Is There an Heir to the Power Throne?
The Lithium-Ion Battery: Power King or Pretender?
Should robots, EVs and autonomous vehicles beware their energy supplies?
Donald Sadoway, MIT electrochemist
Here come the EVs!
Faster than anyone thought possible, the proliferation of electric vehicles (EVs) is taking off. The world is swearing off internal-combustion engines at a record pace, prompting UBS to raise its forecast for global electric vehicle sales by 50 percent, “predicting that 14 percent of all cars sold globally in 2025 will be battery driven.”
In 2009, stats from the International Energy Agency showed fewer than 6,000 EVs on the road in over 40 countries.
Although EV sales today are less than 1 percent of the 80 million passenger cars and light trucks sold worldwide, according to EV Volumes, a Swedish electric car consultancy,” bend an ear for the hum of electric motors on highways to swell in the coming decade.
China, which is already the global leader in the passenger-vehicle market, wants to ditto that with EVs. Its 2020 target is to roll out 5 million EVs.
King of power?
Advancing not nearly as fast as needed is the power source common to most every EV, namely, the lithium-ion battery. Millions of lithium-ion cells are being manufactured worldwide (mostly in the U.S. and Asia) with billions more needed to meet future demand, yet no one seems satisfied with what this power king holds for the future.
There’s certainly demand for EVs, which is always a good sign. McKinsey reports that between “2011 and 2016, the proportion of consumers potentially interested in buying an EV jumped to 23 percent, from just 8 percent
Investors seem the most at ease, pleased with the forecast for the lithium battery market to quadruple from $11 billion to $43 billion in annual sales by 2020. But even they could get burnt in a very big way if the king turns out to be a pretender.
Although most everyone recognizes and appreciates the lithium-ion battery tech tweaks from manufacturers like Tesla and Panasonic that have increased EV range by 60 percent (to 300-plus miles), safety, and cost savings, is it enough to offset the battery’s challenges?
Knocks on the lithium-ion battery
- Charging performance: Repeated cycles degrades battery as it charges and discharges
- Limitation on energy density
- Instability of liquid electrolyte
- Can overheat and, occasionally, explode
- Yet to attain goal of $100 per kWh
- Prices need to fall by an additional 50%-80% to be economically compelling
- Raw material supply chain is weak and unproductive
- Insufficient battery capacity to meet demand from millions of EVs
- Lithium recycling unavailable or too expensive
And for autonomous EVs, what about all the energy-hungry, self-driving tech oozing everywhere? It’s a huge power drain! “Some of today’s prototypes for fully autonomous systems consume two to four kilowatts of electricity—the equivalent of having 50 to 100 laptops continuously running in the trunk,” says a report from BorgWarner Inc. Buzzkill for the odometer!
Explosions are said to be very, very infrequent, but they may be due for an increase as an ever-escalating EV market cranks up for billions more lithium cells. Elon Musk has taken great pains at building safety and QC into Tesla’s batteries, however, as a Battery University points out, QC may get dicey as battery supply expands to aftermarket suppliers who may be less stringent with QC.
No one wants their family sitting atop a bomb. For a stark look at the aggressive nature of a lithium-ion battery explosion and fire, check out the demise of this RoboSimian. Note how difficult the fire is to put out:
Or, a little more down to Earth, a roadside bonfire that may become more frequent when millions of lithium-powered electric engines are zooming around the planet.
Caspar Rawlas, analyst at Benchmark Mineral Intelligence, sees a collision a few brief years away: “When we get to a point when there’s a number of competitive, relatively cheap electric vehicles on the market, which is coming around 2020, that’s when we’ll see potential problems.”
With no easy heir apparent to the power throne, the industry seems perfectly willing to accept incremental changes along the way to something better… whenever that may be.
But there’s a problem with waiting. Part of the Rawlas collision is the fact that like Moore’s Law in IT, lithium-ion battery technology is reaching its theoretical limits, says George Crabtree, Director of the Joint Center for Energy Storage Research (JCESR). In a Forbes interview Crabtree claimed that lithium-ion technology might be squeezed for an additional 50 percent to 100 percent better performance, but that’s it. “To create a true energy transformation, we will have to deploy new technological strategies.”
Transformation means that step rather than incremental change is what’s needed. Step change, however, means uncertainty in the power supply, which is less than a happy place for battery manufacturers to be.
In 1991, lithium-ion technology was a step change; its energy density was twice that of the next best batteries. It was an outsider that the established battery industry shunned until SONY took a chance and commercialized it. Lithium-ion batteries now make our digital lives possible, and have fattened corporate coffers throughout the industry.
Battery expert Naoaki Yabuuchi of Tokyo Denki University says he expects lithium-ion technology to reach its limits around 2020, which means that work in “beyond lithium tech” is going on right now.
The king is dead, long live the king!
In western Spain, far from the well-known halls of lithium research, the city of Yecla seems to have produced a new power king: graphene polymer batteries.
Like lithium before it in 1991, graphene’s advance billing borders on the incredulous. Here’s a bit of the jaw-dropping comparison taken from NextBigFuture.com: “4 times the energy density of the best lithium ion battery available. Recharge speeds 33x and still retaining over 80% capacity after thousands of charges. Cost will be much lower.” In fact, 77 percent cheaper than equivalent lithium ion batteries.
That one sentence, if true, completely destroys the lithium-ion battery.
And for future encounters with RoboSapiens: “TüV and DEKRA [independent testing and certification labs] show that the batteries are safe and are not prone to explosions like lithium batteries.”
There’s a dearth of info on the graphene battery and its makers (here’s a Bloomberg report), which inevitably lends itself to the spread of doubt and negative speculation about the very existence of these wonder batteries. Transport Evolved has written: “We won’t be holding our breath for Graphene battery’d EVs just yet.”
Grabat Energy, owned by Graphenano (Spain), does have at least one believer: CHINT, the Chinese developer of “industrial electrical appliances and new energy” and part of the Zhengtai Group, is reported to have invested $21 million for 10 percent of the Spanish company. As written in El Mundo, the agreement also gives CHINT the ability to manufacture the graphene batteries in China for China.
“The second phase,” according to El Mundo, “will be much more ambitious. The Chinese company will provide 350 million euros [$412 million] for Graphenano to build a second factory in Yecla.” Both Graphenano and CHINT will form a joint venture to market their products in China.
Whether it’s Grabat and CHINT or someone else, it’s just a matter of time before graphene batteries supplant lithium-ion. It just makes sense, and the world is getting busy at making it happen.
As Nano-Werk reports, “Graphene currently is the most studied material on the planet—this is especially true for charge storage and the results from many laboratories confirm its potential to change today’s energy-storage landscape.”
Look for a new king to be on the throne much sooner than anyone thinks.