Isn't LFP now the dominant chemistry in grid scale storage?

Not yet, NMC Li-ion is still the largest represented in grid scale battery storage [1]. Pumped hydro is dominant overall in storage. LFP represents an increasing share of new grid scale battery storage, though [2]

1. https://www.iea.org/energy-system/electricity/grid-scale-sto...

2. https://about.bnef.com/blog/2h-2023-energy-storage-market-ou...