3 ms·

What is the Coulombic efficiency? A paper membrane probably leaks a lot, but a state of the art ion exchange membrane probably runs $1k/m2.

by kleton 2y ago

KennyBlanken 2y ago
It's in the blog. The author mentions finding that matte inkjet paper worked fairly well. There are much cheaper membranes; ESS for example uses a membrane that is used by lithium ion batteries (I think) and thus is commonly available and very inexpensive.
- kragen 2y ago
  where in the blog?
  - jerrysievert 2y ago
    > where in the blog? the blog is listed in the first paragraph of the linked article: https://chemisting.com/2024/03/15/an-open-source-diy-flow-battery/ https://chemisting.com/2024/03/15/an-open-source-diy-flow-ba...
    - kragen 2y ago
      if by 'the blog' you (or you and kennyblanken) mean https://chemisting.com/ https://chemisting.com/, which post do you mean? the post you link to in that blog doesn't say anything about coulombic efficiency or inkjet paper, and there are four years of posts in the blog
      - jerrysievert 2y ago
        https://www.amazon.com/Kodak-photo-paper-matte-count/dp/B0B5B7TQ3K/ https://www.amazon.com/Kodak-photo-paper-matte-count/dp/B0B5... according to the link.
kirksmith 2y ago
It's in the graph image, CE: 88.7%
danielfp248 2y ago
I am the author of the blog (chemisting.com), working on the project with Kirk and Josh. The Coulomb efficiency of a device with a microporous, non-selective membrane depends fundamentally on how fast you charge/discharge it, as the device self-discharges while it runs. The faster you charge/discharge, the higher the CE will be. In the case of the photopaper device, it will be in the 85-90% range when charging to high SOC values at 20mA/cm2. The big advantage is that microporous membranes are really cheap and they still work even if dendrites pierce them. I must me clear that photopaper is meant as a DIY demonstration, a commercial unit would never use that but a polyethylene microporous separator - such as Daramic - with these memrbanes the CE and EE tend to be higher.

What is the Coulombic efficiency? A paper membrane probably leaks a lot, but a state of the art ion exchange membrane probably runs $1k/m2.

by kleton 2y ago

What is the Coulombic efficiency? A paper membrane probably leaks a lot, but a state of the art ion exchange membrane probably runs $1k/m2.

KennyBlanken 2y ago

It's in the blog. The author mentions finding that matte inkjet paper worked fairly well. There are much cheaper membranes; ESS for example uses a membrane that is used by lithium ion batteries (I think) and thus is commonly available and very inexpensive.

kragen 2y ago
where in the blog?
- jerrysievert 2y ago
  > where in the blog? the blog is listed in the first paragraph of the linked article: https://chemisting.com/2024/03/15/an-open-source-diy-flow-battery/ https://chemisting.com/2024/03/15/an-open-source-diy-flow-ba...
  - kragen 2y ago
    if by 'the blog' you (or you and kennyblanken) mean https://chemisting.com/ https://chemisting.com/, which post do you mean? the post you link to in that blog doesn't say anything about coulombic efficiency or inkjet paper, and there are four years of posts in the blog
    - jerrysievert 2y ago
      https://www.amazon.com/Kodak-photo-paper-matte-count/dp/B0B5B7TQ3K/ https://www.amazon.com/Kodak-photo-paper-matte-count/dp/B0B5... according to the link.

kirksmith 2y ago

It's in the graph image, CE: 88.7%

danielfp248 2y ago

I am the author of the blog (chemisting.com), working on the project with Kirk and Josh. The Coulomb efficiency of a device with a microporous, non-selective membrane depends fundamentally on how fast you charge/discharge it, as the device self-discharges while it runs. The faster you charge/discharge, the higher the CE will be. In the case of the photopaper device, it will be in the 85-90% range when charging to high SOC values at 20mA/cm2. The big advantage is that microporous membranes are really cheap and they still work even if dendrites pierce them. I must me clear that photopaper is meant as a DIY demonstration, a commercial unit would never use that but a polyethylene microporous separator - such as Daramic - with these memrbanes the CE and EE tend to be higher.