skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Charge Heterogeneity and Surface Chemistry in Polycrystalline Cathode Materials

Abstract

Nanoscale full-field (FF) transmission X-ray microscopy (TXM) and ensemble-averaged soft X-ray absorption spectroscopy (soft XAS) were used to investigate state-of-charge (SOC) heterogeneities in electrochemically charged or discharged and chemically oxidized samples of LiNi0.6Mn0.2Co0.2O2 cathode materials. We observed considerable and similar non-uniformities in terms of Ni oxidation states (and, by proxy, lithium distributions) for all the samples in the bulk. Therefore, the chemically delithiated samples are similar to the electrochemically charged samples in terms of mesoscale charge heterogeneity in large polycrystalline particle ensembles. However, the gradient oxidation states of transition metals on the surface, which is partly responsible for the electrode degradation mechanism known as surface reconstruction, is much less apparent in chemically delithiated samples. Chemical delithiation is extensively used in preparation of charged cathodes free of inactive components for fundamental battery studies. The surface chemistry and bulk lithium distribution of chemically delithiated samples may not accurately represent the electrochemically charged materials in a real battery. In our work, bulk and surface-sensitive characterization techniques were used to investigate the differences between chemically and electrochemically delithiated layered cathode materials. The two types of materials show similar bulk lithium distributions but distinctly different surface chemistries. The present study not only strongly implies thatmore » the electrolytic solution is an active participant in the reactions that lead to the surface reconstruction to a rock salt structure observed in layered oxide cathode materials, but also develops a chemical basis for understanding and improving charge homogeneity across the length scale of secondary particles. Both chemical and electrochemical delithiation methods lead to state-of-charge non-uniformity in the bulk of layered transition metal oxide cathode particles. Less surface reconstruction to rock salt is observed for chemically delithiated samples compared with electrochemically delithiated ones. This indicates that electrolytic solution plays a significant role in the surface reconstruction phenomenon.« less

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE); USDOE Office of Science (SC), Basic Energy Sciences (BES)
OSTI Identifier:
1548833
Alternate Identifier(s):
OSTI ID: 1601173
Grant/Contract Number:  
AC02-05CH11231; AC02-76SF00515
Resource Type:
Published Article
Journal Name:
Joule
Additional Journal Information:
Journal Name: Joule Journal Volume: 2 Journal Issue: 3; Journal ID: ISSN 2542-4351
Publisher:
Elsevier - Cell Press
Country of Publication:
United States
Language:
English
Subject:
25 ENERGY STORAGE; lithium-ion battery; NMC cathode; transmission X-ray microscopy; TXM; soft X-ray absorption spectroscopy; XAS

Citation Formats

Tian, Chixia, Xu, Yahong, Nordlund, Dennis, Lin, Feng, Liu, Jin, Sun, Zhihong, Liu, Yijin, and Doeff, Marca. Charge Heterogeneity and Surface Chemistry in Polycrystalline Cathode Materials. United States: N. p., 2018. Web. doi:10.1016/j.joule.2017.12.008.
Tian, Chixia, Xu, Yahong, Nordlund, Dennis, Lin, Feng, Liu, Jin, Sun, Zhihong, Liu, Yijin, & Doeff, Marca. Charge Heterogeneity and Surface Chemistry in Polycrystalline Cathode Materials. United States. doi:10.1016/j.joule.2017.12.008.
Tian, Chixia, Xu, Yahong, Nordlund, Dennis, Lin, Feng, Liu, Jin, Sun, Zhihong, Liu, Yijin, and Doeff, Marca. Thu . "Charge Heterogeneity and Surface Chemistry in Polycrystalline Cathode Materials". United States. doi:10.1016/j.joule.2017.12.008.
@article{osti_1548833,
title = {Charge Heterogeneity and Surface Chemistry in Polycrystalline Cathode Materials},
author = {Tian, Chixia and Xu, Yahong and Nordlund, Dennis and Lin, Feng and Liu, Jin and Sun, Zhihong and Liu, Yijin and Doeff, Marca},
abstractNote = {Nanoscale full-field (FF) transmission X-ray microscopy (TXM) and ensemble-averaged soft X-ray absorption spectroscopy (soft XAS) were used to investigate state-of-charge (SOC) heterogeneities in electrochemically charged or discharged and chemically oxidized samples of LiNi0.6Mn0.2Co0.2O2 cathode materials. We observed considerable and similar non-uniformities in terms of Ni oxidation states (and, by proxy, lithium distributions) for all the samples in the bulk. Therefore, the chemically delithiated samples are similar to the electrochemically charged samples in terms of mesoscale charge heterogeneity in large polycrystalline particle ensembles. However, the gradient oxidation states of transition metals on the surface, which is partly responsible for the electrode degradation mechanism known as surface reconstruction, is much less apparent in chemically delithiated samples. Chemical delithiation is extensively used in preparation of charged cathodes free of inactive components for fundamental battery studies. The surface chemistry and bulk lithium distribution of chemically delithiated samples may not accurately represent the electrochemically charged materials in a real battery. In our work, bulk and surface-sensitive characterization techniques were used to investigate the differences between chemically and electrochemically delithiated layered cathode materials. The two types of materials show similar bulk lithium distributions but distinctly different surface chemistries. The present study not only strongly implies that the electrolytic solution is an active participant in the reactions that lead to the surface reconstruction to a rock salt structure observed in layered oxide cathode materials, but also develops a chemical basis for understanding and improving charge homogeneity across the length scale of secondary particles. Both chemical and electrochemical delithiation methods lead to state-of-charge non-uniformity in the bulk of layered transition metal oxide cathode particles. Less surface reconstruction to rock salt is observed for chemically delithiated samples compared with electrochemically delithiated ones. This indicates that electrolytic solution plays a significant role in the surface reconstruction phenomenon.},
doi = {10.1016/j.joule.2017.12.008},
journal = {Joule},
number = 3,
volume = 2,
place = {United States},
year = {2018},
month = {3}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1016/j.joule.2017.12.008

