Tudo sobre batteries
Tudo sobre batteries
Blog Article
The electrochemical reaction in a battery is carried out by moving electrons from one material to another (called electrodes) using an electric current. The first battery was invented in 1800 by Italian physicist Alessandro Volta.
Secondary (rechargeable) batteries can be discharged and recharged multiple times using an applied electric current; the original composition of the electrodes can be restored by reverse current. Examples include the lead–acid batteries used in vehicles and lithium-ion batteries used for portable electronics such as laptops and mobile phones.
While lithium-ion and sodium-ion batteries are commonly used in consumer electronics and are commercialized for use in electric vehicles, scientists are exploring an array of other chemistries that may prove to be more effective, last longer, and are cheaper than those in use today.
Battery life can be extended by storing the batteries at a low temperature, as in a refrigerator or freezer, which slows the side reactions. Such storage can extend the life of alkaline batteries by about 5%; rechargeable batteries can hold their charge much longer, depending upon type.
Batteries can only provide a DC power supply that is generated from a chemical reaction that takes place within the battery. Batteries also only ever feature positive and negative terminals where the current will only ever flow in the same direction between the two terminals.
Silicon-doped graphite already entered the market a few years ago, and now around 30% of anodes contain silicon. Another option is innovative lithium metal anodes, which could yield even greater energy density when they become commercially available.
The acceleration breaks a capsule of electrolyte that activates the battery and powers the fuze's circuits. Reserve batteries are usually designed for a short service life (seconds or minutes) after long storage (years). A water-activated battery for oceanographic instruments or military applications becomes activated on immersion in water.
It is a rechargeable battery used in everyday electronic devices such as smartphones, laptop computers, and portable power tools. In this type, the chemical reaction at the positive electrode is similar to that of a nickel-cadmium cell, with both using nickel oxide hydroxide.
The C-rate is a measure of the rate at which a battery is being charged or discharged. It is defined as the current through the battery divided by the theoretical current draw under which the battery would deliver its nominal rated capacity in one hour.[51] It has the units h−1. Because of internal resistance loss and the chemical processes inside the cells, a battery rarely delivers nameplate rated capacity in only one hour. Typically, maximum capacity is found at a low C-rate, and charging or discharging at a higher C-rate reduces the usable life and capacity акумулатори бургас of a battery.
The casing of batteries is made from steel, and the rest of the battery is made from a combination of materials (listed above) dependent on type and application. The rest of the cell is made from a combination of paper and plastic.
PNNL’s Battery Reliability Test Laboratory is part of its world-class battery development capability. The laboratory was established to accelerate the development of grid energy storage technologies that will help modernize the power grid.
Lithium-Sulfur: These lightweight batteries, which don't have any of the critical materials in positive electrodes, hold potential for electric vehicles. They can store two times the energy of batteries on today’s store shelves, but their charge is often short lived.
These rechargeable batteries have two electrodes: one that's called a positive electrode and contains lithium, and another called a negative electrode that's typically made of graphite. Electricity is generated when electrons flow through a wire that connects the two.
Almost any liquid or moist object that has enough ions to be electrically conductive can serve as the electrolyte for a cell.