A self-adhesive graphene nanoscroll/nanosheet paper with confined Fe_1−xS/Fe₃O₄ hetero-nanoparticles for high-performance anode material of flexible Li-ion batteries

Graphene based free-standing membrane/paper materials have been proved to be promising electrodes for flexible Lithium-ion batteries, whereas the rate capability is still unsatisfied unfortunately due to the typical layer-by-layer configuration of the graphene building blocks. Herein, a novel 3D porous architecture with a graphene nanoscroll (GNS)/nanosheet hybrid as the framework and ultrasmall Fe_1−xS/Fe₃O₄ hetero-nanoparticles (NPs) as the primary active matter is developed by a facile and scalable route of cold quenching, freeze drying and the subsequent roll-in treatment. The crumpled graphene nanosheets and GNSs with high length/diameter ratio are found to intertwine together and construct a 3D network with multiscale pores. Meanwhile, the Fe_1−xS/Fe₃O₄ NPs with a uniform dimension of <10 nm and homogeneous dispersion are firmly anchored on the graphene nanosheets or confined in the gallaries of the GNSs through their strong interface interaction. Benefiting from the unique and robust 3D hybridized design, the self-adhesive flexible electrode exhibits high reversible capacity (946 mAh g⁻¹ at 0.1 A g⁻¹) and excellent long-term stability up to 400 cycles with a low capacity loss rate of 0.047% per cycle. In addition, the prominently enhanced rate performance (capacity retention of 40.1% at 6 A g⁻¹) compared with the traditional 2D structured graphene materials is also stressed.