Vanadium in 2019, page-183

I am justcoming back to this previous post of mine because I have seen this 1 MW equatesto 10 tonnes of V205 been branded about for some time now. Whilst, I thinkthere is some confusion to what is actually implied by it, I don't actuallythink it is 10 tonnes V205 to 1 MWh, but I an sure to be wrong. The continuoususe of 1 MW of stored power is what reduced the battery cost on a long life perkWh basis. Refer: Post #: 37244924

Maybe, I have missed the mark, but on my calcs the theoretical efficiency ofvanadium batteries is around 3kg to 4kg per kWh, but due to issue around energydensity the reality is it is now around the 5.5kg to 6 kg mark per kWh. Appears to be some improvements in energy density in particular and if thatcontinues that will bode well for reducing the implicit capex cost per MW ofinstalled capacity - refer embedded post above - which bodes well for the 2ndstage of vanadium's growth in the 2020s (been battery market share in the largescale energy storage market). But as I said, the main game currently isentering the steel market.

As I understandit the theoretical figure is based on the following:

1. The atomic weight of vanadium is 50.9415 grams/mole - https://www.convertunits.com/elements/

2. Theatomic weight of oxygen atom is 15.9994

https://science.jrank.org/pages/4409/Molecular-Weight.html

3. Thismakes the atomic weight of V205 equal to (50.9415 * 2 = 101.883) +(15.994 *5 =79.997)= 181.88 g/mol

https://www.convertunits.com/molarmass/Vanadium(V)+Oxide

4. Theatomic weight of the battery solution appears to be 240.46, but need to do alittle more research myself to work through the calculation - https://www.researchgate.net/post/How_do_I_make_the_vanadium_solution

.

5. Thereare 96485 coulombs per mole of electrons (or what some may refer to as theFaraday unit of charge)

https://en.wikipedia.org/wiki/Faraday_constant

6. Oneampere is one coulomb per second.

7. OneAmp Hour (Ah) therefore equals 3600 coulomb (60*60)

8. Theoreticalv205 content becomes 96485/3600 = 26.80 AH, then divide by 181.88 grams/moleand you get 1 gram V205 = 0.1473 Ah (or 6.78 grams vanadium is 1 Ah. Appears for electrolyte it is 26.80/240.46 = 0.1115 Ah.

9. Ifyour vanadium battery cell has its voltage at 2.2V - https://en.wikipedia.org/wiki/Flow_battery - multiply this by 0.1115 Ah and you get 0.2453 Watt Hours. (At 0.1473 Ah is 0.324 Wh). For avoidance of doubt not sure which figure to use to calculate vanadium underlying need in the battery so using both to get the range, as still learning so using both at this point in time.

10. 1000 Watt Hours = 1 kWh so divide 1000/0.324= 3,086 g of V205 per kWh. (or 3.1 kg per KwH). Theoretical efficiency implies you need 3.1 tonnes V205 for 1 MWh. At 0.2453 WH translates to 4.1 tonnes for 1 MWh.

11. From the literature it would appear thatthe batteries don’t operate at theoretical efficiency (and lithium batteriesalso don’t operate at theoretical efficiency btw – infact for lithium, lithiumcontent in batteries in passenger vehicles, for example and yes I know thiswould be different to battery types in the stationary energy market, is overtwo times theoretical efficiency which I posted about in a relevant lithiumthread in the past but energy density is higher – refer calc in this post atthe bottom Post #: 37817451which I posted in the AVZ thread as I hold there too) so common estimates arearound 5.5 kg vanadium for each kWh I have read

https://investorintel.com/sectors/technology-metals/technology-metals-intel/vanadium-is-still-a-hot-sector-right-now-but-can-it-be-maintained/

12. Bushveld itself assumes 5.5kg vanadium perkWh, but believes improvements in energy density might see that come down to 3.5kg vanadium per kWh, which appears to be more in line with theoreticalefficiency – page 41 of this

http://www.bushveldminerals.com/wp-content/uploads/2018/11/Energy-Storage-Vanadium-Redox-Flow-Batteries-101.pdf

13. In the past estimates ranged at around 6to 8 kg vanadium per kWh, i.e. 6 tonnes to 8 tonnes vanadium per MWh, but looks like improvements in battery design might be reducing that, which bodes well for reducing costs of vanadium batteries.

http://www.bestpem.com/En/NewsView.asp?ID=18

14. Improvements in battery design might beable to improve energy density and as a result move the vanadium requirements inthe batteries themselves closer to theoretical efficiency and that bodes wellfor takeup as well (as costs reduce as the vanadium need reduces in the batteryitself).

https://www.researchgate.net/publication/229579458_A_Stable_Vanadium_Redox-Flow_Battery_with_High_Energy_Density_for_Large-Scale_Energy_Storage

https://solarbay.com.au/vanadium-batteries-commercial-use-pros-cons/

https://spectrum.ieee.org/green-tech/fuel-cells/its-big-and-longlived-and-it-wont-catch-fire-the-vanadium-redoxflow-battery

15. Finally, where I see potential for vanadium batteries is in the large scale stationary storage market given the number of cycles per day vanadium batteries can run, compared to lithium batteries, and the fact they don’t deteriorate. Small scale batteries, because lithium has a higher energy density than vanadium, will be the lithium’s space such as in EV batteries or small scale home units storage units in the stationary market. It is all about cycles, capex costs, battery replacement and energy density when doing comparisons in a NPV context.

16. Nonetheless, the real key for AVLremains entering the steel market as that is where the current demand is in anyevent. Anyway, IMO more work require din the battery market to improve energy density, but vanadium’s competitive sphere is the steel market (and if there is a move to batteries in the large scale stationary energy storage energy market).

17. My brain cells hurt, so I’ll leave it upto the chemists on this forum to explain the differences etc etc. Crucify the above if it is wrong, as seeking to learn the battery space here as well.

AllIMO