Researchers at the Department of Energy's Argonne National Laboratory are working to develop solid-state batteries they hope will outperform current lithium ion technologies. Photo courtesy of Argonne National Laboratory
Nov. 12 (UPI) -- With the proliferation of wearable electronics, drones and electric cars -- and the race to halt climate change hastening -- demand for better, cheaper, lighter, smaller, safer batteries is soaring.
To meet those demands, researchers, startups, automakers, governments and many others are counting on a few breakthroughs to pan out.
"If we're going to decarbonize the economy, we're going to need a much better battery," Venkat Srinivasan, director of the Argonne Collaborative Center for Energy Storage Science at Argonne National Laboratory, told UPI.
Twenty years ago, mostly electric car enthusiasts were clamoring for a better battery. Today, global capital is driving that call -- including massive efforts aimed at vehicles -- keen to the growing demand for carbon-neutral technologies.
As such, billions of dollars have been pouring into the green economy, and battery startups are rapidly proliferating. Many of them inevitably will pin their hopes on a promising new cathode material or electrolyte chemistry, but it's likely to take longer to bring those to market than anybody wants.
Complicated science, many metrics
Every week, science journals publish a handful of papers promising a new and improved battery. More often than not, these early successes fail to hold up under further testing.
"The main challenge is that to go from a lab breakthrough to a fully validated, commercialized product requires 15 to 20 different metrics be met," Matthew McDowell, a material scientist and associate professor of mechanical engineering at Georgia Tech, told UPI.
"Usually, when we're talking about laboratory breakthroughs, we're talking about researchers working on just one or two metrics," McDowell said.
As a fictional example, say a researcher or team of researchers discovers a new cathode material that can release an accumulated charge more quickly and efficiently than current technologies. The research team may tout their discovery in a peer-reviewed paper.
When subjected to further tests, however, it becomes clear that after a certain number of rapid charge-discharge cycles, the battery's cathode breaks down. And when the battery is tested in cold weather, the decline is more severe.
Unfortunately, improvements to a battery's power capacity often come at the expense of its structural integrity. Battery researchers are constantly managing tradeoffs -- most of which are hard to foresee, only revealing themselves after years of research.
Over the last several years, research labs and battery companies were excited by the performance of cathodes made using the mineral manganese, but more recently, studies have shown manganese begins to dissolve with each cycle, eventually disrupting a battery's reaction chemistry
Efficiency, cost both matter
Scientists must ask themselves numerous questions before they invest time and capital into a new battery technology, no matter how promising.
Beyond metrics, to have a chance at life beyond the lab, new technologies must be able to perform under real world conditions, be produced at scale and meet a variety of longevity and safety standards. Most importantly, they must hit all those marks at a competitive price.
"When companies are considering new battery technologies, they're looking at several metrics: dollars per watt hour, dollars per watt kilogram and dollars per watt volume," Kevin Eberman, material scientist and product development manager at 3M, told UPI.
"They're also looking at its lifespan metrics, both charge cycles and time. It's especially hard to simulate and study accurately the combination of those last two metrics," Eberman said.
Some new battery technologies may be able to withstand thousands of charge cycles, but begin to break down after a year or two, regardless of how often they're used.
Complicating matters, markets, industries and applications each have specific needs. For some, energy density may reign supreme. For others, size and weight may be the top priority.
"Every application has a unique set of metrics that it needs to satisfy," Srinivasan said. "You have to really think about what the markets needs."
In other words, the kinds of batteries and battery performance metrics electric or hybrid car makers are looking for are different than those that will appeal to a company that makes medical imaging technology, fitness watches or drones.
Market demands
For battery technology breakthroughs to make it to market, they must meet the needs of the market, but Srinivasan said it's important for research labs not to become beholden to market trends.
Markets move fast, consumers change their minds and trends shift -- but science tends to happen slowly.
"In the 2000s, most of us thought we would be driving hybrids, but by 2010, we decided we wanted plug-in vehicles," Srinivasan said.
"During the early days, everyone wanted a battery with lots of power. So you see papers coming out saying, 'My battery has amazing power.' But by the time the papers were coming out, car companies could see consumers wanted bigger batteries providing cars longer ranges," he said.
It's also important for scientists to avoid tunnel vision. Whether they're working in an academic lab or for a startup company, researchers must be flexible.
"You don't want to set out thinking about making a battery for an electric vehicle," Srinivasan said. "You'll inevitably fail."
Companies and researchers working on battery breakthroughs need to be willing to sell to smaller markets as they develop burgeoning technologies.
"Companies need to ask: Is there a first market that allows our technology to mature, to give us momentum and buy us some time?" Srinivasan said.
"Instead of selling to car manufacturers right away, where margins are so thin, a better strategy is selling to a smaller niche market where you can make some money and do some learning and additionally testing. Scaling up manufacturing takes time and learning curves take time," he said.
Because the demands of consumers and manufacturers can change so rapidly, technologies that appeared underwhelming at first -- a new battery chemistry that was safe and stable, but not all that powerful, for example -- might become more desirable as trends shift.
Focusing on science
While it's important that lab directors and research and development heads have a sense of the market, it's best to let scientists focus on science.
"On the research side, it's vital to really maintain a focus on technological fundamentals, rather than market trends," McDowell said.
Currently, the vast majority of battery-powered products -- whether smartphones, medical devices or cars -- rely on lithium ion technology.
Lots of researchers are working on improving the performance of lithium ion batteries, but most scientists agree that a decarbonized economy will require new kinds of batteries.
As leaders at federal agencies and technology companies allocate R&D resources, they must weigh today's battery needs with those of tomorrow.
"You have to think about every timescale of innovation," Srinivasan said. "You don't want to focus solely on the Hail Mary solution, but you also don't want to focus all your energy on the near term solution."
The energy density of lithium ion batteries has doubled since their introduction, and Srinivasan thinks there's room for another doubling. But others are less optimistic.
"We are coming pretty rapidly to the energy density limit of lithium ion batteries," McDowell said. "It's extremely impressive how good they are and how cheap they've gotten, but there is a pressing need to develop next-generation technologies."
Those next-generation technologies aren't likely to dethrone lithium ion batteries for a while -- on the order decades, according to McDowell -- but the work on alternative chemistries, like sodium-ion and lithium-sulfur, already has begun.
Even with automakers pledging billions of dollars for battery and electric vehicle R&D spending, established companies mostly will avoid the moonshot ideas. Established companies have too much scar tissue.
"It's really hard to overcome the apprehension that comes with experience," Eberman said. "You know so much about why it's a bad idea to take the risk."
But the experimentation from which scientific breakthroughs are born necessitates risk. According to Eberman, those that take such risks, with all the apparent challenges, will need to "know just enough to be dangerous."
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