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Title: Investigation of Thermal Stability of P2–Na xCoO 2 Cathode Materials for Sodium Ion Batteries Using Real-Time Electron Microscopy

Abstract

In this paper, we take advantage of in situ transmission electron microscopy (TEM) to investigate the thermal stability of P2-type Na xCoO 2 cathode materials for sodium ion batteries, which are promising candidates for next-generation lithium ion batteries. A double-tilt TEM heating holder was used to directly characterize the changes in the morphology and the crystallographic and electronic structures of the materials with increase in temperature. The electron diffraction patterns and the electron energy loss spectra demonstrated the presence of cobalt oxides (Co 3O 4, CoO) and even metallic cobalt (Co) at higher temperatures as a result of reduction of Co ions and loss of oxygen. The bright-field TEM images revealed that the surface of Na xCoO 2 becomes porous at high temperatures. Higher cutoff voltages result in degrading thermal stability of Na xCoO 2. Finally, the observations herein provide a valuable insight that thermal stability is one of the important factors to be considered in addition to the electrochemical properties when developing new electrode materials for novel battery systems.

Authors:
 [1];  [1];  [1];  [1];  [1];  [2]; ORCiD logo [1]
  1. Korea Inst. of Science and Technology (KIST), Seoul (Korea, Republic of). Center for Energy Convergence
  2. KIST Jeonbuk Inst. of Advanced Composite Materials, Chudong (Korea, Republic of). Carbon Composite Materials Research Centre
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States); Korea Inst. of Science and Technology (KIST), Seoul (Korea, Republic of)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); Korea Inst. of Science and Technology (KIST) (Korea, Republic of)
Contributing Org.:
KIST Jeonbuk Inst. of Advanced Composite Materials, Chudong (Korea, Republic of)
OSTI Identifier:
1368663
Report Number(s):
BNL-113970-2017-JA
Journal ID: ISSN 1944-8244; R&D Project: 16060; 16060; KC0403020; TRN: US1701988
Grant/Contract Number:
SC0012704; 2E27062; 2E27090
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
ACS Applied Materials and Interfaces
Additional Journal Information:
Journal Volume: 9; Journal Issue: 22; Journal ID: ISSN 1944-8244
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English
Subject:
29 ENERGY PLANNING, POLICY, AND ECONOMY; cathode materials; in situ heating; NaCoO2; sodium ion batteries; thermal stability; transmission electron microscopy

Citation Formats

Hwang, Sooyeon, Lee, Yongho, Jo, Eunmi, Chung, Kyung Yoon, Choi, Wonchang, Kim, Seung Min, and Chang, Wonyoung. Investigation of Thermal Stability of P2–NaxCoO2 Cathode Materials for Sodium Ion Batteries Using Real-Time Electron Microscopy. United States: N. p., 2017. Web. doi:10.1021/acsami.7b04478.
Hwang, Sooyeon, Lee, Yongho, Jo, Eunmi, Chung, Kyung Yoon, Choi, Wonchang, Kim, Seung Min, & Chang, Wonyoung. Investigation of Thermal Stability of P2–NaxCoO2 Cathode Materials for Sodium Ion Batteries Using Real-Time Electron Microscopy. United States. doi:10.1021/acsami.7b04478.
Hwang, Sooyeon, Lee, Yongho, Jo, Eunmi, Chung, Kyung Yoon, Choi, Wonchang, Kim, Seung Min, and Chang, Wonyoung. Thu . "Investigation of Thermal Stability of P2–NaxCoO2 Cathode Materials for Sodium Ion Batteries Using Real-Time Electron Microscopy". United States. doi:10.1021/acsami.7b04478. https://www.osti.gov/servlets/purl/1368663.
@article{osti_1368663,
title = {Investigation of Thermal Stability of P2–NaxCoO2 Cathode Materials for Sodium Ion Batteries Using Real-Time Electron Microscopy},
author = {Hwang, Sooyeon and Lee, Yongho and Jo, Eunmi and Chung, Kyung Yoon and Choi, Wonchang and Kim, Seung Min and Chang, Wonyoung},
abstractNote = {In this paper, we take advantage of in situ transmission electron microscopy (TEM) to investigate the thermal stability of P2-type NaxCoO2 cathode materials for sodium ion batteries, which are promising candidates for next-generation lithium ion batteries. A double-tilt TEM heating holder was used to directly characterize the changes in the morphology and the crystallographic and electronic structures of the materials with increase in temperature. The electron diffraction patterns and the electron energy loss spectra demonstrated the presence of cobalt oxides (Co3O4, CoO) and even metallic cobalt (Co) at higher temperatures as a result of reduction of Co ions and loss of oxygen. The bright-field TEM images revealed that the surface of NaxCoO2 becomes porous at high temperatures. Higher cutoff voltages result in degrading thermal stability of NaxCoO2. Finally, the observations herein provide a valuable insight that thermal stability is one of the important factors to be considered in addition to the electrochemical properties when developing new electrode materials for novel battery systems.},
doi = {10.1021/acsami.7b04478},
journal = {ACS Applied Materials and Interfaces},
number = 22,
volume = 9,
place = {United States},
year = {Thu May 11 00:00:00 EDT 2017},
month = {Thu May 11 00:00:00 EDT 2017}
}

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