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  • Post in thread: My adventures building a Zinc-Bromine battery

    Hi Guys, My name is Daniel, I am a chemist with a passion for battery technology and currently trying to build a highly efficient Zinc-Bromine battery at home using readily available materials. I have a blog where you can follow my progress (https://chemisting.com/). I am using a DIY USB...
  • Post in thread: My adventures building a Zn-MnO2 battery

    Finally, Exp30 reached 1000 cycles ???. No dendrites, almost no capacity loss. The test has now been stopped and restarted at 1.290mAh of capacity (more than double current capacity) to see how the battery behaves.
  • Post in thread: My adventures building a DIY Mn/Fe flow battery

    I have decided to start doing some experiments to create a Mn/Fe flow battery. I will post links to blog posts on this thread as I write them. https://chemisting.com/2022/11/17/towards-a-diy-manganese-iron-flow-battery-first-experiments-using-cyclic-voltammetry/ Questions are welcome.
  • Post in thread: My adventures building a Zinc-Iodine battery

    Welcome to my adventure building a Zinc-Iodine battery All experiments carried out from #100 are now shared publicly (https://www.dropbox.com/sh/67hdgpm5lijt5s1/AACS0gjDSYHZny_tLSfXXmfza?dl=0). The experiment_summary excel file contains a summary of all important variables in the experiments...
  • Post in thread: My adventures building a Zn-MnO2 battery

    So, I read an article that came out last year that went deep into the characterization of these Mn/Zn systems and the effect that mildly acidic conditions and pH buffers have on the formation of MnO2 oxides and their charging/discharging behavior...
  • Post in thread: My adventures building a Zn-MnO2 battery

    After looking at Zn-halide chemistries and running into big road blocks with both Zn-I and Zn-Br batteries, I have decided to explore the world of Zn-MnO2 batteries. Especially, mildly acidic rechargeable Zn-MnO2 chemistries. These batteries use very earth abundant elements and very low cost...
  • Post in thread: My adventures building a Zinc-Iodine battery

    This is Exp21, using CCP cathode, 3 layers of fiberglass separator, copper anode and the regular ZnCl2 15m + KI 5m electrolyte. This cell is being cycled between 0.8V and 1.275V at 10mA/cm2. So far 100 cycles and the battery capacity went down and then back up close to max capacity. I...
  • Post in thread: My adventures building a Zinc-Iodine battery

    The battery ran for 222 cycles. Decay became significantly more pronounced during the last 30 and the stability in the potentials was only temporary, there were also some small dendrite issues. So far this is the battery I have cycled for the longest yet.
  • Post in thread: My adventures building a Zinc-Iodine battery

    The first WiS (water-in-salt) battery I constructed dried due to some air openings in my Swagelok cell. I added teflon tape to the electrodes to provide a tight seal and prevent contact with the outside environment. I then made a second WiS Zn-I device per the description in the post linked in...
  • Post in thread: My adventures building a Zinc-Iodine battery

    I wanted to see how high the capacity could get for the battery in #19. I managed to charge it to 25mAh, capacity was 14.8mAh. CE 59%, EE 44% on first cycle. This takes the density to 29Wh/L.
  • Post in thread: My adventures building a Zinc-Bromine battery

    I have watched all of Robert's videos, I even decided to pay to become a member of his community to get access to several extra videos about this topic not available to the general public. The videos have not been very useful though, mainly because of the following reasons: While Robert shares...
  • Post in thread: My adventures building a Zinc-Iodine battery

    I then created a battery using my Swagelok cell and the 1.5M ZnI2 electrolyte. I used 10 layers of fiberglass separator, a GFE-1 cathode and graphite electrodes. The battery was charged to 5mAh and discharged to 0.6V, both at 15mA (11.6mA/cm2). CE=72%, EE=64% on first cycle. Average charge...
  • Post in thread: My adventures building a Zinc-Bromine battery

    Here you can see the exact same battery charged/discharged at 0.5 mA. With a low current I can charge it to an even higher capacity (500 uAh) with a higher Coulombic efficiency (94%). The lower current means that only the most favored reactions at that potential will happen and ions will be able...
  • Post in thread: My adventures building a Zn-MnO2 battery

    New record, Exp30 is at 358 cycles so far. No dendrites yet.
  • Post in thread: My adventures building a Zinc-Iodine battery

