# China Fixed Zinc Bromine Batteries.

## Метаданные

- **Канал:** Just Have a Think
- **YouTube:** https://www.youtube.com/watch?v=fKroZGzD9y0

## Содержание

### [0:00](https://www.youtube.com/watch?v=fKroZGzD9y0) Segment 1 (00:00 - 05:00)

Last week I had a think about iron-air batteries, and we looked at how that relatively simple chemistry could deliver very long-duration energy storage at potentially ultra-low cost. If you missed that video, you can jump back to it by clicking up there somewhere or by following the link in the description. There is another contender for long duration stationary energy storage though. Well, there are several contenders actually, but one that’s been talked about a lot recently is the so called ‘redox flow battery’. It’s another ostensibly simple technology with potential for long cycle life, high levels of safety, and decoupled energy & power scaling I’ve talked about these things several times over the years and arguably the most interesting variation was one using a zinc bromine combination pioneered by an Australian company called Redflow. I had high hopes for Redflow, and I suspect they did too. But the batteries were beset with reliability issues and RedFlow found themselves spending more time and money fixing customers units under their warranty terms than they did on actually developing and improving the system. Sadly, in twenty-twenty-four it all went belly up and with no third party interested in taking on the intellectual property as a going concern, the administrators had no choice but to wind up Redflow’s operations for good. Another salutary tale of a hopeful tech startup falling foul of the dreaded valley of death between technology breakthrough and real-world implementation? Well, probably, yes. The end of Zinc Bromine Flow Batteries as a promising concept? Well, apparently not, because in January twenty-twenty-six the mantle has been well and truly taken up elsewhere. And at the risk of being accused of sounding like a broken record here, you’ll never guess where they’re being developed now… Yep. Hello and welcome to Just Have a Think Bloody China, honestly! They just have to have a finger in every technological pie, don’t they? This latest bit of apparently groundbreaking insight comes from a group of researchers at the Dalian Institute of Chemical Physics, which is part of the Chinese Academy of Sciences in Northeastern China. One of the reasons that Zinc Bromine flow batteries are such an attractive proposition compared to the more traditional and much more well-established VANADIUM flow batteries is that they have the potential to deliver double the energy density. The most common flow battery system configurations involve a couple of large tanks filled with solutions OF Vanadium. The key thing to note here is that the Vanadium ions in each container are chemically manipulated so that one tank can effectively act like a positive electrolyte and the other tank can act like a negative electrolyte. Between those two tanks is a stack of cells, which is where the magic happens. The different solutions of Vanadium are pumped into the cell stack where they’re separated by a thin membrane. As the system discharges, the ions in the negatively charged solution release an electron in a process called oxidation. Those electrons move towards an electrode in the cell stack and go out through a circuit to do their useful electrical work before returning to another electrode on the other side of the stack. That electrode feeds the electrons into the positively charged solution which is happy to receive them. The process of ADDING electrons on THAT side is called reduction, hence the name Redox Flow. The reduction process frees up positively charged Hydrogen ions, or protons as the scientists prefer to call them, which flow across the membrane to maintain the charge balance. The whole thing is completely reversible so that the system can be recharged. A Zinc Bromine flow battery still has two separate tanks containing solutions that get pumped across a stack of cells, but instead of using vanadium, they use a zinc bromide solution. When the system is being charged up, the bromide gives up an electron in a process that converts it into bromine, which is then deposited on the electrode. Meanwhile the zinc ions on the other side GAIN a COUPLE of electrons each and the resulting zinc metal gets plated out on the electrode on that side. During discharge the reaction is reversed, and all those lovely electrons can be shuttled back to their original position via an electrical circuit where they can do some useful work. But here’s the thing – because each zinc ion can capture TWO electrons at a time instead of just a single electron in a vanadium set up, you effectively get twice the bang for your buck. But zinc–bromine flow batteries have always faced a stubborn problem which is the production of corrosive elemental bromine during charge. And bromine is aggressively corrosive, highly soluble and generally prone to eating away at membranes, current collectors and other internal components of the system. That corrosion limits cycle life and forces designers to use expensive, corrosion-resistant materials like fluorinated membranes and titanium hardware — which drives up cost and reduces commercial appeal.

