A Time- and Temperature-Based Optimal Charging Method for Li-ion Batteries

Abstract

The invention relates to the technical field of battery charging, in particular to a charging method of a lithium ion battery based on time and temperature. Polarization voltage limited maximum charging current is calculated based on lithium ion battery polarization characteristics, and under the constraint of the maximum charging current, charging temperature rise and charging time are considered comprehensively, genetic algorithm is employed to search the optimal charging current so as to balance the mutual contradictory objects of reducing charging time and lowering charging temperature rise. The result shows that the optimal charging current ensures charging rapidity, at the same time controls the polarization voltage and temperature rise of the charging process within an allowable range, and guarantees the charging capacity, charging efficiency and charging safety and battery life.

Description

technical field [0001] The invention belongs to the technical field of battery charging, and in particular relates to an optimal charging method for a lithium ion battery based on time and temperature. Background technique [0002] Currently, a constant current constant voltage (CC-CV) charging method is widely used for lithium-ion batteries. First, use a constant current (CC) to charge the battery. When the battery voltage reaches the charging cut-off voltage, then perform constant voltage charging (CV). The charging current gradually decreases. When the battery charging current decreases to a certain value, Charging is complete. This charging method is easy to control. In the constant voltage stage, the polarization voltage and ohmic voltage decrease, and the battery can be fully charged, but the charging time is too long, and there are problems such as unclear impact on battery life, which has become a further limitation for electric vehicles. The technical bottleneck o...

AI Technical Summary

Problems solved by technology

Excessive polarization voltage will cause the battery to be fully charged and cause the loss of active materials inside the battery, thereby affecting battery life

High current charging will lead to excessive polarization voltage, therefore, the polarization voltage limits the maximum charging current of lithium-ion batteries

Temperature is an important factor to be considered in the charging process of lithium-ion batteries. If the temperature is too high, the stability of the lattice structure of the positive electrode of the battery will deteriorate, the safety of the battery will decrease, and it will easily cause thermal runaway of the battery.

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