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What are redox flow batteries and why are they important?

Billy Wu - 2021-11-14

Redox flow batteries are potentially cheaper, more durable and safer than traditional lithium-ion batteries however still require further research and development in order for them to scale. Here, we explore the motivation for flow batteries, discuss how they work, the different components, chemistries and compare them. 

00:00 Introduction
00:08 A changing global electricity mix
00:22 Integration of intermittent renewables
01:10 What are redox flow batteries?
02:34 Lithium-ion vs flow batteries
03:42 How does a flow battery work?
04:43 Key components of a flow battery
06:06 Flow battery technologies
07:46 All-vanadium flow battery
09:15 Vanadium production
10:18 Zinc-bromine flow batteries
11:39 Iron-Chromium flow battery
12:53 Comparison of flow battery chemistries
13:51 Conclusions

#redoxflowbattery #vanadiumflowbattery #flowbatteries

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Vandeom - 2021-11-22

Such an informative video! You have a great talent to delve into the first questions that come to my mind, and answer them completely. Is the Zinc-Bromine battery used frequently in residential house batteries? It seemed like you were inferring it would make the best option for that application.

Billy Wu - 2021-11-22

Thanks. Appreciate the comment. Yeah, because one of the half cell reactions is the zinc deposition reaction which is more energy dense than changing the redox state of a liquid, these systems tend to be more compact. An Australian company called Redflow is developing small units ~10 kWh as residential energy storage units. Should be safer than lithium-ion but likely needs more R&D and scale up to drive down cost.

Vegan V - 2022-05-28

@Billy Wu Time-Iapse, 5-10 days 🧟‍♂️🦠🍖🔴... (inside your stomach) https://youtu.be/MRT-vc5zRBY ... 🤮 NO fibre !!! Stays in your body and rots away 🤮🤮🤮.....
That’s why I’m vegan, lots of fibre if you eat plants and fruit and nuts and berries and tubers and lentils beans et cetera. PH 7, no smell.
Which side of history are you on, Jeeffrey Dahmer 👓😩🦠🍖🔴... Or veganism ✅❤️💪😬😉??. You don’t hurt your cute little dog 😍🤗🐶🤥🤥🤥... Covid and Monkeypox, are animals eating 😒🍽🦠🍖🔴...
Go vegan. It’s cheap and no murder. Win-win situation ✅❤️🌎😉.

Dayset Iam - 2021-11-15

I have heard of full FE batteries as an 'alternative' to more expensive vanadium. They are low density and slow, but cheap and can be rebalanced like vanadium.

Billy Wu - 2021-11-16

Great comment. Yes, there are people currently looking at the all-iron flow battery chemistry which would be quite cheap in terms of electrolyte materials. This uses the same Fe2+/Fe3+ redox couple on the cathode but plates iron on the anode. One of the challenges here however is the reversibility of the iron plating reaction and potential for hydrogen evolution which both impact the lifetime.

francesco monaco - 2022-09-05

THank you so much, I could not ask more to have a general overview on Flow battery, touching in 14 min all the key aspects

Billy Wu - 2022-09-05

Glad it was helpful!

bjliuyunli - 2021-11-14

Great video, thanks so much Billy. Are there patent barriers limiting wider adoption and commercialization of the all vanadium chemistry?

Billy Wu - 2021-11-15

Thanks. I think the original all-vanadium flow battery patent was filed in 1986 so likely will have elapsed, though there are new ones covering different advances. This I believe is the original one https://patents.google.com/patent/US4786567A/en

Dave West - 2021-11-16

Thanks, Billy. In the Iron-Chromium diagram, is the Fe intended to be the cathode and Cr intended to be the anode?

Billy Wu - 2021-11-16

Thanks Dave. In this version I show its the Fe3+/Fe2+ and the Cr3+/Cr2+ redox couples where iron has a potential of +0.77V and chromium has a potential of -0.41V so iron is the cathode and chromium is the anode. Just noticed in the diagram I had these flipped but right in the text. Will see what's the best way to update but thanks for spotting this!

Dave West - 2021-11-17

@Billy Wu yes, the text looks right. I was paying close attention because you explained it so clearly!

Blazar - 2022-08-07

Can flow batteries be used in cars, and electric vehicles? and is it easy to make and test your own flow battery with different electrolytes

Billy Wu - 2022-08-08

Good question. Unfortunately, the energy density of flow batteries is quite low which means they're aren't well suited for electric cars, though they are better suited to applications where weight is not an issue. Its a bit difficult to make your own flow battery since this often requires specialised membranes to get good performance.

Janamejaya Channegowda - 2021-11-15

Thank you for sharing.

Billy Wu - 2021-11-15

Thanks for watching

Mike George - 2021-12-09

Do you see mass adoption of VRBS in the future?

Billy Wu - 2021-12-11

Great question. At the moment lithium-ion batteries have the cost reduction momentum due to the development in automotive applications. The vast majority of stationary batteries are therefore LIBs at the moment, but I think through a combination of supply shortage for LIB materials, increased desire for lifetime and cost reductions in RFBs we might see increasing deployments in the coming years. VRBs currently have favourable lifetime cost of storage and very good safety characteristics. Probably need some vertical integration of Vanadium supply and manufacturing to address price volatility of electrolyte.