Recently, it was found that the temperature dropped sharply, and the battery was full after charging, but it ran out of power after using. In this case, let's talk about the relationship between the battery and temperature:
If lithium batteries are used in low temperature environments, that is, below 4℃, the service time of the battery will also be reduced, and some original lithium batteries cannot even be charged in low temperature environments. But don't worry too much. This is just a temporary situation, different from the use in high temperature environment. Once the temperature rises, the molecules in the battery will be heated, and the battery will recover its previous power immediately. The higher the temperature is, the faster the movement rate of the anion and cation in the primary cell, the faster the rate of electron gain and loss on the two electrodes, and the greater the current.
The Influence of Temperature on the Internal Resistance of Battery in the Case of Truck Scale Engineering
When discharging at the ambient temperature of 0℃~30℃, the internal resistance of the battery decreases with the increase of the temperature. On the contrary, when the battery temperature decreases, the internal resistance of the battery gradually increases, and the internal resistance of the battery changes linearly with the temperature Therefore, the working temperature of battery discharge is within the range of 0℃~30℃. The conductivity of electrolyte is good, and the diffusion speed of hydrogen ion and sulfate ion in electrolyte to active substance is also high. This not only improves the concentration polarization effect, but also improves the electrode reaction speed, further improving the impact of electronic chemical polarization, so the discharge capacity of battery increases.
When the ambient temperature drops below 0℃, the internal resistance will increase by about 15% for every 10℃ drop in temperature. Because the viscosity of sulfuric acid solution becomes larger, the specific resistance of sulfuric acid solution will increase, which will aggravate the effect of electrode polarization. The battery capacity will decrease significantly.
Influence of Temperature on Charging and Discharging
Repeat the cycle of discharging and low-voltage constant voltage charging. At the initial stage, the temperature of the battery is not high because of the heat conduction. If the cycle of charging and discharging is repeated, the electrolyte temperature will be very high.
If charging at low temperature, the diffusion current density decreases significantly, while the exchange current density decreases not much, so the concentration polarization intensifies, which will lead to the reduction of charging efficiency On the other hand, the saturation of the last discharged lead sulfate at low temperature increases the resistance of battery charging and discharging reaction, thus further reducing the charging efficiency.
If the battery is charged at an ambient temperature above 10 ℃, the polarization is significantly reduced, and the dissolution rate and solubility of lead sulfate can be improved. In addition, the oxygen diffusion rate increases at a higher temperature, which will improve the battery charging and discharging efficiency under the influence of these comprehensive factors.
Post time: Sep-16-2022