Figure 3: Discharge curves at C/10 rate for (a) -10 °C, (b) 0 °C,
(c) 25 °C and (d) 40 °C
Figure 4a-d illustrates the charging pattern of the cells at -10, 0, 25
and 40 °C. Similar to discharging profiles, during the initial cycles it
was observed that total charging duration is higher for cells discharged
at 40 and 25 °C, as compared to that at 0 °C and -10 °C. The charge
durations are 2, 2.5, 4 and 1.5 h after 120 cycles for 40, 25, 0 and -10
°C, respectively. Similar charging and discharging patterns corroborate
the observed capacity degradation process.