Lithium intercalation in thin amorphous-silicon films

Electrochemical intercalation of lithium in thin films of amorphous hydrogenated silicon (a-Si:H), deposited at temperatures of 100 and 250 degrees C on stainless-steel substrates, is studied. It is shown that the discharge capacity of films of identical thicknesses manufactured at a temperature of 250 degrees C is greater than that for films produced at of 100 degrees C. Dependence of the discharge capacity of the films manufactured at 250 degrees C on their thickness is examined. It is established that an increase in the film thickness leads to acceleration of the decrease in the discharge capacity in the course of cycling. At a current density of 0.175 mA cm(-2), C, the discharge capacity of films 0.25 and 1.35 mu m thick equals nearly 2 Ah g(-1) in a third cycle, whereas in a hundredth cycle it amounts to 1.10 and 0.37 Ah g(-1), respectively. The diffusion coefficient for lithiurn in the films is equal to similar to 10(-13) cm(2) s(-1).