A Flexible Film with SnS2 Nanoparticles Chemically Anchored on 3D-Graphene Framework for High Areal Density and High Rate Sodium Storage
© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim The design and construction of flexible electrodes that can function at high rates and high areal capacities are essential regarding the practical application of flexible sodium-ion batteries (SIBs) and other energy storage devices, which remains significantly challenging by far. Herein, a flexible and 3D porous graphene nanosheet/SnS2 (3D-GNS/SnS2) film is reported as a high-performance SIB electrode. In this hybrid film, the GNS/SnS2 microblocks serve as pillars to assemble into a 3D porous and interconnected framework, enabling fast electron/ion transport; while the GNS bridges the GNS/SnS2 microblocks into a flexible framework to provide satisfactorily mechanical strength and long-range conductivity. Moreover, the SnS2 nanocrystals, which chemically bond with GNS, provide sufficient active sites for Na storage and ensure the cycling stability. Consequently, this flexible 3D-GNS/SnS2 film exhibits excellent Na-storage performances, especially in terms of high areal capacity (2.45 mAh cm−2) and high rates with superior stability (385 mAh g−1 at 1.0 A g−1 over 1000 cycles with ≈100% retention). A flexible SIB full cell using this anode exhibits high and stable performance under various bending situations. Thus, this work provide a feasible route to prepare flexible electrodes with high practical viability for not only SIBs but also other energy storage devices.