Do not raise your hopes on nickel too much because of larger battery needs.

Nickel based batteries are less energetic per unit weight than those of lithium, and cars are very weight intolerant.
Nickel based ones are only an option for hybrids because those cars do not require big batteries and hence do not suffer as heavy a weight penalty.

Just for your info, and note that this was an article from a nickel producer and not of lithium or a car battery manufacturer.