Lithium is a problem because of cost and also for the "rarity" of producers in the world. Also reliability is better in Nickel batteries. Besides, Toyota group is making research of other types of batteries, and chemical vectors like Hydrogen.
Even if the future will be for electric cars, the key issue is how to recharge batteries in a fast way; there is also a problem linked to petrol based global economy, and Hydrogen can be made easily with petrol. Besides, Hydrogen production can be easily controlled and taxed, while potentially electricity can be home made in many ways 😉