Then there is also an environmental issue where they use precious heavy metals found in our earth that are finite, meaning that there will eventually come a time when they are no longer available. However, the folks at IBM might have come up with a new alternative, where they have developed a battery that relies on ingredients extracted from seawater.
This means that this battery, should it ever be mass produced, will be more environmentally-friendly to manufacture. It will also be safer to use due to IBM Research replacing the cobalt and nickel in the cathode of the battery with a new liquid electrolyte. The liquid electrolyte also has a higher flash point, ultimately reducing the potential of the battery short circuiting, which could also lead to it catching on fire or exploding.
However, the research is still in the somewhat early stages and IBM Research plans on working with Mercedes-Benz Research to further its development. This means that it will probably be a while before we ever see it commercialized, if at all.