Batteries that would allow our electric cars to travel more than 1,000 kilometers without having to be recharged. Everyone dreams of it. And researchers have just discovered a way to boost this autonomy. A surprisingly simple way.
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In our electric cars today, we find so-called batteries lithiumlithium-|89edc524d5744de0a98ca4460e251f94| Their autonomy hardly exceeds 500 kilometers. But manufacturers are talking about another technology that could allow us to drive without recharging for almost 1,200 kilometers. So-called lithium technologymetalmetal. So why is it not yet integrated into our electric vehicles? Because this type of battery quickly loses its capacity to storeenergyenergy after relatively few charge and discharge cycles.
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Engineers are working on the issue. And researchers from Stanford University (United States) are now proposing an astonishing solution to this problem. Their work published in the journal Nature show that simply draining the battery and letting it sit for a few hours will restore its capacity, increase its lifespan, and improve its overall performance. The only thing to do, therefore, is to reprogram the battery management software. Simple and inexpensive handling.
The researchers believe their work could help guide other studies that would contribute to widespread commercialization of lithium-metal batteries. And that would be good news in more ways than one. A lithium-metal battery, in fact, can store twice the energy of a batterie lithium-ionbatterie lithium-ion in the same space. It is also lighter thanks to a anodeanode in lithium which replaces the anode in graphitegraphite. As a result, a lithium-metal battery can hold at least a third more energy per pound — per 500 grams or so — than a lithium-ion battery.
To understand how to solve its problem of rapid degradation upon charge/discharge, you should know that when a lithium-metal battery discharges, pieces of metallic lithium the size of a micronmicron become trapped in the electrolyte interphase solidsolid (SEI), a spongy matrix that forms where the anode and electrolyte meet. Isolated lithium that engineers consider dead. And repeated charging and discharging causes this dead lithium to build up, causing the battery to lose capacity quickly.
After a rest period, battery performance is better
Previous work has shown that the SEI matrix begins to dissolve when the battery is inactive. To go further, the researchers completely discharged a battery. Enough to remove all the metallic lithium from the anode. And leave only inactive pieces of isolated lithium surrounded by the SEI matrix. They observed that if the battery remains discharged, the matrix dissolves. Result, when the battery is then recharged, the dead lithium which is no longer bothered by the massemasse solid can reconnect to the anode. A way to bring it back to life.
How can we apply this discovery to the real world? By instructing the battery management system to completely discharge individual modules one after the other. A battery has around 4,000 of these modules. And offering them time to rest can considerably increase the durationduration life of the whole.
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