Through various studies, the inventors have found that cells comprising electrodes based on high capacity nanocomposite anode particles or powders (comprising conversion- or alloying-type active materials) that experience certain volume changes during cycling (moderately high volume changes (e.g., an increase by about 8-about 160 or about 180 vol. % or a reduction by about 8-about 70 vol. %) during the first charge-discharge cycle and moderate volume changes (e.g., about 4-about 50 vol. %) during the subsequent charge-discharge cycles) and an average size in the range from around 0.2 to around 40 microns (such as Si-based nanocomposite anode powders, among many others) may benefit from specific compositions of electrolytes that provide significantly improved performance (particularly for high capacity loadings).

For example, (i) continuous volume changes in high capacity nanocomposite particles during cycling in combination with (ii) electrolyte decomposition on the electrically conductive electrode surface at electrode operating potentials (e.g., mostly electrochemical electrolyte reduction in the case of Si-based anodes) may lead to a continuous (even if relatively slow) growth of a solid electrolyte interphase (SEI) layer on the surface of the nanocomposite particles.