Scientists at the US Department of Energy conducted two studies where they took a careful look at the cathode and anode materials over many charging cycles. What they found was that when lithium ions pass through the battery, a reaction causes the buildup of tiny crystals in the ion channels. These crystals alter the structure of the battery and cause other ions to move less efficiently, thus lowering the usable capacity.
So does this mean batteries are going to stop degrading? Not completely. It’s tiny flaws in the materials used that causes it, and there’s no way to completely get rid of those imperfections. A way to possibly improve the life of batteries would be to fill in as many of the imperfections as possible.
We might eventually figure out how to break up these crystals to improve old batteries, too. That’s good news in a world that’s more and more dependent on rechargeable batteries.
