The basic process of producing batteries haven’t changed much since their first introduction in early 19th century, but today they are made with much better manufacturing technologies and raw materials.
Batteries have simple internal structure, but even though only few components are needed for their creation modern battery types require toxic, expensive, and hard to assemble materials. Here you can learn how batteries are made.
Modern batteries are all using same basic technique for extracting flow of negatively charged ions that are needed for electricity, but the exact mixture of components that can produce that flow varies widely.