Source: cnBeta
Researchers at the U.S. Department of Energy's SLAC National Accelerator Laboratory and Stanford University have just introduced a method that can greatly restore the efficiency of rechargeable lithium batteries. For electric vehicles and next-generation electronic devices, this means that the battery life of the products in question can be further extended. It is reported that after experiencing multiple charge and discharge cycles, lithium batteries will form less active lithium islands between electrodes, thereby reducing the energy storage effect of the battery.
（图自：Greg Stewart / SLAC National Accelerator Laboratory）
The good news is that the researchers found that they were able to send "near-dead" lithium islands to one of the electrodes like worms until they were reconnected, partially reversing the process of poor attenuation.
As the study, published in the journal Nature on December 22, 2021, shows that by introducing this extra step, the team was able to extend the life of lithium batteries by nearly 30 percent.
Fang Liu, a postdoctoral researcher at Stanford University, said: "We are now exploring the possibility of using extremely fast discharge steps to restore the loss of lithium-ion battery capacity."
As shown in the figure above, but when an inactivated lithium metal island is moved to the anode (or negative) of the battery and reconnected, it can be revived, used for charge storage, and supported for electron flow.
And SLAC and Stanford researchers found that they can extend the life of lithium batteries for testing by nearly 30% by pushing the lithium island to grow in the anode direction by applying a short period of high-current discharge action immediately after the battery is charged.
The animation below shows the principle of the experimental device and explains how the "near-death" lithium island squirms back and forth between the yin and yang (red and blue) poles during the battery charge and discharge cycle.
Considering that lithium batteries are now widely used in mobile phones, laptops and electric vehicles, a large number of research teams are looking for rechargeable battery solutions that are lighter in weight, longer in life, safer and faster in charging.
One of the development directions is lithium metal batteries, which can store more capacity and charge more efficiently at the same unit volume weight. If popularized, the next generation of electric vehicles could weigh less and take up less space, or achieve longer ranges at the same battery volume.
However, whether it is a solid-state or lithium-ion battery, they must use positively charged lithium ions to shuttle back and forth between the two poles. Over time, some lithium metals become electrochemically inert, forming lithium islands that are no longer connected to the electrodes, resulting in a loss of capacity.
For more information about this study, please also check out the journal Nature, which became officially published on December 22, 2021.
原标题为《Dynamic spatial progression of isolated lithium during battery operations》。