Metal electrode (M)
Electrolyte solution
(S)
+ Positive charge
–
– Negative charge
–
Solvent molecule
+
+
–
+
+
–
+
–
+
–
+
–
(a)
ψ
ψ –(–ψ 1 )
–ψ 1
d
0
x
(b)
53
Fundamentals of Electrochemical Double-Layer Supercapacitors
FIGURE 2.10
(See color insert.) Double-layer with specific ion adsorption and its corresponding potential
distribution.
total positive charge on the electrode surface, the potential drop of the diffuse
layer would be negative (ψ 1 <0), resulting in ψ – ψ 1 > ψ, as shown in Figure 2.10.
To address the effect of specific adsorption of ions on the electrode surface,
two models were developed to divide the Helmholtz layer into: (1) the inner
Helmholtz plane (IHP) with a thickness of d IHP and (2) the outer Helmholtz
plane (OHP) with a thickness of d OHP , as shown in Figure 2.10. The capacitance of IHP (C IHP ) is induced by the net charge near the electrode surface
Electrolyte solution
(S)
+ Positive charge
–
– Negative charge
–
Solvent molecule
+
+
–
+
+
–
+
–
+
–
+
–
(a)
ψ
ψ –(–ψ 1 )
–ψ 1
d
0
x
(b)
53
Fundamentals of Electrochemical Double-Layer Supercapacitors
FIGURE 2.10
(See color insert.) Double-layer with specific ion adsorption and its corresponding potential
distribution.
total positive charge on the electrode surface, the potential drop of the diffuse
layer would be negative (ψ 1 <0), resulting in ψ – ψ 1 > ψ, as shown in Figure 2.10.
To address the effect of specific adsorption of ions on the electrode surface,
two models were developed to divide the Helmholtz layer into: (1) the inner
Helmholtz plane (IHP) with a thickness of d IHP and (2) the outer Helmholtz
plane (OHP) with a thickness of d OHP , as shown in Figure 2.10. The capacitance of IHP (C IHP ) is induced by the net charge near the electrode surface