Premium
Mechanism of Sodium Storage in Hard Carbon: An X‐Ray Scattering Analysis
Author(s) -
Morikawa Yusuke,
Nishimura Shinichi,
Hashimoto Ryuichi,
Ohnuma Masato,
Yamada Atsuo
Publication year - 2020
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201903176
Subject(s) - materials science , graphene , carbon fibers , anode , crystallinity , scattering , sodium , nanopore , ion , nanotechnology , small angle x ray scattering , chemical engineering , optics , composite material , chemistry , composite number , electrode , organic chemistry , physics , metallurgy , engineering
Hard carbon is a standard anode material for Na‐ion batteries. However, its low crystallinity and diverse microstructures make obtaining a full understanding of the sodium storage mechanism challenging. Here, the results of a systematic ex situ small and wide angle X‐ray scattering study of a series of nanostructured hard carbons, which reveal clear evidence of sodium storage in the graphene–graphene interlayers and nanopores, are presented. Particularly, an emergence of a broad peak around q ≈ 2.0–2.1 Å −1 in the low voltage region is suggested to be an indicator that sodium is densely confined in the nanopores. Thus, classical X‐ray scattering techniques are demonstrated to be effective in elucidating the overall reaction scheme of Na insertion into hard carbon.