Smorster

Electricity Does Not "Split" H₂O. And That's VERY Useful.

NightHawkInLight · 41m 20s · Watch on YouTube · 19 sources

Decision Card

Effort: Weekend-per-project territory — the DIY membrane (grind water-softener resin, mix 50/50 with PVC cement, paint on fiberglass, ~half a day plus drying) is the gateway build; the flow battery and hydrogen cell each add another weekend on top of it.

Honest take: The video calls Robert’s membrane recipe “public domain,” but the actual release is a CCL1.0 license with a defensive patent filing, and the “hundreds to thousands of dollars per square foot” framing for commercial membranes reflects small-quantity lab pricing — bulk Nafion runs closer to $40–190/ft², so the DIY cost advantage is real but less extreme than stated. The bucket battery also delivers only ~0.3 W (1.2 V at 0.25 A); “multiple kilowatt-hours of capacity” via external tanks is honest about energy but glosses over how little power that cell can actually push.

Concrete next steps:

  • DIY ion-exchange membranes — adopt. Start from the canonical recipe repo (github.com/Rowow1/Open-sourced-off-the-shelf-ion-exchange-membrane): cation resin + spice grinder + PVC cement, ~$1/membrane, half a day. Cheapest entry point and prerequisite for everything else.
  • Iron sulfate flow battery — try. Bucket, one cation membrane, 200 g/L iron sulfate + 10 g/L citric acid, carbon electrodes; one weekend. Mild chemistry, good first cell. Skip if you have no use for a low-power demonstration battery — commercial LiFePO4 beats it on every practical metric except chemistry education.
  • Homemade conductive carbon felt — try. Welding-blanket felt, torch burn-off, then white-hot in an outdoor microwave kiln (~$40 in materials, one afternoon). Skip if you can tolerate graphite foil’s lower surface area — it’s cut-with-scissors easy and skips the fume/fiber hazards.
  • Electro-mining / HCl-from-salt cell — skip unless you have acid-handling experience and a disposal plan; dissolving real ore almost guarantees toxic metals (lead, chromium, cadmium) in your waste liquid, per the video’s own warning.
  • Pressurized hydrogen generator — skip unless you already understand oxyhydrogen hazards; a stoichiometric H₂/O₂ mix ignites at ~0.007 mJ (Wikipedia: Oxyhydrogen), and self-pressurizing sealed chambers raise the stakes further.

TL;DR

Water electrolysis is not one clean H₂O-splitting reaction but two separate electrode reactions — acid forms at the anode and base at the cathode — and exploiting that separation with ~$1 DIY ion-exchange membranes (ground water-softener resin + PVC cement) unlocks hardware-store versions of serious electrochemistry. The video demonstrates four builds on that foundation: making hydrochloric acid and lye from table salt, closed-loop refining of magnetite ore into pure plated iron, an iron sulfate flow battery with tank-scalable capacity, and a hydrogen generator whose output is self-pressurizing.

Key Points

  • The middle-school “electricity splits H₂O in half” model fails to explain why the gases appear at separate electrodes; a pH indicator shows acid (red) forming at the anode and base (blue) at the cathode — two distinct simultaneous reactions 02:59
  • At the cathode, water gains an electron and releases H₂ plus alkaline OH⁻; at the anode, electrons are ripped away, releasing O₂ and acidic hydronium (H₃O⁺) — mixed together they neutralize back to green 03:34
  • Ion-exchange membranes conduct no electricity but pass only ions of the correct charge, letting the acid and base chemistry at each electrode accumulate instead of canceling 07:30
  • A small sodium sulfate compartment around the anode keeps chloride ions away from it — otherwise electrolyzing salt water makes chlorine gas instead of acid 09:44
  • The cell converts table salt + water into hydrochloric acid on one side and sodium hydroxide (lye) on the other; any dissolved salt yields its corresponding acid (sulfates → sulfuric, nitrates → nitric) 10:37
  • Iron refining is closed-loop: generated HCl dissolves magnetite into iron chloride, metallic iron plates onto the cathode, and the freed chloride crosses back through the membrane to regenerate more acid — only electricity and fresh ore are consumed 13:16
  • DIY membranes: grind water-softener resin beads in a high-speed spice grinder, mix 50/50 by volume with PVC cement, spread on silicone sheet or paint onto fiberglass; anion resin needs ~2 tsp talc per half cup to grind and 3 ml PVC primer per teaspoon to mix 19:02
  • Homemade conductive carbon felt: torch-burn welding-blanket felt outdoors, then cook it white-hot 8–10 minutes in a microwave kiln made from $15 ceramic fiber blanket, and quench in water 26:36
  • The iron sulfate + citric acid bucket battery holds everything in solution (no plating), so it’s a true flow battery — capacity scales with external tank volume while the cell stays the same size 33:02
  • The membrane-sealed hydrogen cell pressurizes its own output — it fills a balloon straight from the outlet, and the design can theoretically reach ~3,000 PSI with proper structural support 38:35

