IMPEDANCE OF NICKEL-CADMIUM CELLS WITH NYLON SEPARATOR HYDROLYSATE

In sealed nickel/cadmium cells, degradation of the nylon separator lea ds to decrease in the electrolyte and, eventually, to shorting of the cells. To understand this effect further, a study of the influence of nylon hydrolysis on the impedance of nickel/cadmium cells has been und ertaken. Measurements have been made of the impedance of a positive-li mited nickel/cadmium cell (flooded type) with and without nylon hydrol ysate. The nylon hydrolysate was expected to affect the double-layer i mpedance of the nickel oxide electrode around a cell voltage of 0.4 V. Unfortunately, the results show only small changes in the cell impeda nce due to nylon hydrolysate and these are not considered to be signif icant. It appears, therefore, that the impedance technique does not pr ovide unequivocal information about nylon hydrolysis.