why do high temperatures affect a high-voltage battery’s ability to hold a charge?

When high temperatures affect high-voltage batteries, they can lead to several problems. Firstly, high temperatures can slow down ion migration, reducing the charging efficiency and speed of the battery. Second, high temperature accelerates the evaporation and loss of electrolyte, leading to a decrease in the concentration of electrolyte inside the battery and affecting the charging capacity. In addition, high temperatures can lead to electrode material instability, causing capacity loss and reduced charging performance. Finally, high temperature may trigger battery expansion and damage, further affecting the charging capacity.

There are several reasons why high temperatures affect the charging ability of high voltage batteries:

Ion migration slows down: High temperatures increase the activity of the electrolyte, leading to faster ion migration. However, when the temperature exceeds a certain range, the viscosity of the electrolyte increases, resulting in slower ion migration. This can reduce the charging efficiency and speed of the battery.

Electrolyte Evaporation and Loss: High temperatures accelerate the evaporation of the electrolyte, resulting in the loss of liquid inside the battery, which reduces the electrolyte concentration of the battery. The loss of electrolyte will lead to a decrease in the efficiency of the electrochemical reaction inside the battery, affecting the charging capacity.

Electrode material instability: high temperatures can negatively affect the electrode material of the battery. For example, the positive electrode material may undergo structural changes, leading to loss of capacity and reduced charging performance. At the same time, high temperatures may also lead to an intensification of the reaction between the electrodes and the electrolyte, resulting in the formation of decomposition products of the electrolyte, which affects the battery's cycle life and charging capacity.

Expansion and damage: High temperatures trigger an acceleration of chemical reactions within the battery, increasing the potential for heat and gas generation. This can lead to increased pressure inside the battery, causing swelling and damage, which in turn affects charging capacity.

In summary, high temperatures can negatively affect the charging capability of high voltage batteries, including slowed ion migration, electrolyte evaporation and loss, electrode material instability, and swelling and damage. Therefore, when using and charging high-voltage batteries, care should be taken to avoid high-temperature environments in order to maintain battery performance and life.

And high temperature will not only have an effect on charging, but also have a great impact on other things

Capacity Loss: The capacity of a battery decreases in a high temperature environment. This is due to the fact that high temperatures accelerate the rate of chemical reactions within the battery, resulting in a less efficient electrochemical reaction, which reduces the amount of energy that can be stored in the battery.

Shorter life: High temperatures accelerate the aging process of batteries. At high temperatures, the chemical reactions in the battery proceed more quickly, leading to degradation of materials and decomposition of the electrolyte, which reduces the life of the battery.

Increased safety risk: High temperatures increase pressure and heat generation inside the battery, increasing the risk of thermal runaway, leakage, expansion or even explosion. This poses a potential safety threat to both the user and the surrounding environment.

Decreased charging capacity: The charging capacity of a battery is also affected in high temperature environments. High temperatures accelerate the evaporation of the electrolyte and structural changes in the electrode material, leading to a decrease in the charging efficiency of the battery and a longer charging time.

Therefore, when using high-voltage batteries, exposure to high temperatures should be avoided as much as possible. This can be achieved by avoiding prolonged exposure to direct sunlight, not placing the battery in a hot area (e.g. inside a vehicle), and following the manufacturer's recommendations for use and storage. Normal use and storage of batteries is usually within the specified temperature range, which helps to minimise the negative effects of high temperatures on battery performance and life.

In summary, high temperatures negatively affect the charging capability of high-voltage batteries, including slowed ion migration, electrolyte evaporation and loss, electrode material instability, and swelling and damage. Therefore, when using and charging high-voltage batteries, high-temperature environments should be avoided to maintain battery performance and life. Proper use and storage of batteries and following manufacturer's recommendations can reduce the negative effects of high temperatures on batteries and ensure their proper operation and safe use.