The first, a battery, stores energy in chemicals. Capacitors are a less common (and probably less familiar) alternative. They store energy in an electric field. In either case, the stored energy creates an electric potential. (One common name for that potential is voltage.)
Today, designers may choose ceramics or plastics as their nonconductors. A battery can store thousands of times more energy than a capacitor having the same volume. Batteries also can supply that energy in a steady, dependable stream. But sometimes they can’t provide energy as quickly as it is needed. Take, for example, the flashbulb in a camera.
Supercapacitor is supposed to be in between a Capacitor and battery. These types of capacitors charge much faster than a battery and charge more than an electrolytic capacitor per volume unit. That is why a supercapacitor is considered between a battery and an electrolytic capacitor.
When a capacitor is connected to a battery, the charge is developed on each side of the capacitor. Also, there will be a flow of current in the circuit for some time, and then it decreases to zero. Where is energy stored in the capacitor? The energy is stored in the space that is available in the capacitor plates.
A capacitor is that electronic device that stores electrical energy in an electric field. It consists of two conductive plates with a gap filled with an insulating material called a dielectric.
Battery has better energy density as compared to capacitor. For a capacitor, the energy density is lower than a battery. In capacitor, there are two terminals positive and negative. Here, generally positive terminal is longer of the two.