January 06, 2024
By Tina Casey

Harvard Spinoff Lobs Solid State Battery Bomb At Fossil Fuels

New energy storage technology is driving fossil fuels out of the global economy, and a Harvard University spinoff called Adden Energy has just added more fuel to the fire. Their new solid state battery can last for 6,000 cycles and take just 10 minutes to recharge, which is about the same amount of time as filling up a tank of gas. No word yet on cost, but the Adden is betting that the battery’s long lifespan will help make electric vehicles more affordable.

New Solid State Battery Gives Dendrites The Boot

New solid state energy storage technology is the next big thing, replacing the liquid in a conventional lithium-ion battery with a polymer, a high-tech ceramic or some other solid material. Getting lithium ions to move through a solid is a challenging feat, but the payoff is longer range and faster charging times.

Adden Energy is one among many solid state battery innovators to overcome the ion movement hurdle, and they have also come up with a vigorous solution to the problem of dendrite formation, to boot. Dendrites are tiny fernlike growths that develop on the anodes of lithium-ion batteries. They interfere with battery performance and increase the risk of fire.

Adden got its start at Harvard’s John A. Paulson School of Engineering and Applied Sciences, where a research group headed up by Associate Professor Xin Li has been hammering away at the challenges and opportunities posed by solid state EV batteries.

In 2018 the group racked up one solid state battery breakthrough when it published a study of sulfide solid electrolytes in the journal Nature Communications.

“The goal of our paper is to demonstrate that the control and modification of the microstructures in LGPS and LSPS can adjust and improve their voltage stabilities,” the group explained, referring to two types of crystalline sulfide solid electrolytes.

“More importantly, we aim to reveal the underlying mechanism between the microstructure and the performance of sulfide solid electrolytes, which can serve as the guidelines for the future materials and battery cell designs.”

How Does It Work?

They weren’t kidding around. The new battery is the result of additional research, culminating in a new study published on January 8 in the peer reviewed journal Nature Materials under the title, “Fast cycling of lithium metal in solid-state batteries by constriction-susceptible anode materials.”

Dendrite growth was once thought to be a problem only for liquid-electrolyte batteries, but it can bedevil a solid state battery, too. Various workarounds have emerged to slow them down, and the Li team went one step beyond, to stop them altogether.

You can get all the juicy details from the study, or check out a highly readable explainer by Leah Burrows at the Harvard press office.

“In this new research, Li and his team stop dendrites from forming by using micron-sized silicon particles in the anode to constrict the lithiation reaction and facilitate homogeneous plating of a thick layer of lithium metal,” Burrows explains.

“These coated particles create a homogenous surface across which the current density is evenly distributed, preventing the growth of dendrites,” she adds. “And, because plating and stripping can happen quickly on an even surface, the battery can recharge in only about 10 minutes.”

“In our design, lithium metal gets wrapped around the silicon particle, like a hard chocolate shell around a hazelnut core in a chocolate truffle,” Li elaborated.

Hurry Up And Wait, Or Not

The new battery is still in the scaling-up stage. The study involved a pouch cell the size of  a postage stamp. Still, that’s about 10 to 20 times bigger than a typical university lab-made battery, and it was big enough to establish some data.

‘The battery retained 80% of its capacity after 6,000 cycles, outperforming other pouch cell batteries on the market today,” Burrows noted.

In the meantime Adden, which was co-founded by Li and three Harvard alumni, has already scaled the new solid state battery up to the size of a smart phone.

Adden won the exclusive technology license from Harvard University’s Office of Technology Development in 2022, and the company also nailed down a seed round financing of $5.15 million.

“Primavera Capital Group led Adden Energy’s seed round, with participation by Rhapsody Venture Partners and MassVentures,” Adden explained in a press release.

“The license and the venture funding will enable the startup to scale Harvard’s laboratory prototype toward commercial deployment of a solid-state lithium-metal battery that may provide reliable and fast charging for future EVs to help bring them into the mass market,’ the company added.

As for when that might happen, back in 2022 Adden anticipated a palm-sized pouch cell as a first step, and moving on to a full-sized solid state battery for electric vehicles within the next three to five years. About one of those years has already come and gone, but the timeline is consistent with other new solid state batteries, which are generally expected to hit the market sometime before 2030 or thereabouts (see more solid state news here).

Circling back around to that thing about costs, Li suggests that the long lifespan of a solid state battery can help make EVs more affordable by improving their resale value.

“Electric vehicles cannot remain a luxury fashion, literally the ‘one percent’ of vehicles on the road, if we are to make progress toward a clean energy future, and the U.S. won’t have a used-car market if EV batteries last only 3 to 5 years,” he said. “The technology needs to be accessible to everyone. Extending the lifetime of the batteries, as we’re doing here, is an important part of that.”

Why Is Everybody Picking On Harvard?

Speaking of Harvard, the school has been much in the public eye these days because it was among a trio of Ivy League universities to be called to testify before Congress in December. Without going into the details, let’s just say there’s more there than meets the eye.

We’re bringing this up in the context of clean technology because the hearing was called by Republican leadership in the US House of Representatives, with prominent Republican activists in the mix. They have not been shy about expressing their determination to upend diversity, equity and inclusion (DEI) programs at institutions of learning, and the anti-DEI campaign is an element in a well documented multi-state effort to stop investor dollars from flowing into clean tech. Preventing schools from teaching climate science also factors into the campaign.

With that in mind, it’s no accident that Harvard, along with MIT and the University of Pennsylvania, were tapped to provide fodder for the grist mill.

All three schools are front and center in climate research and clean tech innovation, to boot. The new solid state battery is a good example. Harvard’s Climate Change Solutions Fund contributed to help launch Adden into business, following years of support from the school for the foundational research.

MIT has also made numerous contributions to the clean tech industry (see our coverage here). The school also advocates for renewable energy through its Climate Portal, and it has established the MIT Energy Initiative to bring “the totality of MIT’s capabilities to bear on climate change throughout the world with novel technology and science-based guidance for policy makers.”

At the University of Pennsylvania, the Kleinman Center for Energy Policy is also on a climate centered mission. “We firmly believe that solutions to today’s most significant challenges, like climate change, are grounded in a reimagined energy system that can only be realized on a strong foundation of advanced energy policy research,” KCEP states.

The anti-DEI angle is not secret knowledge, by the way. On January 5, ABC reporter Kiara Alfonseca took a deep dive into the topic. Check it out here.

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Image credit: New solid state battery resolves dendrite issues, courtesy of Adden Energy.