Despite having a low electrical conductivity, graphene oxide (GO) is used as an anode material in lithium-ion batteries (LIBs) owing its good processability in large quantities. GO is reduced by chemical or thermal treatments to enhance its electrical conductivity. In this study, high-performance GO anodes with polydopamine (PDA) and polyethylenimine (PEI) as binders were fabricated. Gamma (γ)-ray irradiation was applied to the GO–PDA–PEI hybrid sheets to covalently cross-link the GO sheets and binders with an amide bond. The covalent crosslinking was confirmed by Fourier-transform infrared spectroscopy analysis. Further, X-ray photoelectron spectroscopy results showed that γ-ray irradiation produced a reduced GO sheet, which resulted in an increase in the electrical conductivity by 30%. By characterizing the electrochemical properties, we found that the γ-ray irradiation facilitates the stability and increases the charge/discharge capacity by crosslinking GO and PDA–PEI binders and reducing the GO sheets.

    Abstract
    1 Introduction
    2 Experimental procedure
        2.1 Material
        2.2 Anode material and γ-ray irradiation
        2.3 Electrochemical tests of irradiated GO–PDA–PEI electrodes
    3 Results and discussion
    4 Conclusion
    Acknowledgements 
    References

• Kyoung‑Il Jo(Neutron Science Division, Korea Atomic Energy Research Institute (KAERI))
• Hyeri Kim(Department of Organic Materials Engineering, Chungnam National University)
• Hee‑Sung Jeong(Neutron Science Division, Korea Atomic Energy Research Institute (KAERI), Department of Organic Materials Engineering, Chungnam National University)
• Jinho Kee(Department of Organic Materials Engineering, Chungnam National University)
• Seung‑Hwan Oh(Radiation Research Division for Industry and Environment, Korea Atomic Energy Research Institute (KAERI))
• Seok Hyun Song(Neutron Science Division, Korea Atomic Energy Research Institute (KAERI), Department of Chemical and Biological Engineering, Korea University)
• Hyungsub Kim(Neutron Science Division, Korea Atomic Energy Research Institute (KAERI))
• Jaseung Koo(Department of Organic Materials Engineering, Chungnam National University)