The Influence of Diffusion Barriers on the Capacitance Properties of Composite Anodes with Si–CuSi–Cu Composition

Abstract

Film structures composed of several identical modules [Co(x)/a-Si(100)/Cu(70)], where the x value varies from 2 to 10 nm, are investigated as an anode material for liquid lithium-ion batteries. It is shown that relatively thick cobalt layers are effective diffusion barriers for silicon and copper atoms, as well as for lithium ions. This leads to a decrease in the capacitance characteristics of the films under study. Thin cobalt layers (less than 3 nm) with a network structure, on the contrary, increase the capacitance characteristics of the anode films. This is caused by more uniform distribution of lithium ion drift channels that are formed at the initial stage of electrochemical cycling of electrodes over their volume.