Abundance in the crust is one thing, ability to mine it is another. That's why you need to look at reserves [0] instead of resources. And there are way more lead reserves (88 million tons in 2016 [1]) than lithium ones (17 million tons [2]).
“Worldwide lithium resources identified by USGS started to increase in 2017 owing to continuing exploration. Identified resources in 2016, 2017, 2018, 2019 and 2020 were 41, 47, 54, 62 and 80 million tonnes, respectively.” https://en.wikipedia.org/wiki/Lithium#Reserves
There is little to suggest this trend will suddenly stop unless we simply stop looking. Further, a 5x increase in lithium has minimal impact on the long term EV or grid storage economics. That’s a lot of wiggle room for more expensive extraction.
That’s my point, resources are probable sources of economically extractable resources. It’s mostly a long term vs short term question, so limiting things to reserves vastly underestimates availability in 2040+.
Even resources is an underestimation as again it’s based on economic assumptions that are quite flexible. New technology for example can change what’s considered economically feasible.
Because a single molecule of lead is significantly heavier than a molecule of lithium, that’s technically an order of magnitude more lithium. 2.22E12 moles of lithium vs. 3.85E11 moles of lead.
[0]: https://newpacificmetals.com/mining-101/mineral-estimates-re...
[1]: https://en.wikipedia.org/wiki/Lead#On_Earth
[2]: https://en.wikipedia.org/wiki/Lithium#Reserves