Effect of Limiting Current of Polymer Electrolytes on Peukert Plots of All-Solid Cells with Lithium Metal Anodes

The effect of ion of transport limitations in polymer electrolytes on the accessible capacity of cells with lithium metal anodes and composite cathodes was quantified using Peukert plots. The cells contained a novel separator comprising crosslinked poly(ethylene oxide), and LiTFSI salt swollen with linear poly(pentyl malonate) chains. A series of cells covering a wide range of salt concentrations was used to identify the reason for the decrease in accessible first cycle cell capacity as a function of increasing current density. The Peukert plots contained two characteristic current densities that we define as iT and iB. iB is closely related to the limiting current of the separator and thus represents the current density at which transport limitations in the electrolyte become important. This suggests that iT is related to transport limitations in the electrode.