    I am now repeating Exp12 - the longest lasting yet at 222 cycles - but using a Zn anode instead of a Cu anode to see what effect this has. All other variables are exactly the same.
  • Post in thread: My adventures building a Zn-MnO2 battery

    I ran Exp30b for 32 cycles, no problems happened. I am now going to double the discharge capacity again, to 2.580 mAh, and see what happens. This will be Exp30c. Note all of these Exp30 runs are using the same battery - I haven't taken it apart - so I am basically now pushing it to failure, to...
  • Post in thread: My adventures building a Zn-MnO2 battery

    No, I moved countries again. This time I moved from Colombia to Spain, so I had to leave all my battery experiment stuff in Colombia with family. I will hopefully get the electronic and electrode parts back when they come to Spain later this year.
  • Post in thread: My adventures building a Zinc-Bromine battery

    So guys, I moved countries earlier this year and hadn't had the time to start my home-research into Zn-Br batteries again. However, I have now reached a stable situation and will start researching Zn batteries again. I will start another thread as I will start research into some additional Zn...
  • Post in thread: My adventures building a Zinc-Iodine battery

    I ran the battery for 46 cycles of charge to constant capacity at 3mAh at 15mA: Capacity held for around 30 cycles, then there started to be some evident loss of capacity. It seems that the battery cannot be reliably charged/discharged at 15mA, internal resistance starts to increase too much...
  • Post in thread: My adventures building a Zn-MnO2 battery

    Test experiment running 1m ZnSO4 + 1m MnSO4 + 10% acetic acid pH 5 buffer (adjusted with from acetic acid with potassium carbonate). Anode is Zn metal foil, cathode is CC Carbon cloth. Separator is 3 layers of fiberglass filter. Charging to 0.5mAh at 5mA, discharging to 0.8V at the same current.
  • Post in thread: My adventures building a Zn-MnO2 battery

    Exp27 is marking a new record for stability, so far 301 cycles and counting. Virtually no deterioration in capacity so far. CE at 96%, EE at 51.4%. Energy density is quite low due to the thicker separator, currently around 3Wh/L. If it remains stable we can then think about cycling to higher...
  • Post in thread: My adventures building a Zinc-Iodine battery

    After 3 cycles. Last cycle CE=89.96%, EE=80.04%.
  • Post in thread: My adventures building a Zn-MnO2 battery

    Exp30 is now at 673 cycles. No dendrites yet. In the charge/discharge curves below I am only plotting 1/10 so that the plot is readable. Other graphs do contain all points. No appreciable capacity or efficiency loses yet.
  • Post in thread: My adventures building a Zinc-Iodine battery

    Exp12 is giving some really interesting results. It uses a copper anode, a Spectracarb 2050A-0850 Cathode, 3 layers of fiberglass separator and an electrolyte made of 15m ZnCl2 + 5m KI + 1m NaCl in distilled water. I am testing this at a current density of 10mA/cm2, charging to 1.45V and...
  • Post in thread: My adventures building a Zinc-Iodine battery

    I was finally able to take a ZnI2 battery to charge to 15mAh, which gives me an energy density of around 20Wh/L. The battery was charged at a current of 20mA and discharged to 0.6V. Battery was made of a GFE-1 cathode, 10 layers of fiberglass separator, and a graphite anode. The electrolyte is...
  • Post in thread: My adventures building a Zn-MnO2 battery

    That test didn't last for long, cell died pretty quickly (12 cycles). I am now doing a test (Exp31), with the newly prepared MnCl2 solution, to create a 2m MnCl2 + 4m ZnCl2. As expected, this time the electrolyte had zero precipitates upon preparation, due to the complete absence of sulfates. I...
  • Post in thread: My adventures building a Zn-MnO2 battery

    Exp 28 after 50 cycles. Capacity and CE stability continue to be amazing compared to previous batteries. Charge/Discharge potential changes were quite drastic in the beginning but are also beginning to stabilize.
  • Post in thread: My adventures building a Zn-MnO2 battery

    I finished preparation of my MnCl2 solution from MnSO4+CaCl2. The precipitate was hard to filter - as CaSO4 has quite fine particle size - but in the end I was able to obtain the solution as planned. The density of the solution was 1.428 g/cm3 (measured with a pycnometer) which gave me a final...
  • Post in thread: My adventures building a Zinc-Bromine battery

