A while ago my friend Joop Soesan had the opportunity to interview Aviv Tzidal from Phinergy. Phinergy recently announced their battery technology based on aluminium and promises ranges of 1000km with a relatively cheap solution.
Rusting of Aluminium
The battery which has been developped by Phinergy is a so-called Metal-Air battery. These types of batteries use a rusting process to free up electrons which can be used to power motors. In chemistry, a clean metal has a higher energetic value than their rusted counterpart. As a normal process, rusting can take many years to complete. For aluminium rusting takes a lot longer even, as the rust on the aluminium provides a sort of coating, making it immuun to further rusting.
A(n Alkalyne) Solution
Phinergy uses an alkalyne solution (water) to clean the aluminium plates in the battery from rust so that the rusting process can continue. Electricity is being generated when the water clears off the rust. When the aluminium plates are not in contact with the water, the rusting stops and there is no electricity coming from the battery. The battery is in a dry-state and can stay like that forever. Over time when it is used, the aluminium gets consumed and the water solution gets saturated with aluminium-rust.
Primary / Secondary
The aluminium in the battery gets consumed in the process, that is why it is a better bet to have the aluminium battery act as the secondary energy source in your car. The primary battery will be for example a lithium based one that is sized for your normal daily usage. In the West, average daily usage of a car is 39km a day. In this way, the size of the lithium battery can be decreased from the 'standard' 150km to be suitable for just 50km. This is enough for the average trip you would make, decrease the lithium battery to a third of its original size and result in a lighter/cheaper solution. The aluminium battery gets added and gets used only when you have to drive a longer trip.
The lithium battery provides the power for your basic mobility and if you need more, you can 'borrow' the extra energy from the aluminium battery. It is similar to the credit line you have with a bank. The aluminium battery is a credit line for energy which you can draw from when you drive a longer trip.
At some point, the water can not hold more rust (aluminium). The water that is fully saturated with rust can be replaced at a gas station for free; you will get free clean water. For a gas station, this dirty water is worth €3-4, because they can sell back the rust (in powder form) to an aluminium producer like Alcoa.
The rusty water will be separated to water and aluminium hydroxide (powder) at each station. The powder will be transported back to Alcoa and Alcoa pays the gas station for this powder.
Aluminium cheaper than fuel?
A comparison is made between conventional gas and consuming aluminium in the battery. The details are shown below:
For Aluminium it is assumed:
- €2-3 per kg aluminium
- 75 kg aluminium battery
- 600 kWh battery
- 4000 km range
- 4000 km range
- 1:20 Fuel Consumption
- 200 liters needed
- €2 per liter fuel
It appears the principles behind this technology are not exactly new, however, recent developments in nano technology have improved on it, making this a viable solution. Earlier attempts at a metal-air battery have failed due to CO2 poisoning and not being able to last for long periods on end.
Availability of Technology
Currently Phinergy works closely together with Renault on developping a car that uses the aluminium battery. The first car will be on the street before 2017 and by the end of this year, other OEMs can also join in on developping this technology with Phinergy and create a vehicle that utilizes this technology.
I would like to thank Joop Soesan for his time recording this interview and Aviv Tzidal for taking time to have this interview. For those interested in the full interview, please listen to the audio file below: