A battery is a device which transforms chemical energy into electricity to supply a static power charge.
A capacitor, on the other hand, is an electronic component used to store electrostatic energy in an electrical field.
Would capacitors be able to replace batteries?
Emilio
Both capacitors and batteries perform the same duty of storing and releasing energy. However, the functioning of the capacitor and the battery differ significantly.
Major differences between capacitors and batteries
Capacitor
Potential energy storage
The potential energy is stored in the electrical field.
Working principle
Once the voltage is applied across the capacitor terminals, it begins storing energy within.
Size
The size of the capacitor is comparatively large as compared to the batteries for the same capacity rating.
Type of device
It is a passive electronic component, consisting of two conductive plates and an insulator (dielectric) between them.
Energy density
The capacitor energy density is lower than that of a battery.
Charging and discharging
The charging and discharge rates of the capacitor are quicker than a battery because it directly transfers energy to the plates.
Voltage
In the discharging process, the voltage decreases rapidly.
Composition
A capacitor consists of thin sheet metals which are held close to each other or isolated by an insulator.
Life span
The capacitor does not run for a longer time.
Applications
They are extensively used in pulsed applications for load sharing, in motor starters, as power back-up for most of the memory functions in various products.
Batteries
Potential energy storage
The potential energy is stored in the form of chemical energy which is eventually transformed into electricity.
Working principle
Battery works on the basis of a chemical reaction called an oxidation-reduction response.
Size
The battery size is small compared to a capacitor for the same charging capacity.
Type of device
The battery is an active component (storage and release energy). It is made of metal plates called Anode (positive terminal) & Cathode (negative terminal) & an electrolyte.
Energy density
It has greater energy density than a capacitor.
Charging and discharging
The rates of charging and discharge are comparatively slower due to the conversion of chemical energy to electrical energy.
Voltage
It delivers a constant voltage while discharging.
Composition
The composition of batteries is generally metals and chemicals.
Life span
Batteries can run for a longer time.
Applications
Their uses are mostly found for emergency power, in robots and automobiles, local energy storage or in submarines.
Elizebeth
Capacitors are also called condensers which is an old term. Although the energy storage mechanisms are the same for both batteries and condensers, the main difference is how these tasks are performed.