    These are some curves I just measured at a higher current (5 mA/ 1.3cm^2) vs the 1 mA I usually use. The resistance of the conductive HDPE is also so high that to increase the current, the potential needs to increase a ton and a lot of energy efficiency is lost. The coulombic efficiency is still...
  • Post in thread: My adventures building a DIY Mn/Fe flow battery

    Systems of this sort will generally do 20-40Wh/L, so a 125gal tank of catholyte + 125gal tank of anolyte could give you ~30kWh of storage. However, there are currently no commercial systems that work with earth abundant chemistries at safe pH values for lay people. The only commercial setups so...
  • Post in thread: My adventures building a Zn-MnO2 battery

    After 5 cycles at 1.5mAh you can see how stable potentials and efficiencies are when you pre-generate the MO2 and don't go to high potentials on charging. Mean charge potential is 1.7V.
  • Post in thread: My adventures building a Zn-MnO2 battery

    After 440 cycles, no dendrites yet in Exp30. Capacity is still stable.
  • Post in thread: My adventures building a Zinc-Iodine battery

    First cycle of the glass separator WiS battery. I used four layers of fiberglass separator and an HB-1070 cathode. Charged to 1.35V, discharged to 0.5V at 5mA. CE = 87.9%, EE = 80.73%, Thickness = 0.055cm, Diameter = 1.29cm2, Energy Density = 30.43Wh/L, Mean Discharge Potential = 1.27V.
  • Post in thread: My adventures building a Zn-MnO2 battery

    Exp33, after 30 cycles. Everything is still stable. (failed after 32 cycles due to dendrites, note the cell was ran vertically - anode at the bottom - as in the 1000 cycle experiment)
  • Post in thread: My adventures building a Zinc-Iodine battery

    I'm happy to do so! Thanks for all your support.
  • Post in thread: My adventures building a Zinc-Iodine battery

    I ran 15 cycles for the battery described in #6, charging to 5mAh at 15mA. These are the results: There was very slight deterioration of potentials and capacity, but so far no catastrophic failure or large deterioration of CE or EE. So far, no zinc dendrites either. I am now going to cycle...
  • Post in thread: My adventures building a Zinc-Iodine battery

    The battery in #19 did not last too long under these conditions, with evident mounting damage as a function of time. With the low CE (<60%) a lot of side reactions were likely happening in the battery which led to strong capacity loss as a function of cycle number. This battery has been a...
  • Post in thread: My adventures building a Zn-MnO2 battery

    Exp28 is evolving nicely. The 4m ZnCl2 + 2m MnCl2 is generating much more stable curves at a much higher starting CE (already close to 96%) and a record EE for my Zn-MnO2 batteries of 55-56%.
  • Post in thread: My adventures building a Zinc-Bromine battery

    I cycled 25 times to 15mAh, no problems at all: I have decided to stop cycling at this point and run a "max capacity" experiment. I am going to charge the battery to 2.1V, see how much charge I am able to store and how much I can recover, test the limits of the battery's energy density.
  • Post in thread: My adventures building a Zinc-Iodine battery

    I also wanted to point your attention to one of the previous results. When I forced charging to 3mAh on a battery with the original ZnCl2+KI electrolyte (#45). Notice how in cycles where the charging potential went very high - above 1.6V - we actually got some discharge at the 1.6V level. This...
  • Post in thread: My adventures building a Zinc-Iodine battery

    Charging to 10mAh I do see a sharp decrease in CE and EE, which are now 60% and 50% respectively. I believe this is because of the presence of only ZnI2 in the solution. When I oxidize a lot of the Iodide into elemental Iodine, there is a lot of free Iodide available to form polyiodides that...
  • Post in thread: My adventures building a Zinc-Bromine battery

    Plot of all cycles together so far for this battery (13). I coded this plot so that more recent curves are plotted darker. Notice how we have no issues due to dendrites so far.
  • Post in thread: My adventures building a Zn-MnO2 battery

    Exp25 showed substantial improvements, basically no large changes in capacity up until failure due to dendrites, better CE (~92%) and EE (~50%). However, dendrites were mainly present on Zn anode edges and some crystals - presumably Na sulfate - were also present at electrode edges. The...
  • Post in thread: My adventures building a Zn-MnO2 battery

