Lithium-ion battery technology is probably already familiar to us in our daily lives. Whether it's in mobile phones or tablets, the power supply components all use lithium-ion batteries. Of course, you've also noticed that the longer a battery is used and the more times it's charged, the weaker its battery life becomes with each charge. So what causes batteries to gradually become obsolete? Many people may not know the reasons behind this, so let me explain the truth behind why batteries shrink with each charge.
Lithium-ion batteries are now widely used in mobile devices, but their lifespan is short; they lose about one-fifth of their capacity after 500 charge cycles. To investigate the causes of lithium-ion battery performance degradation, scientists at the Pacific Northwest National Laboratory in the United States successfully observed the real-time charging and discharging states of lithium-ion batteries using a powerful microscope.
Researchers discovered that batteries experience stress during use, causing electrodes to crack. Furthermore, each charge-discharge cycle leaves traces of lithium outside the electrodes; this "dead" lithium cannot function in future charges and contributes to a decrease in battery capacity. Researchers also observed the formation of a solid electrolyte interphase layer on the electrode surface, which "blocks" the battery and affects its charging capability.
One way to solve these problems with lithium batteries is to use alternative elements. In the future, metals such as magnesium, aluminum, or copper may become cheaper and more stable alternatives; however, the performance of these batteries currently does not reach the level of lithium batteries.
