Grid Think

 Time for a short anecdote - An aunt of mine recently visited me. She had a beautiful EV, while we were seeing her off, her car just wouldn't start, she had to wait for 20 mins for an authorized executive to guide her into resetting the whole software because it had some issue. This made me think that if this was an old school gas car, she would not have needed a software to start her car, maybe she would have opened the hood or checked for coolant or engine oil, but it wouldn't freeze the whole car. A black box technology running completely on a fancy software sounds great for a pitch deck or a VC, but everyone asks a question before buying a product, if this stops working, what do I do ? For gas cars, the customers have a very established manual, not so much for EVs. Maybe that's why gas cars are still being bought, not because people love gas, but because they understand it, they can repair it, maintain it and it runs forever, even if its mileage degrades very badly.  Bu...

So I have decided to embrace the fact that Fe-Cr batteries operate at a fundamentally higher temperature. But now you'll say it makes no sense to heat the battery, the costs alone would bankrupt me.  Let's take a sample system of 1 MW / 10 MWh,  If we assume a conservative energy density of 10 Wh/L, Volume of electrolyte (L) = Total energy required  / Energy density  Volume =  10,000,000Wh / 10 Wh/L  =1,000,000 L  We would need 1 million liters of electrolyte and calculate the mass of water as by keeping density as 1 kg/L.  mass (kg) = volume  x density of water  m = 1,000,000 L x 1 kg/L = 1,000,000 kg  If I take the conservative specific heat of water as 4,187 J/kg·K, s tart with an ambient temperature of 20°C and keep my ΔT as 20°C,  Q (heat energy) = m x c x ΔT   m = mass of water = 1,000,000 kg , c = specific heat capacity of water = 4,187 J/(kg·K)  ΔT = temperature change = 40°C - 20°C = 20 K   Q =...

Nafion and FumaSep, both membranes are pretty expensive for me, and if they are expensive for me I don't think they would be any cheaper for any Flow Battery manufacturer. Because its basic economics, if your raw materials are expensive your end product can't be cheap. So most flow battery manufacturers don't really bother with inventing new membranes, they use a material called DARAMIC separator, it is made up of Polypropylene (PP) or Polyethylene (PE) sheets with micro level holes in them, nothing new, its a 50 year old separator material which is used to separate positive and negative side. Daramic is used in literally all batteries, you name it, Lithium Ion, Sodium Ion, Lead Acid , All- Iron Hybrid Batteries and yes even Vanadium Redox Flow Batteries.  Source There has been substantial amount of research on cheap membranes, but most of them last only a few weeks and the membranes that actually last.... well they are Nafion and Fumasep. But Daramic works in a fundamental...

Full disclosure, I haven't made the best flow battery cell stack. If you have been reading my blog, I haven't even designed it myself. I have been replicating the cell stack from a Youtuber named CAYREX , every battery enthusiast should check his channel out.  But I have been lazy, instead of reading books, research papers and patents on stack design and designing my own cell stack, I just took the STL files from Cayrex's Patreon page and got them 3d printed, but after months of battery testing and troubleshooting with someone else's stack. I'll be breaking down the difference between Industrial grade stacks and a DIY stack. The images I will show will be mainly of CAYREX's stack, but this is applicable for all DIY and lab scale stacks Problem 1- Screws This is a photo of flow battery cell stack from the internet - Image 1-   Source  This is a good stack but, its problem is that the screws are inside the stack housing. These will corrode very badly the moment th...

I'll be honest, I have a tendency to nerd out about stuff and not really take action on it, so every once in a while I push myself to BUILD the battery, because AI can "brainstorm" all day, but can't build a battery So after reading some research papers on Iron-Chromium battery, I decided to build one, but this time I wanted to get some visual result, something a 5 year old kid can recognize, I had to light up an LED, but a single of Iron-Chromium battery has voltage of 1 Volt. That doesn't do anything. So I had to build another cell stack to get 2 V, this easily lights up a Red LED  . Making the Stack So ordered the 3D printed parts from online shop, I already had Iron chloride from my all iron build, I ordered Chromium Chloride (very cheap, very easily available, order online). If you want to know how to build it you can see my previous post . Since I already had a leak proof cell, making another one was not really a problem I just used some RO fittings and join...