    Exp30b has now more than doubled the discharge capacity, the CE is at 87% and the EE is at 52%. Charging and discharging at 10mA/cm2, charging to 1.29mAh, discharging to 0.0V. So far, 12 cycles, no sign of dendrites.
  • Post in thread: My adventures building a Zinc-Iodine battery

    All the experiments were showing shorts quickly after running at either 2.5 or 5 mA. I tried several different concentrations of Tween-20 and cetrimonium chloride with no difference in shorting. However I had previously ran cells with 15m ZnCl2 + 5m KI in distilled water for long times without...
  • Post in thread: My adventures building a Zinc-Bromine battery

    Charging at 5mA to 500uAh, then discharging at 5mA to 0.5V. So far so good. Last cycle CE=95.24%, EE=67.51%
  • Post in thread: My adventures building a Zinc-Bromine battery

    I just published a blog post (https://chemisting.com/2020/09/12/zinc-bromine-batteries-can-they-really-be-that-good/) discussing the results in this paper (https://www.sciencedirect.com/science/article/pii/S2589004220305356#mmc1) and how the published specific capacity/energy/power values for...
  • Post in thread: My adventures building a Zn-MnO2 battery

    So far I've been able to cycle the battery 9 times at 1mAh. I discharged to 0.8V. The discharge capacity is up to 0.90mAh, with a discharge potential of 1.42V this gives me an energy density of around 13Wh/L. The CE, EE and capacity are all stable so far. The EE>70% and the CE>90%.
  • Post in thread: My adventures building a Zinc-Iodine battery

    I just assembled a battery using a CCP cathode, a Whatman 42 filter separator, a zinc anode and an electrolyte using 19m ZnCl2 + 5m KI in white vinegar. I want to see the effect of a higher ZnCl2 concentration, as I am probably using a lower purity ZnCl2 compared to that used in the article. I...
  • Post in thread: My adventures building a Zn-MnO2 battery

    After 107 cycles there are no signs of degradation (the small drop at cycle 65 was because my computer restarted and I had to restart the testing process). Both charge and discharge potentials have started to stabilize. The battery has a CE > 95% and EE > 80%.
  • Post in thread: My adventures building a DIY Mn/Fe flow battery

    A new friend who is currently doing a post doc in France and did his Ph.D. in flow batteries donated me a basic setup for flow battery research, including two motors and a cell with a small area (many thanks if you read this!!). You can see the setup below. He was also kind enough to send me...
  • Post in thread: My adventures building a Zinc-Iodine battery

    Using information from a 2019 paper, I have made a massive breakthrough in my Zn-I batteries (https://chemisting.com/2021/10/06/towards-a-practical-high-efficiency-high-capacity-diy-zinc-iodine-battery/). CE values > 90% and EE values > 80% now seem achievable.
  • Post in thread: My adventures building a Zn-MnO2 battery

    It is worth mentioning that many papers that work on Zn/MnO2 chemistry will do constant potential, instead of constant current charging. This means that they will hold the device at a given potential until a given mAh is accumulated and then discharge at constant current to a given threshold...
  • Post in thread: My adventures building a Zinc-Iodine battery

    This cell charged to much higher capacity (1.2mAh) but died due to a short - probably caused by dendrites - after 3 cycles. It seems devices with higher capacity die due to dendrites when using a 200um Whatman 42 separator quiet quickly, the formation of dendrites is the most likely culprit...
  • Post in thread: My adventures building a Zinc-Iodine battery

    Six cycles of the battery described in #31 charging to 3mAh, then discharging to 0.5V at 15mA.
  • Post in thread: My adventures building a Zn-MnO2 battery

    I decided to try higher energy density and go with a much thinner separator. The fiberglass is too porous, so I still get shorts from stray carbon fibers from the carbon fiber papers going through. For this reason, I changed to 1 layer of W42 filter paper separator, which measures around 200...
  • Post in thread: My adventures building a Zinc-Bromine battery

    These results were pretty exciting, so I decided to try doing higher current density and higher capacity. Below you can see a cycle doing 10mA charging to 5000uAh. The results seem pretty amazing! CE=87.45% EE=76.11%. ? I will leave this cycling tonight and should have some results of CE and...
  • Post in thread: My adventures building a Zinc-Bromine battery

