GITT Limitations and EIS Insights into Kinetics of NMC622

Conventional applications of the Galvanostatic Intermittent Titration Technique (GITT) and EIS for estimating chemical diffusivity in battery electrodes face issues such as insufficient relaxation time to reach equilibrium, excessively long pulse durations that violate the short-time diffusion assum...

Full description

Saved in:
Bibliographic Details
Main Authors: Intizar Abbas, Huyen Tran Tran, Tran Thi Ngoc Tran, Thuy Linh Pham, Eui-Chol Shin, Chan-Woo Park, Sung-Bong Yu, Oh Jeong Lee, An-Giang Nguyen, Daeho Jeong, Bok Hyun Ka, Hoon-Hwe Cho, Jongwoo Lim, Namsoo Shin, Miran Gaberšček, Su-Mi Hur, Chan-Jin Park, Jaekook Kim, Jong-Sook Lee
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Batteries
Subjects:
Online Access:https://www.mdpi.com/2313-0105/11/6/234
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850156146516557824
author Intizar Abbas
Huyen Tran Tran
Tran Thi Ngoc Tran
Thuy Linh Pham
Eui-Chol Shin
Chan-Woo Park
Sung-Bong Yu
Oh Jeong Lee
An-Giang Nguyen
Daeho Jeong
Bok Hyun Ka
Hoon-Hwe Cho
Jongwoo Lim
Namsoo Shin
Miran Gaberšček
Su-Mi Hur
Chan-Jin Park
Jaekook Kim
Jong-Sook Lee
author_facet Intizar Abbas
Huyen Tran Tran
Tran Thi Ngoc Tran
Thuy Linh Pham
Eui-Chol Shin
Chan-Woo Park
Sung-Bong Yu
Oh Jeong Lee
An-Giang Nguyen
Daeho Jeong
Bok Hyun Ka
Hoon-Hwe Cho
Jongwoo Lim
Namsoo Shin
Miran Gaberšček
Su-Mi Hur
Chan-Jin Park
Jaekook Kim
Jong-Sook Lee
author_sort Intizar Abbas
collection DOAJ
description Conventional applications of the Galvanostatic Intermittent Titration Technique (GITT) and EIS for estimating chemical diffusivity in battery electrodes face issues such as insufficient relaxation time to reach equilibrium, excessively long pulse durations that violate the short-time diffusion assumption, and the assumption of sequential electrode reaction and diffusion processes. In this work, a quasi-equilibrium criterion of 0.1 mV h<sup>−1</sup> was applied to NMC622 electrodes, yielding 8–9 h relaxations below 3.8 V, but above 3.8 V, voltage decayed linearly and indefinitely, even upon discharging titration, showing unusual nonmonotonic relaxation behavior. The initial 36-s transients of a 10-min galvanostatic pulse and diffusion impedance in series with the electrode reaction yielded consistent diffusivity values. However, solid-state diffusion in spherical active particles within porous electrodes, where ambipolar diffusion occurs in the pore electrolyte with <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>t</mi><mo>+</mo></msub><mo>=</mo><mn>0.3</mn></mrow></semantics></math></inline-formula>, requires a physics-based three-rail transmission line model (TLM). The corrected diffusivity may be three to four times higher. An analytic two-rail TLM approximating the three-rail numerical model was applied to temperature- and frequency-dependent EIS data. This approach mitigates parameter ambiguity and unphysical correlations in EIS. Physics-based EIS enables the identification of multistep energetics and the diagnosis of performance and degradation mechanisms.
format Article
id doaj-art-6c673814b68e4c4893b5de5fea6f9c8a
institution OA Journals
issn 2313-0105
language English
publishDate 2025-06-01
publisher MDPI AG
record_format Article
series Batteries
spelling doaj-art-6c673814b68e4c4893b5de5fea6f9c8a2025-08-20T02:24:39ZengMDPI AGBatteries2313-01052025-06-0111623410.3390/batteries11060234GITT Limitations and EIS Insights into Kinetics of NMC622Intizar Abbas0Huyen Tran Tran1Tran Thi Ngoc Tran2Thuy Linh Pham3Eui-Chol Shin4Chan-Woo Park5Sung-Bong Yu6Oh Jeong Lee7An-Giang Nguyen8Daeho Jeong9Bok Hyun Ka10Hoon-Hwe Cho11Jongwoo Lim12Namsoo Shin13Miran Gaberšček14Su-Mi Hur15Chan-Jin Park16Jaekook Kim17Jong-Sook Lee18School of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of KoreaSchool of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of KoreaSchool of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of KoreaSchool of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of KoreaSchool of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of KoreaSchool of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of KoreaSchool of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of KoreaSchool of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of KoreaSchool of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of KoreaBattery Diagnosis Lab, Samsung SDI, Suwon 16678, Republic of KoreaBattery Diagnosis Lab, Samsung SDI, Suwon 16678, Republic of KoreaDepartment of Materials Science and