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An electric battery is a chemical source of reusable current, the main specificity of which is the reversibility of internal chemical processes, which ensures its repeated cyclic use (through charge-discharge) for energy storage and autonomous power supply of various electrical devices and equipment.
Principle of operation
The principle of operation of the battery is based on the reversibility of the chemical reaction. The battery can be restored by charging, that is, by passing an electric current in the direction opposite to the direction of the current during discharge. Several batteries, combined into one electric circuit, make up the battery.
Characteristics
The maximum possible useful battery charge is called a charging capacity, or just a capacity. The battery capacity is the charge given by a fully charged battery when discharged to the lowest allowable voltage. In the SI system, the battery capacity is measured in pendants, in practice, an out-of-system unit is often used - an ampere-hour. 1 A⋅ch = 3600 Cl. Less often, energy capacity is indicated on batteries - the energy given by a fully charged battery when discharged to the lowest permissible voltage. In the SI system, it is measured in joules, in practice, an off-system unit is sometimes used - a watt-hour. 1 Vt⋅ch = 3600 J.
The electrical and operational characteristics of the battery depend on the electrode material and electrolyte composition.
As the chemical energy is exhausted, the voltage and current drop, the battery ceases to work. You can charge the battery (battery of batteries) from any DC source with a higher voltage when limiting the current. A charging current (in amperes) of 1/10 of the rated battery capacity (in amper⋅chasakh) is considered standard. Many types of batteries have various limitations that must be taken into account when charging and subsequent operation, for example, NiMH batteries are sensitive to recharge, lithium batteries are sensitive to recharge, voltage and temperature. NiCd and NiMH batteries have the so-called memory effect of reducing capacity in the case when charging is carried out with an incompletely discharged battery. Also, these types of batteries have a noticeable self-discharge, that is, they gradually lose charge, even without being connected to the load. Drip charging can be used to combat this effect.
Battery types
- Iron-air battery
- Iron-nickel battery
- Lanthanum-fluoride battery
- Lithium-iron-sulfide battery
- Lithium-iron-phosphate battery
- Lithium Ion Battery (Li-Ion)
- Lithium-air battery (Li-air)
- Lithium polymer battery
- Lithium Fluorine Battery
- Lithium chlorine battery
- Lithium Sulphur Battery
- Sodium-nickel-chloride battery
- Sodium Sulphur Battery
- Nickel-Cadmium Battery (NiCd)
- Nickel Metal Hydride Battery (NiMH)
- Nickel-zinc battery
- Lead-hydrogen battery
- Lead-acid battery
- Silver-cadmium battery
- Silver-zinc battery
- Zinc bromine battery
- Zinc-air battery
- Zinc-chlorine battery
- Nickel-hydrogen battery
New technologies
Electroceramics
Russian scientists have developed innovative electric ceramics that can significantly increase the capacity and durability of capacitors and batteries. This was announced on October 2, 2024 by the National Research University of MIET (NIU MIET) on its official website. The new material, created in the framework of international cooperation, has increased sensitivity even at high temperatures. Read more here
Electric battery from electric eel
Researchers from the University of Michigan and the University of Fribourg report in 2017 in their paper in Nature that they were able to construct a current source operating on the same principle as the electric organ of the electric eel. In eels, electrical organs consist of a variety of cells through which a stream of positive potassium and sodium ions passes; as a result, each cell has a positively charged pole (directed towards the head of the fish) and a negatively charged pole (directed towards the tail). Each cell creates a voltage of about 150 millivolts, but all together, stacked one after another, like batteries, they generate hundreds and hundreds of volts[1].
Michael Mayer and his colleagues did something similar. Instead of living cells, they used cells filled with a hydrogel polymer that retained water. The hydrogel in the cells holds either pure water or water with salts breaking down into positive and negative ions in solution. The cell walls are made of a semipermeable membrane that passes these ions back and forth. When the cells contact each other, the ions in them begin to move in different directions, and an electric voltage arises.
The hydrogels in the cells differ in their own composition and in the composition of the solutions they retain; if compared with the electric cells of eels, then four cells correspond to one cell (in the photo they are indicated by different colors). One block of four cells gives from 130 to 185 millivolts, in the experiment it was possible to make a large "battery" of several hundred cells, which in total gave 110 volts.
But the main trick here is how the battery was made to work. Artificial electrical cells in one case were distributed between two elastic polymer sheets: by superimposing the sheets on top of each other, the cells could be combined in the right order (as in photo 2). In another version, they were all placed on the same sheet, but so that they could be combined by folding the sheet several times (as in photo 3). When both sheets were compressed, or when the folded sheet was compressed, there was contact between all the cells at once - and all the cells worked simultaneously.
It is expected that such batteries can be used to power various biomedical devices, and, moreover, that such batteries can use the natural charge of some internal tissues and organs. "Eel-like" batteries are more flexible and easier to make biocompatible so that they do not irritate living cells. The problem, however, is that so far the voltage they produce is not very high, although the inventors believe that in the near future they will be able to force their batteries to generate a current of the same voltage as the actual electric eels.
Battery spray
Researchers from Rice University in Houston (Rice University) presented in 2016 a prototype battery that is applied as a spray, which could radically change the approach to the design of portable electronic devices.
Such a battery is rechargeable and has the same electrical characteristics as lithium-ion batteries, which are built into all mobile gadgets, but the battery itself can be applied to almost any surface using a conventional paint spray, said Neelam Singh, a university graduate who has led the team of researchers for more than a year.
Today, lithium-ion batteries, with all the variety of devices where they are used, look about the same: they are removable rectangular blocks with electrodes at one end. Because these batteries don't bend, they severely limit handheld designers to choosing new form factors, especially curved ones, but that could now change. "Batteries of a new type will be able to be manufactured directly in the form of the space that remains free in the device," Sing said.
The battery is sprayed in five layers: some of which work as a cathode, others as an anode, and a polymer separator is also present. The scientists said they had problems picking up paint that was not initially moisture resistant and could stand, but adding polymers and introducing a heat treatment procedure solved the issue.
As a result, a new type of battery can be sprayed on plastic, metal and not even ceramics. During the experiment, a team of scientists sprayed such a battery on nine ceramic tiles, which is usually used to finish bathrooms. These tiles were combined into a battery, and their power was enough for 6 hours of LEDs, which they posted the name of the university - "Rice."
At the moment, the team has started patenting its invention. According to Sing, further work will be carried out so that even non-professionals can produce such batteries at home from improvised materials. In addition, the developers hope to interest their prototypes of electronics manufacturers, since they believe that the production of such batteries with the current level of industrial development can be established very quickly.
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