    I just published a blog post on another organic solvent candidate to serve as a Bromine sequestering electrolyte for the cathode side of the battery. https://chemisting.com/2020/12/10/zinc-bromine-batteries-is-there-anything-that-can-work-just-like-propionitrile/
  • Post in thread: My adventures building a Zinc-Iodine battery

    First five cycles of the battery first tested in #31: So far, there is some loss in initial capacity, which matches the WiS paper results. If my results continue to match, we should see a decrease in capacity for the first ~50 cycles, followed by an increase in capacity for the following...
  • Post in thread: My adventures building a Zinc-Bromine battery

    A lot of people want to experiment with these batteries but find Zinc Bromide either too costly or not available at all. Today I have released a post about how to accurately prepare Zinc Bromide solutions and figure out their concentrations using the widely available Zinc Sulfate and Sodium...
  • Post in thread: My adventures building a Zinc-Bromine battery

    Before continuing with my work with propylene carbonate - which is more time consuming - I wanted to see if the use of a ZnBr2 1.5M + 1% Tween 20 electrolyte makes the use of separators viable and, if this is the case, whether this leads to the first stable configuration that could be built by...
  • Post in thread: My adventures building a Zinc-Iodine battery

    That cycling inevitably damaged the battery built in #31. I therefore built another one from scratch using the same process. Two layers of fiberglass, a CC6P cathode and the WiS solution. I am going to charge it to 1.3V and discharge to 0.5V but this time I am going to do so at 5mA, as the...
  • Post in thread: My adventures building a Zinc-Bromine battery

    I have also been doing some tests of miscibility and solubility with propylene carbonate (PC) which is a polar aprotic solvent that I thought could be used in these batteries. Sadly the solubility of ZnBr2 in PC is not very high (I estimate it to be 0.5-1M at 20C), so making an electrolyte...
  • Post in thread: My adventures building a Zn-MnO2 battery

    Another person is coming to visit me and bringing me a good chunk of my battery materials next week. I will therefore be restarting the Zn/Mn battery research, while I gather the resources to continue my research into flow batteries. Stay tuned for some new experiments on this thread!
  • Post in thread: My adventures building a Zinc-Bromine battery

    After 28 cycles, the battery is now at 90% Coulombic efficiency with an energy efficiency of 74%. This is the last curve measured: This seems to be a complete success so far :) I will keep on cycling to see how stable it is!
  • Post in thread: My adventures building a Zinc-Bromine battery

    Also note that static Zinc bromine batteries without any complexing agents - like the one shown in Robert's zinc bromine battery video outside the members channel - are of no interest to me as the self-discharge rate because of bromine diffusion is way too high, plus having any presence of pure...
  • Post in thread: My adventures building a Zinc-Iodine battery

    Thanks for your support! This cycling is really exciting, 4th cycle, CE=92.37% EE=82.38%, capacity=2.19mAh, energy density=61.60Wh/L.
  • Post in thread: My adventures building a Zinc-Iodine battery

    This battery lasted for 14 cycles when dendrite issues started showing up. Charged to 1.35V at 2.5mA. Results are below:
  • Post in thread: My adventures building a Zinc-Bromine battery

    It also seems that I have been underestimating compression in my cells by a very large amount when using fiberglass separators. I measured the inner cell height as a function of the distances between the caps of the swagelok cell on the outside and found out that I am actually working with...
  • Post in thread: My adventures building a Zinc-Iodine battery

    After 4 cycles, the battery had a big voltage drop and seems to have failed. After opening it up, it seems the Whatman filter paper reacted with the Iodine or most of the iodine got deposited in it instead of the carbon cloth. I took a picture for you guys. HB-1070 cathode on the left...
  • Post in thread: My adventures building a DIY Zn/I flow battery

    Robert is very good at making people interested in science and DYI things, but his numbers about efficiencies - given that he doesn't seem to measure actual cycling - are often plain wrong or poorly explained. A density of ~400 Wh/kg for these batteries is not true. The numbers in Li-Ion...
  • Post in thread: My adventures building a Zn-MnO2 battery

    The latest test charging to 1mAh is at 45 cycles. The energy density of this battery is at 15 Wh/L. So far no problems have showed up:
  • Post in thread: My adventures building a Zinc-Iodine battery

