Electrodeposition kinetics of Li—Al alloys on Al: Effect of the third component

Abstract

During cathodic intercalation of lithium from a 1 M LiC1O4 solution in a mixture of propylene carbonate and dimethoxyethane (1 : 1 volume ratio), the process is limited by the lithium diffusion in the solid phase, no matter the nature of the third component. The activation energies for the process during formation of α-phase and subsequent formation of intermetallic compound β-LiAl are close and increase from 20.4-22.9 to 27.3-28.3 kJ mol-1 after introducing Zn, Pb, and Cd, respectively. The initial concentration of lithium defects decreases from 3.6 × 10-2 to 1.14 × 10-2 mol cm-3 in the series Al(Pb) > Al(Zn) > Al(Cd) > Al(Cr) > Al(Co) > Al > Al(Mn). The diffusion coefficient for lithium in β-LiAl varies from 8.25 × 10-9 to 3.43 × 10-9 cm2 s-1 in initial aluminum modified by lead or chromium, respectively. The incorporation of the third component in the aluminum matrix presumably facilitates the formation of additional vacancies and defects that make the lithium diffusion easier