PROTON CONDUCTION AND DIFFUSION IN LI2SO4

Both theoretical and experimental investigations on proton conduction and diffusion in Li2SO4 have been carried out in this work. A theoreti cal method has been developed based on Fick's diffusion theory to calc ulate the proton diffusivity under an external electric field. Using t he results obtained from de polarisation measurements the proton diffu sivity has been calculated to be of the order of 10(-5) cm(2) s(-1) fo r alpha-Li2SO4. Using de conductivity values, a calculation has been m ade to determine the proton concentration in the sample. The concentra tion obtained is of the order of 10(19) to 10(20) cm(-3) with small st ructure dependence. The proton concentration is only about one percent of the Li+ ions, so the protons exist as an impurity in the sample. N evertheless, these protons are very mobile, resulting in high conducti vities and diffusivities.