Article

Manipulating Adsorption–Insertion Mechanisms in Nanostructured Carbon Materials for High‐Efficiency Sodium Ion Storage

Qiu ShenCollege of Chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power Sources Wuhan University Wuhan 430072 ChinaLifen XiaoCollege of Chemistry Central China Normal University Wuhan 430079 ChinaMaria L. SushkoPacific Northwest National Laboratory Richland WA 99352 USAKee Sung HanPacific Northwest National Laboratory Richland WA 99352 USAYuyan ShaoPacific Northwest National Laboratory Richland WA 99352 USAMengyu YanState Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and Engineering Wuhan University of Technology Wuhan 430070 ChinaXinmiao LiangState Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics, Chinese Academy of Science Wuhan 430071 ChinaLiqiang MaiState Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and Engineering Wuhan University of Technology Wuhan 430070 ChinaJiwen FengState Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics, Chinese Academy of Science Wuhan 430071 ChinaYuliang CaoCollege of Chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power Sources Wuhan University Wuhan 430072 ChinaXinping AiCollege of Chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power Sources Wuhan University Wuhan 430072 ChinaHanxi YangCollege of Chemistry and Molecular Sciences Hubei Key Laboratory of Electrochemical Power Sources Wuhan University Wuhan 430072 ChinaJun LiuPacific Northwest National Laboratory Richland WA 99352 USA

2017en

ABI

Abstract

Hard carbon is one of the most promising anode materials for sodium‐ion batteries, but the low Coulombic efficiency is still a key barrier. In this paper, a series of nanostructured hard carbon materials with controlled architectures is synthesized. Using a combination of in situ X‐ray diffraction mapping, ex situ nuclear magnetic resonance (NMR), electron paramagnetic resonance, electrochemical techniques, and simulations, an “adsorption–intercalation” mechanism is established for Na ion storage. During the initial stages of Na insertion, Na ions adsorb on the defect sites of hard carbon with a wide adsorption energy distribution, producing a sloping voltage profile. In the second stage, Na ions intercalate into graphitic layers with suitable spacing to form NaC x compounds similar to the Li ion intercalation process in graphite, producing a flat low voltage plateau. The cation intercalation with a flat voltage plateau should be enhanced and the sloping region should be avoided. Guided by this knowledge, nonporous hard carbon material has been developed which has achieved high reversible capacity and Coulombic efficiency to fulfill practical application.

Identifiers

DOI: 10.1002/aenm.201700403

Citations and references

Cited by 20 references

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