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Showing posts from September, 2026

Design for Entropy

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 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...

Its a feature not a Bug

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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 =...

If You Can't Win Em Join Em

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You know I have been wrong before, but never so pleasantly surprised. I spent the last two months trying to copy VRFB........ well, not exactly. I wanted to make an Iron-Chromium Redox Flow Battery that was just as good as VRFB. That means its power density, efficiencies and performance should match closely with VRFB.  But as I have stated many times earlier, Fe-Cr batteries have a fundamental flaw, they can't operate at room temperature, which is the fundamental reason why they have not been commercialized yet. In my previous post I wrote about a paper that I had recently found, it added salt to the battery in order to enable it to operate  at room temperature. Let's understand how  The paper used salt to increase the kinetics of chromium at room temperature. This happened because the lithium (or in my case sodium) chloride increased the concentration of chloride ions in the electrolyte solution. This causes excessive Cl⁻ ions in the electrolyte solution and increased c...

Why I don't rely on Bismuth to fix my Battery problems

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In my previous posts I have written a lot about the trident of problems with Iron-Chromium Redox Flow Battery, which are -  Hydrogen Evolution Reaction Slow Chromium Kinetics High operating temperature for the battery Now if you ask an AI (Gemini in my case), one of the first answers it will give would be Bismuth as master solution to all 3. It stops Hydrogen evolution and makes chromium react faster, hence solving all the problems of the battery. It does that by  acting as a catalyst. It forces the Cr3+ to accept electron quickly and react faster, and it has a more positive electrode potential (+0.32 V), as compared to chromium (-0.41 V), this stops water from splitting into hydrogen. Source But first you need to understand how Bismuth is incorporated in the battery - The Mechanisms- In order to use bismuth or any other catalyst in a flow battery, you have 2 choices - Electrodeposition-   Dissolve bismuth chloride in the liquid electrolyte and when you apply voltage...