Liquid phase exfoliation of natural graphite is an industrially effective solution for graphene preparation. However, many countries have identified natural graphite as a strategic resource and restricted its mining. In this report, we used abundant and readily available needle coke (NC) as a graphene exfoliation precursor and sodium carboxymethyl cellulose (CMC) as a dispersant to prepare a sandwich structured conductive graphitized NC nanosheets (GNCNs) by liquid phase exfoliation, freeze-drying and high-temperature graphitization, in which a graphene layer is sandwiched between two thin CMC layers. CMC could increase the liquid absorption and retention ability of the conductive agent and improve the migration rate of lithium ions. The highly ordered graphene layer could accelerate the transmission of electrons. The GNCNs with 0.4 wt% CMC addition showed good rate performance (144.6 mAh g− 1 at 5 C) and high cycle stability (96.2% after 200 cycles at 1 C) for LiFePO4 (LFP) battery. The traditional Super-P (SP) conductive agent exhibited low-rate performance (113.9 mAh g− 1 at 5 C) and cycle performance (89.9% after 200 cycles at 1 C). This study offers a novel approach to selecting graphene precursors and has promising applications for conductive additives in high-performance LFP batteries.

A sandwich-like CMC-basedgrapheneCMC-based conductive agent prepared from needle coke for high-performance LiFePO4 batteries
    Abstract
    1 Introduction
    2 Experimental section
        2.1 Materials
        2.2 Preparation of GNCNs
        2.3 Characterization
        2.4 Electrochemical measurements
    3 Results and discussion
    4 Conclusions
    Anchor 11
    Acknowledgements 
    References

• Jin Zou(Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China)
• Xi‑Xi Long(Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China)
• Jia‑Le He(Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China)
• Shi‑Peng Yu(Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China)
• Sheng‑Wen Zhong(Faculty of Materials Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, China)