EIS parameters of Al alloy in 4 M NaOH without and with EDTA-2Na additive.

C (mM)	R s (Ω cm2)	CPE1		R ct,1 (Ω cm2)	L (10−5 H cm2)	R (Ω cm2)	CPE2		R ct,2 (Ω cm2)	R p (Ω cm2)	η EIS (%)
		Y 0 (10−4 S sn cm−2)	n 1				Y 0 (10−1 S sn cm−2)	n 2
Blank	0.632	5.855	1.000	0.180	3.064	0.082	1.146	1.000	0.123	0.179	—
1	0.725	1.502	1.000	0.328	5.398	0.130	0.712	1.000	0.151	0.234	23.4
3	0.564	1.845	1.000	0.288	4.187	0.123	0.842	0.992	0.160	0.246	27.2
5	0.838	1.548	1.000	0.312	4.728	0.127	0.692	1.000	0.181	0.271	33.9
7	1.152	1.001	1.000	0.333	4.044	0.125	5.434	1.000	0.270	0.371	51.7