American scientists find the reason for the shorter life of lithium batteries

Xinhua News Agency, Washington, January 16th. American scientists published a paper in the latest issue of 'Science Advances' magazine, saying that the concentration of lithium ions in lithium-ion batteries fluctuates and changes, which explains the shorter lifespan of lithium-ion batteries. It is expected to help develop batteries with faster charging and longer standby time. A research team led by the Brookhaven National Laboratory of the U.S. Department of Energy recently discovered that when the battery generates current, if the battery’s electrodes are made of nanoparticles, the concentration of lithium ions in some areas of the nanoparticles will increase first, and then Decrease, rather than the concentration previously thought will continue to increase. The lattice is a structure in which the particles inside the crystal are arranged in a certain geometric pattern. The working principle of lithium ion batteries is that lithium ions move between the positive and negative lattices. When charging, lithium ions flow from the positive electrode to the negative electrode, and the opposite is true during discharge. 'Similar to sponge absorbing water, we see that the total concentration of lithium ions in nanoparticles is increasing,' said Wang Feng, a scientist in the Sustainable Energy Technology Department of Brookhaven National Laboratory, who led the study. 'But unlike water, lithium ions Will selectively flow out from certain areas, which results in inconsistent lithium ion concentration between lattices.' The researchers pointed out that before lithium ions enter the lattice, the structure of the lattice is very uniform. Once the lithium ions enter, the lattice will be stretched. , When lithium ions flow out, the lattice shrinks again. The uneven movement of lithium ions may cause permanent damage because it deforms the structure of the active ingredients in the battery and may cause the battery to fail due to fatigue. Researchers speculate that this phenomenon may also occur in other high-performance battery chemistries, and the results of this study could help develop batteries with shorter charging times and longer standby times.