Low-temperature rapid self-heating method for lithium-ion battery

Abstract

The invention relates to a low-temperature rapid self-heating method for a lithium-ion battery. The method comprises the following steps: (S1) determining a polarization voltage amplitude range which does not have influence on the service lifetime of the lithium-ion battery and is safely used, and selecting a sine AC voltage amplitude according to the range; (S2) calculating the relationship between heat production power and frequency and obtaining a frequency point, namely the optimal heat production frequency point, with the maximum heat production power according to the relationship between battery impedance and frequency under the selected sine AC voltage amplitude; and (S3) carrying out heating free of lifetime loss on the battery by a sine AC signal according to the amplitude determined in the step (S1) and the frequency determined in the step (S2). The low-temperature rapid self-heating method for the lithium-ion battery has the effects of being high in heating rate, obvious in low-temperature performance improvement, free of an influence on the service lifetime of the lithium-ion battery, good in heating temperature uniformity and the like; and the target of reducing the influence on the service lifetime of the lithium-ion battery to the maximal extent is achieved.

Description

technical field [0001] The invention relates to the technical field of battery self-heating, in particular to a low-temperature rapid self-heating method for lithium-ion batteries. In particular, it refers to a low-temperature rapid self-heating method for a lithium-ion battery that has no effect on the life of the lithium-ion battery. Background technique [0002] The dual pressure of energy shortage and environmental pollution has boosted the rapid development of electric vehicles. Lithium-ion batteries have become the preferred battery for electric vehicles due to their advantages such as high single voltage, high energy density, long life, no memory effect, and no pollution. . [0003] However, due to the obvious decrease in the conductivity of the electrolyte and conductive materials at low temperatures, the chemical reaction kinetics and diffusion kinetics of lithium-ion batteries are significantly slow, and the internal resistance increases tenfold compared to room t...

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Problems solved by technology

[0010] In view of the defects existing in the prior art, the purpose of the present invention is to provide a low-temperature rapid self-heating method for lithium-ion batteries, which improves the low efficiency of externally heating lithium-ion batteries in the prior art, which has a great impact on the service life of the battery and produces Problems such as low heat rate and uneven battery temperature distribution

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