Flexible and Freestanding Silicon/MXene Composite Papers for High-Performance Lithium-Ion Batteries.

Silicon has been developed as the exceptionally desirable anode candidate for lithium-ion batteries (LIBs), attributing to its highest theoretical capacity, low working potential, and abundant resource. However, large volume expansion and poor conductivity hinder its practical application. Herein, we fabricate flexible, freestanding, and binder-free silicon/MXene composite papers directly as anodes for LIBs. The Silicon/MXene composite papers are synthesized via covalently anchoring silicon nanospheres on the highly conductive networks based on MXene sheets by vacuum filtration. This unique architecture can accommodate large volume expansion, enhance conductivity of composites, prevent restacking of MXene sheets, offer additional active sites, and facilitate efficient ion transport, which exhibits superior electrochemical performance with a high capacity of 2118 mAh·g-1 at 200 mA·g-1 current density after 100 cycles, a steady cycling ability of 1672 mAh·g-1 at 1000 mA·g-1 after 200 cycles, and a rate performance of 890 mAh·g-1 at 5000 mA·g-1. This work may shed lights on the development of silicon-based anodes for LIBs.