Energy & Green Tech
A sustainable source for clean energy may lie in old soda cans and seawater. MIT engineers have found that when the aluminum in soda cans is exposed in its pure form and mixed with seawater, the solution bubbles up and naturally ...
Jul 25, 2024
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154
Electronics & Semiconductors
When it comes to batteries, lithium-ion are the best we have as far as energy density and convenience.
May 3, 2021
1
2527
Energy & Green Tech
As the world builds out ever larger installations of wind and solar power systems, the need is growing fast for economical, large-scale backup systems to provide power when the sun is down and the air is calm. Today's lithium-ion ...
Aug 24, 2022
2
154
Energy & Green Tech
In the switch to "greener" energy sources, the demand for rechargeable lithium-ion batteries is surging. However, their cathodes typically contain cobalt—a metal whose extraction has high environmental and societal costs. ...
Jan 18, 2024
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88
Engineering
Engineers at the University of California San Diego have developed lithium-ion batteries that perform well at freezing cold and scorching hot temperatures, while packing a lot of energy. The researchers accomplished this ...
Jul 4, 2022
2
71
Energy & Green Tech
Researchers in China have developed a battery with organic compound electrodes that can function at -70 degrees Celsius—far colder than the temperature at which lithium-ion batteries lose most of their ability to conduct ...
Feb 28, 2018
5
847
Energy & Green Tech
Lithium-ion batteries (LIBs), which store energy leveraging the reversible reduction of lithium ions, power most devices and electronics on the market today. Due to their wide range of operating temperatures, long lifespan, ...
Engineering
Long-lasting, quick-charging batteries are essential to the expansion of the electric vehicle market, but today's lithium-ion batteries fall short of what's needed—they're too heavy, too expensive and take too long to charge.
May 12, 2021
1
137
Energy & Green Tech
The element lithium is used widely in batteries because it results in long-lasting, stable energy storage. However, it's a finite resource, so researchers are hard at work trying to identify alternate materials to use in ...
Jul 11, 2024
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33
Hi Tech & Innovation
Smartwatches as devices for messaging and search are far eclipsed by the desktop, laptop, tablet and phones, for obvious reasons, namely their tiny touchscreens. In tech parlance, the smartwatch "input-output bottleneck" ...
An ion is an atom or molecule where the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge.
Since protons are positively charged and electrons are negatively charged, if there are more electrons than protons, the atom or molecule will be negatively charged. This is called an anion (pronounced /ˈænaɪən/; an-eye-on), from the Greek ἀνά (ana), meaning 'up'.
Conversely, if there are more protons than electrons, the atom or molecule will be positively charged. This is called a cation (pronounced /ˈkætaɪən/; cat-eye-on), from the Greek κατά (kata), meaning 'down'.
An ion consisting of a single atom is called a monatomic ion. If it consists of two or more atoms, it is called a polyatomic ion. Polyatomic ions containing oxygen, such as carbonate and sulfate, are called oxyanions.
When writing the chemical formula for an ion, its charge is written as a superscript '+' or '−' following a number indicating the difference between the number of protons and the number of electrons. The number is omitted if it is equal to 1. For example, the sodium cation is written as Na+, the '+' indicating that it has one less electron than it has protons. The sulfate anion is written as SO42−, the '2−' indicating that it has two more electrons than it has protons.
If an ion contains unpaired electrons, it is called a radical ion. Just like neutral radicals, radical ions are very reactive.
This text uses material from Wikipedia, licensed under CC BY-SA
