Method for estimating instantaneous heat generation rate of pouch cell

Abstract

A method for estimating the instantaneous heat generation rate of a pouch cell comprises the following steps: (1) measuring temperature rise-per-second data of a cell at a charge/discharge rate in an adiabatic environment, and calculating the storage heat generation power per second q1 of the cell under the rate condition; (2) measuring static temperature drop data of the cell at the end of the charge/discharge rate in the adiabatic environment, and getting the natural convection heat transfer coefficient h in the environment through curve fitting; (3) calculating the corresponding natural convection loss power per second q2 in the charge/discharge process in the environment according to the natural convection heat transfer coefficient h and the temperature rise-per-second data in the adiabatic environment; and (4) adding the storage heat generation power per second q1 and the natural convection loss power per second q2 together to get the heat generation power per second under the condition, and getting the instantaneous heat generation rate through polynomial fitting according to the heat generation power per second. Through the method, the heat generation rate of a pouch cell in the charge/discharge process can be easily calculated. The method is of certain value to the study on performance of cells in the charge and discharge process.

Description

Technical field [0001] The invention belongs to the technical field of batteries, and relates to a test method of a soft pack battery. Background technique [0002] With the continuous development of power batteries, soft-pack batteries are favored by the new energy automobile industry due to their low cost and high specific energy. Estimating changes in the heat generation rate of soft-pack batteries during charging and discharging is important for their further research. significance. [0003] The current tests on the heat generation power of power batteries mainly include: (1) Use an adiabatic accelerating calorimeter to measure the heat generation rate, which is expensive; (2) measure the temperature rise of the battery and divide the battery heat into three parts, respectively It is the natural convection heat exchange between the battery and the air, the heat exchange between the battery and the outside radiation and the remaining heat of its own, such as patent CN104569836A...

AI Technical Summary

Problems solved by technology

These are mainly obtained from the average heat generation rate of the battery at a certain discharge rate or under variable current conditions. The average heat generation rate cannot reflect the changes in the heat generation process during the charging / discharging process of the battery, and some natural convection The values ​​of heat coefficient and radiation heat transfer coefficient are empirical values, and there may be certain errors in the calculation results

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