Energy storage cell overcharge

Does single overcharge affect cell capacity?

The results indicate that single overcharge has little influence on cell capacity, while it severely degrades thermal stability. Degradation mechanisms are investigated by utilizing the incremental capacity–differential voltage and relaxation voltage analyses.

What happens if a fully discharged fresh pouch cell is overcharged?

Thus, a fully discharged fresh pouch cell is overcharged at C/5-rate until failure to characterize the overcharge behavior of the working cell. The electrochemical result is used to select the E upper values to be used for cycling under the continuous overcharge condition. Figure 1 a shows that the cell starts to fail as the voltage rises to 5.0 V.

How does overcharge affect cell cyclability?

The two cells under this condition exhibit a slight volume expansion due to the aforementioned gas generation processes. This degradation scenario is represented by the cell charged up to E upper = 4.8 V. Degradation imposed by overcharge drastically hinders the cell cyclability and leads the cell to an early failure.

How to protect a battery from overcharge?

The factors of battery material, charging pattern, and battery structure design on the overcharge effect are also summarized. To some extent, using external protection devices (such as BMS, OSD, CID) can improve overcharging security. But the internal protection of overcharge additives is more effective.

How does overcharge affect cell performance?

Overcharge became more relevant on the cells cycled beyond 4.6 V, where electrolyte decomposition and lithium plating dominate the cell performance. A characteristic feature of this degradation was voltage undershoot. The overcharge extreme regime, 4.8 V, showed an excessive presence of lithium plating and an accelerated production of gases.

Does overcharging cause accelerated degradation of battery power and capacity?

This indicates that overcharging during long-term cycling leads to accelerated degradation of battery power and capacity. After 100 cycles, the capacity of cycling under condition 1 retains 92.30 % of the initial capacity, while cycling under condition 2 has degraded to 88.58 % of the initial capacity, as depicted in Fig. 2 (b).