All iron battery
 

So, I've started reading about all iron batteries. Apparently they've been around for at least a little while.

Here is what I have gathered so far:

Pros:
- They are made nearly entirely of iron components.
- They are environmentally friendly with no caustic or harmful parts.
- No exotic materials. Its mostly iron and water.
- Very good cycle life (not sure how good).
- Iron is cheap and there is tons of it readily available.
- You can make these batteries yourself (though it does not look super easy).

Cons:
- Low energy density. Each cell puts out about .5V.
- They're made of iron so they are heavy.
- Low discharge rate.

Here are a few videos I've seen.

https://www.youtube.com/watch?v=HmtI8Wat7rY

https://www.youtube.com/watch?v=WZkqgj1J_WE



Have you guys heard of this type of battery? It sounds pretty ideal for stationary applications. Who cares if you have a large heavy battery if its cheap, right? Cost has always been the main determinant in dissuading use of battery technology. This appears to possibly fix it. Though, I haven't seen any cost analysis done yet.

Nickel Iron batteries? i've heard of them, i think the main issue is $/kWh. from what I've researched, used tesla packs are the best at about $1500/5kWh.

Nope, not nickle iron, just iron.

I've heard of them, also called Edison batteries. One has been functional for over one hundred years at a college (can't remember which one). They are waiting for it to fail to take it apart and see how it works.
An iron battery could be the perfect match to a small solar install as they don't hold a charge well or have a strong discharge but are cheap and last indefinitely.

"edison batteries" are Nickel-Iron.

my understanding is that they're extremely durable, but low energy density and high self discharge. to get a battery bank big enough to be useful (start up motors), you'd need to dump in a lot of money. you can see by the size of their battery. 50kw/400kwh is the size of a shipping container. the same kwh in Li-ion would be the size of a small car, maybe smaller.

I used to be more excited about them, but used EV traction batteries is where the numbers line up for me.

the video makes this sound more like a flow version of Aquion's saltwater battery.

i also find their comments about how li-ion only lasts a few hours disingenuous. that's 100% related to discharge rate vs capacity, NOT chemistry. 400kWh / 4h = 100kWh/h no matter what flavor it is. also not sold on the capacity fade argument just yet.


long term the judgement will be economics, i think. electric cars have turned up the needle on economies of scale.