danielfp248
Battery researcher
- Joined
- Sep 7, 2020
- Messages
- 429
Would be cool too, I love the blog post and your post here it's more detailed, having to see more pictures on Instagram would be very fine as well...I've been thinking about starting an Instagram account to share pictures and stories about the fabrication of these devices and my experiments. Do you guys think this would be interesting for you? Let me know![]()
Hi Daniel.I've been thinking about starting an Instagram account to share pictures and stories about the fabrication of these devices and my experiments. Do you guys think this would be interesting for you? Let me know![]()
Doesn't seem like it. It seems to be an issue with electrolyte leaking or cathode/graphite contact. It'll take me some time to figure out and fix.Faulty/loose connection?
Thanks for your comment! The problem with this design is that the internal resistance is so high - due to the distance between electrodes - that the energy efficiency will be abysmal (probably lower than 10%). Putting 10 Wh in to get 1Wh out is not practical unless you have a lot of energy to waste. In practice if you want to get high energy efficiencies (>50%) you will need to keep your electrode distance below 5mm. This is because of limits in the conductivity of Zinc Bromide solutions. This is why these "jar batteries" are not practical Zn-Br batteries. Note that their Coulombic efficiency can still be quite high (>80%) but this does not mean the battery is any good in real terms.According to Rob on YouTube, this design doesn't or shouldn't have much issues with dendrites problems, please if you have the time and resources do take a look this too
Thanks for helping clarify! Note that it is not just energy density but energy efficiency that is critical. I want a battery where I can get out at least 60%+ of the energy I put in.@Juptron danielfp248 is trying to make a more energy dense version, and is aware of Robert see the third post on this thread. https://diysolarforum.com/threads/my-adventures-building-a-zinc-bromine-battery.11910/#post-132445
Thanks for the information, Just that this is one of the most diyest... Battery I have ever come across hence my fascination for it ?. ... Thanks for what you are also doing! I see this https://www.sciencedirect.com/science/article/pii/S2589004220305356 is helpful for your current work too...Thanks for your comment! The problem with this design is that the internal resistance is so high - due to the distance between electrodes - that the energy efficiency will be abysmal (probably lower than 10%). Putting 10 Wh in to get 1Wh out is not practical unless you have a lot of energy to waste. In practice if you want to get high energy efficiencies (>50%) you will need to keep your electrode distance below 5mm. This is because of limits in the conductivity of Zinc Bromide solutions. This is why these "jar batteries" are not practical Zn-Br batteries. Note that their Coulombic efficiency can still be quite high (>80%) but this does not mean the battery is any good in real terms.
With electrode distances so short, zinc dendrites are sadly going to be a problem we will have to solve.
Thanks for the information, Just that this is one of the most diyest... Battery I have ever come across hence my fascination for it ?. ... Thanks for what you are also doing! I see this https://www.sciencedirect.com/science/article/pii/S2589004220305356 is helpful for your current work too...
Ok, but anything practically from 30wh/l looks good to me ?Thanks for your reply! I discuss that paper extensively on my blog. Note that their capacity, energy density and specific power numbers are incredibly misleading, since they are calculated without considering the mass of the electrolyte or total mass of the cathode (for the capacity) or the total mass of the cathode and water in the electrolyte (for the density and specific power). When you consider these factors their values drop by around 100x which matches what we know about commercial Zn-Br technology. If these numbers actually held, this paper would have been published in Nature or another top tier journal![]()