140
3 – Transport in ionic solids
M m and ρ are the molar mass and the density of the polymer electrolyte,
respectively.
We obtain
.
.
V
c m mol
1 3
1740
1338 5
m
3
1
–
=
=
and
V = 2.78 # 10
−2 # 1 338.5 = 37.2 cm
3
Finally, the number of lithium ions effectively participating in the electric
conduction is
n Li = 8.46 # 10
−6 # 37.2
.
n
m ol
3 15 10
Li
4
#
=
−
2. Assuming that all the free Li
+
ions effectively participate in the electric
conduction, the dissociation rate τ for the salt LiCF 3 SO 3 by the reaction
LiCF 3 SO 3 m Li
+ + CF 3 SO
−
3
is
n
n Li
τ =
2.78 10
3.15 10
–2
–4
#
#
τ =
1.13 %
τ =
Solution 3.7 – Electrical conductivity as a function of composition
in (CeO 2 ) 1−x (YO 1.5 ) x
1. The curve for the function σ e = f (x) is given in logarithmic coordinates in
figure 57.
Figure 57 – Electrical
conductivity of solid solution
(CeO 2 ) 1−x (YO 1.5 ) x as a function
of doping rate x in logarithmic
coordinates.
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