Think of a battery as a small power plant that converts chemical energy through a reaction into electrical energy. First of all there is the container (1). This is a steel cylinder housing the cell’s ingredients.
Then you insert the positive element of the chemical reaction, which is a mix of finely ground Manganese dioxide mixed with conductors (like Carbon) which carry a naturally occurring electrical charge. This is called the cathode, and it is molded inside the empty wall of the container (2).
A separator paper is inserted to keep the cathode from touching the