About battery self-discharge?

There is no connection between the electrodes, and the extremely small amount of chemical substances in the battery will also react. These internal reactions will reduce the stored charge of the battery, thereby gradually reducing the capacity of the battery. This phenomenon is called self discharge.

Three main points of self-discharge:

1. After the battery is stored for a long time, the sulfuric acid will sink, causing a potential difference between the upper and lower plates.

2. Electrolyte and battery plate materials are impure.

3. The active material of the battery plate falls off, and the lower part of the deposit is too much, resulting in a short circuit of the plate, and the upper and lower layers of the battery electrolyte, resulting in self-discharge.

Side reactions of electrochemical materials:

Material side reactions mainly occur in three aspects: positive electrode materials, negative electrode materials and electrolytes.

Internal short circuit:

In the production process of batteries, some impurities will inevitably be mixed. The nature of these impurities is complex, and some impurities will cause slight conduction of the positive and negative electrodes, which will neutralize the charge and damage the power supply.

SEI film defect:

The original function of the SEI film is to isolate the positive and negative electrodes that electrons cannot pass through. If there is a problem with the quality of the film, its effect will not be able to function normally.

Target factor:

The self-discharge rate of a battery varies with the application environment, use phase, and application state.

Lithium-sulfur battery has low self-discharge, the annual self-discharge rate is less than 1% at room temperature, and the storage period can reach 15 years in an environment below 35°C.