Batteries are devices that convert chemical energy into electrical energy.
The batteries have two electrodes in which the chemical reactions that produce and use the generated electrons occur. The electrodes are connected with a solution called electrolytic to which the ions can move, complementing the electrical circuit. Electrons are produced in the anode and these electrons can flow through an external circuit towards the cathode. This movement of electrons is the electric current used to power simple devices.
The batteries consist of one or more electrochemical cells which then store chemical energy for conversion to electrical energy. The batteries consist of at least one electrochemical cell used to store and produce electricity. Although there are several electrochemical cells, the batteries generally consist of at least one voltaic cell. Volta cells are sometimes called galvanic cells. Chemical reactions and generation of electrical energy occur spontaneously in a voltaic cell instead of electrolytic cells and fuel cell reactions.
Batteries are divided into two general groups:
- Primary Battery
- Seconder Battery
Primary batteries are non-rechargeable and single-use. The electrochemical reactions in these batteries cannot be reversed. The materials in the electrodes are completely used and therefore the electricity cannot be reproduced. Primary batteries are usually used when long-term storage is required.
Primary batteries are designed to be used until the voltage is too low to operate a specific device and then discarded.
The secondary batteries can be charged. These batteries are subject to electrochemical reactions that can be easily reversed. The chemical reactions in the secondary batteries can be reversed because the reacting components are not used completely. Rechargeable batteries require an external power supply to recharge after they have consumed their energy. Secondary batteries have many special design features as well as special materials for reconfiguring (recharging) the electrodes. After partial or full discharge, they can be recharged by applying DC voltage. While the original condition is usually not fully restored, the loss per refill cycle in commercial batteries is only a small fraction of 1 percent, even under various conditions.