We explain what a battery is and how this device works. Also, the types of batteries that exist and what is a battery.
What is a battery?
An electric battery, also called an electric battery or accumulator, is a device made up of electrochemical cells capable of converting the chemical energy inside in electric power. Thus, batteries generate direct current and, in this way, serve to power different electrical circuits, depending on their size and power.
Batteries have been fully incorporated into our daily lives since their invention in the 19th century and their mass commercialization in the 20th. The development of batteries goes hand in hand with the technological advancement of electronics. Remote controls, clocks, computers Of all kinds, cell phones and a huge group of contemporary gadgets use batteries as a source of electrical power, so they are manufactured with different powers.
Batteries have a charge capacity determined by the nature of their composition and which is measured in ampere-hours (Ah), which means that the battery can deliver one ampere of current over a continuous hour of time. The higher its charging capacity, the more current it can store inside.
Lastly, the short life cycle of most commercial batteries has made them a powerful pollutant of waters Y soils, given that once their life cycle is completed they cannot be recharged or reused, and are discarded. After rusting their metallic cover, the batteries discharge to the environment its chemical content and alter its composition and pH.
How does a battery work?
The fundamental principle of a battery consists of oxidation-reduction reactions (redox) of certain chemical substances, one of which loses electrons (oxidizes) while the other gains electrons (reduces), being able to return to its initial configuration given the necessary conditions: the application of electricity (charging) or closing the circuit (discharge).
Batteries contain chemical cells that have a positive pole (anode) and a negative pole (cathode), as well as electrolytes that allow electrical flow to the outside. These cells convert chemical energy into electrical energy, through a reversible or irreversible process, depending on the type of battery, which, once complete, exhausts its capacity to receive Energy. In this, two types of cells are distinguished:
- Primary. Those that, once the reaction has occurred, cannot return to their original state, thus depleting their ability to store electric current. They are also called non-rechargeable batteries.
- High schools. Those that can receive an application of electrical energy to restore their original chemical composition, and can be used numerous times before being completely exhausted. They are also called rechargeable batteries.
Battery types
There are many types of batteries, depending on the elements used in their manufacture, such as:
- Alkaline batteries. Commonly disposable. They use potassium hydroxide (KOH) as the electrolyte. The chemical reaction that produces energy occurs between zinc (Zn, anode) and manganese dioxide (MnO2, cathode). They are extremely stable batteries, but short-lived.
- Lead acid batteries. Common in vehicles and motorcycles. They are rechargeable batteries that when charged have two electrodes of lead: a lead dioxide cathode (PbO2) and a spongy lead anode (Pb). The electrolyte used is sulfuric acid (H2SO4) in aqueous solution. On the other hand, when the battery is discharged, lead is in the form of lead (II) sulfate (PbSO4) deposited on metallic lead (Pb). Then, during the initial charge, PbSO4 is reduced to Pb on negative plates, and PbO2 is formed on positive ones. In this process, lead is oxidized and reduced at the same time. On the other hand, during discharge, PbO2 is reduced to PbSO4 and Pb is oxidized to also produce PbSO4. These two processes can be repeated cyclically until the PbSO4 crystals become too large to lose chemical reactivity. This is the case where it is colloquially said that the battery has been sulphated and must be replaced with a new one.
- Batteries nickel. Very low cost but terrible performance, they are some of the first to be manufactured in history. In turn, they gave rise to new batteries such as:
- Nickel-iron (Ni-Fe). They consisted of thin tubes wound by sheets of nickel-plated steel. On the positive plates they had nickel (III) hydroxide (Ni (OH) 3) and on the negative plates iron (Fe). The electrolyte used is potassium hydroxide (KOH). Although their life span was very long, they were discontinued due to their low performance and high cost.
- Nickel-cadmium (Ni-Cd). They are composed of a cadmium (Cd) anode and a nickel (III) hydroxide (Ni (OH) 3) cathode, and potassium hydroxide (KOH) as electrolyte. These accumulators are perfectly rechargeable, but have low energy density (barely 50Wh / kg). In addition, they are used less and less due to their high memory effect (reduction in the capacity of batteries when we carry out incomplete charges) and because cadmium is very polluting.
- Nickel-hydride (Ni-MH). They use nickel oxyhydroxide (NiOOH) for the anode and a alloy metal hydride as a cathode. They have a higher load capacity and less memory effect compared to Ni-Cd batteries, and they also do not affect the environment since they do not have Cd (very polluting and dangerous). They were the pioneers in being used for electric vehicles, since they are perfectly rechargeable.
- Lithium-ion (Li-ION) batteries. They use a lithium salt as the electrolyte. They are the most used batteries in the electronics small, such as cell phones and other portable devices. They stand out for their enormous energy density, added to the fact that they are very light, have a small size and good performance, but have a maximum life of three years. Another advantage they have is their low memory effect. In addition, when overheated they can explode, since their elements are flammable, so their production cost is high due to the fact that safety elements must be incorporated.
- Lithium polymer (LiPo) batteries. They are a variation of the ordinary batteries of lithium, have a better energy density and a better discharge rate, but have the disadvantage of being unusable if they lose their charge below 30%, so it is essential not to let them discharge completely. They can also overheat and explode, so it is very important never to wait too long to look at the battery, or always keep it in a safe place away from flammable substances.
Battery and battery
In many Spanish-speaking countries only the termbattery.
The terms battery Y battery in this context they are synonymous, and come from the early days of human manipulation of electricity. The first accumulators consisted of groups of cells or metallic discs to increase the current supplied initially, and that could be arranged in two ways: one above the other, forming a battery, or next to each other, in the form of battery.
It should be clarified, however, that in many Spanish-speaking countries only the term battery, and it is preferred accumulator for other electrical appliances, such as capacitors, etc.