2021 total world energy production of approximately 172 PWh would require 27.5 billion metric tons of lithium metal at typical 0.16g/Wh of a modern LFP cell; meanwhile, we have approximately 230 billion metric tons of lithium for taking (e.g. as part of desalination plants producing many other elements at the same time from the pre-consecrated brine) from the oceans.

Note that we require only a fraction of a year's worth of energy to be stored, I think less than 5% if we accept energy intensive industry in high latitude to take winter breaks, or even more with further tactics like higher overproduction or larger interconnected grid areas.

And that's all without even the sodium batteries that do seem to be viable already.