Relationship between water departure and capacity loss of a and beta-PbO_2 using an all solid-state system: Estimation of proton diffusion coefficient

摘要

The proton diffusion coefficient for both fresh and heat-treated (140 and 230 deg C, respectively) a and beta-PbO_2 electrodes was estimated at room temperature using Galvanostatic Intermittent Titration Technique (GITT). PbO_2 samples were prepared by electroformation of cured plates. HSbO_3 centre dot xH_2O with a conductivity of 3.29 X 10~(-1) OMEGA~(-1) cm~(-1), was used as solid protonic conductor (SPC) electrolyte. It was found that when structural water is removed, the capacity of both a and beta-PbO_2 electrodes decreases and the ohmic drop increases. The departure of structural water affects considerably the value of proton diffusion coefficient.