2.Impact on battery internal resistance and magnification charge and discharge performance
What is the internal resistance of lithium ion batteries?
The internal resistance refers to the resistance of current when it passes through the battery. It includes the ohmic internal resistance and the polarization resistance of the electrode during the electrochemical process. For lithium-ion batteries, it should include the interface resistance between the electrode and electrolyte.
Thus, the sum of ohmic internal resistance, electrode/electrolyte interface resistance and polarization internal resistance is the total internal resistance of lithium-ion batteries.
It is an important indicator to measure the performance of chemical power supplies and directly affects the battery’s operating voltage, operating current, output energy and power.
Why do electrolyte have impact on battery internal resistance?
The ohmic internal resistance of the battery is mainly due to the conductivity of the electrolyte, and it should also include the resistance of the electrode material and the diaphragm.
The conductive mechanism of the electrolyte part is ion conductivity, and the resistance during the conductive process is usually much greater than that of the electronic conductive part.
The resistance of the interface between the electrode and the electrolyte is of great significance in lithium-ion batteries.
The greater the resistance of lithium ions when passing through the interface, the higher the internal resistance of the battery. Under normal circumstances, the interface resistance is significantly higher than the ohm internal resistance.
Why do electrolyte have impact on magnification charge and discharge performance?
The definition of discharge and charge rate:
Magnification charge and discharge performance is an important indicator to measure the capacity retention capacity of lithium-ion batteries under fast charge and discharge conditions.
Reasons of electrolyte have impact on magnification charge and discharge performance:
The magnification charge and discharge performance of the battery are determined by
1.the mobility of lithium ions in the electrode material,
2.the conductivity of the electrolyte,
3.the mobility of lithium ions at the electrode or electrolyte phase interface.
The latter two are closely related to the composition and properties of the electrolyte.