It depends on what you value. For performance and power density, nothing really beats lithium at the moment.
However, for grid-scale battery these parameters are not necessarily very important. What matters most is cost over the lifetime, and that's wher zinc batteries could be useful. They have the potential to be much cheaper than the cheapest lithium batteries.
Eli5? Don't zinc batteries suck compared to lithium?
It depends on what you value. For performance and power density, nothing really beats lithium at the moment.
However, for grid-scale battery these parameters are not necessarily very important. What matters most is cost over the lifetime, and that's wher zinc batteries could be useful. They have the potential to be much cheaper than the cheapest lithium batteries.