Salt water battery, is it too good to be true? - Page 1
Forum section: electronics / general

author: cdwijs
author_rank: Regular Contributor
timestamp: February 27, 2016, 08:41:16 am
content: Hi All,I just saw a dutch commercial about a gay that has invented a new type of battery that he called the "zoutwaterbatterij". It's supposed to be clean, efficient, cheap, and heavy. I did some digging around, but I could not find a story that told me how it works. I have found a system that flows alternating streams of salt and freshwater true it:http://www.gizmag.com/rechargeable-battery-freshwater-seawater/18565/Here's the commercial:http://www.drten.nl/zeezout-batterij/?lang=enDoes anybody know what the real story is? How does this actually work? Is it viable?Kind regards,Cedric

author: T3sl4co1l
author_rank: Super Contributor
timestamp: February 27, 2016, 09:22:36 am
content: It's the inverse of desalination, electrolytically. Much like a temperature gradient in semiconductors produces a potential, an ionic gradient in solution produces a potential. The voltage is small, like 60mV for strong salt water, probably a lot less for sea water.You'd have to use quite a lot of them in series to get anything of use. Which doesn't help much if all the water is connected (each cell has to be insulated from the next if you want to connect them in series).I'd assume a freshwater outflow into the sea would generate fairly considerable power, but as with most such things, I would imagine the capital and maintenance required to operate it would compare quite poorly with, say, solar roadways...Tim

author: mij59
author_rank: Frequent Contributor
timestamp: February 27, 2016, 09:47:59 am
content: Sounds familiar take a look at thishttp://www.duurzaambedrijfsleven.nl/energie/2091/eerste-blauwe-energiecentrale-ter-wereld-op-de-afsluitdijk] http://www.duurzaambedrijfsleven.nl/energie/2091/eerste-blauwe-energiecentrale-ter-wereld-op-de-afsluitdijk

author: cdwijs
author_rank: Regular Contributor
timestamp: February 27, 2016, 11:17:08 am
content: Thank you. i knew this could be done if you have a stream of salt water and fresh water, but could this actually be turned into something that can be a sealed system, and then electrically charged and discharged?The guy in this ad claims he can put it into a box, charge and discharge with 90% efficiency, and with thousants of cycles. And that I think is too good to be true.http://aquabattery.nl/product-2/Kind regards,Cedric

author: VK3DRB
author_rank: Super Contributor
timestamp: February 27, 2016, 11:48:57 am
content: Quote from: cdwijs on February 27, 2016, 08:41:16 amSo what if he is gay.

author: zapta
author_rank: Super Contributor
timestamp: February 27, 2016, 12:51:59 pm
content: Quote from: VK3DRB on February 27, 2016, 11:48:57 amHe meant guy.

author: dannyf
author_rank: Super Contributor
timestamp: February 27, 2016, 12:57:04 pm
content: The principle behind it is no different from the principle behind any (chemical) battery, two electods plus a solvent.Lots of rust will be in the end, however.

author: Zero999
author_rank: Super Contributor
timestamp: February 27, 2016, 02:23:28 pm
content: Quote from: dannyf on February 27, 2016, 12:57:04 pmI believe it's totally different to a normal battery where the energy comes from the metal.The energy comes from the entropy gained when mixing salt water and fresh water.

author: amyk
author_rank: Super Contributor
timestamp: February 27, 2016, 05:33:46 pm
content: I vaguely remember mikeselectricstuff did a video on a battery like this...

author: jwm_
author_rank: Frequent Contributor
timestamp: February 27, 2016, 10:20:54 pm
content: Quote from: cdwijs on February 27, 2016, 11:17:08 amNo, the chemical binding energy liberated in conventional batteries is thousands of times greater than the mixing entropy used here. However, when you have an entire rivers flow to work with that doesn't matter so much

author: CatalinaWOW
author_rank: Super Contributor
timestamp: February 28, 2016, 03:54:16 am
content: In general, if you have large amounts of fresh water ready to mix with salt water there are better things to do with it than to generate energy.

author: Kjelt
author_rank: Super Contributor
timestamp: July 10, 2019, 10:13:41 am
content: Interestingly there is now a car advertised (not mass produced yet ofcourse) that can run 600km on a single charge of a salt water battery.Energy density supposedly bigger than LiIon.https://www.anonews.co/the-car-is-powered-by-salt-water-920-hp-top-speed-217-5-mph-373-miles-tank/It uses 200l tanks, so what needs to be done to recharge, replace the contents of the tank or just as with EVs charge and reverse the process, anyone have any idea ?

author: Echo88
author_rank: Frequent Contributor
timestamp: July 10, 2019, 10:29:48 am
content: Read the text Kjelt, just another fraud.

author: SiliconWizard
author_rank: Super Contributor
timestamp: July 10, 2019, 10:30:14 am
content: Nice, although wasting large amounts of fresh water may not be that great an idea. Where does the salt go though?

author: Kjelt
author_rank: Super Contributor
timestamp: July 10, 2019, 10:56:01 am
content: Quote from: Echo88 on July 10, 2019, 10:29:48 amIs itThis car was introduced in 2014, they state it is based on the nanoFlowcell and more other tests are performed.Another link then:https://emagazine.nanoflowcell.com/technology/1167-kilometre-test-drive-in-the-quantino/

author: Kjelt
author_rank: Super Contributor
timestamp: July 10, 2019, 10:59:41 am
content: I must say reading this, there are some alarmbells going offhttps://en.wikipedia.org/wiki/NanoFlowcellQuote

author: ogden
author_rank: Super Contributor
timestamp: July 10, 2019, 01:56:59 pm
content: Quote from: Zero999 on February 27, 2016, 02:23:28 pmThey talk about manganese sulfate dissolved in the freshwater(?), charging cycle, then swapping electrolyte with saltwater before discharge. Sounds like fancy battery which is refurbished with new electrolyte after *every* charging cycle:https://news.stanford.edu/2018/04/30/new-water-based-battery-offers-large-scale-energy-storage/I am puzzled about environmental impact: it really will be just river water + ocean water mix coming out of power plant?

author: m98
author_rank: Frequent Contributor
timestamp: July 11, 2019, 12:06:03 am
content: Quote from: SiliconWizard on July 10, 2019, 10:30:14 amEver heard of rivers? They usually tend to waste a lot of fresh water at their end...

author: ogden
author_rank: Super Contributor
timestamp: July 11, 2019, 12:30:22 am
content: Quote from: m98 on July 11, 2019, 12:06:03 amUsually water of rivers is not that "fresh water" as you like to think - contains loads of hard particles and dissolved calcium as well. Latter could be bad for said battery, thus need to be filtered away.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: July 11, 2019, 02:27:17 am
content: Not to mention biological growth on the electrodes, blocking useful area.By the way, there is a potential associated with dissolving salts, or diluting brines. It's on the order of 10mV, so doesn't count for much -- though on the scale of something like the Amazon, or Mississippi, the total power would be quite large.As with all harvesting schemes, the problem is concentrating enough power density to be economical. I'm guessing this mechanism is even worse than tidal or wave power.Tim