Gamma-ray irradiated graphene nanosheets/polydopamine hybrids as a superior anode material for lithium-ion batteries

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 (gamma)-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 gamma-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 gamma-ray irradiation facilitates the stability and increases the charge/discharge capacity by crosslinking GO and PDA-PEI binders and reducing the GO sheets.

Automated summary

In this study, high-performance graphene oxide (GO) anodes were fabricated by using gamma (γ)-ray irradiation to enhance the electrical conductivity of GO. The results showed that the covalent crosslinking of GO-PDA-PEI hybrid sheets improved the conductivity and stability, resulting in an increase in charge/discharge capacity.