That’s the point brakes,, the whole use of cobalt in a lithium...

That’s the point brakes,, the whole use of cobalt in a lithium ion battery is the safety factor . If the amount is reduced to much it can affect the benefit of cobalts attributes. It must be included to allow the nickel to produce intense power. It cools down battery to avert bad reactions to be dangerous, The other main reason for inclusion is it slows breakdown of the cathodes. Battery makers have to comply with long term warranty of multiple years cover so any deterioration cannot be accepted. Cobalt is definitely crucial for all high quality batteries to be marketed to a discerning market IMO.