Notable Quotes

“In case the wonder of what we just did was lost on you, we just made hydrochloric acid from table salt and water.” 11:50

“On top of everything else, this simple, incredible metal refining setup is also a battery.” 14:35

“So, however much pressure that membrane can take before bursting is the pressure that can be provided at the gas outlet.” 38:45

Verified Claims

  1. Electrolysis creates locally acidic conditions at the anode and alkaline conditions at the cathode. 02:59 — Wikipedia: Electrolysis of water, PMC: Water electrolysis review. Verdict: Confirmed — H₃O⁺ accumulates at the anode, OH⁻ at the cathode; they recombine to water when mixed.

  2. Commercial ion-exchange membranes cost “hundreds, even thousands of dollars per square foot.” 16:12 — Thunder Said Energy: Nafion costs, Membranes International price list. Verdict: Disputed in magnitude — estimates around $400–2,000/m² put typical Nafion at roughly $40–190/ft²; only small-quantity lab pricing approaches the video’s figures, though the ~100–1000× DIY cost advantage stands.

  3. Robert (RO AL channel) released a simplified membrane recipe from water-softener resin and PVC cement for everyone to use. 18:15 — Flow Battery Research Collective forum thread, GitHub: Rowow1 open-sourced membrane. Verdict: Confirmed with a caveat — the release is CCL1.0-licensed with a defensive patent filing rather than strict public domain; reported cost is under $1 per square yard with ~100–200 mA/cm² current density.

  4. Electrolyzing salt water produces chlorine gas at the anode instead of oxygen/acid. 09:31 — Wikipedia: Chloralkali process, Lenntech: membrane cell chlor-alkali. Verdict: Confirmed — chloride oxidation at the anode is the basis of industrial chlor-alkali production, which uses ion-exchange membranes exactly as the video describes (2NaCl + 2H₂O → Cl₂ + H₂ + 2NaOH).

  5. Citric acid stabilizes the iron sulfate electrolyte and prevents iron from precipitating or plating out. 29:32 — ScienceDirect: low-cost sulfate-based all-iron redox flow battery, Nature Communications: complexing agents in iron flow batteries. Verdict: Confirmed — citrate is a documented ligand in iron flow battery research; Fe–citrate coordination suppresses Fe(OH)₃ precipitation and hydrogen evolution.

  6. Flow battery capacity is set by tank size, not cell size, because all charge-carrying species stay dissolved. 33:02 — Wikipedia: Iron redox flow battery, SGL Carbon: redox flow batteries. Verdict: Confirmed — decoupling of power (stack) from energy (tank volume) is the defining property of redox flow batteries.

  7. A membrane electrolyzer can deliver hydrogen at up to ~3,000 PSI with no compressor. 39:11 — Wikipedia: High-pressure electrolysis, ScienceDirect: PEM electrolyser at 180 bar differential pressure. Verdict: Confirmed as a ceiling for the technology class — commercial high-pressure PEM electrolyzers output 120–200 bar (~1,740–2,900 PSI) electrochemically, and research units exceed that; a hot-glued DIY cylinder achieves only a few PSI, as the video admits.

  8. Even a tiny bubble of mixed stoichiometric hydrogen and oxygen is dangerously explosive. 35:09 — Wikipedia: Oxyhydrogen. Verdict: Confirmed — minimum spark ignition energy is ~0.007 mJ, far below a static discharge, which is why gas separation is the central design problem in electrolyzers.

  9. Carbon felt is the gold-standard electrode for flow batteries due to enormous surface area. 25:28 — SGL Carbon: SIGRACELL battery felts, ScienceDirect: carbon felt electrodes for redox flow batteries. Verdict: Confirmed — carbon/graphite felt is the first-choice commercial electrode material for vanadium and iron flow batteries.

Tools, Papers & Standards Mentioned

Follow-up Questions

  1. What is the actual coulombic and energy efficiency of the resin/PVC membrane versus Nafion in an iron flow battery — and how fast does iron crossover through the DIY membrane self-discharge the cell over days?
  2. Can the closed-loop electro-mining cell selectively separate co-dissolved metals (e.g., iron vs. copper vs. lead from real ore or mine tailings) by controlling plating voltage, and what does the waste stream actually contain after extraction?
  3. What structural design (fiberglass-wrapped cylinder, sintered support, commercial pipe fittings) would let a hot-glue-free version of the membrane hydrogen cell safely hold tens of PSI, and where is the practical failure pressure of the PVC/resin composite itself?

Sources