Flexible free-standing ternary CoSnO3/graphene/carbon nanotubes composite papers as anodes for enhanced performance of lithium-ion batteries

A facile strategy is designed for the fabrication of flexible and free-standing ternary CoSnO3/graphene/carbon nanotubes (CoSnO3/GN/CNTs) composite papers through a simple filtration, followed by annealing process. The CoSnO3/GN/CNTs composite papers with high flexibility and tailorability can be easily fabricated. The CoSn(OH)6 nanoparticles/graphene oxide/carbon nanotubes (CoSn(OH)6/GO/CNTs) composite papers obtained by a simple filtration method are transformed into CoSnO3/GN/CNTs composite papers after a thermal treatment process. In this unique composite structure, CoSnO3 nanoparticles (nanocubes and nanoboxes) are embedded homogenously into the 3D framework of graphene and carbon nanotubes, respectively, in which offers not only a 3D conductive network and a dual restriction on the aggregation of CoSnO3 nanoparticles, but also accommodates the large volume expansion of CoSnO3 nanoparticles. When used directly as binder- and conductive agent-free anodes for lithium-ion batteries, the CoSnO3/GN/CNTs composite papers exhibit superb electrochemical properties including extraordinary reversible capacities, superior rate capabilities and stable cycle performances compared to CoSnO3 nanoparticles and GN/CNTs paper, suggesting a new pathway for the rational engineering of anode materials.