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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

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.
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  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:
Report Number(s):
Journal ID: ISSN 1944-8244; R&D Project: 16060; 16060; KC0403020; TRN: US1701988
Grant/Contract Number:
SC0012704; 2E27062; 2E27090
Accepted Manuscript
Journal Name:
ACS Applied Materials and Interfaces
Additional Journal Information:
Journal Volume: 9; Journal Issue: 22; Journal ID: ISSN 1944-8244
American Chemical Society (ACS)
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 Orgs:
KIST Jeonbuk Inst. of Advanced Composite Materials, Chudong (Korea, Republic of)
Country of Publication:
United States
29 ENERGY PLANNING, POLICY, AND ECONOMY; cathode materials; in situ heating; NaCoO2; sodium ion batteries; thermal stability; transmission electron microscopy
OSTI Identifier: