Capacity Fading Analysis
Capacity Fading of Li/S and Li/Si Systems as a Central Problem
A novel linear four-state model was developed and applied to various data from literature. The Figure on the right shows a fit of this model to data that are typical for Li/S-cells so far. A fast fading process destroys nearly half of the storage capacity of the cell, whereas a slow process leads to much lower fading for higher numbers of cycles. Yet in some cases the capacity may even go up, through the activation of “sleeping” material. As one of the main results of this analysis, it turned out that composite cathodes that make use of metal or metal oxides exhibit the most stable cycle performance.