Sakti3's Big Claim: EV Batteries with Double the Energy Density and Half the Weight and Cost

Jim Motavalli

Jim Motavalli | Mar 13, 2014

Everyone agrees that liquid-electrolyte lithium-ion batteries are the state of the art for electric cars, but for how much longer? Conventional wisdom says current technology has maybe 10 years as king of the heap before it’s replaced with something disruptive. But what if that day is coming much sooner?

A Sakti3 battery cell on thin film. That's right, no liquid electrolyte. (Sakti3 photo)
A Sakti3 battery cell on thin film. That's right, no liquid electrolyte. (Sakti3 photo)

As I wrote last week, we have to think about these things as companies like Tesla prepare “gigafactories” to dramatically ramp up battery production for electric vehicles. Ann Marie Sastry, until recently a tenured engineering professor at the University of Michigan, thinks her company, Sakti3, has that disruptive tech—solid-state lithium-based batteries printed on thin film. Yes, they also make solar cells this way, also food packaging and flat-panel TV screens.
Now here’s the big claim. Sakti3 has attracted $30 million in venture capital funding, including from Khosla Ventures and General Motors, and Sastry says the company can, in two years, produce cells at half the cost of conventional li-ion, but with double the energy density and half the weight. And they’ll also be very safe, she says. If true, that’s darned disruptive!
Sakti3, which has been notably reticent about making bold pronouncements up to now, has working batteries that Sastry says deliver on the company’s promises. Sometime today, Sakti3 is announcing an affiliation with the Department of Energy’s Joint Center for Energy Storage Research (JCESR), which is led by Argonne National Laboratories. "Argonne has been given the responsibility of managing a $100-million battery hub, but it's working on technology that is a decade or more off in the future," Sastry said. "It's good that the federal government is placing long-term bets on storage technology, but we'll work with them on implementing any innovations that could give a nearer-term benefit." 

The next step for Sakti3 is for the company to partner with a manufacturer, possibly including major battery producers. “The reality is no single company can do everything,” Sastry said. “It’s a team of teams.” She said Sakti3, which has less than two dozen employees, is engaged in partnership talks aimed at scaling up production and supplying multiple automakers. "Given the volume of thin-film products on the market now, thin-film batteries could easily scale quickly," she said.

Ann Marie Sastry with a prototype battery substrate. She wants to have commerce-ready product in two years. (Bill Bowen/Henry Ford Magazine)
Ann Marie Sastry with a prototype battery substrate. She wants to have commerce-ready product in two years. (Bill Bowen/Henry Ford Magazine)

In part because other battery/capacitor companies have made big claims (Envia and EEStor come to mind) that haven’t proved out, at least one analyst says he's not breaking out the champagne just yet.
“I’d say this is not beyond the realm of possibility, but I think we’d all have to see it before we believe it,” said Jack Nerad, an executive market analyst at Kelley Blue Book. “Further, things that work in a lab setting might still present difficulties in the manufacturing process. Since car OEMs are desperate to find ways to meet future Corporate Average Fuel Economy (CAFE), I would think they would jump on such technology if it holds promise.”
The industry, Nerad said, “is certainly looking for a battery breakthrough that would include increased capacity, lower weight and especially lower cost.”
There are other caveats out there. One battery expert, Eric Carlson, a senior fellow at Boston Power, says he hasn’t seen Sakti3’s specific technology, but, “in my experience, solid-state batteries are high resistance, which means they tend not to have much power for delivering the instantaneous current you need for rapid acceleration.”
Sastry counters. “We have demonstrated both high power and low resistance. That complaint about solid-state has been out there for some time, and a number of cells do have that issue. The key is proper engineering of the interface, and with tuning of the layers you can achieve very impressive power.”
Despite fairly substantial EV battery subsidies from the Obama Administration, large-scale production remains abroad. Sastry comments, in her careful way, on why she needs a big and experienced battery partner. “The markets are large and varied, but the reality is that large battery companies are already scaled in Asia and can readily scale the same or similar technologies here as needed,” she said. “Even when companies find new, niche markets, sales are often short lived and difficult to maintain. Companies with scaled production are advantaged in all battery markets—hundreds of commoditized cell formats spanning all sectors, years of test results, and technical sales and marketing teams that have already sold into more difficult sectors, like automotive.”

Here's a Sakti3 video that looks at the science of next-generation lithium batteries:

Get the Car Talk Newsletter

Got a question about your car?

Ask Someone Who Owns One