I made a youtube video every weekday in 2017. That experience pulled me into the world of battery chemistry. Daily vlogging was hard but taught me something about social media, science outreach, and the topics that people are interested in. I was a little surprised to find that people were so interested in batteries. I like the opportunity to explore something that is of wide interest. Everyone has a battery in their pocket, and everyone wants them to last longer.
While lithium batteries are great for mobile applications, I suggest that lithium is probably not the chemistry of the future for large-scale grid batteries. Cars demand higher performance batteries and are willing to pay more per watt-hour for low weight options. They will likely be the preferred customers for the foreseeable future.
Lithium batteries are also not especially friendly to a do-it-yourself approach. They are oxygen and moisture sensitive.
Heavier chemistry that is much, much cheaper than lithium is a good match for stationary storage. If it can hit $1 per watt, utilities will buy as can be produced. By my calculation, if storage costs $0.25 per watt-hour, it looks economical for grid storage. Lithium-ion is already there.
We set out to make a battery that’s safer and cheaper than lithium and settled on iron chemistry. At least two companies have tried to develop iron flow batteries. ESS is currently developing a system as of 2018; Arotech worked on a system until 2016. The Allen Lab Cell is not a flow battery but is similar all-iron chemistry. The ability to make it without a glove box was critical.
We succeeded in making a cell. The performance is not lithium ion level (10-30x lower in specific energy). I’m still hopeful that the price might still make this cell chemistry attractive for stationary batteries. Here’s the video on how we made it.