I think we're working on the same job.
I'm not sure about the Nickel term but I saw this 脱Co in a different context that suggested it meant wnated to move away from cobalt based lithium ion batteries (maybe toward lithium polymer, lithium iron phosphate, etc.). Cadnica are Ni-Cd batteries so I don't know how you can get away from using nickel in those. It could mean that they are moving away from Cadnica completely. You might need to check the context.

Lates battery seems to avoid using Co material due to increasing high cost for this material. This is what I found by checking Japanese web site for battery industry. Therefore it should mean "not to use" Co rather than chemical procedure of extraction.
I used this term for my translation for power point due to restriction of space.