(A) novel extraction technique for the entropy profiles of lithium-ion battery

Abstract

Studies on the battery model based on the thermodynamic parameters are very useful to identify the chemical state of battery correctly. However, applying the extraction method of the entropy in the actual battery management system(BMS) involves some constraints. One of the major constraints is the need to use a temperature adjustment device for the battery entropy extraction. Therefore, this new extraction tech-nique, being thermostat-free, is considered to be easily applicable in real BMS. When the proposed extraction method is used in the actual BMS, it is possible to observe the level of risk of the battery, and to determine the cause of the reduction in battery life without increasing costs. Basically entropy is extracted with open circuit voltage(OCV) on temperature change in accordance with the laws of thermodynamics. This novel ex-traction technique extracts entropy by differentiating measured OCV curves under different fixed tempera-tures. This report verifies the validity of the technique by comparing its implementation with the reference entropy extraction method known as Electrochemical thermodynamics measurements (ETMs)