The metals needed to make the battery – nickel and iron – are also more common than, say, cobalt which is used to make conventional batteries.
Nickel is running about $20/kg. Cobalt is about $50/kg.
But, lithium batteries have very little cobalt, about 5% by weight in a Tesla battery. Nickel iron batteries are about half nickel in rough numbers. Combine in that a nickel iron battery is about 20Wh/kg and Tesla batteries are around 250Wh/kg and you get something like 100 times as much nickel used as cobalt to store the same energy. You can mostly ignore the 2.5x price multiplier at that point.
The specific energy differences rule nickel iron out for mobile uses, but it has a lot going for it for stationary. I have looked at it each time my off grid lead acid battery banks expire, the cost has come down over the decades, but not enough to make me switch (freeze tolerance is also an issue in NiFe's favor). But I swear, this is the last half-ton of lead acid batteries I'm hauling out there and back. When these go it's either lithium or nickel even if I have to dig an 8' deep battery vault to keep the lithium's electronics in their operating temperature range.
How much more expensive then SLA batteries are these? I've never had a UPS battery last more than 3 years so if they could last 15 years in a UPS, I could shell out up to 5x the cost and not be behind.
I've read before that it's pretty hard to kill a nickle-iron battery. You can't do it by overcharging or letting it sit discharged. Or so I've heard. This article also claims at least a 40-year lifespan. They're not without downsides though.
"The battery invented 120 years before its time" I'm not sure what this article is trying to prove, the Nickel–iron battery has done its 120 years service already and it's questionable if it has a future life except in limited applications where ruggedness is needed as it's electrical capacity it's pretty terrible—as so much bulk battery material is needed for so little storage capacity and there are likely better ways of producing hydrogen.
We need to put this into perspective the Nickel–iron battery has one great feature and one good feature and the rest are rather doubtful by today's standards.
Their great feature is their longevity. I can recall a short but memorable news article about nickel–iron batteries of some decades ago in an electronics magazine, which I thought was in Electronics/Wireless World (but I can't find it in the index). It was a report that the Nickel–iron batteries in a London telephone exchange that were ≈80 years old had been removed from service not because they needed replacing but because they were surplus to requirements when new equipment was installed. What was memorable was that they were still working after 80 or so years after installation. The only maintenance that was needed was to replace the electrolyte (potassium hydroxide) every decade or so.
The good feature of Nickel-Iron batteries is that they're reasonably ecologically sound (but even this is a little doubtful given their very low capacity—meaning more batteries are need for a given storage capacity). Frankly, they're pretty woeful when it comes to output capacity. Below are some Wiki extracts that compare nickel-iron, lead-acid and lithium iron batteries:
The mention of hydrogen in the headline made me think they were talking about nickel-hydrogen batteries, but this article is actually about nickel-iron batteries. Not sure why they made such a big deal about the hydrogen production as it is an undesirable side reaction that lowers the efficiency of the cell and creates a fire hazard.
The hydrogen production is meant to be a feature while the batteries are fully charged.
> "When electricity prices are high, then you can discharge this battery, but when the electricity price is low, you can charge the battery and make hydrogen," says Mulder.
> "useful substances can be generated from it too, such as ammonia or methanol, which are typically easier to store and transport."
> "...it became a better battery when it was used as an electrolyser too. They were also surprised to see how well the electrodes held up to the electrolysis, which can excessively tax and degrade more traditional batteries."
The metals needed to make the battery – nickel and iron – are also more common than, say, cobalt which is used to make conventional batteries.
Nickel is running about $20/kg. Cobalt is about $50/kg.
But, lithium batteries have very little cobalt, about 5% by weight in a Tesla battery. Nickel iron batteries are about half nickel in rough numbers. Combine in that a nickel iron battery is about 20Wh/kg and Tesla batteries are around 250Wh/kg and you get something like 100 times as much nickel used as cobalt to store the same energy. You can mostly ignore the 2.5x price multiplier at that point.
The specific energy differences rule nickel iron out for mobile uses, but it has a lot going for it for stationary. I have looked at it each time my off grid lead acid battery banks expire, the cost has come down over the decades, but not enough to make me switch (freeze tolerance is also an issue in NiFe's favor). But I swear, this is the last half-ton of lead acid batteries I'm hauling out there and back. When these go it's either lithium or nickel even if I have to dig an 8' deep battery vault to keep the lithium's electronics in their operating temperature range.