Engineering, Hanbat National University, Daejeon 34158, Republic of KoreaDepartment of Chemistry, Seoul National University, Seoul 08826, Republic of KoreaDeep Solution Inc., Seoul 06738, Republic of KoreaDepartment of Materials Chemistry, National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, SloveniaSchool of Polymer Science and Engineering, Chonnam National University, Gwangju 61186, Republic of KoreaSchool of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of KoreaSchool of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of KoreaSchool of Materials Science and Engineering, Chonnam National University, Gwangju 61186, Republic of KoreaConventional applications of the Galvanostatic Intermittent Titration Technique (GITT) and EIS for estimating chemical diffusivity in battery electrodes face issues such as insufficient relaxation time to reach equilibrium, excessively long pulse durations that violate the short-time diffusion assumption, and the assumption of sequential electrode reaction and diffusion processes. In this work, a quasi-equilibrium criterion of 0.1 mV h<sup>−1</sup> was applied to NMC622 electrodes, yielding 8–9 h relaxations below 3.8 V, but above 3.8 V, voltage decayed linearly and indefinitely, even upon discharging titration, showing unusual nonmonotonic relaxation behavior. The initial 36-s transients of a 10-min galvanostatic pulse and diffusion impedance in series with the electrode reaction yielded consistent diffusivity values. However, solid-state diffusion in spherical active particles within porous electrodes, where ambipolar diffusion occurs in the pore electrolyte with <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>t</mi><mo>+</mo></msub><mo>=</mo><mn>0.3</mn></mrow></semantics></math></inline-formula>, requires a physics-based three-rail transmission line model (TLM). The corrected diffusivity may be three to four times higher. An analytic two-rail TLM approximating the three-rail numerical model was applied to temperature- and frequency-dependent EIS data. This approach mitigates parameter ambiguity and unphysical correlations in EIS. Physics-based EIS enables the identification of multistep energetics and the diagnosis of performance and degradation mechanisms.https://www.mdpi.com/2313-0105/11/6/234GITTEISspherical diffusionchemical diffusivityrelaxationpulse times
spellingShingle Intizar Abbas
Huyen Tran Tran
Tran Thi Ngoc Tran
Thuy Linh Pham
Eui-Chol Shin
Chan-Woo Park
Sung-Bong Yu
Oh Jeong Lee
An-Giang Nguyen
Daeho Jeong
Bok Hyun Ka
Hoon-Hwe Cho
Jongwoo Lim
Namsoo Shin
Miran Gaberšček
Su-Mi Hur
Chan-Jin Park
Jaekook Kim
Jong-Sook Lee
GITT Limitations and EIS Insights into Kinetics of NMC622
Batteries
GITT
EIS
spherical diffusion
chemical diffusivity
relaxation
pulse times
title GITT Limitations and EIS Insights into Kinetics of NMC622
title_full GITT Limitations and EIS Insights into Kinetics of NMC622
title_fullStr GITT Limitations and EIS Insights into Kinetics of NMC622
title_full_unstemmed GITT Limitations and EIS Insights into Kinetics of NMC622
title_short GITT Limitations and EIS Insights into Kinetics of NMC622
title_sort gitt limitations and eis insights into kinetics of nmc622
topic GITT
EIS
spherical diffusion
chemical diffusivity
relaxation
pulse times
url https://www.mdpi.com/2313-0105/11/6/234
work_keys_str_mv AT intizarabbas gittlimitationsandeisinsightsintokineticsofnmc622
AT huyentrantran gittlimitationsandeisinsightsintokineticsofnmc622
AT tranthingoctran gittlimitationsandeisinsightsintokineticsofnmc622
AT thuylinhpham gittlimitationsandeisinsightsintokineticsofnmc622
AT euicholshin gittlimitationsandeisinsightsintokineticsofnmc622
AT chanwoopark gittlimitationsandeisinsightsintokineticsofnmc622
AT sungbongyu gittlimitationsandeisinsightsintokineticsofnmc622
AT ohjeonglee gittlimitationsandeisinsightsintokineticsofnmc622
AT angiangnguyen gittlimitationsandeisinsightsintokineticsofnmc622
AT daehojeong gittlimitationsandeisinsightsintokineticsofnmc622
AT bokhyunka gittlimitationsandeisinsightsintokineticsofnmc622
AT hoonhwecho gittlimitationsandeisinsightsintokineticsofnmc622
AT jongwoolim gittlimitationsandeisinsightsintokineticsofnmc622
AT namsooshin gittlimitationsandeisinsightsintokineticsofnmc622
AT mirangaberscek gittlimitationsandeisinsightsintokineticsofnmc622
AT sumihur gittlimitationsandeisinsightsintokineticsofnmc622
AT chanjinpark gittlimitationsandeisinsightsintokineticsofnmc622
AT jaekookkim gittlimitationsandeisinsightsintokineticsofnmc622
AT jongsooklee gittlimitationsandeisinsightsintokineticsofnmc622