Page 164 - Lindens Handbook of Batteries

0.65

0.6
Discharge
0.55
Discharge
Cathode Separator Anode
0.5
Porosity 0.45

0.4

0.35

0.3

0.25
0 0.2 0.4 0.6 0.8 1
Dimensionless distance
FiguRE 6.9 Porosity distribution across the thickness of the electrodes as a func-
tion of time during discharge in a lead-acid cell. The porosity at the electrode-separator
interface decreases in both the anode and the cathode/separator interfaces due to the
formation of PbSO . 17
4
50

40
30

20
Cathode Separator Anode
10
di 2 /dx (A/cm 3 ) –10 0

–20

–30
–40

–50
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Dimensionless distance
FiguRE 6.10 Reaction rate distribution across the thickness of a lead-acid cell [see
Eq. (6.40)]. The blockage of the electrode surface by the formation of PhSO creates a
4
nonuniform distribution of the reaction across the thickness. 17
6.17