Self-assembled Ti3C2Tx/poly(diallyldimethylammonium chloride)-graphene oxide multilayers with large layer spacing for high capacity sodium-ion batteries.

MXenes are considered as potential high-performance sodium-intercalation electrode materials. However, the aggregation tendency and low capacity of the pristine MXenes limit their application in sodium-ion batteries (SIBs). Herein, Ti 3 C 2 T x /poly(diallyldimethylammonium chloride)-graphene oxide (Ti 3 C 2 T x /PDDA-GO) multilayers with high specific surface area and expanded layer spacing have been prepared by an electrostatic self-assembly, which provide more accessible electroactive sites and efficient ion transport channels to buffer volume changes during energy conversion. The results show that the Ti 3 C 2 T x /PDDA-GO multilayer electrode has large sodium storage capacity, high initial coulombic efficiency and reversible capacity, and excellent cycle stability and rate performance. Specifically, at a current density of 5 A g−1, the specific capacity remains at 65 mAh g−1 after 1000 cycles. The present work provides a possible strategy for the preparation of MXenes-based materials with high electrochemical performance. Ti 3 C 2 T x /PDDA-GO multilayers were prepared by a simple liquid-phase self-assembly process, which have high specific surface area and stable expansion layer spacing, achieving high initial coulombic efficiency and excellent rate cycling stability in SIBs. [Display omitted] • Ti 3 C 2 T x /PDDA-GO multilayers were fabricated by electrostatic self-assembly. • Achieved high specific surface area and stable expansion of interlayer spacing. • The electrode presented a large capacity and high initial coulombic efficiency. • Exhibited impressive rate performance of 65 mAh g−1 after 1000 cycles at 5 A g−1. [ABSTRACT FROM AUTHOR]