Reasons for the Reduced Durability of Lithium Batteries in Low Temperatures

The reduced durability of lithium batteries in low temperatures can primarily be attributed to the following factors:

1. Slowed Internal Chemical Reactions

Impact of Temperature on Chemical Reactions: The chemical reactions occurring inside batteries require a certain temperature to proceed effectively. When temperatures drop, the rate of these chemical reactions significantly slows down, resulting in reduced electrical energy output. For instance, experiments have demonstrated that in environments below 0°C, the capacity of standard alkaline batteries decreases by approximately 20% to 40%.

Electrolyte Changes: At low temperatures, the liquid electrolyte inside the battery becomes viscous, restricting the movement of electrons and ions within the battery and thereby increasing its resistance. This increase in resistance leads to a reduction in the battery's energy density, causing it to release energy more rapidly while simultaneously decreasing its discharge efficiency.

2. Reduced Activity of Electrode Materials

Material Activity and Temperature: In low-temperature environments, the activity of battery electrode materials decreases. The diffusion mobility of charged ions deteriorates, making it difficult for them to traverse the passivation layers of electrodes and electrolytes, leading to diminished battery performance.

Capacity Degradation: At low temperatures, reduced activity in cathode materials decreases the number of lithium ions capable of migration to generate discharge current, constituting the fundamental cause of capacity decline.

3. Reduced Conductivity of Electrolyte

Conductivity Changes: Under low-temperature conditions, the conductivity of the electrolyte decreases. This hinders the movement of charged ions within the battery, further impairing its discharge performance.

4. Increased Battery Internal Resistance

Relationship between internal resistance and temperature: At low temperatures, a battery's internal resistance increases significantly. During discharge, substantial electrical energy is dissipated as heat generated by internal resistance, leading to reduced coulombic efficiency and shorter effective battery runtime.

To address the issue of reduced battery durability in low-temperature environments, several technical solutions are currently available:Battery Preheating: Preheating batteries in low-temperature environments raises their operating temperature to restore normal performance. The Battery Management System (BMS) onboard electric vehicles typically includes battery heating functions, comprising both external heating (e.g., air heating, liquid heating) and internal heating (e.g., AC heating).

Optimized Charging Strategy: In cold conditions, appropriately extending charging duration—particularly the trickle charging phase (a continuous low-current charge maintaining the battery near full capacity, also known as maintenance charging)—enables greater energy storage. This reduces discharge rate, thereby increasing driving range.

Select an appropriate charging environment: Avoid charging at excessively low temperatures. Choose a warm environment for charging to enhance charging efficiency and battery performance.

Battery insulation measures: Provide insulation for the battery, such as wrapping it with insulating materials, to minimize heat loss in cold conditions.

Rechargeable heating blanket: