As a rough distinction, I'd not call it a battery unless you can recharge it in-place, and the fact the a very hot reaction creates the energy further sways that opinion.
There are companies making gasoline from atmospheric CO2 too. Does that make gas a battery?
Wouldn't be surprised if the word "battery" genericized over the next few years to mean any form of energy storage, especially given the growth in the relevance of geod scale storage. I've already seen a couple of folks refer to pumped storage as massive batteries and if those count, then yeah do does your gasoline generator
Calling a gas generator a battery is about as perverse as ‘literally’ meaning not literally. :s
The word "battery" has already drifted a lot more over the last ~500 years than the word "literally"!
And yet the vast majority of batteries in use are primary cells which aren’t rechargeable at all without recycling?
Neat, that's a fair point.
It’s more akin to pumping water up hill at times of excess energy and then generating hydro power during times of peak power. Such a system is essentially a water battery, and the iron system would be an iron battery.
Either one competes with having a fossil fuel power plant that you operate when renewables are not available and turn off when they are.