If you want to operate a battery-powered device or equipment in environments with extreme temperatures, it’s important to ensure not only that the machine itself can handle such conditions, but also that its power source can operate safely and efficiently in these settings. When choosing a battery for powering a product in extremely cold environments, it’s important to understand how batteries are affected by low temperatures, and which types of batteries can not only withstand these conditions, but continue to operate safely, efficiently, and reliably for extended periods of time in such low temperatures. In this article, we’ll cover all of this to help you choose a product that meets your exact needs.

How does low temperature affect lithium batteries?

In short, extremely low temperatures slow down the chemical reactions occurring within the battery, leading to poor performance and permanent damage. In such conditions, the charge capacity decreases, while the internal resistance increases. All of this leads to reduced run time, shortened battery life, and battery failure. To prevent these issues, the recommended temperature range for common lithium batteries is between -20°C and -55°C. For conditions outside of this range, special low-temperature batteries are required to ensure safety and battery life.

Is the damage to lithium batteries from low temperatures permanent?

Because extremely low temperatures create irreversible chemical reactions inside standard lithium batteries, the damage is permanent. To understand exactly what happens inside a battery and how it happens, let's start with some basics.

Lithium-ion batteries have a positive electrode and a negative electrode. When charging, lithium ions start from the positive electrode lattice, pass through the electrolyte separator to the negative electrode, and become embedded in the graphite layers. When discharging, the opposite happens: lithium ions move from the graphite negative electrode layer to the positive electrode lattice.

When exposed to low temperatures, everything slows down, from the movement of transported molecules to reaction rates and overall material transport. This slowdown is particularly pronounced for lithium ions and atoms in the graphite layers and cathode lattice. Lithium begins to accumulate at the electrode-electrolyte interface instead of being embedded in the graphite layers, which leads to the formation of lithium dendrites (metallic lithium accumulates on the surface of the anode) during charging.

This is an irreversible conversion reaction that can lead to capacity loss, increased short circuits and safety hazards due to structural damage caused by lithium dendrites.

When batteries are discharged under extreme low temperature conditions, the cathode active material is lost and metal particles accumulate due to the rupture of active particles from the cathode and the migration of transition metal elements to the anode. This leads to lithium deposition within the battery.

How much capacity do standard lithium batteries lose when exposed to cold temperatures?

In a study, researchers demonstrated how much capacity standard lithium batteries lose when exposed to cold temperatures. In the study, the researchers left the batteries in cold temperatures for 48 hours, then returned the batteries to room temperature and tested them for capacity loss in two settings. Batteries that were charged and discharged at a slow/small rate lost 3.2% of their capacity, and batteries that were charged and discharged at a fast/high rate lost 6% of the battery capacity.

There are two main reasons for storage problems caused by low temperature exposure, as shown in the figure:

1. Cathode rupture.
2. The detachment of cathode particles forms a binder, resulting in reduced electrochemical activity.

In addition to storage issues, this permanent damage can lead to complete battery failure or even safety hazards such as battery explosion. This is why it is recommended to use specially designed cryogenic lithium batteries for extremely cold environments.

How do cryogenic lithium batteries differ from standard batteries?

While standard batteries have a recommended temperature range of -20°C to +50°C, specially designed cryogenic lithium batteries can operate safely and effectively at temperatures below -20°C. These batteries are similar in construction to standard lithium batteries, but their electrolytes and membranes are modified to accommodate charging, discharging, and storing energy at lower temperatures.