If Iron Chromium Redox Flow Battery is so cheap, abundant, simple and elegant...... Why isn't it everywhere ? Why was Vanadium even needed in the first place ? Why hasn't anyone commercialized it yet ? Well..... because it has its own set of problems. Physics and economics aren't really best friends, the more money you spend the better battery you get, the cheaper you get, your efficiency takes a plunge. And trust me you DON'T want a shitty battery. The way I see it for flow batteries- Vanadium is expensive but simple and has good efficiency Iron Chromium is cheaper than Vanadium, but more expensive than Iron, so it has Hydrogen problem of Iron but manufacturing simplicity and efficiency of Vanadium. Iron is dirt cheap, but I would personally not buy it, I don't want a battery that wastes half its energy, because you have to pay for every unit you put in. This is my take on viable redox flow battery chemistries. Don't get me wrong, there are many newer more amaz...

Energy Storage Systems Technology (ESS Tech Inc), the star child of flow battery industry, one of the few flow battery companies to ever go public, a technology with raw materials so cheap that you could buy them for pennies. This is the company I looked up to for 3 months, the ingenuity in their technology. Of course, a battery of iron is the way to go, its an economic masterstroke. Source But I was missing something, if it was so easy to build, why wasn't everyone doing this. All Iron redox flow battery should be easy, if any Indian or Chinese manufacturer knew about this technology, they would reverse engineer it in 1 year.  But I was wrong, not only because they hold a LOT of patents (103 granted, 214 filed), but also because physics doesn't give free lunch. So here are the roadblocks I ran headfirst into, while trying to copy ESS. 1. The Stack  As I mentioned in the last post , charging an Iron Redox Flow Battery is like electroplating, it requires slow charging, which me...

Iron and Vanadium based electrolytes can both be used Redox flow batteries, both use tanks, pumps and cell stack, but they don't operate the same way. While Vanadium Redox Flow Batteries stay completely liquid in their operation, All Iron Hybrid Batteries don't. And the name itself tells you why-  Hybrid. When you charge an All Iron battery, its positive side converts Fe2+ to Fe3+, and stays liquid, but the negative side converts Fe2+ to Fe0, or solid iron.  So why is solid iron a problem ? Well because - 1.The electrode that we have used i.e. graphitic carbon felt, is a conductive sponge, it is designed to absorb liquid and transfer electrical energy to it, it instantly clogs when solid iron is deposited on it. 2. Solid iron is not soft, nor does it grow evenly, it grows in the shape of needles or dendrites (if you have ever seen iron filings, that's solid iron). Iron dendrites 3. Deposition of solid iron is also called electroplating, and current density in electroplating...

 I'll be honest, I didn't dream of Iron Chromium Redox flow battery in my dreams, nor did I have any secret information from NASA. I did what any other 22 year old would, ask Gemini about it. If you ask Gemini or ChatGPT about VRFBs, there are high chances that it will suggest alternate chemistries also. Now that can be a good thing or a bad thing. If you know a little bit electrochemistry, it would spit out a very obvious answer. If you don't, you'll go down the same rabbit hole I did. AI doesn't know your intentions. So it acts as the most efficient information summarizer, and that's great, if you just want information, not if you want action. So one of the first alternatives to VRFBs Gemini suggested was Iron - Chromium, and it made a lot of sense because Iron and Chromium are commodity metals, Iron is literally the most mined metal on earth and chromium comes third [ source ]. Their commodity prices are - Iron - $110 per ton   (at the time of writing) Chromi...

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 posit...

We all know what a battery is, that same thing in almost every portable electronic device in your room has. Most batteries we use in our day to day are static batteries, i.e. once they are manufactured, their chemical composition doesn't really change. Now the chemicals used in a battery dictate everything about it, like its - 1. Cyclability  2. Efficiency 3. Safety 4. Supply chain constraints. Let me explain in a little more detail using examples - The AA and AAA batteries (chemical composition is Zinc and Manganese) normally used in T.V remotes are not rechargeable, they are single use. Once the energy inside them is used them, they are pretty much dead. They are mildly toxic, but safe to use, efficiency doesn't come into picture as they can't be recharged, energy density is ( 50-150 Wh/kg ) The Lithium Ion batteries in your phones and EVs are rechargeable (Duh !). Its of many types, i am aware of only two- a) NMC (Nickel Manganese Cobalt along with Lithium)  b) LFP (Lith...