Citation Metrics:
Cited by: 41 works
Citation information provided by
Web of Science

Save / Share:

Works referencing / citing this record:

Revealing the Atomic Origin of Heterogeneous Li‐Ion Diffusion by Probing Na
journal, May 2019


Ameliorating the Interfacial Problems of Cathode and Solid‐State Electrolytes by Interface Modification of Functional Polymers
journal, July 2018

  • Wang, Li‐Ping; Zhang, Xu‐Dong; Wang, Tai‐Shan
  • Advanced Energy Materials, Vol. 8, Issue 24
  • DOI: 10.1002/aenm.201801528

Quantification of Heterogeneous Degradation in Li‐Ion Batteries
journal, May 2019


Operando Observation of Formation and Annihilation of Inhomogeneous Reaction Distribution in a Composite Electrode for Lithium‐Ion Batteries
journal, April 2019

  • Nakamura, Takashi; Chiba, Kazuki; Fakkao, Mahunnop
  • Batteries & Supercaps, Vol. 2, Issue 8
  • DOI: 10.1002/batt.201900018

Propagation topography of redox phase transformations in heterogeneous layered oxide cathode materials
journal, July 2018


Charge distribution guided by grain crystallographic orientations in polycrystalline battery materials
journal, January 2020


Spatial quantification of dynamic inter and intra particle crystallographic heterogeneities within lithium ion electrodes
journal, January 2020


Chemomechanical behaviors of layered cathode materials in alkali metal ion batteries
journal, January 2018

  • Xu, Zhengrui; Rahman, Muhammad Mominur; Mu, Linqin
  • Journal of Materials Chemistry A, Vol. 6, Issue 44
  • DOI: 10.1039/c8ta06875e

Thermally driven mesoscale chemomechanical interplay in Li 0.5 Ni 0.6 Mn 0.2 Co 0.2 O 2 cathode materials
journal, January 2018

  • Wei, Chenxi; Zhang, Yan; Lee, Sang-Jun
  • Journal of Materials Chemistry A, Vol. 6, Issue 45
  • DOI: 10.1039/c8ta08973f

Thermally-driven mesopore formation and oxygen release in delithiated NCA cathode particles
journal, January 2019

  • Besli, Münir M.; Shukla, Alpesh Khushalchand; Wei, Chenxi
  • Journal of Materials Chemistry A, Vol. 7, Issue 20
  • DOI: 10.1039/c9ta01720h

Probing and quantifying cathode charge heterogeneity in Li ion batteries
journal, January 2019

  • Zhang, Yuxin; Yang, Zhijie; Tian, Chixia
  • Journal of Materials Chemistry A, Vol. 7, Issue 41
  • DOI: 10.1039/c9ta06977a

Laboratory-Based X-ray Absorption Spectroscopy on a Working Pouch Cell Battery at Industrially-Relevant Charging Rates
journal, January 2019

  • Jahrman, Evan P.; Pellerin, Lisa A.; Ditter, Alexander S.
  • Journal of The Electrochemical Society, Vol. 166, Issue 12
  • DOI: 10.1149/2.0721912jes

Degradation and Aging Routes of Ni-Rich Cathode Based Li-Ion Batteries
journal, January 2020

  • Teichert, Philipp; Eshetu, Gebrekidan Gebresilassie; Jahnke, Hannes
  • Batteries, Vol. 6, Issue 1
  • DOI: 10.3390/batteries6010008