A scalable, robust, and highly oriented flexible composite film inspired by a “brick–mortar” pillared structure for lithium ion batteries

Macro-assembled silicon-based films can be taken into account as a possible anode material for the lithium ion batteries (LIBs) in portable electronics. However, most previously proposed preparation strategies are labor-intensive, intricate, and not appropriate for large-scale manufacturing. Herein, a multifunctional flexible silicon/carbon nanotube/reduced graphene oxide (Si/CNT/rGO) film was fabricated by one-step coating method based on the lyotropic nematic liquid crystals of graphene oxide (GO). The composite film’s structure is made up of stacked rGO nanosheets, with nano-Si and CNT interspersed between the layers, resembling a “brick–mortar” pillared configuration. The prepared Si/CNT/rGO film demonstrates an exceptional tensile strength, reaching up to 134 MPa, and manifests commendable lithium storing properties in terms of initial charge capacity (1885 mAh/g at 200 mA/g) and cyclability (1376.4 mAh/g beyond 200 cycles). The straightforward preparation method offers a fresh path to create stable and mechanically robust composite film for advanced engineering applications.