Dehydration process on niquel hydroxide. Its influence on the electrochemical behavior of Pt/Ni(OH)2 electrodes

MARCELO J. AVENA; MARIO V. VÁZQUEZ; CARLOS P. DE PAULI

ELECTROCHIMICA ACTA

PERGAMON-ELSEVIER SCIENCE LTD

Año: 1995 vol. 40 p. 907 - 912

0013-4686

The effects of dehydration on the structural and electrochemical properties of Ni(OH), , pre- pared by massive precipitation from NiSO, and KOH solutions or by precipitation on Pt substrates were studied. The so prepared materials showed gel characteristics. They were composed by an approximately 5% of Ni(OH), and a 95% of water. Dehydration of these materials resulted in a gel shrinkage until the final volume was a 4-lo%, of the initial one. Dehydration treatments produced a significant increase in the voltammetric discharge efficiency of Ni(OH), coated Pt electrodes. Such improvement can be qualitatively explained by an increase in the concentration of Ni(OH), particles near the substrate surface due to the gel shrinkage.