Analysts warn that innovation in the lab could take 15 years to become a viable commercial EV battery
John Goodenough may have done it again. Thirty-seven years after co-inventing the technical breakthrough that made lithium-ion batteries commercially viable, the 94-year old engineering professor has developed a solid-state battery he thinks will solve the high cost and low range holding back EV adoption.
“Cost, safety, energy density, rates of charge and discharge and cycle life are critical for battery-driven cars to be more widely adopted. We believe our discovery solves many of the problems that are inherent in today’s batteries,” Goodenough said in a press release from the Cockrell School of Engineering at The University of Texas at Austin.
In 1980, Goodenough was a researcher at Oxford University when he demonstrated a rechargeable lithium cell using lithium cobalt oxide as the cathode (the positive side of the battery) and lithium metal as the anode (the negative side of the battery). His subsequent work helped turn the li-ion battery into the most common rechargeable battery for consumer electronics like cell phones.
Modern Li-ion batteries use liquid electrolytes to transport lithium ions between the anode and the cathode. If a battery cell is charged too quickly, it can cause a short circuit, leading to explosions and fires.
Instead of liquid, Goodenough and senior research fellow Maria Helena Braga used glass electrolytes, which in turn enabled the use of an alkali-metal anode that prevented the formation of dendrites (“metal whiskers” that cause the short circuits).
The solid-state batteries have three times the energy density (the measure of how much electricity can be stored in the battery) of conventional Li-ion EV batteries. If the Chevy Bolt can go 320 kms with its current Li-ion battery, it should be able to travel almost 1,000 kms with a solid-state battery.
But higher energy density isn’t the solid-state battery’s only advantage: cells can be made from earth-friendly materials.
“The glass electrolytes allow for the substitution of low-cost sodium for lithium. Sodium is extracted from seawater that is widely available,” Braga said.
The engineers describe their new technology in a recent paper published in the journal Energy & Environmental Science.
The solid-state battery also performs well at -20 degrees Celsius, a big advantage for markets with cold weather climate, like Canada.
Goodenough and Braga also claim a long cycle life. In experiments, the cells have demonstrated more than 1,200 cycles with low cell resistance, according to the release.
That’s the good news. Now, what does the innovation mean for future EV batteries?
The short version is, don’t get excited too soon. Chris Robinson of LUX Research says translating laboratory breakthroughs into commercialized products is “no small feat.”
“This will have no tangible effect on electric vehicle adoption in the next 15 years, if it does at all. A key hurdle that many solid-state electrolytes face is lack of a scalable and cost-effective manufacturing process,” he said in an email.
A key issue for potentially disruptive technologies is creating a scalable, low-cost manufacturing process.
“The authors note that input materials are affordable, but the automotive companies buying batteries don’t care about material costs, they are concerned about the total price of a complete battery,” said Robinson.
“If we take an example from cathode materials in conventional batteries, it takes about 10 years to bring the concept from discovery to commercial implementation. However, if we look at new cell architectures not just materials, that lead time is even longer.”
Robinson doesn’t expect to see vehicles using solid-state batteries before 2030. “Even then, we are much more likely to see solid-state electrolytes based on polymers, not glassy inorganic materials, as they are much easier to manufacture at scale,” he said.
Fred Beach is the assistant director for the Energy Institute of the University of Texas at Austin. He says Goodenough’s reputation lends significant credibility to the research.
“This is almost too good to believe. And if it was coming from just about anyone else, I would be pretty skeptical,” he said in an email. “I do have high confidence in the findings because John was involved.”
Beach notes that Goodenough and Braga’s work has made big strides in five aspects of battery performance, “any one of which would be noteworthy.
- increased voltage potential of the cell which leads to higher energy density
- higher charge rate of the cell for quicker recharging
- more charge/discharge cycles for longer cell life
- higher and lower operating temperatures without cell degradation
- potentially lower cost through the use of sodium vice lithium.
“There might still be some hurdles involved in engineering this for practical application and manufacturing, but at first read nothing really pops out at me. So yeah, pretty big news!” he said.
Where to from here for EV batteries?
As I noted in a previous column, leading EV battery scientist Dr. Yi Cui of Stanford University estimates that Li-ion batteries will increase in energy density by 50 per cent and drop in price by 50 per cent over the next 10 years.
Given the huge investments automakers have already made in Li-ion (e.g. Tesla Motors’s $5 billion Gigafactory) and the long lead-time to design and bring a new EV to market, Robinson’s 15-year forecast for the solid-state battery seems reasonable. Even if time to market is shorter, it’s not likely it will be radically shorter.
And as Prof. Halah Ardebili noted in my earlier column, there are other EV battery chemistries that could produce 20 times the energy density of Li-ion, rather than the three times of solid-state. One of those innovations may yet get to market faster than solid-state.
The takeaway from yesterday’s announcement is that EV battery research is alive and well (which wasn’t all that certain when I wrote this column), and will almost certainly result in a battery that finally makes EVs competitive with internal combustion engine cars.
But even John Goodenough’s work doesn’t change my forecast that EVs will take at least 50 years to reach 70 to 80 percent of the global vehicle market.