Just in time for President Joe Biden’s big vehicle electrification announcement, a team of Energy Department scientists has won a decades-long fight over the electric vehicle battery of the future. When the dust clears, the energy density of your everyday EV battery will weigh in at 500 watt-hours per kilogram, a doubling of the current state of the energy storage art.
US Army Invests In The Electric Vehicle Battery Of The Future
The big energy storage news comes from Brookhaven National Laboratory, part of the Energy Department’s sprawling network of A-list research facilities, and it’s a fine example of how science never sleeps.
The Energy Department has been hammering away at Obama-era decarbonization initiatives all during the past four years, despite a detour into fossil-friendly territory by former President Trump.
One of those initiatives is called the Battery500 consortium, of which Brookhaven is a part. Battery500 launched in 2016 under the leadership of Pacific Northwest National Laboratory and received a generous assist of $1 million from the US Army, through something else called the Advanced Vehicle Power Technology Alliance, which also chipped in with another $1.8 million in 2018.
AVPTA is another Obama-era program, having launched in 2011 between the departments of Energy and Army, tasked with accelerating the “conceptualization and transition into deployment of inventive and creative energy-saving concepts that the Nation needs to achieve energy security,” with a focus on “advanced technologies that enable commercial and military ground vehicles to become significantly more energy efficient.”
Where were we? Oh right, Battery500. CleanTechnica caught wind of Battery500 in 2017, when the Trump administration juiced Battery500 with another $5.7 million for 15 “seed” projects aimed at doubling the energy density of the electric vehicle battery and lowering the cost, with that goal of 500 watt-hours per kilogram.
For those of you keeping score at home, the other Battery500 members are Idaho National Laboratory, the SLAC National Accelerator Laboratory, Binghamton University, Stanford University (which operates SLAC for the Energy Department), University of California – San Diego, University of Texas – Austin, and University of Washington, and IBM.
Rescuing Lithium Metal Anodes From The Reject Pile
IBM launched its own electric vehicle battery research initiative, dubbed Battery 500, all the way back in 2012. Among other findings, IBM has been contributing its cobalt-free energy storage research to the electric vehicle battery cause. That dovetails with the Battery500 Consorium mission, as it relieves the US from supply chain and human rights issues that have bedeviled the global cobalt market.
The new Brookhaven research tackled another angle of keen interest to the Battery500 Consortium, which is the development of an electric vehicle battery with a lithium metal anode.
That’s quite a heavy lift, considering that the idea of a lithium metal anode was explored by battery researchers decades ago, only to be rejected.
“Scientists have long recognized the advantages of lithium metal anodes; in fact, they were the first anode to be coupled with a cathode. But due to their lack of ‘reversibility,’ the ability to be recharged through a reversible electrochemical reaction, the battery community ultimately replaced lithium metal anodes with graphite anodes, creating lithium-ion batteries,” explains Brookhaven.
The Battle Over The Electric Vehicle Battery Of The Future
Still, the siren call of improved specific capacity and higher voltage is difficult to ignore, and the Brookhaven researchers are confident that they have spotted something that decades of previous research has failed to spot.
The key to the breakthrough is something called the interphase, a nanometer-scale film that develops on the electrode of a battery. A precise understanding of the interphase would enable researchers to develop a reversible lithium metal battery.
The problem, until now, was getting this tiny bit of nanoscale floss up off the electrode and subjecting it to high tech analytical equipment without exposing it to air and moisture.
For all the juicy details on how the Brookhaven team went where no researchers have gone before, check out their study in the latest issue of Nature Nanotechnology (spoiler alert: it involved Brookhaven’s National Synchrotron Light Source II and the X-ray Powder Diffraction beamline).
The shorter version is that the Brookhaven team identified the existence of lithium hydride in the interphase, which opens the door to reversibility, and which is sure to set off sparks all over the energy storage research field.
Brookhaven chemist Enyuan Hu, who is leading author of the study, seems ready to fight off any naysayers.
“When we first saw the existence of LiH, we were very excited because this was the first time that LiH was shown to exist in the interphase using techniques with statistical reliability,” Hu explained. “But we were also cautious because people have been doubting this for a long time.”
The basic idea is that other research teams failed to spot lithium hydride because they were confusing it with lithium fluoride. The two have similar crystal structures, and the Brookhaven team suggests that exposure to moisture may have muddled the results in previous research.
There Goes That Pesky Transportation Thing Again
Also of interest is what must have been a hair-raising journey that took the interface sample from Pacific Northwest National Laboratory in Richland, Washington clear across the country to Brookhaven in Upton, New York.
“The sample preparation done at PNNL was critical to this work. We also suspect that many people could not identify LiH because their samples had been exposed to moisture prior to experimentation. If you don’t collect the sample, seal it, and transport it correctly, you miss out,” observed co-author Xiao-Qing Yang.
The first author of the study, Brookhaven chemist Zulipiya Shadike, also credits careful handling and transportation with playing a critical role in the breakthrough.
“From sample preparation to data analysis, we closely collaborated with PNNL, the U.S. Army Research Laboratory, and the University of Maryland,” she noted.
US Army Eyeballs Electric Vehicle Battery Of The Future
When President Joe Biden has vowed to transition the entire federal vehicle fleet to a zero emission model, he also said that he expects private sector stakeholders to play a leading role, over and above any decarbonization legislation that makes its way through Congress.
That’s where the US Army comes in. The Department of Defense is the largest single institutional fleet owner in the world, and it has been front and center in electric vehicle battery research and EV adoption, regardless of the previous Commander-in-Chief’s fossil-friendly rhetoric. Those efforts began to coalesce last spring, when the Army Futures and Concepts Center announced that is formulating a new EV policy in step with the availability of commercial electric vehicle technology.
That means a quick pivot is in store for auto makers like GM, which just nailed down a $214.3 million contract last summer with the US Army for the new Infantry Squad Vehicle.
Sure enough, this week GM cut loose with a flurry of decarbonization and electrification news, including a zero emission pledge by 2035 for new light-duty vehicles and carbon neutrality across all operations globally by 2040. With an eye on the heavy duty market, GM is also farming out zero emission technology to other vehicle manufacturers, one recent example being a fuel cell deal with Navistar for long haul trucks and heavy duty off-road equipment (the green-ness of which will depend on the availability of green hydrogen).
On its part, the Energy Department is already planning for an additional pot of $60 million for advanced vehicle research that includes a hefty share for EVs, so stay tuned for more on that.
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Photo: “Brookhaven chemists Enyuan Hu (left, lead author) and Zulipiya Shadike (right, first author) are shown holding a model of 1,2-dimethoxyethane, a solvent for lithium metal battery electrolytes” by Brookhaven National Laboratory.
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