Some people have spent some time and effort to work that out....

Some people have spent some time and effort to work that out. Would be interesting to know the Cobalt content, it will be higher... Obviously battery chemistry is a closely guarded secret for many producers...

https://www.researchgate.net/post/W...in_Li-ion_batteries_used_in_electric_vehicles

"Tesla uses Panasonic's "NCR18650B" s (http://blog.evandmore.com/lets-talk-about-the-panasonic-ncr18650b/), which has a capacity of 3250 mAh and operates at around 4.2 V.
According to battery university "A 2Ah 18650 Li-ion cell has 0.6 grams of lithium content." (http://batteryuniversity.com/learn/archive/is_lithium_ion_the_ideal_battery). So, for Tesla's 3250 mAh batteries, the lithium content would be (0.6/2)*3.250 = 0.975 g Li.
Now, with an operating voltage of 4.2V, the lithium content would be:
0.975/(3.250*4.2) = 0.0714 g/Wh = 0.0714 kg/kWh.
This is for Tesla. But Chevy Volt for instance uses pouch cells, which can have a different lithium content. So, this might be the reason why you see this variation in lithium content. It depends on the model, manufacturer and also cell geometry."

"Lithium -Ion batteries do not use 'pure Lithium' , that is Lithium Metal. Lithium salts are used in Lithium-Ion cells to attain storage via development of intercalation species. To calculate the "Lithium Metal Equivalent" of a Lithium-Ion cell you can work from the coulombic value i.e. 96400 \Coulombs are derived from 7g Lithium (26.77AH) or about 3.825AH per gram of Lithium."

"
specially you Saeed! Your information was very helpfull. I looked deeper and I found in different sources that Panasonic's cells 18650 (different models with different capacity) contains about 1g of lithium. So as you wrote above. It is about 0,07-0,08 kg Li/kWh. So for Tesla S (85 kWh) about 7 kg lithium in the whole pack.
The question is what the content of lithium is in batteries used by e.g VW or Renault. For instance e-Golf has capacity of 24,2 kWh and its battery pack weighs 319 kg - 76 Wh/kg, for Tesla S (85) is about 160 Wh/kg, twice as much..."