Performance Analysis of Empirical Open-Circuit Voltage Modeling in Lithium Ion Batteries, Part-2: Data Collection Procedure

TL;DR

This paper details a systematic approach for collecting low-rate OCV data in lithium-ion batteries, improving the accuracy of empirical OCV-SOC models by considering various parameters affecting experimental efficiency.

Contribution

It introduces a comprehensive data collection procedure for OCV modeling, including methods for full charge at different C-Rates and resistance estimation, enhancing model accuracy.

Findings

Defined a method for fully charging batteries at various C-Rates.

Described procedures for OCV characterization post full charge.

Discussed optimal resistance estimation profiles.

Abstract

This paper is the second part of a series of papers about empirical approaches to open circuit voltage (OCV) modeling and its performance comparison in lithium-ion batteries. The first part of the series introduced various sources of uncertainties in the OCV models and established a theoretical relationship between uncertainties and the performance of a battery management system. In this paper, clearly defined approaches for low-rate OCV data collection are defined and described in detail. The data collection is designed with consideration to several parameters that affect the experimental time. Firstly, a more suitable method to fully charge the battery at different C-Rates is defined. Secondly, the OCV characterization following the full charge is described for various performance comparisons. Finally, optimal and efficient resistance estimation profiles are discussed. From the voltage, current and time data recorded using the procedure described in this paper, the OCV-SOC relationship is characterized and its uncertainties are modeled in the third part of this series of papers.