This is simply false. The amount of lithium in a battery is about 400 g/kWh

http://www.meridian-int-res.com/Projects/How_Much_Lithium_Pe...

Putting a 100 kWh battery in a car would then require 40 kg of lithium, and with 2bn cars (projection for mid-21st century) you're looking at 80 million tonnes of lithium. The ocean contains about 240 billion tonnes of lithium, 3000x requirements, and extracting lithium from seawater costs about $30/kg:

http://gas2.org/2008/10/13/lithium-counterpoint-no-shortage-...

so the total value of that lithium comes to less than $2.4T. While not a small figure, this is miniscule compared to the global oil industry, which brings in more than that per year:

https://en.wikipedia.org/wiki/List_of_largest_oil_and_gas_co...

and that's using some of the most pessimistic numbers for lithium costs and requirements that I can find. The actual operation of the global lithium market will probably bring the total cost well below $1T, and seawater extraction will probably never be necessary:

https://gigaom.com/2010/03/10/will-seawater-stave-off-a-lith...

Lithium absolutely will not, ever, be in any way comparable to oil in terms of price, environmental damage, or political impact. Lithium Chicken-Littling is not helpful to anyone.