Method for Accurately Calculating the Coulombic Efficiency of Batteries at Different Temperatures

Abstract

The present invention discloses a method of calculating battery coulomb efficiency accurately under different temperatures. The method comprises the following steps of 1 carrying out the standard charge-discharge experiment on a battery with an experiment current I<n> under a standard charge-discharge temperature defined by a battery manufacturer and according to a rated charging cut-off voltage V<max>, a rated discharge cut-off voltage V<min> and a rated charge-discharge current I of the battery, and utilizing a formula to calculate the coulomb efficiency Eta n of the battery under the standard temperature; 2 selecting a plurality of test temperature points, carrying out the specific test temperature charge-discharge experiments on the battery separately, and utilizing a formula to calculate the coulomb efficiency Eta t of the battery under the test temperatures. The method calculates the coulomb efficiency under the standard charge-discharge temperature as the standard of the battery coulomb efficiency under a correction test temperature, is accurate and reliable in calculation result, and provides the effective data for calculating the state of charge (SOC).

Description

technical field [0001] The invention relates to the technical field of battery characteristics, in particular to a method for accurately calculating the coulombic efficiency of batteries at different temperatures. Background technique [0002] The promotion of clean energy has prompted the electric vehicle market to continue to heat up. As the main power source of electric vehicles, batteries have become a hot spot for people to pay attention to. Among them, SOC (percentage of remaining power), as the most important factor affecting battery characteristics, is one of the hotspots and difficulties in the research of battery pack management systems in recent years. [0003] The ampere-hour measurement method is currently the most commonly used battery SOC estimation method for electric vehicles. Its principle is to estimate the SOC through the integral of the load current. It is easy to use and the algorithm is stable. The formula is as follows: [0004] [0005] where SO...

AI Technical Summary

Problems solved by technology

[0006] The existing calculation of Coulombic efficiency is to place the battery at a certain test temperature and directly charge and discharge the battery. The maximum and minimum cut-off voltages of charge and discharge are provided by the battery manufacturer at a specific temperature. The two values ​​will change and be ignored by people, so the efficiency of the calculation is very different from the real value

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