Lithium ion diffusion coefficient measurements were carried out on LISICON (Li3.5Zn0.25GeO4) and on a zinc-rich analogue (ZRA; Li3Zn0.5GeO4) using neutron radiography (NR). Smearing 6LiNO3-saturated solution on a surface of a rectangle-shaped sample consisting of 7Li and subsequent annealing enabled the relatively low temperature diffusion experiment down to 300C. The measured isotope concentration profiles agreed well with the diffusion model from the surface into the semi-infinite media, and the diffusion coefficients could be obtained for both LISICON and ZRA between 300 and 500C. The diffusion coefficient of LISICON was essentially larger than that of ZRA, while similar a Haven ratio was found. This indicated that the larger conductivity in LISICON was mainly caused by the higher lithium ion mobility and not by the difference of diffusion path.

Tracer Diffusion Experiments on LISICON and its Solid Solutions by Means of Neutron Radiography. S.Takai, K.Kurihara, K.Yoneda, S.Fujine, Y.Kawabata, T.Esaka: Solid State Ionics, 2004, 171[1-2], 107-12