Controllable self-repairing system and method of lithium battery

Abstract

The invention provides a controllable self-repairing method of a lithium battery, which comprises the steps of when the maintenance condition of a lithium battery pack is met, independently discharging each string of single lithium batteries of the lithium battery pack, and pulling back the charged state of all the single lithium batteries to the same zero-charged state again. The invention further provides a controllable self-repairing system of the lithium battery. The system and method have the beneficial effects that the battery equalization problem can be better solved, and the cost is low.

Description

technical field [0001] The invention relates to a lithium battery system, in particular to a controllable self-repair system and method for a lithium battery. Background technique [0002] The advantages of lithium-ion batteries are high energy density, light weight, and long service life, but it also has many disadvantages. Lithium-ion batteries need to use a management system to manage the work of the battery, otherwise overcharging and over-discharging will occur. It leads to negative electrochemical reactions inside the battery, and produces a large amount of flammable and explosive gases, causing bulges and irreversible losses. In addition to overcharging and overdischarging, the most important thing is battery balancing. [0003] Balance means that the capacity, voltage, and internal resistance of each single battery in the battery pack must always be kept the same. Only in this way can the battery pack exert its maximum capacity when charging and discharging, and the ...

AI Technical Summary

Problems solved by technology

[0002] The advantages of lithium-ion batteries are high energy density, light weight, and long service life, but it also has many disadvantages. Lithium-ion batteries need to use a management system to manage the work of the battery, otherwise overcharging and over-discharging will occur. It leads to negative electrochemical reactions inside the battery, and produces a large amount of flammable and explosive gases, causing bulges and irreversible losses. In addition to overcharging and overdischarging, the most important thing is the battery balance problem.

[0003] Balance means that the capacity, voltage, and internal resistance of each single battery in the battery pack must always be kept the same. Only in this way can the battery pack exert its maximum capacity when charging and discharging, and the lithium battery will show capacity after a period of use. In the case of unbalanced and unbalanced voltage, even if the capacity of each single battery is accurately divided during assembly, the problem of uneven capacity of each single battery will still appear after a period of use. It will cause the battery to explode and burn. At present, most of them use passive balancing BMS management system to solve this problem. In fact, using passive balancing to solve the balancing problem is just a drop in the bucket and cannot solve the problem of battery balancing at all. Balanced, but the current active balance is immature, it will have a counterproductive effect, and the cost of active balance is high, and the system is complicated. At present, the market's price requirements for lithium battery systems are getting higher and higher. The cost and effect of active balance are causing most Reasons why market users will not choose

During the use of the lithium battery pack, once the voltage of a single battery is low and the BMS system detects the low-voltage battery, the BMS system will use the lowest battery as the capacity parameter to calculate the shutdown standard, otherwise the single battery The battery will be overcharged and overdischarged, resulting in the risk of swelling or even explosion

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