    This is going to take a while ? Doing the first charging cycle at 5mA to 1.3V, the battery charged all the way to around 9.5mAh. If I am able to discharge to 9mAh (which would be around 95% CE) at an average discharge voltage of 1.1V, this would give a total energy density of 88Wh/L. I will...
  • Post in thread: My adventures building a Zinc-Bromine battery

    So I ran a cycle until the battery reached 2.1V at 15mA, discharging at this same current to 0.5V. The battery had a CE=78.57% with an EE=58.59%. Total charge I was was able to extract was 26.56mAh, which would give the battery a capacity of 62Wh/L. However the battery failed during the second...
  • Post in thread: My adventures building a Zn-MnO2 battery

    Exp30, still running strong at 700 cycles. So far, this shows that placing the Swagelok cell vertically - with the anode at the bottom - leads to much lower dendrite formation. I will run this cell to 1000 cycles, then I will increase charging to 1.290mAh (1mAh/cm2) and see if we see dendrites...
  • Post in thread: My adventures building a Zn-MnO2 battery

    No problem after 57 cycles. I am now going to try cycling to 1mAh. Equipment seems to be in good working order :)
  • Post in thread: My adventures building a Zinc-Iodine battery

    So both cetrimonium chloride and Tween-20 gave similar results when using graphite electrodes, both had shorts after only a few cycles. Interestingly the cetrimonium chloride at 300ppm enhanced the capacity of the device significantly (allowing me to go near 40 Wh/L at 2.5mA) but dendrites...
  • Post in thread: My adventures building a Zinc-Iodine battery

    I've been trying to increase the cycling stability of the batteries, as most of the batteries I made were either dying due to shorts after 5-10 cycles or their capacity was fading quickly after the first 10-20 cycles. I tested a battery using a CCP cathode (150um) with a Whatman 42 filter...
  • Post in thread: My adventures building a DIY Mn/Fe flow battery

    I replaced my old potentiostat with a mystat potentiostat from this paper (https://www.sciencedirect.com/science/article/pii/S2468067220300729). I had it made on pcbway and shared it on the site so anyone interested can order their own. (make sure to select PCB+assembly to get the full board)...
  • Post in thread: My adventures building a Zinc-Iodine battery

    I noticed that the original paper barely studies the effect of KI concentration, as they say that 5m is the highest concentration they are able to reach. However, I am able to easily dissolve 7.5m KI in the ZnCl2 solution, so I'm going to try that and see the effect it has on the battery...
  • Post in thread: My adventures building a Zn-MnO2 battery

    Exp26, game me 81 cycles, again, failure due to dendrites. Stability however remained quite high. Note that I also increased current density to 10mA/cm2, with little drop in the CE and EE of the battery. Capacity remained stable until the dendrite related failure. I am now running this exact...
  • Post in thread: My adventures building a Zn-MnO2 battery

    Exp30 is a total repeat of Exp28, except that I'm holding the Swagelok cell in a vertical position through the entire test (this to make sure any excess electrolyte just drips to the bottom of the cell and is not against the wall of the cell). So far the battery has gone through 125 cycles. The...
  • Post in thread: My adventures building a Zinc-Bromine battery

    There's been some deterioration but the battery is still working fine. Capacity and energy density are still within 20% of the highest value. Threshold for a 20% drop from highest values are 46.4% for energy efficiency and 18 Wh/L for energy density. Current values are 50.58% for EE and 19.55...
  • Post in thread: My adventures building a Zn-MnO2 battery

    I ran this experiment for 43 cycles (Exp31b, results below), charging to 1.5mAh at 5mA/cm2. The CE remains high, EE remains high, capacity was 1.38mAh on average. Energy density at this capacity, given total device volume,, is 16Wh/L. I have now done another single conditioning cycle...
  • Post in thread: My adventures building a DIY Mn/Fe flow battery

    For anyone who was interested in this thread, you might be interested in my new thread on Zn-I flow batteries https://diysolarforum.com/threads/my-adventures-building-a-diy-zn-i-flow-battery.69145/. This now includes actual experimental results of flow batteries I've built.
  • Post in thread: My adventures building a DIY Zn/I flow battery

