Renault-Nissan To Use Phinergy’s Aluminum-Air Battery

While details are yet scarce, yesterday Phinergy CEO and Founder, Aviv Tzidon confirmed talks with Renault-Nissan are tentatively set for a proposed series production electric car due in 2017 using its range-extending aluminum-air battery.

This was first revealed in a video-recorded semi-private talk with President Barack Obama and Israeli Prime Minister Netanyahu (see video @4:29).

After we questioned further, Tzidon said this would be under ideal circumstances, and unforeseen delays on the the French automaker’s side could conceivably push it back to maybe 2018 or 2019, he conjectured, although 2017 was by all appearances the date that is “on the table.”

In any case, Phinergy is ready for this customer and all others, and initially, Tzidon divulged, he did not even expect an automaker would be first to adopt aluminum-air. Phinergy is “patient” and in it for the long term, he said.

Thus, if things go according to plan, Phinergy hopes its aluminum-air battery may prove to be the greatest thing for transportation – and other industries – since sliced bread.

But unlike bread slices you would eat, the company has developed a carbon-neutral electric car battery which slowly consumes slices of aluminum and yields several-times more energy density than the best lithium-ion batteries.


Every start-up CEO’s dream come true – President Obama and Prime Minister Nethanyaho visit with Phinergy’s CEO Aviv Tzidon.

Based on work begun in Israel in 2008, the company is collaborating with Alcoa on this cost-effective and safe energy source. It’s being proposed as a range extender – not a primary propulsion battery – to automakers, including Renault-Nissan.

As for the “slice” of aluminum analogy, that’s an oversimplification, but it is more accurate than other reports that have said Phinergy’s 1,100-plus-mile range range-extended electric car runs merely on “air” or “water.”

Almost that amazing, Phinergy’s aluminum-air battery combines de-ionized (drinkable) water into an alkaline electrolyte solution and breathes in air to create a chemical reaction that dissolves aluminum plates to produce electricity.

Aluminum is the most abundant metal in the earth’s crust and Phinergy’s durable technology reliably extracts 8.1 kilowatt-hours of energy – half of which is electricity, and half byproduct heat – per kilogram.

The notion of aluminum-air and other metal-air batteries is not new, but Phinergy has worked out the bugs and is ready to put it into production – not just for cars, but consumer electronics, stationary energy storage, defense, industrial – all sorts of applications.

While aluminum is normally thought of as a structural material, it contains much electrical potential. A lot of electricity goes into its smelting process and is effectively stored. Phinergy’s controlled reaction releases the electricity in a process with the reverse effect of smelting. Plans in Montreal are to use sustainable hydroelectric power in the aluminum’s smelting.

Additional markets that can use Phinergy's aluminum-air and zinc-air tech.

Additional markets that can use Phinergy’s aluminum-air and zinc-air tech.

What’s more, after the aluminum-air battery chemically extracts stored electrical energy from the ever-diminishing aluminum plates, it leaves a recyclable byproduct in liquid that can be easily processed back into fresh aluminum.

Technically, consumers would only be buying the energy stored in aluminum, not so much the aluminum itself which merely dissolves to a different form and is taken away as a valuable byproduct.

A Little Bit Different

If any of this sounds unclear, we’ll explain how it works further below, but the takeaway is the company is past the “proof of concept” stage.

This was shown in Montreal this week by the Phinergy/Alcoa EV converted from a formerly gas-burning Citreon C1. The car covered a several-hour-long demonstration drive without recharging – and actually the car can go 1,850-2,500 miles on 100 kg of aluminum.

Pictured: 2014 Nissan Leaf. We were told very little about the 2017 European Renault-Nissan mentioned in a video not widely disseminated, but will explain the concept behind Phinergy's vision.

Pictured: 2014 Nissan Leaf. We were told very little about the 2017 European Renault-Nissan mentioned in a video not widely disseminated, but will explain the concept behind Phinergy’s vision for its technology.

Compare that to the 750 kg battery pack assembly in a Tesla Model S. While this is a radical improvement over a 265-mile Tesla, as mentioned, Phinergy envisions the best use for its tech as a range extender – or actually an on-board recharging system.

In other words, its C1-based test mule operates a lot like an extended-range electric Chevy Volt, albeit without gas engine.

In a Volt, the engine maintains the battery charge and provides propulsion energy. In Phinergy’s case, the aluminum-air battery charges the lithium-ion battery and gives off heat that can be shed, or captured by a heat exchanger to warm the cabin as needed.

Thus, Phinergy’s prototype car is primarily powered by a rather ordinary lithium-ion battery and motor and its aluminum-air pack can recharge it on the go.

As its aluminum “cartridges” or plates slowly dissolve away over months to eventually nothing, the plan is they’ll be replaced by service personnel.

The exact composition of the aluminum is proprietary, and Alcoa’s alliance with Phinergy puts it in line to profit from the exclusive arrangement.

Aviv Tzidon.

Aviv Tzidon.

According to Alcoa Project Manager Hasso Wieland, the well-to-wheel analysis is actually better than carbon neutral because of valuable byproducts of the battery’s process of oxidizing aluminum.

As great as it sounds, this means Phinergy is not proposing its new technology replace lithium-ion, but rather, says Aviv Tzidon, it’s a complement.

Why? Tzidon, said Phinergy’s approach is “humble” enough to see the strengths and weaknesses of the aluminum-air battery. Its strength is vastly improved energy storage to make range limitations no longer a concern.

However, lithium-ion battery packs are useful to create powerful, quick cars that recharge from plugging into the grid or by regenerative braking.

“Our aluminum system cannot do that,” he conceded, but this is not a problem given how most people use their cars.

