Will zinc-air batteries ever replace lithium-ion for long-range EVs?
No matter how proud the owners of a $400-500 per month leased Chevy Volt may boast, the cost of electrification for automobile is too high for the masses. And all this talk that it will come down when the production volume rises lacks economic common sense. It’s not the production volume that will bring the cost down for the masses this time, but technology advances and a cheaper EV fuel storage; and one with sufficient energy density that avails the same driving range as a IC engine but without a $90K price tag.
One area of the electrification of the automobile under research for many years now has been the early commercialization of the zinc-air battery for energy storage. For the record, zinc is far cheaper and far more plentiful than lithium; and due to its lower cost, avails greater energy density within the same package size for an automotive application which demands 400-500 miles of range plus fast recharging.
When I attempted a recent web search, Fluidic Energy, a for-profit corporation based in Scottsdale, Arizona showed up. It focused on the development of energy storage devices, and specifically on metal-air cell technology. Founded in 2007, as a spin-off technology company from research done at Arizona State University, it received funding from both private sources and an energy development grant from the United States Department of Energy. I emailed the firm requesting an update, but still waiting for reply. [Jan. 30, 2012 Note: see comments below for update]
I also wrote in 2010 on this subject and noted Zinc Air Inc. based in Kalispell, Montana, Their website seems more active now, but not by much with regard to advancements. Zinc Air Inc. has since developed the Zinc Redox flow battery, designed to achieve rapid payback periods while also being the greenest battery technology on the market. This competitive storage solution allows a wind farm to store and shift wind power for flexible use by utility operators.
So, where are we now for EVs?
I affirm I did not see or hear any mention of Zinc-air battery technology at the The Battery Show 2011 in Novi. Michigan this past Fall. That means we have the EV industry still steeped in lithium-ion cell technology. My visits in 2011 to just about every tech seminar, including the SAE World Congress in Detroit, revealed the same.
Although fully functional, the cost of getting an affordable, long-range vehicle using that lithium cell technology seems on the surface far more remote than ever. The general public simply cannot afford it, though, which explains why sales of Ford’s EcoBoost IC engines and GM’s Ecotec Eco models have been much, much higher.
Fact is, the lithium technology is the culprit behind an EV’s high cost, along with the lack of economic vision by the automakers, in my opinion. The most cost-effective driving range the OEMs can achieve using lithium-ion technology is between 20-40 miles, as noted by the Toyota Prius and the Chevy Volt which are hybrids, requiring an IC engine to extend the driving range.
Any more than that and the price is out the ceiling for the average buyer. Yes, and with all respect, check out the cost and size of that Nissan Leaf with a 100-mile range; and the Tesla Model S, although a fine looking vehicle, is price prohibitive for most. Another consideration is, that taxpayer subsidy is viewed by many as an insult to those who cannot afford the car even with the subsidy, but is given to those who can afford a BMW 3 Series. (I know, I read their sharp emails condemning me for comparing a Volt’s cost and size to a more-affordable Chevy Cruze.)
In Search of Zinc-air Battery Technology
Reiterating what I wrote in TorqueNews in Dec. 2010, the main advantage of utilizing zinc-air batteries for vehicle propulsion is still its energy availability, 100 times greater than that of lithium, per unit of battery energy. And that implies greater driving range, not to mention faster recharging.
The second advantage is, zinc's supply in the world is more readily available. Regarding supply just five years ago, zinc was produced at 11 mines in 6 States with Alaska being the leading zinc-producing State. Other zinc producing States included Idaho, Missouri, Montana, New York, and Washington.
According to an article in Machine Design at that time, approximately 35% of the world's supply, or 1.8 giga-tons of zinc reserves were in the United States, whereas the U.S. held less than 1% of known lithium reserves. This was supported by ev.world.com that reported zinc production ranked fourth in the world, after iron, aluminum and copper.
Zinc is still plentiful, which is great news; but the technology in a car battery is far from mature. While zinc has been used for many decades in small batteries for instruments and navigation beacons, use as automotive batteries has been nil and relegated to research labs. The primary development effort had been to investigate new approaches to ionic liquids and to overcome some of the problems specific to Zinc-air cells.
In the form that these electrical cells were typically manufactured, these kind of cells were not usually recharged due to dendrite buildup during the recharging cycle. This resulted in the cell shorting out and not holding a charge when the dendrites connected the anode with the cathode. So, a need for an ionic fluid that repels this condition as well as does not use water is crucial; and one was reported in 2010 in the labs.
Regardless of the challenges, which are no greater than that of lithium which have a greater end cost, the advantages against the high cost of lithium are undisputed facts that automakers need to consider, especially if they want to sell to the masses in high volume. And since the cost of cars are already beyond real affordability by the masses, and government giveaways will not last forever, the OEMs best rethink their lithium position.
Furthermore, current yearly global zinc production is, in practical terms, sufficient to produce enough zinc-air batteries to power over ten times more electric vehicles than current lithium production can support. If nothing else, it would buy the time needed until hydrogen fuel cells mature and become economically feasible to the masses. And based on my own web searches, zinc has the potential to be an onboard resource for fuel cells as well.
So, in light of 2016 to 2025 goverment mandates toward 54.5 MPG, where are the zinc-air batteries? I wish those who have them in development would start speaking up. Or are they under some insidious industry gag order?