Model after model, it is always the same problem. Autonomy is never as good as one would like. Nothing surprising. The functionalities are more and more numerous but the battery technology is always the same. Fortunately, the situation could change in a few years thanks to a new innovation: lithium-air batteries! What to make our smartphones last for several days.
A short reminder about lithium-ion batteries
So far, it is the lithium-ion batteries found in our smartphones. The principle of a li-ion battery is quite simple. Lithium ions are exchanged between a positive electrode (cathode) in cobalt dioxide and a negative in graphite (anode). Between the two, a sparer usually plastic fast contact between the two electrodes while letting pass the lithium ions.
During charging, the lithium ions pass from the positive electrode (cobalt dioxide) to the negative electrode (graphite). When unloading, the opposite occurs.
How is the lithium-air battery revolutionary?
This discovery of the lithium-air battery (Li-O2 to be precise was made by scientists from the University of Cambridge who made it public in late October in the journal Science Lide lithium-air batteries is therefore to replace the medium through which the ions transit to go from the cathode lanode to the ambient air.
According to these researchers, lithium-air batteries would have the ability to maintain an energy density ten times higher than lithium-ion batteries. These batteries would also be five times lighter and cheaper. And finally, they could support up to 2000 charge cycles without major loss of capacity! The Li-O2 battery could reach 3450 watt hours per kilogram (Wh / kg) against about 200 Wh / kg for the batteries of our current phones.
On paper, the technology looks promising but presents some problems. These batteries use oxygen as the raw material, which results in the formation of lithium peroxide (Li2O2) after its encounter with lithium. Li2O2 can then accumulate on the cathode and foul it, blocking the chemical reactions and thus the use of the battery. Worse, it can be aggressive and destroy other materials present in the battery.
To overcome this concern, researchers have developed a more porous graphite electrode capable of displacing Li2O2 formation and allowing the battery to continue to function. Clare Gray, one of the academics involved in the research, summarizes his innovation as follows: a powerful Li-O2 battery must solve all these problems at once.
Unfortunately, this revolutionary technology is not yet ready to see an industrial level. It is still several years before being able to dream a smartphone whose autonomy could exceed the week. However, the advantages of lithium-air batteries are such that they can enjoy multiple uses in many areas. We are obviously thinking of the electric car sector. What to expect a public exit earlier than expected.
Do you dream of a battery that can last a week?
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