2 ms·
Close, the typical problem is that the cation of the lithium compound used in the cathode (LiFePO4, LiCoO2, etc) becomes oxidized or otherwise degraded in a way
by LeifCarrotson 5y ago
Close, the typical problem is that the cation of the lithium compound used in the cathode (LiFePO4, LiCoO2, etc) becomes oxidized or otherwise degraded in a way that the electrochemical reaction can't reverse. In an LiFePO4 battery, you might get some iron oxide. In a traditional lead and sulfuric acid battery, you get lead sulfate crystals. There's typically the exact same amount of lithium present (it doesn't become gaseous and float away) but its constituent elements are unavailable for electrochem.
- samatman 5y agoThe most common failure mode is actually dendrites growing off the cathode and puncturing the thin layers of the cylindrical battery. Typically these are cobalt or iron, depending on the chemistry. Note that I'm discussing failure of a cell, not slow degradation in its ability to hold a charge, which has a variety of causes including the one you sketched out.