Saltwater powered EV?

Primary cells are easier to design but have no home recharging capability. As a general rule of thumb, if it sounds too good to be true, it often is.

Bob Wilson

 

If you are willing to kiss say $1,000,000 or more good bye, this company may be willing to make you an investor and share their secret. I will however do it for free, such a product is not commercially viable. Reported cost is over $1 million per car in 2014, but we have not seen a car since that announcement (https://www.dailymail.co.uk/sciencetech/article-2739768/The-sports-car-runs-SALTWATER-Vehicle-goes-0-60mph-2-8-seconds-just-approved-EU-roads.html). They want still more time

What they are claiming to have produced is a flow battery (https://en.wikipedia.org/wiki/Flow_battery)

A flow battery, or redox flow battery (after reduction–oxidation), is a type of electrochemical cell where chemical energy is provided by two chemical components dissolved in liquids contained within the system and separated by a membrane.[2][3] Ion exchange (accompanied by flow of electric current) occurs through the membrane while both liquids circulate in their own respective space. Cell voltage is chemically determined by the Nernst equation and ranges, in practical applications, from 1.0 to 2.2 volts.

For 373 mile range you need 400 liters of saltwater, which is over 900 pounds of saltwater. So every re-charge you have to pump in 900 pounds plus. The membranes are very costly and it does not tell you how often you have to change the membrane. Further, it is not very stable and if you have to add catalysts, it will increase cost further.

Also think of the cost of transporting the saltwater from the sea. It is corrosive and would need special vehicles. Alternatively, you have to get the salt from the sea, transport it, and then mix it at the fueling station. You may reduce emissions, but you now have the problem of getting the water in those quantities. We already have a water shortage in many places. May work experimentally or in small fleets, cannot really be a mass transportation solution.

 

Might see better use in stationary applications, like grid storage?

_H*

 

They claim that their company is not a car company, but a tech company.

I think automobile is not the best application of their ideas. They introduced a car back in 2009 but nothing came of it. I think this time is no different.

 

That is a thought, that you could place it on the sea coast and generate electricity which could be used or stored. It will become a cost benefit issue i.e. what would be the cost of generating a KWH of electricity. Unlikely it will come close to Solar or conventional sources (diesel, natural gas, coal, etc.). However, I do not know the costs so I am just guessing and my guess could be very wrong. If it is close, then the question is "Is it scalable, can you generate large amounts with this?"


However there is a lot of skepticism that this company has a real product (https://en.wikipedia.org/wiki/NanoFlowcell)

On the other hand, there is a lot of research going on to use Salt/Saltwater, so may be one day this technology (flow cells) or another technology will become viable.

There are other approaches researchers are taking to see if salt can be used to power cars. One of them is Sodium-Ion battery as a replacement for Lithium ion.

A US company started by an Carnegie Mellon Professor, Aquion Energy received over $190 million in funding to develop a Saltwater battery (also called Sodium Ion). They went bankrupt in 2017 and were sold for less than $10 million to a mysterious Chinese company. It is rumored that the Chinese Government is trying to develop this technology commercially (https://en.wikipedia.org/wiki/Salt_water_battery)

Another approach being tried is salt water fuel cell.

Here is a nice demo of a toy car that uses a fuel cell and salt water, but you have to replace the magnesium (which is what gets used up) every 7 hours and magnesium is not cheap. (https://www.real-world-physics-problems.com/salt-water-fuel-cell-car.html)

 

Right. First of all, getting energy from salt-water isn't going to be cost-effective except -- perhaps -- for a stationary installation at the seashore. Secondly, despite the claims from this company that it can power a car, I rather doubt the energy density of such a system would be high enough to be practical to power a street-legal passenger car.

Furthermore, getting energy from salt-water isn't exactly a new concept, and I am rather doubtful this company has anything new to offer, despite their pie-in-the-sky claims.

"Extraordinary claims require extraordinary evidence." -- Carl Sagan

​

 

This company has been making these claims for years and have an actual prototype that people have driven under close scrutiny.

I believe they can deliver on their "pie-in-sky" claim if you are willing to pay their stratospheric (pun intended) price. Like say a million bucks + per pop to buy in addition to $$$$$ for annual operations.

 

Source: https://en.wikipedia.org/wiki/Salt_water_battery

. . . the battery's specific energy was approximately 100 watt-hour/kg and it displayed consistent performance over 1,000 charge/discharge cycles.[4] The device operated with nearly 100% coulombic efficiency at both low (0.15 C) and high (4.5 C) discharge and charge rates.[4]​

Source_2: https://www.dnkpower.com/advantages-disadvantages-21700-battery/

According to Tesla, Power density of 21700 goes up to 300 Wh/kg, which is about 20% more than current 8650 batteries that rates at 250Wh/kg. so apparently 21700 battery power density is better than 18650 batteries, as it can increase by 20% or more Compared with 18650.​

Bob Wilson

 

Bob, in all fairness, if you continue down that article, there is another quote

In May 2019, researchers published an article where the voltage increased to 4.2 volts.[7] High specific capacity from a densely packed stage-I graphite intercalation compound of C3.5[Br0.5Cl0.5] can form reversibly in water-in-bisalt electrolyte.[7] By coupling this cathode with a passivated graphite anode, a cell can achieve an energy density of 460 watt-hours per kilogram of total composite electrode and about 100 per cent coulombic efficiency.[8]

Again, this experimental and is just an article in Nature, and so is still far away from commercialization. If true, this will be higher that of the 21700. But, it still needs to be proven and for now 21700 is still the king.

 

Sorry, I quoted the first performance metric which is one reasons why I prefer to cite my source(s). Regardless, the low, initial results explains why an early business attempt went out of business. I really got the impression they were after replacing lead-acid cells in facility UPS.

Bob Wilson