The low - temperature performance of nickel - cadmium (Ni - Cd) energy storage batteries is a crucial aspect that significantly impacts their application scenarios.  the performance of most batteries tends to degrade as the temperature drops, and Ni - Cd batteries are no exception. However, compared to some other battery chemistries, Ni - Cd batteries exhibit relatively better low - temperature characteristics.

At low temperatures, the electrochemical reactions within the battery slow down. This results in a decrease in the battery's capacity. For example, when the temperature drops to around - 20°C, the capacity of a Ni - Cd battery may reduce to about 60 - 70% of its rated capacity at room temperature. The reduction in capacity is mainly due to the increased internal resistance of the battery at low temperatures. The electrolyte in the battery becomes more viscous, which restricts the movement of ions between the anode and the cathode, thus limiting the battery's ability to deliver power.

Nevertheless, Ni - Cd batteries have certain advantages in low - temperature environments. Their discharge voltage is relatively stable even at low temperatures. This stability is beneficial for applications where a constant voltage output is required, such as in some emergency lighting systems or certain types of industrial sensors. In contrast, some lithium - ion batteries may experience a more significant drop in discharge voltage at low temperatures, which can lead to premature shutdown of the devices they power.

Moreover, Ni - Cd batteries can still maintain a certain level of charge acceptance at low temperatures. Although the charging efficiency will be lower than at room temperature, they can still be charged to a usable state. This is important for applications in cold regions where the battery needs to be recharged regularly. For instance, in remote areas with extremely cold winters, Ni - Cd batteries can be used in off - grid energy storage systems, and their ability to be charged at low temperatures ensures the continuous operation of the system.