Flexible energy storage devices show promising advantages in next-generation bendable, wearable, and implantable electronic systems, and therefore, they attract considerable interest for researchers to fulfill requirements of future energy storage devices. Here, we report a facile two-step strategy to construct flexible and binder-free NaTi2(PO4)3/graphene film with a sandwich structure (GN/NaTi2(PO4)3/GN). Such a design makes the resulting film with an excellent flexibility, which can be used for a binder-free anode for flexible sodium-ion batteries (SIBs). GN nanosheet supported NaTi2(PO4)3 nanocrystals (NaTi2(PO4)3/GN) are first prepared by a facile hydrothermal route. Then, the resultant NaTi2(PO4)3/GN hybrid is embedded homogeneously in interconnected GN nanosheet framework to form three-dimensional flexible GN/NaTi2(PO4)3/GN film. The flexible film exhibits excellent cycling stability (91% capacity retention over 1000 cycles at 500 mA g–1) for sodium half cells. Furthermore, it can be assembled into...