From the outside it seems simple enough, if even rather elegant. On the inside, however, things aren't that simple.
Batteries are highly engineered electrochemical cells.
How these materials get picked for the job depends on how well they give up or attract electrons, something that must happen for an electric current to be generated. The anode is often a metal, the cathode a metallic oxide, the electrolyte an electricity conductor. Click to find out. Click to learn about battery chemistry. Click to see why battery placement matters.