Search flow batteries anywhere on the internet, you'll find Vanadium's monopoly, ask any AI model about flow batteries and they'll assume vanadium and give you all the information. That's because Vanadium Redox Flow Batteries (or VRFBs in short) are already being commercialized, or at least they're trying their best.
I'll try to explain why, but before i move further, i forgot to explain the redox part in the last 2 posts.
All Batteries are Redox Batteries-
Batteries have 3 basic parts, positive side (cathode), negative side (anode) and a membrane or separator. So, when you connect a charger to your phone, the charger takes electrons from positive and gives it to the negative side, but if the positive and negative mix together they will neutralize each other, so they need to be separated by separator (or membrane). The word "redox" is made of two words :
- Reduction- gaining of electrons (by the negative side)
- Oxidation - loss of electrons (by the positive side)
Now that we know the basics of battery. Buck up we are going into the depths of electrochemistry now-
Vanadium's Magic
Vanadium is one of those few elements that can have more than 2 oxidation states, V2+, V3+, V4+ and V5+. So on the positive side (cathode) we have V4+ and V5+ in solution and on the negative side (anode) we have V2+ and V3+ in solution. The solution here is water and sulfuric acid, lots and lots of it, because we get these oxidation states in acidic environment only.
The beauty is on both sides the battery has only Vanadium, so starting liquid for both sides is same.
Let's Try to Build One
If you want to make your own VRFB electrolyte, its very easy, just mix -
- 25 g of Vanadyl Sulfate
- 100ml water
- 16 ml of concentrated sulfuric acid
You'll get a perfect working mixture that can store energy, you would then just need a decent membrane and two graphite rods (take pencils) and a charger.
Let's build it, first step, source the materials -
- Sulfuric acid - available in every high school chemistry laboratory in the world, so free
- Water- Free (Duh !!)
- Vanadyl Sulfate - Rs 3,500 ($36) per kg, and this is IndiaMart price, which is artificially low to dupe innocent customers. So check lab chemical suppliers, Ottokemi website shows Rs 3600 ($37) for 25 grams.
Clearly we are looking at retail prices, so let's look at the
commodity price of vanadium, as of writing this post, the price of
unprocessed, raw vanadium was $4.79 /lb (or $10 /kg), almost Rs 1000/ kg. This has to be further converted into our desired salt Vanadyl Sulfate, since I clearly don't own a chemical processing plant, We'll have to buy the expensive one. So our fun science project to just turned into a cash crunch, to put that into perspective my monthly pocket money at the time i started was Rs 5000 ($50).
The Energy Density
Here's something i didn't mention in the last post, flow batteries have low energy density, much lower than static batteries, to put that into perspective, to power your laptop for 2 hours, right now you use a flat lithium battery, if you were to buy the1kg of vanadium and use it for laptop, you would need 2 bottles of 2 liters ( and cell stack, and pump, but lets neglect that for simplicity), thats a very big difference, how much you may ask ?
- Lithium Ion: 250-700 Wh/L
- AAA battery: 200-400 Wh/L
- Vanadium Battery: 25 Wh/L
- Iron- Chromium Battery : 15Wh/L
That's a 100x difference !!!. Just to clarify Wh/L means, you can power a 1W LED light, for 1 hour by using 1 Liter of battery volume.
The Economics-
So if i need to power my house (5kW) for 5 hours (25kWh), assuming 25Wh/L of energy density for VRFB, I need 1000L of electrolyte volume, and 250 kgs of Vanadyl Sulfate (scaling up directly from our lab), so -
250 kgs x 3500 Rs/kg = Rs 875,000 ($ 8800)
Just for electrolyte, now add tanks, cell, pumps, pipes, inverters, this will very easily bump the cost up to 10- 12 lakhs ($11,000 to $13000). For perspective, that is Rs 35,000 ($350) per kWh (or for the purposes of your electricity bill, per unit of electricity). Oh, by the way, my per unit cost with VRFB is almost my whole year's electricity bill. That's expensive, very expensive, very very expensive. Even if i assume cheap labor, manufacturing, and raw materials for cell stack, pipes and tanks. VRFBs are currently more expensive than lithium ion batteries, which by the way would cost 4 lakhs only
But its proven, it doesn't catch fire, doesn't degrade like lithium ion batteries and works for 25+ years. That is why giants like
Sumitomo Electric have invested in them, and there are also startups like
Delectrik Systems,
VFlowTech,
Arkle Energy manufacturing these batteries in India.
The Broke Code -
But I am not a giant, I am a student, I don't have 25 years of industry connections or millions of dollars to spend on Vanadium electrolyte, nor do I have a mine of Vanadium attached to my backyard. I will definitely make a post on supply chain, economics. But I can safely say my battery costs less, significantly less , I'll break down the numbers in a dedicated post. It has its own set of issues, but more on that later 😁.
Till then stay tuned.
None of this is AI generated, so feel free to fact check me and looking forward to your views and help.
Mayank Jately
If you want to follow this blog
Comments
Post a Comment