Citing statistics once used to make a case for the Chevy Volt, Tzidon said that a driver who travels 12,000 miles per year on average only drives 33 miles per day.

A 30-50 mile-range EV – more or less – would meet the daily need, but what about when the driver wants to go farther on the odd occasion? Here is where the driver could tap into the on-board aluminum in the supplemental aluminum-air battery system.

Unlike other batteries, aluminum can be stored for decades without degradation or needing maintenance charging.

Phinergy’s ideal scenario is the driver use the regular lithium-ion batteries day to day, and when needed expend some aluminum and water.

A typical usage scenario would see the cartridges expended maybe once a year, more or less. Costs – while still fuzzy at this stage – are projected to be cheaper than present solutions.

“Energy from aluminum is cheaper than gasoline and close to grid electricity price,” says the company in an executive summary. “Battery systems, pre industrial scale-up, are already cheaper than forecasted li-on in 2020.”

How It Works

In simplified terms, the cross-section of the battery (see graphics below) shows where a chemical reaction takes place to release electrons and thus generate electricity.

The 10mm-thick aluminum plate is the battery’s anode, and the cathode is a semi-permeable membrane using the same technology as Gore-Tex.

These plates can be added as needed, and each plate provides about enough energy for 20 miles. So, 50 plates – or aluminum-air battery cells – would offer 1,000 miles of extended-range driving.

Cross-section aluminum-air battery. Air freely flows in, while aqueous alkaline electrolyte is retained despite pressure and heat.

Cross-section of the aluminum-air battery. Air freely flows in, while aqueous alkaline electrolyte is retained despite pressure and heat.

In general terms, one kilogram of aluminum requires one kilogram of oxygen and one liter of water for the reaction to take place.

Sandwiched between the aluminum and air cathode is the water-based alkaline electrolyte containing potassium hydroxide.

Several technologies make this long-known lab concept commercially viable, and Phinergy and its PhD-laden staff has applied for or received over 22 patents.

The aluminum, as mentioned, is an alloy that oxidizes at a controlled rate. The fluid electrolyte in contact with it serves as a conductive layer, a solvent, and temperature evacuator as it extracts oxygen from the air cathode.

The air cathode uses a Teflon-based material that lets ambient air (thus oxygen) through from the environment, but it prevents the water-based electrode from seeping out.

On the cathode side, three elements laminated into a thin layer are used to make the cathode effective.

Immediately in contact with the electrolyte is a nanoporous silver structure patented by Phinergy, and based on work done at Bar Ilan University in Israel.

Laminated to the nanoporous layer is a current collector to gather electrons – electrical energy – liberated in the chemical reaction between the alkaline electrolyte and bare aluminum.

Laminated beyond that is the Gore-Tex like material sourced from a major manufacturer.

The air cathode uses Teflon (like Gore-Tex) to keep water in, and let air pass through as well. It also has a nanoporous silver inner layer, and current collector.

The air cathode uses Teflon (like Gore-Tex) to keep water in, and let air pass through as well. It also has a nanoporous silver inner layer, and current collector.

The chemical reaction involves oxidizing the bare aluminum which forms a layer of aluminum hydroxide – kind of like an aluminum rust.

The novelty of the system is it is all microprocessor controlled. The electrolyte bath can be flushed as needed by a pump, and in doing so, it wipes clean the oxidation exposing again a fresh surface of aluminum. Phinergy’s microcontroller and battery management system monitor temperature, chemical composition, and oxidation rate.

Here we see aluminum hydroxide (Al(OH)3 – oxidation – building on the aluminum's surface. OH- is also suspended in the electrolyte. Electricity is being produced as the aluminum undergoes this catalyzed reaction. Ambient air flows in freely, it is not pumped. It is like breathing.

Here we see aluminum hydroxide (Al(OH)3 – oxidation – building on the aluminum’s surface. OH- is also suspended in the electrolyte. Electricity is being produced as the aluminum undergoes this catalyzed reaction. Ambient air flows in freely, it is not pumped. It is like breathing.

The trick is to oxidize the aluminum enough that electricity is given off but no so badly that the entire reaction stops. So, the system flushes through the electrolyte solution as required at a rate that exposes aluminum just enough to repeat the oxidation, and not so aggressively as to prematurely erode the aluminum.

This incredible difficulty of this process – and contamination of the air cathode in previous experimental attempts by carbon dioxide – has been what relegated aluminum-air batteries to a lab experiment until now.

Here we see a fresh surface of aluminum exposed. The system's electrolyte bath flushes upwards taking away the oxidized surface and exposing new to repeat the process. This continues until the aluminum is gone, and the system is ready for a new cartridge.

Here we see a fresh surface of aluminum exposed. The system’s electrolyte bath flushes upwards taking away the oxidized surface and exposing new to repeat the process. This continues until the aluminum is gone, and the system is ready for a new cartridge.

The controlled dissolving away of the aluminum is what makes the system viable, not to mention the recyclability of the electrolyte.

Maintenance would involve car owners needing to periodically refill the battery with tap water that’s been run through a simple de-ionizing process. This would be as required – perhaps every month or two depending on usage – and the electrolyte would enable the chemical reaction.

The aluminum plates that erode away would be swapped with new ones during a “quick operation” at a local service station.

alcoa_phinergy_citreon_C1

Since releasing formerly confidential info last month, the company is gaining the attention of the public, as it has behind-the-scenes talks underway with European automakers.

President Obama asked Tzidon whether Phinergy was talking with American companies and Tzidon asked in turn with a smile whether the president had any connection with GM or Ford?

At this, Obama laughed, saying he thought he did, as Phinergy continues to work toward further proving its tech, and bringing it toward production.