A battery heating method based on battery state of health

Abstract

The invention discloses a battery heating method based on battery health status, and belongs to the technical field of battery heating. The method aims to solve the problem that a battery is incapable of being heated uniformly when the battery is charged and used at a low temperature or that aging of the battery is accelerated due to improper battery low-temperature heating pulse amplitude selection and control caused by the facts that the difference between the charging internal resistance of the battery and the discharging internal resistance of the battery is ignored in the heating process and the influence of the battery health status on battery performance is not taken into account. Alternating-current pulse current is applied to the battery, the battery is heated internally by using the heat generated by the battery internal resistance, the battery internal resistance is finely divided into the charging internal resistance and the discharging internal resistance in the heating process, and the influence of the battery health status on the battery performance is taken into account by using a certain constant polarization voltage as a restricted condition, so that the accuracy of battery low-temperature heating pulse amplitude selection and control is improved, and the influence on the aging of the battery in the heating process of the battery is effectively inhibited.

Description

technical field [0001] The invention relates to a battery heating method, in particular to a battery heating method based on the health state of the battery, and belongs to the technical field of low-temperature heating of electric vehicle batteries. Background technique [0002] Lithium-ion batteries are gradually replacing other batteries as the main power battery due to their advantages such as high specific power, high energy density, low self-discharge rate and long storage time. Although lithium-ion batteries have many advantages, there are still major problems in the charging and discharging performance of lithium-ion batteries at low temperatures, such as: the activity of various active materials is reduced, the reaction rate of the battery electrode is low, and the graphite negative electrode inside the lithium-ion battery All kinds of impedances have increased significantly, the available capacity of the battery has decreased, and the output power has dropped signi...

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Problems solved by technology

However, this method cannot heat the battery evenly, which will cause great trouble to the balance of the battery pack.

Another approach in the related art is to use sinusoidal alternating current to charge and discharge the battery, and use the heat generated by the internal resistance of the battery at low temperature to heat the battery internally. However, when selecting and controlling the pulse current amplitude, the internal resistance of the battery charging and The difference between the discharge internal resistance, and does not take into account the impact of battery health on battery performance, so that the selection and control of the AC pulse amplitude when the battery is heated is improper, thus accelerating the decline of the battery during the heating process

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