Method for increasing low-temperature discharge capacity by adjusting discharge cut-off voltage of battery

Abstract

The invention provides a method for increasing the low-temperature discharge capacity by adjusting a discharge cut-off voltage of a battery, and belongs to the technical field of batteries. The method comprises the following steps: calibrating the battery and measuring DC internal resistances of the battery at different temperatures in a relatively low charged state; obtaining discharge curves of the battery under the conditions of different temperatures, different rates and different heat dissipation conditions, and obtaining voltage recovery points generated by thermoelectric coupling actions from the discharge curves in a low-temperature discharge process of the battery; and obtaining the current temperature of the battery, and adjusting the discharge cut-off voltage of the battery according to the discharge rate of the battery, the internal resistances of the battery at different temperatures and the voltage recovery points of the discharge curves of the battery. According to the low-temperature discharge method provided by the invention, the battery can be relatively well used at a low temperature; and the battery discharges more energy.

Description

technical field [0001] The invention belongs to the technical field of batteries, in particular to a method for increasing low-temperature discharge capacity by adjusting the battery discharge cut-off voltage. Background technique [0002] Lithium-ion batteries have the advantages of high energy density, long cycle life, low self-discharge rate, and no memory effect. Compared with lead-acid batteries and nickel-metal hydride batteries, they are more suitable for pure electric vehicles, plug-in electric vehicles and hybrid vehicles. It is also the main driving power of mobile phones and notebook computers and other main energy storage components. However, various internal impedances of lithium-ion batteries increase significantly at low temperatures. Even when a battery with a high state of charge is discharged at low temperature, according to the normal temperature discharge procedure, the amount of electricity that can be released is less, and the available electricity is r...

AI Technical Summary

Problems solved by technology

Although the method of battery preheating can fundamentally solve the problem of battery low-temperature use, it requires additional development of heating strategies and hardware, which consumes additional warm-up time; usually the method of battery preheating is more effective for low-temperature charging of batteries

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