ELECTROCRYSTALLIZATION OF NI CO AND FE DENDRITES FROM AQUEOUS SOLUTIONS

Electrocrystallization from aqueous solutions of macroscopic dendrites of the 'inert metals' (so-called by Piontelli) such as Ni, Co and Fe has been attained galvanostatically under unusual electrolytic conditions, viz, for Ni, 3M NiCl2, cd (on original cathode surface) 5 A/cm2, 105°C. In the case of linear dendrites, wherein the side growth rate is negligible (1:100 against the forward growth rate), the cd at the forward growth site is estimated as about 2400 A/cm2, which is nearly twice the value of the calculated limiting cd on Ni at 18°C. Under such circumstances, Ni deposits at 100%. current efficiency without evolution of hydrogen. Various factors affecting dendrite foilnation (temperature, concentration of electrolytes and cd) have been examined. © 1968.