Sodium ion battery modeling method

Abstract

The invention provides a modeling method of a sodium ion battery, which comprises the following steps: acquiring real-time temperature data of different parts of the sodium ion battery during charging and discharging, and acquiring a temperature-space distribution curve of the sodium ion battery; based on a thermoelectric coupling experiment, measuring calorific values and a charge change relation at different temperatures, and obtaining initial calorific values under different temperature profiles; establishing a five-layer module area battery model under a non-isothermal condition in a three-dimensional space based on a second law of thermodynamics, and acquiring an electrochemical-thermal-mass transfer multi-physics field coupling relationship in the battery; an entropy production expression and a control equation set of the sodium ion battery at different temperatures are established, and entropy production is calculated; and constructing a three-dimensional non-uniform thermal field model based on entropy production of each layer, and coupling the three-dimensional non-uniform thermal field model with the electrochemical model to obtain a sodium ion thermal coupling battery model under a non-isothermal condition. According to the method, the real state of the sodium ion battery under the dynamic working condition is captured, the failure problem of a traditional model at low temperature or high temperature can be avoided, and the precision of the model is improved.

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