Rapid charging method of lithium ion battery

Abstract

The invention discloses a rapid charging method of a lithium ion battery. The method mainly comprises the steps of S1, preparing a three-electrode battery by using a three-electrode battery preparation process; S2, obtaining a lithium precipitation boundary window when the lithium ion battery is charged by using the three-electrode battery; S3, designing a fast step charging strategy according tothe lithium precipitation boundary window; and S4, charging the lithium ion battery by utilizing the fast step charging strategy. The lithium precipitation boundary window of the lithium ion battery to be charged is obtained by using the three-electrode battery, and then the rapid step charging strategy is designed for the lithium precipitation boundary window; the rapid step charging strategy canenable a charging curve in the whole charging process of the battery to meet three Malus laws as far as possible, namely, can enable a charging current to be close to the optimal charging curve as much as possible; and the polarization phenomenon of the battery is controlled, so that the lithium precipitation phenomenon of the battery in charging is avoided, the charging time is shortened, the safety is improved, the service life of the battery is prolonged, and the battery is effectively protected.

Description

technical field [0001] The invention relates to power battery energy storage technology, in particular to a lithium-ion battery fast charging method. Background technique [0002] The purpose of battery charging is to recover the power of the battery when the battery is insufficient, so that the battery can continue to supply power to the outside world. In theory, the greater the current, the faster the battery will be fully charged. Battery charging is generally divided into conventional charging and fast charging. At present, the most commonly used fast charging methods include constant current and constant voltage charging and pulse charging. Constant current and constant voltage charging is the first stage to charge lithium-ion batteries with a constant current; when When the voltage reaches the predetermined value, it will switch to the second stage for constant voltage charging, and the current will gradually decrease at this time; when the charging current drops to ze...

AI Technical Summary

Problems solved by technology

In the traditional constant current and constant voltage charging method, if the charging current is too high, the polarization phenomenon of the battery is too intensified. The polarization phenomenon of the battery is divided into ohmic polarization, concentration polarization, and electrochemical polarization. The battery remains unchanged throughout the charging process, while the concentration polarization and electrochemical polarization become more and more intense with the charging and discharging cycle of the battery. The phenomenon of severe polarization makes the battery temperature rise rapidly, and the external performance is internal resistance. increase, resulting in a decline in battery charging acceptance, affecting battery charging efficiency, severe polarization and even lithium precipitation in the battery, resulting in loss of active lithium, irreversible damage to the battery, and a great safety risk

The disadvantage of pulse charging is that the charging in the pulse phase exceeds the upper limit voltage, and there will be safety risks of overcharging and lithium deposition. In order to ensure safety, a power supply with a current limiting function is required, which will increase the cost of pulse charging.

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