Why do electric vehicle lithium batteries reduce capacity as they are used?

The old man next door, talking about his own electric car battery the day before yesterday, he asked me very confused, why the electric car lithium battery will reduce the capacity with the use, I think many people know about this problem, but specifically why Maybe everyone will not be clear. Recently, the US Energy Agency discovered the cause of battery "aging": nano-sized crystals.

The researchers carefully studied the materials of modern battery anodes and cathodes. They found that these materials were directly corroded during use, but the mechanism of corrosion was not clear. The Brook haven National Laboratory team observed high-quality nickel-oxygen cathodes by transmission electron microscopy and recorded them in repeated Changes during charging and discharging. The experiment shows that when lithium ions pass through the anode and cathode, they will "snap" in the ion channel, and they will oxidize with nickel.

The matter reacts and produces tiny crystals. These crystals change the structure inside the battery and prevent other ions from reacting efficiently, reducing the available battery capacity. Surprisingly, such weakness is random and there is no law at all. The reason why the lithium battery is not perfect is that the components of the battery are not perfect. No matter how much we pay attention to the structure of the anode and the cathode, tiny damage will produce crystals. Just like when boiling water, containers with uneven surfaces make it easier for hot water to create bubbles. It can be said that as long as the battery material has a gap, nanocrystals will be produced.

The US Energy Agency also launched a second study to explore the impact of charging speed on battery capacity. They found that modern batteries are getting smaller and smaller, which in turn will shorten battery life. The larger the battery, the faster the charging speed, and the slower the formation of nanocrystals.

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