context: The concentration of 7Li electrolyte as a function of time is, ce7(t) = [Li+]fe7(t) with the initial condition for the fraction of 7Li in the electrolyte, fe7(0) = 0.92 (the natural abundance of 7Li). Since the diffusion coefficient in lithium metal, Dm, is more than four orders of magnitude smaller than the diffusion Li+ coefficient in the electrolyte (Table 1), the diffusion of Li+ throughout the electrolyte is considered instantaneous.