American scientists have found the truth about the shorter life span of lithium batteries

In a paper published in the latest issue of the journal scientific progress, us scientists say the lithium ion concentration in lithium-ion batteries is subject to fluctuations, which explains the shorter life span of lithium-ion batteries and is expected to help develop batteries that charge more quickly and stay on hold longer.

A team of researchers led by the Department of Energy's Brookhaven National Laboratory recently found that when batteries generate electricity, if the battery's electrodes are made of nanoparticles, the concentration of lithium ions in parts of the nanoparticles will rise first and then decrease. Instead of the concentration that has been thought to continue to increase.

The lattice is a structure in which particles inside the crystal are arranged in a certain geometry. The working principle of lithium ion batteries is that lithium ions move between positive and negative polar lattices. When charged, lithium ions flow from positive to negative poles, and discharge is the opposite.

"Similar to sponge water absorption, we see an increasing total concentration of lithium ions in nanoparticles," said Wangfengshuo, a scientist at the Brookhaven National Laboratory's Sustainable Energy Technology Department, who led the study. "But unlike water, lithium ions selectively flow out of certain areas. This results in inconsistent concentrations of lithium ions between lattices. "

The researchers pointed out that before lithium ions enter the lattice, the lattice structure is very uniform. Once lithium ions enter, they stretch the lattice. When lithium ions flow out, the lattice shrinks again. The uneven movement of lithium ions may cause persistent damage because it deforms the structure of the active components in the battery and may cause battery fatigue failure.

The researchers speculate that this phenomenon may also occur in other high-performance battery chemicals. The results of this study can help develop batteries with shorter charging time and longer standby time.

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