatest energy storage that lithium-air batteries can offer. Better yet, because the material isn’t dependent on the mining of platinum or other precious metals, this EV technology could be a blessing to the environment in more ways than one.

The promise of supercapacitors

But batteries aren’t the only option for electrical storage. Capacitors, although capable of storing less energy, come with near-instant charge and discharge rates, whereas batteries store more but can take a painful amount of time to charge. The solution with the most promise is the supercapacitor, which combines fast charging and discharging with high power density and high capacitance of batteries.

These alternatives to batteries have already entered the marketplace for EVs and portable electronics, but researchers agree that they’re far from perfect, particularly as far as the electrode is concerned.

The electrodes, or conductor for electricity that shuttles energy to and from the battery, are carbon-based, but graphene has surprisingly gone untapped thus far. In hopes of remedying this, NERSC supers have been running simulations to understand how graphene’s shape could affect its electrical properties, and perhaps hold a stable enough charge to come to the rescue of supercapacitors.