Page 155 - Lindens Handbook of Batteries

6.8 PRINCIPLES OF OPERATION

4.4 4.4
4.2 4.2
4 3.8 4
3.8
Cell voltage (V) 3.6 Cell voltage (V) 3.6

3.4
3.4
3.2
3 3.2 3
2.8 2.8
2.6 2.6
0 1000 2000 3000 4000 5000 6000 7000 0 1000 2000 3000 4000 5000 6000 7000
Time (s) Time (s)
(a) (c)
0
150
–10
–20
–30 100
Current (A) –40 Current (A)

–50
–60 50
–70
–80
–90 0
0 1000 2000 3000 4000 5000 6000 7000 0 1000 2000 3000 4000 5000 6000 7000
Time (s) Time (s)
(b) (d)
6
FiguRE 6.5 Model predictions vs. experimental data from the equivalent circuit model under constant power discharge for a
lithium-ion cell at 0°C. (a) Cell voltage during charge at constant power; the power supplied was set to 10, 25, 50, 100, 200 W, respec-
tively, for each curve shown in the figure. (b) The charge current corresponding to the cell voltages shown in (a); since the voltage
rises rapidly at higher rates of charge, the current tapers at the end of charge in order to maintain constant power during the entire
process. (c) Cell voltage during discharge at constant power; the power drawn from the cell was set to the same values as described
in (a). (d) Cell current during discharge, corresponding to (c). The symbols represent the experimental data and the solid lines the
model predictions.

5
TABLE 6.2 Parameters Used in the
Equivalent Circuit Model to Predict the
Response of a Lithium-Ion Cell as Shown
in Fig. 6.5.
Parameter Discharge Charge
τ (s) 5 5
C (F) 12500 16667
D
R, mΩ 1.637 1.637
R , mΩ 0.4 0.3
ct