Car Battery Polarization

One of the requirements for automotive batteries is that there must be a large current discharge. That is, the reaction rate is required to be very large, which inevitably produces a phenomenon that deviates from the equilibrium value, that is, a polarization phenomenon. The resistance of the battery includes the resistance of the electrolyte, the resistance of the electrode material, and even the resistance caused by the adhesion of the reaction product (such as the precipitation of hydroxide on the electrode). Ohmic polarization refers to the polarization caused thereby. Concentration polarization is the deviation of the electrode potential from the equilibrium value caused by changes in the concentration of the reactant when the electrochemical reaction is in progress.

The anode and cathode polarization refers to the phenomenon that the anode and cathode potential deviates from the static value after the battery enters the working state. Any electrode process includes the process of one or several reaction particles accepting or losing electrons. The polarization caused by this process is called electrochemical polarization. Charging rate (C-rate): C is the first letter of Capacity, used to indicate the magnitude of the current when the battery is charged and discharged. For example, when the rated capacity of a car's rechargeable battery is 1100mAh, it means that the discharge time of 1100mAh (1C) can last for 1 hour. If the discharge time of 200mA (0.2C) can last for 5 hours, charging can also be calculated according to this comparison.