Do Zinc-Air Batteries Provide a Low-cost Energy Storage Solution?
[youtube http://www.youtube.com/watch?v=44EaTcV_-4o]
Here’s an interview with Steve Hellman, president of Eos Energy Storage, in which Steve claims that zinc-air batteries can finally provide a low-cost answer for utilities and electric vehicle manufacturers. But is it true? We’ve certainly seen stories about zinc-air before. I’ll let you come to your own conclusion.
Craig,
Congratulations for this interview and webinar – I attended it with great interest.
I’m not trying to drill holes in anyone’s technology, especially in energy storage space – but I would challenge Steve Hellman’s presentation on two accounts: energy density and safety.
He states that a Zinc-Air battery doesn’t carry the oxidant (cathode reactant) and for this reason it has a very high energy density, suitable for electric transportation. The truth is, during discharge, a metal-air battery is gaining weight because oxygen is taken from the air and stuck in a chemical compound inside the battery. In other words, the more we drive the heavier the battery becomes – unlike the ICE vehicles which are losing weight because all oxidized compounds are exhausted.
So comparing Zinc-Air battery’s energy density with other technologies is not correct unless the weight of the battery during discharge is stated. In other words, metrics cannot be the same because weight is variable. In contrast, Li-Ion batteries are keeping the same weight during discharge.
For this reason, I find Steve’s slide entitled Zinc-Air Advantages (with the car towing a trailer of said reactant) is a little bit misleading.
The second problem is safety. As Steve said, Zinc-Air batteries are gassing oxygen when charged. This could be a real fire hazard as some substances (such as grease) are spontaneously catching fire in an oxygen-rich atmosphere. I wouldn’t charge it in my garage!
In my opinion, this safety concern could be addressed in industrial applications (controlled environment) and probably metal-air batteries may not be applied to electric vehicles.
Thanks very much. I’m having lunch with him next week in NY City, and I’ll run all this by him.