Lead ion and tetrabutylammonium bromide as inhibitors of the spongy growth of zinc in single flow zinc/nickel batteries

摘要

The effectiveness of lead ion and tetrabutylammonium bromide (TBAB) as inhibitors of spongy zinc deposits from flowing zincate solutions has been testified. To assess the efficacy of the two additives, current-time technique using potentiostatic electro-deposition, scanning electron microscopy and cycling test were undertaken. The results show that the spongy growth of zinc can be effectively inhibited by the individual addition of 10~(-4)M Pb(II) or TBAB at the cathodic potential (η=-100mV). But, the dual addition of 10~(-4)M Pb(II) and 5×10~(-5)M TBAB produces more effective suppression on spongy zinc deposits. Obvious synergistic effect of Pb(II) and TBAB on the spongy inhibition of zinc electrode is found in flowing electrolytes. From the charge/discharge cycling tests of the single flow Zn-Ni test cells, it is shown that the rechargeability of deposited Zn anode is highly improved by the mixed introduction of 10~(-4)M Pb(II) and 5×10~(-5)M TBAB.