Ultrafast and simple integration engineering of graphene-based flexible films with extensive tunability and simple trial in lithium-ion batteries

Rational construction of film electrodes remains challenge for the development of flexible energy storage devices. With excellent mechanical and electrical properties, graphene is the most promising flexible matrix material that can give full play to synergistic effects among components. However, typical methods for preparation of graphene-based films usually require complex production process. Herein, we propose a general strategy that can integrate the ultrafast construction of reduced graphene oxide (rGO)-based flexible composite films within 1–5 min by facile reduction and crosslinking. Using such approach, the obtained rGO-based films have extensively tunable architectures, compositions, and loadings simply by modulating components, ratio, concentration, and amount of the blended slurry. Meanwhile, these porous conductive films have excellent structural stability and volume buffering effect. The Fe3O4@rGO flexible film as an example for LIBs anode was evaluated and showed favorable cycling stability and rate capability. Even the mass loading was 6.0 mg cm−2, it was able to maintain a high specific capacity of 396 mA h g−1 at 1.0 A g−1 after 100 cycles. Compared with previous graphene-based film preparation processes, this work provides a rather novel and speedy fabrication strategy for functional and flexible graphene-based composites.