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/science...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.