### [5:00](https://www.youtube.com/watch?v=fKroZGzD9y0&t=300s) Segment 2 (05:00 - 10:00)

So even though on paper this chemistry is attractive, with abundant materials, high energy density and intrinsically safe aqueous solvents, the whole bromine corrosion thing has proved to be a bit of a headache. The Dalian Institute researchers claim to have developed a “corrosion-free” bromine flow battery by actually changing underlying redox chemistry, rather than just trying to build better hardware to withstand corrosion. Instead of allowing bromide ions to be converted to free elemental bromine, the researchers introduced what they describe as ‘amine-based bromine scavengers’ into the electrolyte. These scavengers react with bromine immediately as it forms, producing stable brominated amine compounds. So rather than accumulating free bromine in the system, the bromine stays bound up in a form that is far less corrosive. That’s a small tweak in chemistry — but it has big consequences. And because of the way these brominated amines participate in the redox reaction, the system still maintains that double-electron transfer, nearly doubling the theoretical energy density of the bromine catholyte. The team built a five-kilowatt demo system in the lab that ran for more than seven hundred stable cycles, achieved an energy efficiency of just over seventy-eight percent, and used INEXPENSIVE, non-fluorinated membranes without any signs of corrosion in any of the internal components. What makes this particularly interesting is the mechanistic nature of the innovation: by understanding and re-shaping the chemical pathway, the researchers have tackled one of the core limitations that plagued bromine flow batteries for decades. That’s the sort of advancement that doesn’t just make one prototype a bit better. It’s more your fundamental breakthrough type stuff that could open up a whole new design space. No champagne and party hats just yet though, obviously. This is only a laboratory set up so as usual there’s a long way before this thing gets anywhere near the real world. But it does raise the intriguing question of whether there’s anyone out there who’s in a position to pick this up and run with it? Because if you’re going to take a brand-new chemistry tweak from a prestigious Chinese Academy of Sciences lab and turn it into rugged commercial hardware, you really need industrial capacity, supply chains, and — crucially — people already familiar with zinc–bromine systems. And as it happens, China has at least one company that fits that bill rather neatly. There’s a firm called JUNAN Energy, and unlike most of the Western players that have either pivoted away from zinc–bromine or disappeared entirely, JUNAN is still actively developing and manufacturing zinc–bromine flow batteries. They’ve got everything from residential-scale ten kilowatt-hour units right up to two hundred and forty kilowatt / nine-hundred and sixty kilowatt-hour containerised flow systems, all running on zinc-bromine chemistry. And because they’re already producing all the real hardware like tanks, pumps, membranes, stacks, control systems and all the rest of it, they’re arguably in the best position anywhere in the world to benefit if this corrosion-free chemistry reaches engineering readiness. Now, there’s no public indication yet that JUNAN is collaborating with the Dalian team. But the ecosystem in China is far more intertwined than what we’re used to in the West. Research institutes regularly partner with domestic manufacturers, and technology hand-offs happen much more quickly there than in Europe or North America. So, if this electrolyte innovation does start to look commercially viable, JUNAN would be a very natural early adopter. It could let them strip out those expensive corrosion-resistant components, boost energy density, and offer a genuinely competitive long-duration storage solution at lower cost. And that’s where bromine flow batteries might start to slot into the global energy storage landscape. If you think back to the iron-air batteries we looked at last week, they’re targeting multi-day, ultra-cheap storage — albeit with big footprints and slow charge-discharge cycles. Bromine flow batteries are shooting for a slightly different sweet spot though - four to twelve hours, high cycle life, and safe operation in harsh conditions. They're not trying to replace lithium-ion in your car or in your mobile gadgets. Instead they could become the workhorses for daily cycling, renewables balancing, and industrial microgrids. So, it looks like bromine flow batteries are not dead yet. Far from it in fact. Redflow’s struggles were really about scaling a very difficult technology in a very tough capital environment. But the underlying chemistry always had potential — and what the Dalian group have shown is that the biggest weakness of that chemistry might not be a dead end after all. If companies like JUNAN Energy decide to pick up the baton, and if these ideas survive the brutal transition from lab bench to shipping container, then zinc–bromine flow batteries could yet have a very respectable second act. As ever, time will tell. But it’s certainly one to watch. If you’re developing one of these technologies

### [10:00](https://www.youtube.com/watch?v=fKroZGzD9y0&t=600s) Segment 3 (10:00 - 10:00)

or working for one of these companies, it’d be great to get your insights. And of course, if you just want to voice your opinion on any of the points raised today then the place to leave your thoughts is in the comments section below. That’s it for this week though. Thanks, as always, to the wonderful people over at patreon dot com forward slash just have a think, who help me keep ads and sponsorship messages out of all my videos, and also a big thank you if you’ve supported me via the Buy Me a Coffee platform or YouTube SuperThanks in recent weeks – all very much appreciated I can assure you. Don’t forget to like and subscribe to help us get to our next milestone of seven hundred thousand subscribers. And most important of all, Thanks for watching to the end and helping to convince the algorithm to share this video with a few other people. Have a great week, and remember to Just Have a Think See you next week.

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*Источник: https://ekstraktznaniy.ru/video/36971*