Method for estimating low temperature available energy of power lithium ion battery pack

A lithium-ion battery pack, lithium-ion battery technology, applied in the measurement of electrical variables, measurement of electricity, measurement devices, etc., can solve the problems of charge and discharge performance degradation, poor customer experience, insufficient vehicle cruising range, etc., to achieve simple and easy. Achieve and facilitate the effect of engineering application

CN109342967AInactive Publication Date: 2019-02-15HEFEI GUOXUAN HIGH TECH POWER ENERGY
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2019-02-15
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to a method for estimating low temperature available energy of a power lithium ion battery pack, comprising the following steps of: (1) performing a discharge test on a single-cell power lithium ion battery at 25 DEG C, and recording the discharge energy value; (2) performing the discharge test on the single-cell power lithium ion battery at different temperatures, and recording discharge energy values at different temperatures; (3) fitting the discharge energy and the temperature, establishing a discharge energy-temperature model of the lithium ion battery, and obtaininga relationship between the energy attenuation coefficient and the temperature; (4) performing the discharge test on the battery pack to be tested at 25 DEG C, and recording the discharge energy value; and (5) establishing an energy estimation model of the lithium ion battery pack. The method for estimating the low temperature available energy of the power lithium ion battery pack provided by theinvention is simple and easy to implement, and is convenient for engineering application, and can obtain a relationship between the available energy parameters and the temperature of the power lithiumion battery pack under the full temperature range.
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Description

technical field

[0001] The invention relates to the technical field of lithium-ion batteries, in particular to a method for estimating the low-temperature available energy of a power lithium-ion battery pack. Background technique

[0002] In recent years, with the expansion of the application area of ​​electric vehicles, the performance of lithium-ion electric vehicles at low temperatures has gradually attracted people's attention and attention. In a low temperature environment, the charging and discharging performance of lithium batteries will have a certain attenuation, especially at low temperature, the energy attenuation is too fast, resulting in insufficient mileage of the vehicle and poor customer experience. How to quickly estimate the available energy of the battery pack under low temperature conditions is particularly important . Contents of the invention

[0003] The purpose of the present invention is to provide a method for estimating the low-temperature avail...

Examples

Embodiment Construction

[0023] The present invention will be further described below in conjunction with accompanying drawing:

[0024] Such as figure 1 , 2 As shown, the method for estimating the low-temperature available energy of the power lithium-ion battery pack in this embodiment includes the following steps:

[0025] S1: Under the condition of 25°C, conduct a discharge test on the single power lithium battery, and record the discharge energy as E 0 =318.45Wh, under different temperatures (10°C, 0°C, -10°C, -20°C, -30°C), discharge the single power lithium-ion battery and record the discharge energy E T . As shown in Table 1:

[0026] Table 1

[0027]

[0028] S2: Polynomial fitting is carried out on the discharge energy of the lithium battery measured at different temperatures in the incubator, and a battery discharge energy-temperature model is established. In this embodiment, a quadratic polynomial is used for fitting, and the fitting model is as follows:

[0029] λ=1-E T / E 0 = ...