Question

how dc current is stored

Answer 1

Current is not a quantity to store. It produces due to motion of electrons. Whenever we apply voltage in a circuit current flows through it.

DC or direct current is a current in which the electron always flows in one direction. Batteries, fuel cells and solar cells all produce direct current (DC). The positive and negative terminals of a battery are always, respectively, positive and negative. Current always flows in the same direction between those two terminals.

AC or alternating current is a current in which the direction of flow of electron changes regularly.