Friday is here, and the "A Taste of Science for the Weekend" corner is back — number 67.
And this time: will salt-based batteries change the future of humanity?
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Lithium batteries are the oxygen of digital and technological life in the modern age.
They power the computers and gadgets around us, and to an ever-growing extent, our electric and hybrid vehicles as well.
But lithium batteries have significant drawbacks.
Their lithium and cobalt content makes them expensive to produce, polluting, and hazardous.
At low temperatures, the electrolyte (the liquid through which ions travel between the battery's electrodes) becomes viscous and inefficient, and the lithium forms a metallic layer on the anode that irreversibly damages its capacity.
At high temperatures, the lithium decomposes into a gas that destroys the insulating layer between the electrodes, causing particularly dangerous ignition and explosion.
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Sodium-based batteries are a promising technology already making its way to market.
In these batteries, lithium ions are replaced by sodium ions.
Sodium ions are larger, so to allow them to flow between the battery's electrodes, the other components must be chemically adapted.
In lithium batteries, the anode is made of graphite — a material with flat, ordered carbon layers sized to match lithium ions.
In sodium batteries, the graphite is replaced by hard carbon, whose disordered carbon structure can accommodate the larger sodium ions.
The cobalt used in lithium batteries to improve the conductivity, structure, and energy density of the cathode is replaced in sodium batteries by inexpensive manganese.
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Sodium-based batteries decompose into gas at a higher temperature than lithium ones, making them safer to use.
They deliver high efficiency even at extremely low temperatures, and they do not form the metallic layer that causes irreversible damage in lithium batteries.
And above all — they are exceptionally cheap to produce and manufacture, given that salt and manganese are inexpensive, abundant materials, with no environmental harm in the production process.
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Their main drawback is lower energy density — they store and deliver less electricity per kilogram of battery compared to lithium.
This makes them better suited for energy storage applications, such as wind turbines and solar farms, and less suitable as a replacement for batteries in portable devices.
In the coming years, these batteries will likely see growing adoption for energy storage across a wide range of applications — and the opening shot has already been fired in China, where CATL launched a sodium battery for the automotive market.
Let's hope the technology continues to gain momentum and propels humanity forward into a cleaner, more efficient era.
Shabbat Shalom 😊
Video: From a CNBC report on sodium batteries. | Credit: CNBC YouTube channel.
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