Aluminum giant takes on major challenge with a battery to help spark electric vehicle technology, consumer acceptance
May 2015 - “…Never ending potency” is heard in the lyrics of “Battery” by Metallica, from the band’s 1986 “Master of Puppets” album.
It’s a pledge Alcoa Inc. and technology partner Phinergy expect they’ll deliver in the aluminum-air battery they have developed. The technology goes the extra mile(s), taking the worry out of driving electric vehicles.
Ray Kilmer, Chief Technology Officer for Alcoa, lays out the battery’s creation and development, inherent usefulness, environmental sensibilities and timetable for commercialization.
The aluminum-air battery goes back to U.S. Department of Energy-sponsored work done in the 1980s, says Kilmer. “What killed that original project is there were two chemical reactions: One reaction consumes oxygen, which is good, but the other is carbon dioxide, which is not.” The CO2 could not satisfactorily be eliminated from the mix. In addition, the anode used metals such as gold or platinum, which are both heavy and expensive.
Since then, Israeli scientists from Phinergy created a solution that allows smaller oxygen molecules in but keeps larger CO2 molecules out. This is the “air,” the cathode part of the battery, while aluminum serves as the anode.
“Phinergy approached Alcoa because our knowledge complements their core competency,” says Kilmer. “The aluminum anode—we know about that. We could make it efficiently and cost effectively and we brought our alloy development expertise into it. And we know the automotive industry very well. So, together, we can now make a light, cost-effective solution.”
Green byproduct
When the aluminum anode dissolves, it makes a byproduct that can be repurposed. “The byproduct is an aluminum oxide that has value and is used in a variety of applications. We can use the aluminum as the [battery] fuel and at end of its lifetime, the byproduct has additional value so it is a very green solution,” Kilmer says. Alcoa plans to leverage its knowledge of refining aluminum to manage the byproduct by processing it effectively and then marketing it to the right audience.
Overcoming drawbacks
“The future is electric vehicles, period. The days of internal combustion engine cars is limited,” Kilmer says, but it could be 2025 or 2030 by the time automakers switch entirely to alternative engines.
“Carmakers won’t argue the point. You are seeing more hybrids, the Nissan LEAF and the Tesla. But what are the challenges slowing EV today? Lithium-ion batteries are rechargeable and storable. But they are expensive—$500 a kilowatt hour—and they are heavy.”
Today’s EV models are weighed down by the battery, engine and passengers. A lightweight aluminum-air battery won’t replace lithium-ion batteries in the vehicle, but can reduce the number needed.
Range anxiety
Most EV drivers have a regular pattern and their daily driving is consistently 50 miles or less. They will use lithium-ion for 90 percent of the distance and then recharge the battery at night. A supplemental aluminum-air battery will kick in when driving beyond the normal range.
Drivers can go significantly longer distances “without worry or concern and don’t need to stop along the way to recharge. It takes away range anxiety for people who have electric vehicles, some of which can do 60 to 70 miles [before recharging]. Most drivers today will risk only 45 miles a day,” Kilmer says.
Aluminum-air batteries also allow EV drivers to go places where there are no recharging stations. “A high-rise in Tokyo won’t have enough charging stations for all residents. We are seeing interest from Asian carmakers who see it solves the problem of too few stations while still being practical in urban environments.”
And, what if a family wants to spend the weekend at a cabin in the woods with no electricity? Without recharging, the aluminum-air battery will get them home.
Performance tests
The aluminum-air battery has passed customer performance tests and is undergoing trials at a handful of OEMs already. “First they check it from minus 40 to 40 degrees Celsius,” Kilmer says. “That is a severe-duty measure. Does the battery still work in those environments? It passed those tests, which was exciting.”
Then, with Phinergy, Alcoa built a vehicle (photo, page 28) that runs on lithium-ion and aluminum-air batteries. The software architecture is very different from Tesla or LEAF so “you need to have car companies integrate that [battery] into the first level of design” before full-scale production is feasible, he says.
For trials, some OEMs will place the batteries in the trunk but that isn’t optimized for handling performance. Next, a carmaker will amend its own computer architecture and “run a fleet of cars that demonstrate the technology over 12 months to get a sense of how they operate. We are in that phase,” Kilmer says.
Assuming the trials succeed, the battery producers and automakers must integrate into the architecture where the battery should be located from a weight distribution, handling and service perspective. Then they must undergo crash tests and even test the maintenance schedule for equipment. “The testing is very conservative and it has to be. It takes time,” he says.
Commercialization
Alcoa and Phinergy have patents and many pending patents filed on the battery’s anode, cathode, configuration, servicing, etc. “It is not uncommon to wait two to three years for approval. We will protect the battery heavily.”
For factory installation in retail vehicles, the earliest a consumer could expect to buy an aluminum-air equipped electrical vehicle would be 2018, Kilmer estimates, “but fleets will be on the road before that.” For performance trials, each automaker might build 50 to 60 cars to be tested. “It’s a sizable investment. And, depending on how many cars, our supply chain has to be ready.”
Asked how many batteries, conceivably, Alcoa could sell or produce per year, Kilmer suggests the market opportunity is a reasonable percentage of the electric vehicles in urban areas where there isn’t a sufficient recharging infrastructure. Automakers sold 118,500 EVs last year, up 27 percent from the 93,000 sold in 2013, according to GreenCarReports.com.
As batteries run out of juice, they have to be replaced. “The first year you sell a certain number of cars that consume aluminum (batteries). The second year, you need to build twice as many batteries, and the third year, you require three times as much aluminum,” says Kilmer.
Alcoa, he says, is working to make this technology produce “the lowest carbon footprint of any battery in the business. Unless the life cycle is green, it won’t work. We believe we got that right.”
The company has a range of options for production, whether that means building its own battery plants or licensing the technology to others to produce economically. Either way, it will be a global endeavor.
Application growth
In addition to use in vehicles, Alcoa and Phinergy believe electrical utilities will be able to adopt aluminum-air batteries to help provide power during emergencies, and for electricity storage.
When a power plant is shut down by a hurricane, it may be down for some time and restart from black. They traditionally use diesel generators for that, but there is a high cost to refresh the fuel and keep generators maintained around the clock. “Aluminum-air batteries can provide emergency power with a 20- to 30-year shelf life. It is there when you need it. The value proposition is different because reliability outweighs other considerations,” Kilmer says.
Second, energy companies typically have enough power but with peak and off-peak usage, it’s unevenly available. “In California, where there is a lot of solar contribution, too much power gets delivered during the day but the utility would like to use it at night. Aluminum-air batteries can store that and then deliver it to locations and at times where needed,” Kilmer explains. Alcoa and Phinergy have begun those trials as well.
“Powerhouse of energy ... we create the battery,” Metallica sings. Alcoa hopes car buyers and utility customers will love it. MM
