Solid State Ionics, Vol.136-137, 279-284, 2000
Protonic conductivity of novel composite superionic conductors
The compound of composition Ti(H2L)(4). 10H(3)L . 6H(2)O (H3L = H-3[(COO)OC6H3(SO3)]) is synthesized. Its conductivity measured using impedance spectroscopy is amounts to 4.8 x 10(-5) S cm(-1) at 25 degreesC. The electronic conductivity is negligibly small, so the transfer number of proton (t(H)(+)) is close to 1. This compound (named 'Ti-composite') is stable in a humid atmosphere up to 90% relative humidity. In the humidity range from 30 to 80% its conductivity increases linearly, but at higher Values of humidity (> 90%) the conductivity grows sharply. An exchange current (i(o)) of the TiHx/Ti-composite interface describing the speed of the reaction 2H(+) + 2e(-) double left right arrow H-2, is 17 muA cm(-2) at 25 degreesC.