eli5 Can co2 be used as batteries?

Question

Is it possible to use energy from renewable energy sources to break down CO2 and when needed, turn that back into another molecule? Or am I dumb?

And is it efficient?

In: 1

Answer 1

We already do that by making ethanol from corn. Does it work? Yes. Is it efficient? No as you waste a lot of energy with farming equipment, processing, transportation, and of course the inefficiency of combustion.

Now if we could make a gasoline fuel cell hybrid that would be pretty interesting as you would double the efficiency vs combustion and give gas cars a reason to still exist.