Table 1.

Fitting results of electrochemical impedance spectroscopy (EIS) spectra in Figure 4a.

Sample	Rs (Ω)	Cc (F)	Rc (Ω)	Cdl (F)	Rt (Ω)
Ni/G-50W	32.8	1.82 × 10−4	1188	2.77 × 10−7	74.1
Ni/G-100W	33.3	2.77 × 10−4	1928	4.88 × 10−6	55.6
Ni/G-150W	34.3	1.93 × 10−4	859.5	4.86 × 10−7	72.9
Ni/G-200W	32.7	2.34 × 10−4	902.2	1.22 × 10−6	68.1