Lithium electrodes based upon aluminium and alloy substrates I. Impedance measurements on aluminium

Abstract

Impedance measurements have been used to confirm that, for the LiAl electrode based upon a pure aluminium substrate in propylene carbonate/LiClO4 (1.0 mol dm-3) at room temperature, the rate-limiting process at the equilibrium potential in the overall exchange reaction {A figure is presented} is the phase change α-Li(Al) = β-Li(Al). At potentials sufficiently far from equilibrium the rates are limited partly by the phase change and partly by the interfacial charge transfer process. In addition, in the case of electrodes carrying thick layers of β-Li(Al), diffusion of lithium through the alloy phase makes a further contribution to rate control. © 1989.