    We have also started a non-profit for the development of open source flow batteries (https://opencollective.com/fbrc). It is called FBRC (Flow Battery Research Collective). I started it with my colleague Kirk Smith and professor Sanli Faez...
  • Post in thread: My adventures building a Zinc-Iodine battery

    I have now run the battery built in #31 for 116 cycles. The results are below: Contrary to what the original WiS paper shows, there has been no increase at all in the capacity after the initial 20-50 cycle decline. The discharge capacity at constant voltage charging has been dropping...
  • Post in thread: My adventures building a Zinc-Iodine battery

    It is interesting to note that as the cycle number has increased the CE has reached higher and higher values, some cycles reaching very close to 100%. This does mean the electrochemical process is becoming more stable as a function of time and it is something not observed in the original WiS...
  • Post in thread: My adventures building a Zinc-Bromine battery

    Thanks for posting ? Glad to see someone else joining! I don't use any conductive plastics, the Swagelok cell I use - described in my last blog post in chemisting.com - uses graphite electrodes and a GFE-1 carbon felt electrode, the resistance of the graphitic felt electrode is below 10 ohm...
  • Post in thread: My adventures building a Zinc-Iodine battery

    Charging the battery to 3mAh can be done with a final charging potential below 1.35V (from charging to 0.9mAh to 3.0mAh there was only a 50mV increase in charging potential). Charging these batteries to constant potential might be a mistake - as the charging potential required might increase...
  • Post in thread: My adventures building a Zinc-Iodine battery

    I believe I have been unsystematic with the current experimentation. There has been a lot of impulse to try a lot of things, wanting to observer interesting phenomena and learn more about the subject, but this has actually caused some confusion and a lack of direction in how to proceed. For...
  • Post in thread: My adventures building a DIY Mn/Fe flow battery

    Thanks for sharing what you have been reading! Organics in flow batteries are definitely very interesting from a research perspective and likely the future in 20+ years, as the molecule manufacturing gets scaled and more stable molecules are found. I wanted to find a chemistry using things...
  • Post in thread: My adventures building a Zinc-Iodine battery

    The CC6P cathode really changed the dynamics of the battery. This carbon cloth is significantly thicker, at 350um, and the total cell thickness is now larger at 870um. However, the internal resistance of the battery is also significantly lower and the potential increases much more slowly, so I...
  • Post in thread: My adventures building a Zn-MnO2 battery

    I don't like sulfates very much, in my experience, the presence of sulfate leads to easy dendrite formation. This is because some Zn sulfate hydroxide salts tend to deposit on the anode and the passivation of anode surface area leads to much higher electric field density in the areas that aren't...
  • Post in thread: My adventures building a Zinc-Bromine battery

    I just published a post sharing how I would propose scaling to the next level if anyone wants to build a battery that is larger than mine. This proposed design uses a petri dish and should be able to provide 2Ah of charge...
  • Post in thread: My adventures building a DIY Zn/I flow battery

    The problem is not hurricanes. Even normal wind speeds are very problematic in these approaches. I would suggest watching these videos, which summarize a lot of the technical problems with this idea. Also note the titles of the videos are overly antagonistic for views, I don't view the idea as...
  • Post in thread: My adventures building a Zn-MnO2 battery

    Thanks for commenting! It is interesting to hear about your experiments with water-in-salt electrolytes for Zn-Br. I never tried ZnCl2 + NaBr, since I moved away from this chemistry a while ago. It makes sense for ZnCl2+NaBr to have less self-discharge and less hydrogen evolution. The...
  • Post in thread: My adventures building a Zinc-Iodine battery

    Thanks for following my progress! Hopefully I'll be able to achieve some longer term stability soon, this has been the most elusive property so far.
  • Post in thread: My adventures building a Zinc-Iodine battery

    I cycled the device 21 times, charging to 1mAh, discharging to 0.5V, at 10mA, the results show it is very stable :cool: , even gaining capacity up until the last cycle. Moreover, it is improving significantly on CE and EE values (final values are CE=91.12%, EE=74.91%). I have now stopped the...
  • Post in thread: My adventures building a Zinc-Bromine battery

    Finally there was a very high increase in the potential required for charging and a big drop in the discharge potential during the 24th cycle. Reason why I stopped cycling the battery at this point. It is interesting though that this is not the characteristic failure due to zinc dendrites...

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