The diffusion of lithium ions (DLi+) in nano-Si was studied using cyclic voltammetry, electrochemical impedance spectroscopy and the galvanostatic intermittent titration technique. The DLi+ values were estimated to be of the order of 10−12cm2/s, and exhibited W-type behaviour; varying with the lithium concentration. Two minimum regions of DLi+ (at Li2.1Si and Li3.2Si) were found, and were suggested to result from two amorphous compositions (a-Li7Si3 and a-Li13Si4). As well as the two minimum regions, one maximum DLi+ was observed at Li15Si4; corresponding to the crystallization of highly lithiated amorphous LixSi.

Determination of the Diffusion Coefficient of Lithium Ions in Nano-Si. N.Ding, J.Xu, Y.X.Yao, G.Wegner, X.Fang, C.H.Chen, I.Lieberwirth: Solid State Ionics, 2009, 180[2-3], 222-5